Published

Doi:
24(1): 1-1,1992

Published

Doi:
24(1): 2-2,1992

Published

Doi:
24(1): 3-4,1992

Pneumatophore density of mangrove Avicennia marina from different locations of Karachi ranged from 56-520 m-2 with a mean value of 278m-2 +/- 135 SD, their height ranged from 2-32 cm with a mean value of 11.8 +/- 3.2 SD and maximum thickness from 2-11 mm with a mean value of 6.3 +/- 1.57 SD. Pneumatophore density was positively correlated with tree height, tree girth and negatively with its own height. There was a positive relationship between the density and mud content in mangrove soil suggesting that mangroves adapt to anaerobic and water- logged conditions by increasing their numbers and hence large surface area for maximum aeration.

Published

Doi:
24(1): 5-10,1992

The distribution and frequency of marine algae along the eastern coast of Libya (Cyrenaica) showed the presence of 168 species, 6 varieties and 2 forms. This includes 56 Chlorophyceae, 37 Phaeophyceae and 76 Rhodophyceae including varieties and forms. The R/P ratio was 2.05. Hence it is rather subtropical than boreal.

Published

Doi:
24(1): 11-21,1992

Taxonomy, morpho-anatomy and some biological notes of 4 genera with 6 species viz., Colpomenia sinuosa (Mertens ex Roth) Derbes & Solier, Igengaria stellata (Boerg.) Boergesen; Rosenvingia fastigiata (Zanardini) Boergesen, R orientalis (J. Agardh) Boergesen; Hydrocla thrus clathratus (C. Agardh) Howe including one new record of Colpomenia ecuticulata Parson of Scytosiphonales from Karachi coast is pre sented.

Published

Doi:
24(1): 22-30,1992

Cultures of Fusarium solani extracted in toluene/ethyl acetate/90% formic acid (5/4/1, v/v) showed consistent profiles, of secondary metabolites on thin layer chromatographic plates. These profiles, alongwith macromorphological characters, can be used as taxonomic criteria for identification of F. solani

Published

Doi:
24(1): 31-34,1992

Growth and fruiting of five cultivars of tomato viz., Tropic, pearson, Monte Carlo, ACE-55 and Strain B were studied at different salinity levels ranging between 34-272 mM NaCl. Reduction in growth at lower salinities (34 mM NaCl) was less in comparison to high salinity levels ( > 68 MM NaCl). Cv. Tropic produced the highest vegetative biomass under control condition but gave least reproductive yield in terms of fruit weight per plant. However, maximum fruit weight per plant was observed at 34 mM NaCl level. At moderate salinity level (68 mM NaCl), cv. ACE-55 produced the highest fruit weight though showing a reduction of about 65.91% as compared to control. Highest reproductive biomass was produced in cv. Tropical at 272 mM NaCl which was 25 times less than its control.

Published

Doi:
24(1): 35-39,1992

The effects of 0, 25,50 75 and 100 meq.l-i sodium chloride on some physiological proceses of gram was studied in solution culture. Fresh and dry weight of cotyledons significantly changed (P < 0.05) at different salinity levels. Concentration of carbohydrate and total nitrogen in cotyledons showed a marked decrease from the 2nd day. Length and weight of root and shoot were affected at different salinity levels. Carbohydrate concentration showed marked reduction at 75 and 100 meq.l-1 NaCl, whereas, significant differences were observed in the nitrogen content in control and salinity treatments.

Published

Doi:
24(1): 40-48,1992

A drought resistant variety of wheat (Pak-15800) was compared with a susceptible variety (Sarsabz) under water stress and the relationship between leaf water, osmotic, turgor potentials and relative water contents (RWC) were studied. The water stressed plants had lower leaf water potential than control and at a given RWC Pak-15800 had lower water potential than Sarsabz which partly accounts for its better drought resistance. In both the varieties pre-stressed plants maintained osmotic potentials lower than control. In Pak-15800 osmotic potential was significantly lower (-0.06 to -0.11) than Sarsabz. Both control and pre-stressed Pak-15800 plants had higher turgor (0.1 to 0.15 MPa) than Sarsabz at RWC between 65 and 80%. Both pre-stressed and control Pak-15800 had greater elasticity (a lower elastic modulus) than Sarsabz. An understanding of the differences between osmotic and turgor potentials between varieties could be used as a tool in breeding program for wheat.

Published

Doi:
24(1): 49-53,1992

Callus cultures of Zingiber officinale obtained from rhizome explants bearing shoot primordia and juve nile shoots on Murashige and Skoog basal medium supplemented with various growth hormones produced plantlets which were transferred in the field. Multiple plantlet formation occurred in two week old shoot buds. Essential oils extracted from callus cultures, from rhizomes obtained from our experimental medicinal plants garden and commercial rhizomes showed only slight difference in the oil contents.

Published

Doi:
24(1): 54-59,1992

A micropropagation method was developed from immature embryo-derived shoot tips of Delonix regia on Murashige and Skoog's medium. Shoot multiplication occurred through proliferation of axillary leaf buds and the best multiplication rates were obtained;with 1.0 mg/l BAP and 0.5 mg/l NAA. No response was observed in 2ip supplemented media other than rhizogenesis and callogenesis. In vitro formed shoots when ransferred onto half strength of MS salts + 0.5 mg/l IBA & 0.5 mg/l NAA produced profuse roots in all the shoots.

Published

Doi:
24(1): 60-63,1992

Methods were developed for callus induction and efficient plant regeneration from mature embryos and immature inflorescences of basmati rice (Oryza sativa L cv. Basmati-370). Callusing from seeds of rice was observed in MS or N6 media with various levels of 2,4-D. Somatic embryogenesis was achieved in both media however, response was better in the presence of Kinetin (2 mg l-1). Using field grown immature inflorescences and embryos induction of callus and regeneration was observed. Cell suspension cultures were initiated from 2-3 months old calli of B-370. A fast growing and finely dispersed cell line of Basmati-370 was established. Regeneration of plants was achieved in MS-0 (no hormone).

Published

Doi:
24(1): 64-71,1992

Mesocotyl segments of Brassica juncea var. poorbiraya from in vitro grown seedlings were tested for their callogenic and thence morphogenic potential with various treatments of plant growth regulators. Calli grown at 1.0 mg/l of BAP gave a maximum frequencey(2.25 buds/culture) of shoot regeneration. Regenerated buds were induced to root when cultured on half strength MS medium containing IAA @ 0.5 mg/l. Embryogenesis was induced in mesocotyl callus in MS medium containing 2,4-D (0.022 mg/l) + KIN (0.215 mg/l). Phenotype of regenerated plants looked similar to in vitro grown Brassica juncea plants.

Published

Doi:
24(1): 72-78,1992

Aristolochia bracteolata Lamk. is partially Protogynous. The flower exibits fly-trapping mechanism. Only one pollinator, belonging to the genus Forcipomya (Diptera; Ceratopogonidae) is involved. The pollen germination takes place within the dehisced anthers and on perianth parts i.e., within the- trap and the prison, producing the pollen tubes, which ultimately reach the stigma and bring about fertilization. Breeding system study revealed that Aristolochia is self-compatible. Significant difference between treatments (bagged and open - pollinated flowers) in terms of fruit set, fruit and seed weight was observed. In all the 3 populations studied, difference in seed set and seed weight was significant while non-significant in fruit set and fruit weight.

Published

Doi:
24(1): 79-87,1992

The hybridization between Acacia nilotica subsp. indica and A. nilotica subsp. cupressiformis is substaintiated by the study of phenolic constituents, The hybrids have additive or some new compounds, not present in either parent. Small number of phenolic constituent and their uniform pattern indicate that the Indian population of A. nilotica subsp. indica and the populations of A. nilotica sub sp. cupressiformis from N. Punjab genetically were purer than the populations from Sindh which have higher number of phenolic constituents and a variable pattern.

Published

Doi:
24(1): 88-94,1992

The genus Gentiana L. (s.l.) is a heteromorphic assemblage. A synthetic approach is adopted to treat Gentiana L (sl.) from Pakistan and adjoining areas by utilizing the data from palynology, seed morphology and chemistry. Nine genera viz., Ciminalis Adans., Gentianodes Love & Love, Qaisera Omer, Aliopsis Omer & Qaiser, Gentianopsis Ma, Aloitis Rafin., Comastoma Toyok., Jaeschkea Kurz and a new genus Kurramiana Omer & Qaiser have been recognized. Gentiana L (s.str.) and Gentianella Moench (s.str.) do not occur in Pakistan and adjoining areas. The generic limits and their affinities of all the taxa have been discussed. A new genus Kurramiana Omer & Qaiser is described, and compared in detail with other related genera. The numerical analysis suggests its affinities with the genus Jaeschkea Kurz.

Published

Doi:
24(1): 95-106,1992

Ipomoea sindica Stapf is reinstated as a species distinct from I. eriocarpa R. Br. on the basis of chemotaxonomical and micromorphological evidences. Further, it is made clear that I. sindica Stapf is not based on Convolvulus scindicus stocks.

Published

Doi:
24(1): 107-111,1992

One hundred and twelve mungbean genotypes selected from a broad based local as well as exotic germplasm during last three years, were evaluated for agronomic characters and incidence of yellow mosaic and leaf crinkle virus under natural infection conditions. Twenty eight genotypes were found to be superior on the basis of yield potential and resistance/tolerance to YMV and LCV. A high yielding line (NCM 201) showed resistance to both viral diseases. Maximum CV was observed for pods per plant, biological yield per plant and grain yield per plant indicating greater scope of selection for these traits. A strong correlation of yield was observed with pods per plant and biological yield per plant. Large scale testing of selected lines and their utilization in breeding programme would be of great use in mungbean improvement.

Published

Doi:
24(1): 112-118,1992

A Monte Carlo algorithm is proposed to assign a new or unclassified operational taxonomic unit (O.T.U.), with variable characters, to the group it is closest to. The method involves a bootstrap resampling plan. The algorithm is limited to binary data but may easily be extended to cope with data sets involving qualitative as well as quantitative characters.

Published

Doi:
24(1): 119-124,1992

Published

Doi:
24(2): 126-126,1992

Published

Doi:
24(2): 127-128,1992

Published

Doi:
24(2): 129-130,1992

The morphology and types of trichomes on the leaves, stems and floral parts of Lavandula stricta Del., (= L. coronopifolia Poir.) and L. coronopifolia Lam., were investigated. Both the species showed nonglandular trichomes with cells having warty walls. The two species also have glandular trichomes with unicellular, bicellular or multicellular heads. Nonglandular trichomes with smooth cell walls and branched glandular trichomes were not observed in L. coronopifolia. ne trichomes of the two species could be grouped into 8 types comprising of 17 forms of nonglandular and 13 forms of glandular trichomes.

Published

Doi:
24(2): 131-141,1992

Rhizobial infection on roots of Leucaena leucocephala started with curling and deformation of root hairs. Infection threads were seen in the young infected cells travelling both inter and intracellularly. Bacteroid region of the nodule composed of both the infected parenchymatous cells and uninfected interestitial cells. Two types of infected cells viz., young vacuolated cell and older non vacuolated cells with deformed nuclei were observed in the developing nodules. Both determinate and indeterminate nodules were observed in L. leucocephala.

Published

Doi:
24(2): 142-152,1992

Rhizobia isolated from root nodules of Albizia lebbeck, Arachis hypogaea, Clitoria ternatea, Leucaena leucocephala, Medicago sativa, Pithecellobium dulce, Sesbania sesban and Vigna unguiculata were tested for their ability to produce root nodules on Leucaena leucocephala. Amount of fixed N2 was measured. Except Arachis hypogaea isolates from all leguminous plants produced nodules on L. leucocephala. Isolates from V. unguiculata, A. lebbeck and P. dulce were most effective in nitrogen fixation and induced substantial increase in dry weight and nitrogen contents of the host plant.

Published

Doi:
24(2): 153-156,1992

The primary vascular system of the shoot of Tessaria absinthioides was studied by the use of serial cross sections. It is a system of the open type, with eight sympodia, 2/5 helical phyllotaxy and trilacunar three-trace nodes. All the bundles are interpreted as leaf traces diverging towards the left along a sinistrorse genetic spiral. Leaf insertion is of the separated type and there are two sets (2 + 3) of contact parastichies in the apex. The phylogenetic implications of these characters are discussed.

Published

Doi:
24(2): 157-164,1992

The performance of anthers from in vitro produced flower buds and those derived from glasshouse-grown plants was compared. In liquid medium anthers of all types exhibited some degree of browning. In vivo produced anthers were moderately prone to browning irrespective of the presence or absence of hormones in the culture medium. Browning in anthers derived from in vitro produced flower buds was far more in hormone-free media. The anther response based on the number of anthers incubated was much higher in hormone free media than in the media containing hormones. In vitro produced anthers exhibited a strong dependence of anther response to the stage of pollen development at excision. The productivity of the in vitro produced anthers was greater in the hormone supplemented media whereas the in vivo produced anthers did so in the basal medium.

Published

Doi:
24(2): 165-172,1992

The Wagner Tree algorithm was used as an aid in estimating the phylogeny. Using 15 multistate attributes, 66 species of Dampiera were analysed in a numerical phylogenetic study. During the construction of the Wagner Tree or network no weighting of attributes was undertaken. The polarity of attribute states was also not determined, except for 6 attributes in which primitive states were suggested. However, in most cases, the attribute states were arranged in possible logical transformation series. A diagram showing the probable phylogenetic relationship of Dampiera species has been developed, in view of primitive characters, found in the species. It is suggested that the root of the phylogenetic tree is somewhere at the junction of Sect. Dicoelia and Sect. Dampiera.

Published

Doi:
24(2): 173-181,1992

Latent period was measured in number of days from inoculation to flecking and sporulation in five bread wheat cultivars inoculated with 25 isolates of Puccinia recondita Rob. ex Desm. A differential interaction between the cultivars and the parasite isolates indicated the presence of genetic specificity between factors controlling latent period in both the host and the parasite. Depending upon the host: parasite combination. differences of one to two days were observed in the latent period required by brown rust under the conditions of this study.

Published

Doi:
24(2): 183-186,1992

Isometric virus particles measuring 3540 nm in diameter with double stranded RNA genomes of molecular weight (1.48 - 6.1) x 10(6) dalton was detected in the field isolates of the wheat take all fungus Gaeumannomyces graminis var. tritici. Out of three isolates of Ggt four different viruses based on particle size, size of RNA and molecular weight of coat protein belonging to three groups of mycoviruses were detected.

Published

Doi:
24(2): 187-196,1992

Pre-mature fruit drop decreases mango yield. The effect of aqueous sprays of 1-naphthaleneacetic acid (NAA), gibberellic acid (GA3), silver nitrate (AgNO3) or cobalt nitrate [Co (NO3)2], alone or in combination, on fruit retention in mango (cv. Sindhri) was studied. Spray was done : once when fruitlets were of pea-size and then two weeks later when fruitlets increased to marble-size. Compared to control, applications of Co (100 mg/L), Ag (100 mg/L) ions, NAA (20 mg/L) and GA3 (50 mg/L) enhanced fruit retention by 131,127. 100 and 50%, respectively. No additive effect was observed when these chemicals were sprayed in combination.

Published

Doi:
24(2): 197-200,1992

The present study was undertaken to screen the thermotolerant varieties of soybean and analyse the changes brought about by heat shock conditions in least resistant variety. Four varieties of soybean viz., Williams, Chippewa, S-73 and Improved Pelican were subjected to 7 different heat shock conditions. 'Chippewa' was found to be the most theremotolerant and 'Williams' was the least. It was observed that 45-degrees-C-2 h had lethal effect on growth of soybean seedlings. A short pulse of 10 minutes at 45-degrees-C triggers the synthesis of some heat shock proteins which were accumulated at 45-degrees-C-2 h and then gradually decreased during recovery period. Altered levels of RNA, DNA, total phenols and anthocyanins were also observed in cv. Williams. An increase in temperature had adverse effect on growth however, Hsps-induced during shock may help in the recovery of growth and provide thermal tolerance in soybean seedlings.

Published

Doi:
24(2): 201-208,1992

Growth and nodulation of Sesbania sesban were compared at eight levels (0-2.0%) of NaCl salinity in sandy clay loam soil (ECe: 1.0 dS m-1). Dry weight of shoots and roots and number of nodule per plant decreased with increasing salinity levels. Nodule dry weight, however, increased at low levels of salinity (0.1% and 0.2% NaCl) and decreased at higher levels. Maximum diameter of nodules increased at all the salinity levels except in 2% NaCl. The decrease in nodule numbers was partially compensated by an increase in nodule size.

Published

Doi:
24(2): 209-212,1992

A new species of Padiastrum Mayen (Chlorococcales, Chlorophyta) has been described from India. The collection was made during November 1990 from Shankha river, Bareilly district, Uttar Pradesh, India. Pediastrum habibii sp. nov. consists of 15 cells only with inner cells having inter cellular spaces in between them

Published

Doi:
24(2): 213-216,1992

Trichoderma viride, T. hamatum and Rhizobium meliloti used as seed dressing and or as soil drench reduced Macrophomina phaseolina infection by more than 50% on 30 day old fenugreek seedlings. Combined use of T. koningii and R. meliloti showed better control of M. phaseolina infection on both 30 and 60 day old plants. T. harzianum, T. hamatum, T. pseudokoningii and R meliloti (KUMH 555 & KUMH 653) used either as seed dressing and or as soil drench completely controlled the infection of Rhizoctonia solani both on 30 and 60 day old plants. Combined use of T. viride and T. koningii with rhizobia were also found effective. T. harzianum, T. koningii alone or R. meliloti used with T. viride, T. hamatum, T. koningii and T. pseudokoningii completely controlled the infection of Fusarium spp., on 30 day old seedlings, while in 60 day old-plants more than 50% reduction was found by Trichoderma spp., and R. meliloti used alone or rhizobia mixed with Trichoderma spp., when used either as seed dressing and or as soil drench.

Published

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24(2): 217-221,1992

Published

Doi:
24(2): 223-224,1992

Published

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24(2): 225-226,1992

Combining ability analysis was conducted for grain yield and yield Components viz., plant height. branches per plant, pods per plant, pod length, seeds per pod, 100 grain weight in a five parent diallel population of mash (Vigna mungo) including parents, F1's and reciprocals. Non-additive gene action (dominance or epistasis) contributed the major portion in total genetic variance for all the plant characters studied.Significant reciprocal effects were also observed for all the characters which indicated the importance of maternal contribution iii the performance of hybrids. Therefore a biparental mating among the selected F2 segregants followed by selection in advanced generations, F6 or later, is suggested. The genotype 87/88 proved to be the best general combiner for pods per plant and grain yield and could be exploited in future mash breeding programme to develop high yielding varieties.

Published

Doi:
25(1): 1-6,1993

Heterosis studies were undertaken in seven intervarietal F1 hybrids of Gossypium hirsunum L, for number of sympodia, mimber of monopodia, number of bolls, boll weight, ginning outturn percentage, staple length and seed cotton yield. Mean squares revealed that all the hybrids and their parents were significantly (P < 0.01) different for all the characters except boll weight. All the hybrids manifested hybrid vigour over their mid parent values for all the characters under study except monopodia per plant, where four hybrids also exhibited positive heterotic effect. Majority of the hybrids transgressed over their better parent values and all the hybrids showed heterobeltiotic effects for seed cotton yield per plant. The hybird of Qalandari X CIM-109 out yielded the performance than the other crosses, the values being 100.56 and 89.24 % in comparison to their mid and better parent values respectively. TIle results indicate that all the cross combinations could be utilized for getting higher yield as hybrid production.

Published

Doi:
25(1): 7-12,1993

Both F1 and F2 hybrids of cotton manifested considerable amount of heterosis against the parents. The F2 hybrids which produce more quantity of seed as compared to F1 may be considered for hybrid cotton production. The average heterosis of F2s over the parents recorded was 16.44% in yield, 9.68% in bolls/plant, 16.21% in seed index, 1.34% in lint and 3.45% in staple length. In all the crosses, observed inbreeding depression was greater than what was expected based on coefficient of inbreeding. The discrepancy between the observed and expected depression could be due to factors like linkage disequilibrium, epistasis and ploidy level.

Published

Doi:
25(1): 13-19,1993

Aqueous extracts and leachates of young, mature, and senesced anthers of Ceratonia siliqua were tested for their inhibition of lettuce seed gemlination. Only senesced anthers was found to contain substantial amounts of germination inhibitors. Isolation of the inhibitors from the anthers revealed the inhibitors to be soluble in water, methanol, ethanol, ethyl acetate and was acidic in nature. Kinetin and GA3 were found to counteract the inhibition of the aqueous extract and leachates of the senesced anthers. Little,loss in the inhibitory activity of the aqueous extract occured even after subjecting the anthers to the highest soil temperature of 80°C for 60 minutes, which indicated that the inhibitors were not proteinaceous.

Published

Doi:
25(1): 21-28,1993

Three salt tolerant plant types viz., Atriplex amllicola, Leptochloa fusca (L) Kunth. (Pakistani origin) and Leptochloa fusca (L) Kunth (Australian origin) were used for a comparative study of altered gene expression under salt stress. The plants were aseptically grown in hydroponic medium and exposed to increasing levels of salt starting from 50mM NaCI to 500mM NaCI. Under these stress treatments there was variable expression of a number of proteins as revealed by SDS-PAGE. Specific activities of plant GDH, GOGATand GSin response to salt stress were also determined. Klebsiella sp., NIAB-l, adiazotroph isolated from roots of Leptochloa fusca (L.) Kunth was also exposed to 50mM NaCI to 1000mM NaCI treatments, to examine salt responsive protein profiles. Blots of protein profiles from the three plant types were probed with antibodies raised against p-20 of Atriplex amnicola and p-26 of Klebsiellasp., NIAB-1, to reveal common epitopes among the salt responsive proteins.

Published

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25(1): 29-39,1993

 Leaf samples of Phragmites australis collected from five locations varying from totally flooded to dry regime showed a sharp decrease in the fresh leaf water content of the plant from flooding to dry locations accompanied by an incomparable decrease in OP. This incremental osmotic regulation occurred due to the accumulation of soluble sugars, amino acids, proteins, proline and the nutrient elements K, Na, Ca, Mg and Fe. Low OP under flooding was attributed to the condensation of sugars and amino acids into polysaccharides and protein. Both drought and flooding conditions n:sulted in the accumulation of polysaccharides, protein and proline.

Published

Doi:
25(1): 41-46,1993

Growth, seed yield and nodulation of Cicer arietinum were compared at 0, 0.1, 0.2, 0.4, 0.8, 1.2, 1.6 and 2.0% levels of NaCI salinity in sandy clay loam. Fresh weight of shoots and roots after 8, 12 and 15 weeks salinity treatment, generally decreased with increasing salinity levels. Compared to vegetative growth, reproductive growth was more affected since pods were formed upto 0.4% NaCl levels, whereas, seeds were formed at NaCl level of upto 0.1%only. Numberofnodule per plant, nodule weight and nodule size decreased with increasing salinity levels.

Published

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25(1): 47-50,1993

The vegetation of 20 different graveyards in District Swabi was sampled quantitatively. Three main communities: Dalbergia sissoo-Melia azedarach, Ziziphus mauritiana with 2 subtypes, and Acacia modesta with 5 subtypes, were recognized on the basis of similarity indices, importance values and floristic composition of the stands. A. modesta community was widely distributed in the area. The first two communities represent secondary succession in the area. The vegetation of all the stands was stratified into tree, shrub and herb layers. The variation in the dominant species was dueto edaphic and biotic disturbance. It is suggested that the existing vegetation might funher change due to underground seepage of water from nearby Tarbela dam. A vegetation profile of all the communities is given.

Published

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25(1): 51-66,1993

Survivorship pattern of some common summer annuals and perennials showed quite varied mortality patterns which can be tentatively grouped, according to Deevey system of classification. Annuals like Indigofera cordifolia and I. hochesttetri showed a gradual decrease in number of plants after initial lengthy recruitment period and appeared close to type II Deevey curve. However, annuals like Eragrostis ciliaris, Aristida mutabilis, Cynodon dactylon and Tephrosia strigosa showed little mortality at the early phase of life cycle and high mortality at the time of flowering and fruiting following type I Deevey curve. Perennials like Blepharis sindica, Senna holosericea, and Corchorus depressus initially showed a higher level of mortality leaving only few seedlings to continue their life cycle thus following type 3 Deevey curve.

Published

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25(1): 67-72,1993

Species of seed bank and those occurring in vegetation were compared for six desert halophytic shrub communities. Perennial shrubs like Suaeda fruticosa, Haloxylon recurvum, Cressa cretica and Salsola baryosma dominated the six communities studied. Communities also showed very low species diversity. The seed bank was represented by a large number of species as compared to the species present in the vegetation, indicating a poor relationship between seed bank and vegetation. S. fruticosa maintains a persistent seed bank thereby dominating the seed bank flora of almost all communities irrespective of the dominant species. All other perennial halophytic species studied showed a transient nature of the seed bank. Monthly seed bank data was collected for 2 halophytic species for 12 months. Presence of H. recurvum, S. fruticosa and C. cretica was higher in the seed bank after seed dispersal and except for S. fruticosa seeds, the number of all other species declined substantially in the soil.

Published

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25(1): 73-82,1993

The taxonomy and morpho-anatomy of Dilophus fasciola (Roth) Howe var. repens (J. Agardh) Feldmann and Spatoglossum australasicum Kuetzing is reported for the first time from the coast of Karachi.

Published

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25(1): 83-92,1993

Using TLC patterns and growth response to tannin, the profiles of secondary metabolites in 5 species of Fusarium viz., F. anthophilum, F. proliferatum, F. subglutinans, F: scirpi and F. sporotrichioides isolated from wheat, corn and pearl millet is presented as additional criteria for species identification.

Published

Doi:
25(1): 93-97,1993

Extra early pigeonpea genotypes selected from ICRISAT materials planted at the National Agricultural Research Centre, Islamabad were found infected by a pod rot disease during September-October, 1990. The disease appeared as water soaked lesions which subsequently developed into a wet rot affecting both young and mature pods showing luxuriant whitish growth with black headed pin like sporangia around the pods. The pods damaged by insects were more affected than non-damaged pods. Withered and detached flowers also showed fungal growth. Pods near maturity were more susceptible than the young pods specially under humid conditions. The fungus isolated in pure culture on PDA medium was identified as Choanephora cucurbitarum (Berk and Rav.) Thaxter (Stevens, 1913). Detached healthy pods of pigeonpea cultivar ICCP-83015 surface sterilized with 0.5% sodium hypochlorite solution for 1.5 minutes, followed by washing in sterilized distilled water were dipped in a conidial suspension of C. cucurbitarum (6.5x104 conidia/ml) and placed in sterilized Petri plates at room temperature (24±2°C) developed characteristic symptoms of the disease. There does not appear to be any previous report of C. cucurbitarum on pigeonpea in Pakistan. Pod rot of pigeonpea caused by C. cucurbitarum has been reported from India (Misra & Mehra, 1969). The fungus has been reported to parasitize Luffa acutangula Roxb., (Ghaffar & Kafi, 1968), Capsicum annum L., (Mirza & Qureshi, 1978), Vigna unguiculata (L.) Wilp (Bashir et al., 1985) and Vigna radiata (L.) Wilczek (Alam et al., 1984).

Published

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25(1): 99-102,1993

Cotton (Gossypium hirsutum L.) is one of the most important crop of Pakistan which accounts for 60% of the export product of the country. In the last few years cotton leaf curl disease has acquired epidemic proportions in Pakistan and has seriously threatened cotton production. The characteristic symptoms of the disease are severe leaf curling, thick dark veins and enations which sometimes differentiate into cup shaped leaf-like structures on the underside of the leaf (Fig 1a). Whitefly (Bemisia tabaci) was suspected as the insect vector of cotton leaf curl disease. Whiteflies maintained in the controlled conditions were used for insect transmission of the disease from cotton to cotton and from cotton to tobacco (Nicotiana tabacum). The symptoms developed on cotton and tobacco were similar to leaf curling in cotton plant with thick dark veins and development of cup shaped structures on underside ofleaf (Fig.1b).

Published

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25(1): 103-103,1993

Published

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25(1): 105-107,1993

Dr. Manzur Ahmed Bajwa, an eminent scientist, breathed his last on 16th June 1993 due to heart failure auhe Combined Military Hospital, Rawalpindi. May God Almighty shower His choicest blessings upon the departed soul. Ameen.

Published

Doi:
25(2): 109-110,1993

The flavonoid chemistry of 7 species belonging to 4 subgenera of the genus Medicago L, has been reported for the first time from Pakistan. The flavonoid pattern strongly support the infrageneric classification of the genus. It also seems to be useful to solve the problems at inter and infraspeciflc levels.

Published

Doi:
25(2): 111-117,1993

Diaspore morphology has long been assigned a role for dispersal byvarious mechanisms. An experiment was designed to investigate the effect of dispersal unit and the position of seed relative to substrate on germination of three composites (Iphonia grantioides, Tridax procumbens and Sonchus arvensis). Seed morphology of the three species was studied and pappus appeared to influence the overall germination percentage. Diaspore having attached pappus and lying horizontally on the surface of the soil showed maximum germination compared to other positions. Diaspore having detached pappus and lying horizontally on the soil surface showed lower germination percentage than the seed with attached pappus. The angle of contact with soil is also important besides pappus which presumably regulates water absorption by seed and consequently the rate and overall germinat}on percentage.

Published

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25(2): 118-126,1993

Experiments were conducted with Westar rapeseed (Brassica napus L) to determine the effect of weeds at different growth stages on topping dry matter and seed yield of ratooned crop. Dry matter yield of weed-free plots was greater than that of weedy plot; this was most pronounced with topping at the bud stage and at first flower. At the earlier topping stages, the crop dry matter was more than that of the oats, indicating greater early season growth of the rapeseed than of the oats. Early topping between pre-bud and bud stage allowed competition from the weeds for the longest period of time and resulted in the lowest seed yield and highest weed dry matter as compared to crop topped late at first flower (3/4 plant cut) or removal of secondary branches, even lowest in the check plots (un-topped). The removal of secondary branches produced highest seed yield over all treatments including check plots under both weedy and weed-free conditions but was worst for topping dry matter.

Published

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25(2): 127-133,1993

Studies were carried out for comparing the magnitude of heterotic expression in F1 hybrids from two ploidy levels i.e., pentaploid x tetraploid and tetraploid x tetraploid. The pentaploid hybrids expressed 22.18% average heterosis over mid parents whereas corresponding value in tetraploid hybrids was 14.17% for plant height. With respect of mid-lobe leaf length, the average increase of pentaploid hybrids against mid and better parents respectively were 22.82 and 6.30% while the corresponding values in tetraploid hybrids were 8.46 and 7.02%. In case of mid-lobe leaf width, pentaploid hybrids on an average, expressed heterosis of 35.74 and 10.33% respectively over mid and better parents as compared to 12.35 and 10.40% respectively in tetraploid hybrids over corresponding parents. On an average pentaploid crosses gave increased seed cotton yield of 136% against mid parents. Regarding ginning outturn percentage, the pentaploid hybrids produced maximum heterosis of 6.09 and 4.39% respectively, against mid and better parents while in tetraploid hybrids, corresponding values of 3.00 and 2.54% were recorded. Concerning staple length, hybrids from two ploidy levels did not show apparent differences.

Published

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25(2): 134-144,1993

Kallar grass [Leptochloa fusca (L.) Kunth] was grown in mono-cultures and in mixed-cultures with Suaeda fruticosa (L.) Forssk., Cynlodon doctylon (L.) Pers., and Sporobolus arabicus Boiss., under different soil salinity and water conditions. The biomass yield data indicated that Kallar grass is a weak competitor against S. fruticosa at high salinity and against C. doctylon at low salinity, while its growth was not affected due to competition by S. arabicus. However, the yield of Kallar grass in mono-cultures (2 plants/pot) was significantly higher than that in corresponding mixed-cultures (2 plants Kallar grass + 2 plants of weed/pot). Although Kallar grass growth was low in its mono-cultures with 4 plants/pot compared to 2 plants/pot, it suffered more severe' interference from weed species under certain conditions than from its own individuals. In general, at a particular salinity and watering treatment, nutrient concentrations in plant shoots of a species grown in mono- and mixed-cultures were similar. However, total uptake of nutrients (N,P,K,Ca and Na) by Kallar grass and competing species differed significantly and weed species removed proportionately higher amounts of nutrients in mixed-cultures. The significance of competitive interactions among species with regard to their coexistence and productivity in a common environment in saline areas is discussed.

Published

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25(2): 145-155,1993

The effect of different levels of salinities on germination and growth of alfalfa (Medicago sativa), sunflower (Helianthus annuus) and sorghum (Sorghum bicolor) plants was studied. NaCl and CaCl2 (1:1 w/w) @ 1000, 3000, 5000 and 7000 ppm in Hoagland solution were used. During germination stage, sunflower tolerated salinity upto 5000 ppm and alfalfa and sorghum upto 3000 ppm. During growth stage, dry matter, leaf area and pigment fractions in alfalfa and sunflower increased at low levels of salinity but decreased at higher levels. In sorghum plants growth parameters decreased at all the salinity levels.

Published

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25(2): 156-160,1993

Using EMS, MMS and SA, mutations were induced in two mungbean (Vigna radiato (L) Wilczek) varieties viz., PS-16 and Pusa Baisakhi. Three different types of chlorophyll mutants viz., albina, Chlorina and Viridis were observed in M2 generation. Chlorophyll mutation frequency increased with increase in concentration of various mutagens. EMS produced highest frequency of mutations followed by MMS and SA. On the basis of their effectiveness, three mutagens stood in the declining order of MMSSAEMS whereas on the basis of their efficiency, the sequence was EMS, MMS and SA. All the three mutagens were found to be effective and efficient at the lower mutagen concentrations.

Published

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25(2): 161-166,1993

The nodal and diurnal abscission patterns in two determinate (Lee, MG Vi and Essex MgV) and one indeterminate (Williams MG III) cultivars of soybean (Glycine max (L) Merrill) were examined. Lee, Essex and Williams aborted 15.4, 6.7 and 3.2 flowers and 4.8, 1.8 and 1.6 pods per node, respectively. Total flower and pod abortion was 57.9 and 38.1% in Lee, 59 and 31.8% in Essex and 42.8 and 36.7% in Williams, respectively. Flower and pod abortion in the lower two-third canopy accounted for 77 and 83.4% in Lee, 83.8 and 61% in Essex and 88 and 84.6% in Williams, respectively. The period of blooming, pod setting and pod filling differed for different cultivars and even within the same cultivar. In Lee and Essex maximum reproductive abscission occurred during the first two-third of the period and in Williams during the middle.

Published

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25(2): 167-174,1993

CO2 assimilation rate in beans (Phaseolus vulgaris L) was investigated under field conditions. The rate of CO2 assimilation in leaves was significantly affected by ontogenetic stages, leaf position and their interactions. Maximum CO2 assimilation rate (15.332 mg CO2/dm-2 hr-1 was recorded at flowering stage followed by budding whereas, among the leaf positions. the higher rate of (14.985 mg CO2/dm-2 hr-1 was observed in upper leaves followed by central and lower leaves. Both leaf area and dry matter accumulation was higher at the pod forming stage, highest CO2 assimilation was recorded in deep green leaves followed by light green and yellow leaves. CO2 assimilation rate drastically reduced after pod formation as the case with dry matter accumulation and leaf area. CO2 assimilation was maximum in upper as well as deep green leaves as compared to lower leaves with light green or yellow colouring.

Published

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25(2): 175-178,1993

Wood chemical constituents such as holocellulose, alphacellulose and lignin contents of Casuarina cqllisclifolia were investigated from extractive - free wood of trunks and branches. In trunk wood amount of holocellulose, alphacellulose and lignin wee 73.08±3.91, 46.41 ±4.49 and 26.32±3.71% respectively, whereas for branch wood the corresponding values were 72.14±: 2.20, 42.87± 2.66 and 27.73± 1.55% respectively. The average fiber length, fiber diameter and fiber wall thickness was 978.28±48.26 mm, 14.81±4.97 µ.m and 6.95±t2.86 µ.m respectively. The amount of holocellulose, alphacellulose and lignin in the trunk wood and branch wood when compared with other types of wood suggest that relatively high pulp yield can be obtained r rom them. However, short lengt h and small diameter of fibers would render Casuarina wood unsuitable for making strong paper.

Published

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25(2): 179-182,1993

Shoot apices of peanut seedlings inoculated on MS medium containing 1 mg/I BA arid 0.01 mg/I NAA showed a prolific development of callus without differentiation after about 5 months of culture period with regular subcultures of one month. The calli regenerated plants when transferred to MS medium supplemented with 0.5 mg/I each of BA, 2 ip, Z and IAA (0.1 mg/I) after one month of culture. At least 10 plantlets/callus were obtained and the plantlets could be grown to adult stage under field conditions.

Published

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25(2): 183-188,1993

A procedure for the rapid clonal propagation of (Carica papaya L) was developed by culturing apices of mature field grown plants. The explants were successfully established on MS medium supplemented with 10 mg/1 kinetin and 2 mg/1 NAA. The growing explants upon transfer to a proliferation medium containing reduced levcls of BA (0.5 mg/1) and NAA (0.1 mg/1) produced maximum number of shoots per explant. Shoots rooted well in IBA supplemented MS medium and plantlets developed were transferred to soil.

Published

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25(2): 189-192,1993

Callus cultures were initiated from flower cups of cultivars of Rosa hybrida. Copious callus formation and growth was observed in cv. Diamond Jubly with 0.5 mg/l 2,4-D + 0.1 mg/1 kn and in cv. Lans France with 0.5 mg/1 2,4-D + 0.5 mg/I kn. Sodium diethyldithiocarbamate (SDC) at 250 mg/1 effectively controlled browning in cultures of both cultivars. SDC effect was related to concentration of phytohormones required by cultures at every 24 day cycle.

Published

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25(2): 193-198,1993

Taonia atomaria f. ciliata (Lamour.) Nizamuddin is raised to specific level and designated as Taonia pseudo ciliata (Lamour.) Nizamuddin & Godeh comb. nov. characterized by twisted, linear, narrow, ciliatodentate, strongly marginally proliferated segments, in cell structure of the thallus which basipetally grades from (3-) 4-6(-8) layers and a single sporangial basal stalk cell partially embedded in the thallus.

Published

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25(2): 199-207,1993

A new alga, Codium tobrukense Nizamuddin & Fathalla sr. nov., and a new form, C. tobrukense f. eImasirelise Nizamuddin & Fathalla f. nov.,. are described from Tobruk in the eastern coast of Libya.

Published

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25(2): 208-214,1993

Effect of VAM-fungus Glomus intraradices on the growth of sorghum, maize,.cotton and Pennisetum sp., was studied in soil under salt stress. The VAM-inoculated 20 day old seedlings growing in 1% (16.0m mho em-1) saline soil showed better growth and increase in fresh and dry weight over the non-inoculated plants.

Published

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25(2): 215-218,1993

Effect of seed pelleting with Stachyboays atra, Memnoniella echinata and Rhizobium meliloti on colonization of mungbean and cowpea roots by Macrophomina phaseolina, Rhizoctonio solani and Fusarium spp., was studied. A combined use of S. atra and R. meliloti was more effective in suppressing colonization of M. phaseolina and Fusarium spp., on mungbean and R. solani on cowpea roots than their separate use. Colonization of cowpea roots by all the three pathogens, and of mungbean roots by Fusarium spp., was greatly suppressed by a combined use of M. echinata and R. meliloti than their separate use. Use of S. atra showed greater phytotoxicity on cowpea as compared to mungbean.

Published

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25(2): 219-224,1993

Using agar plate, blotter and deep freezing method, 14 genera and 26 species of fungi were isolated from fourteen seed samples of Pinus gerardiana. About 70% of the samples were infected with Aspergillus flavus and A.niger with an infection range of 4 to 56% and 4 to 100% respectively. Agar plate method yielded greater number of fungi (19) as compared to deep freezing method (13) and blotter method (12). Deep freezing method was found superior to standard blotter and agar plate method for the detection of Altemaria, Cladosporium and Fusarium spp.

Published

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25(2): 225-231,1993

Effect of tillage practices on population and viability of sclerotia of Sclerotium oryzae and yield of rice was examined. Maximum tillage showed complete loss in viability of sclerotia at 0-5 cm soil surface and at (15-20 cm) depth. Yield of rice increased by 59% in maximum tillage as compared to minimum and no-tillage treatments.

Published

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25(2): 232-234,1993

Mashbean (Vigna mungo L) Hepper) an important pulse crop of Pakistan is planted over 85,000 hectares giving an yield of 30- 40 thousand metric tonnes (Anon., 1990). Of the fungal, bacterial and viral diseases which produce an annual loss of 12-14% the charcoal rot caused by Macrophomina phaseolina (Tassi) Goid., produces 100% damage to the crop in severe cases (Bashir & Malik, 1988). The fungus infects the seedling, root, stem or pods producing small black sclerotia which are liberated in soil upon tissue decomposition or during tillage operation (Cook et al., 1973).

Published

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25(2): 235-236,1993

The genus Pythium Pringsh., includes many plant pathogenic species which cause damping-off and root rot disease on important crops resulting in severe losses (PlaatsNiterink, 1981). Although reports of fungi like Macrophomina phaseolina (Tassi) Goid, Rhizoctonia solani Kühn, Fusarium spp., Sclerotium spp., and Sclerotinia spp., attacking under ground parts of crop plants in Pakistan have been made (Mirza & Qureshi, 1978; Shahzad & Ghaffar, 1986, 1990; Shahzad et al., 1988), Pythium spp., have received little attention. Of over 120 species of Pythium (Dick, 1990), P. aphanidermatum (Edson) Fitzpatrick from Capsicum annuum L. and unidentified Pythium sp., from soil have been reported form Pakistan (Mirza & Qureshi, 1978). During a survey of cultivated fields in different parts of Pakistan, P. aphanidermatum and P. periplocum Drechsler were isolated and identified after reference to Plaats-Niterink (1981) and Dick (1990).

Published

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25(2): 237-238,1993

Dr. Ralph Randles Stewart died on 6th November, 1993 at the age of 103 years at Duarte, Calif., USA. May God Almighty shower His blessings upon the departed soul and may his soul rest in peace in heaven. Amen. Dr. Ralph Randles Stewart was born on 15th April 1890 and grew up at Manhattan Island, New York city, USA. He obtained his Ph.D. degree (1916) from Columbia University, New York; D.Sc. Honorary (1953) from the University of the Punjab, Lahore and LLD Honorary (1963) from Alma College, Michigan, USA.

Published

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26(1): 1-2,1994

Dr. Syed Fakhrul Hassan died of cardiac arrest due to respiratory failure on 1st March 1994. May God Almighty shower his choicest blessings upon the departed soul and may his soul rest in peace in heaven. Amen.

Published

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26(1): 3-4,1994

Dr. Ghulam Rasool Solangi S/O Mr. Alam Khan Solangi was born on 6th December, 1938 at Larkana, Sindh. After obtaining early education from his home town, he studied at the Sindh Agriculture College, now Sindh Agricultural University, Tandojam from where he graduated in Agriculture in 1962. He received his M.Sc degree in Plant Pathology from the Sindh University, Jamshoro in 1965. In 1968 he went to USA and worked with Prof. H.K.Kiesling at the North Dakota State University, Fargo, U.S.A. He was awarded the degree of Ph.D in 1973 for his research studies on the "Genetic systems in Cochliobolus sativus".

Published

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26(1): 5-6,1994

A survey of 115 leguminous plants comprising of 79 species of Papilionaceae, 16 of Mimosaceae and 20 of Caesalpiniaceae was made for their nodulation status. Nodules were found in all the species of Papilionaceae, all the species of Mimosaceae except Adenanthera pavonina but not in Caesalpiniaceae. Vigna dalzelliana (O. Kuntze) Verde., V. mimgo (L) Hepper var. Sialkot; V. radiata (L) Wilezek. Pak.17. V. radiata (L.) Wilczek var. 71-17, V. radiata (L) Wilczek var. 3854, V. radiata (L) Wilczek var. 6601, V. Utlguiculata (L.) Walp. Tvx-O2F.3871 and V. unguiculata (L) Walp 1182 E-13 of the family Papilionaceae are reported for the first time as nodule bearing. Caesalpinia gilliesii (Hook) Dietr, Cassia italica(Mill). F.P. Andr, ssp.italica and C. italica ssp. micrantha Brenan of the family Mimosaceae are reported for the first time as non-nodulating. The shapes of'nodules were mainly elongate, globose and branched whereas semiglobose and irregular shapes were also observed. The colour of the nodules varied from white to brown and pink. Pink coloured nodules were mainly associated with members of Papilionaceae.

Published

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26(1): 7-20,1994

Pollen morphology of 25 monocotyledonous species belonging to 14 genera distributed in 8 families from Karachi have been investigated by light and scanning electron microscope. Pollen occur either singly or in tetrads. In most of the species simple apertures are found i.e., colpate and porate. However, in some cases iII-defined apertures or no apertures as in Commelinaceae are also found. Tectum of these families are also quite variable which ranges from reticulate, rugulate, striate, fossulate- echinate or scabrate/areolate.

Published

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26(1): 21-34,1994

The correlation between pollen characters and pollination types in 218 genera and 351 species belonging to 67 angiosperm families from Karachi was studied. Entomophily is the dominant (65.24%) pollination type, while 33.04% taxa are anemophilous and about 1.71 % taxa altogether exhibit ornithophily, hydrophily and zoophily. A definite relationship occurs between pollen characters and pollination types especially in entomophily and anemophily. Pollen grains of entomophilous taxa are characterized by compound apertures i.e., 3-colporate, prolate-spheroidal shape, generally large, thick walled, sticky and with reticulate tectum, while pollen grains of anemophilous taxa are with simple apertures i.e., monoporate, spheroidal, small, thin walled, dry and with scabrate-areolate tectum.

Published

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26(1): 35-56,1994

Numerical phenetic analysis of Pogostemon Desf. (Lamiaceae) species was carried out using a Reading Taxonomy Computer Programme. Thirteen species found in Bangladesh were analyzed for 34 characters. Three Phenograms derived from nearest neighbour, furthest neighbour and group average clustering were produced. The results obtained are discussed in the light of previous classification.

Published

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26(1): 57-62,1994

Rhoeo spachacea exhibits uncommon and unique chromosomal configurations at diakinesis and metaphase I in the form of rings or chains. Chain configurations range from a chain of two to twelve chromosomes with every intermediate size in one, two or three groups. A chain of twelve chromosomes was the common configuration than ring. In the case of two chains per cell highest frequency (10.71 %) was observed with 7+5 chromosomes and lowest (4.28%) with 10+2 configuration. Different configurations of three chains per cell were found in 0.7-4.28% cells. However by comparisons of chromosome configurations in R spathaceastudied by different workers significant variations were observed. These variations could be due to the use of different clones of Rhoeo or to different horticultural environments.

Published

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26(1): 63-67,1994

Actively growing root tips of onion (Allium cepa L) were used to evaluate cytotoxic effects of herbicide, Ronstar. The dividing cells exposed to 1000, 2000, 3000 and 4000 ppm of Ronstar for 3, 6, 9 and 12 h durations showed a significant reduction in mitotic index especially in treatments of higher concentrations and longer durations. Stickiness and fragmentation of chromosomes were the most frequent aberrations observed, bi- and multi-nucleate cells were noted as well. Abnormalities in lesser frequencies included Cmitosis and polyploidy. Such chromosomal abnormalities may effect adversely the vigor, fertility, yield or competitive ability of the plants exposed to the herbicide.

Published

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26(1): 69-74,1994

 Knowledge of heritability and correlation among traits is important in determining the effectiveness of direct and indirect selection. The objective of this study was to determine the potential effectiveness of selection for early maturity, and seed size, in two peanut crosses (NC 7/Chico and 73-30/Chico) byestimating the heritability for each trait and the correlations among the traits. Both narrow sense heritability and broad sense heritability estimates were fairly high for seed weight, maturity index, and pod length in both the crosses. Broad-sense heritability estimates were much greater than parent-offspring regressions and were biased upward due to nonadditive genetic effects and genotype x environment interaction. The results suggested that selection for early maturity, seed weight, and pod length could be practiced in early segregating generations. Correlations of maturity with shelling percentage were positive and highly significant in both crosses but correlation between maturity and seed number was positive and significant in cross 1 (NC 7/Chico). Maturity was negatively correlated with pod length and seed weight in cross 2. The highest positive and significant correlation was found between pod length and seed weight.

Published

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26(1): 75-82,1994

Breeding studies reconfinned the hybridization between Sida avata Forssk., and Sida tiagii Bhandari. All the three taxa i.e., S. avata Forssk., S. tiagii Bhandari and the hybrid are facultative autogamous as indicated by pollen - ovule ratios and breeding experiments. Chrysis sp., (Hymenoptera) seems to be responsible for pollen transfer between S. avata and S. tiagii in natural populations. Certain insect pollinators were specific such as Bembix sp., and Bambus sp., for S. avata, Apis sp., and Vespa sp., for S. tiagii and Ponera sp., for the hybrid. The limited number of hybrids may be due to less frequent visitation of common pollinator (Chrysis sp.) alongwith the incomplete reproductive barder between both the parents. The restricted gene flow is also evident by least fruit and seed set in hand pollinated reciprocal crosses of the putative parents as compared to the self pollination. It seems that back crosses are impeded due to the absence of common pollinators between the parents and hybrid and meiotic irregularities as indicated by the failure of hand pollinated (back crosses) experiments.

Published

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26(1): 83-97,1994

Soaked seeds of an exotic variety 5toneville-231 (Gossypium hirsutum L) were treated with gamma rays at 30 kR from 60CO source having dose rate of 40 kR per hour and planted in the field as M1 genera fion during 1984. From the segregating generations, a high yielding mutant was selected and named as NIAB-92. The plant of NIAB-92 is a semi-haily, compact sympodial type of medium stature. It has 0-2 fruit bearing monopodial branches and more number of shorter sympodial branches as compared to the parent, Stoneville-231 and commercial cotton variety NIAB-78. The mutant is early maturing and matures twenty days earlier than the parent 5toneville-231. It has higher yield potential alongwith desirable fibre properties such as G.O.T.(%), fibre length, fibre fineness and fibre strength. In the comparative yield trials the mutant NIAB-92 significantly outyielded both the prevalent commercial cotton varieties i.e., NIAB- 78 and S-12. At NIAB it gave 15.3 % and 19.1 % higher yield than NIAB-78 and 5-12, respectively, while at farmers fields the increase in yield was 8.8 % and 14.1 % as compared with NIAB-78 and 5-12. The mutant has also shown resistance against leaf curl virus disease.

Published

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26(1): 99-104,1994

Experiment was conducted on four cotton (Gossypium hirsutum L) cultivars viz., B.557, Niab-78, Sar. mast, Qalandari to evaluate their growth in terms of plant height, stem diameter, biomass production and ion transport from root to shoot when exposed to salinity levels of 4, 16, 21, 22 and 24 dS, m-1. Increasing salinity levels reduced growth of all the cultivars with higher inhibition in shoot as compared to root, Cw, Niab 78 and Qalandari exhibited higher salt tolerance where lower salinity levels promoted root development. Increasing salt levels also increased the net ionic uptake in all the cultivars with more affinity for K +. KINa ratio was > 1 in all cultivars, Niab- 78, however, showed minimum uptake and accumulation of salts under increasing salinity regimes and can be rated as more salt tolerant.

Published

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26(1): 105-114,1994

Sporobolus arabicus and Sesbania aegyptica grown in sandy soil as mono- and mix-culture using saline water (ECiw: 6 & 12 dS.m-1) for irrigation showed that the productivity of grass - legume mix-culture per unit area was much higher irrespective of the salinity of irrigation water. Reduction in growth of S. aegyptica at higher salinty (ECiw: 12 dS.m-1) was more as compared to S. arabicus. No significant reduction in growth of S. aegyptica was observed at low salinity (ECiw: 6 dS.m-1), whereas growth in S. arabicus was promoted. Increase in proline content at higher salinity was evident in S. aegyptica with no effect in S. arabicus. Alteration in the absorption of radiant energy (quantum yield) were non-significant in Sporobolus in response to salinity and cropping system, while Sesbania plants showed a positive response with respect to salinity and inter-cropping with Sporobolus. The same trend was evident for stomatal conductance. Transpiration rate of Sporobolus was low when grown as mix-culture, while that of Sesbania was highly reduced by salinity under both cropping systems.

Published

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26(1): 115-125,1994

The effect of 0.25-1.0% NaCI salinity and water stress on growth and biomass production in Helianthus annuus L, was examined. All growth parameters showed reduction under both salt and salt water stress. One percent NaCI salinity adversely affected the relative growth rate (RGR), net assimilation rate (NAR) and leaf area ratio (LAR). Salt stress together with moisture stress also adversely affected the growth rate. Plants grown both under salt or salt and water stress conditions showed a better growth response after 1 month interval followed by a decline at subsequent harvests.

Published

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26(1): 127-138,1994

The effect of aqueous extracts obtained from various plant parts of Albizia samons and the under canopy soil was studied on germination and early seedling growth of different cultivars of Zea mays, Triticum aestivum and Albizia lebbeck. Stem and seed extracts delayed germination and inhibited seedling growth. Root and leaf extracts delayed germination and inhibited seedling growth in some test species. Rower and soil extracts had no effects on germination and growth.

Published

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26(1): 139-147,1994

The study deals with the multivariate analysis of the vegetation of Swabi District. Sociological relationships among the leading dominants in tree, shrub and herb layers are discussed separately. Chcmical and physical analysis of soils of each stand are given. The vegetation pattern of each layer of the community and its relationship to soil were examined with the help of polar ordination. Soil pH, CaCO3 and P2O5 were found to be the controlling factors in the distribution of vegetation. The overall vegetation is dominated by Acacia modesta, followed by Ziziphus mauritiana in the tree layer. Asparagus, lmodon, Torilis, Thymelaea, Qxalis and Desmostachya were important in the lower strata.

Published

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26(1): 149-160,1994

Studies on the effect of storage temperature of 0,7 and 25°C before planting were conducted on four garlic cultivars with respect to their leaf initiation, clove differentiation, development and yield under field conditions during 1990/91 season. All cultivars, except Omani, showed less leaf initation at 25°C than at either 0 or 7°c. In contrast, Omani garlic produced more leaves at 25°C than at lower storage temperatures. A varied cultivar response to temperature was noticeable in leaf development over a 15 weeks period from planting. Bulb diameter was greater at low temperatures. Clove differentiation was higher in Omani cultivar and least in Indian cuItivar. Single clove bulbing was found to increase with temperature, reaching .80% at 25°c. Bulb weight and number of days to reach maturity were both favoured by low storage temperature. Bulb yield showed progressive decrease with the increase in storage temperature. However. all cultivars, except Indian, attained a 3 fold increase in bulb yield at OOC than at 25°C.

Published

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26(1): 161-165,1994

The effects of different planting dates were studied to determine the influence of topping at different growth stages on yield components, seed weight, seed yield and other agronomic characters. The time of topping had a significant effect on initial flowering and maturity periods. More days were required for initial flowering and maturity for the ratooned crop topped at first flower followed by the bud and pre-bud stage except where the secondary branches were removed, which appeared to be almost similar to the controls. Topping, however, had a negative effect on yield components. Removal of secondary branches had minimum effect on yield components and produced yield per plant and plot very close to the controls whereas, topping response was clearly evident on seed weight.

Published

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26(1): 167-171,1994

Wheat cultivars Punjab 76 (Lr1), Chenab 70 (Lr13), Khyber 79 (Lr13), ZA-77 (Lr1 + 13), Faisalabad 83 (Lr+13), Lyallpur 73 (Lr1+13), Pari-73 (Lr1+13), Sandal (Lr1+13), Sindh 81 (Lr1 + 13). Yecora (Lr1 + 13), Zamindar (Lr1 + 13), Zarghoon (Lr1), Arz (Lr3 + 13), Barani 83 (Lr3 + 13), Punjab 81 (U13 + ) and Morocco (without gene) for leaf rust resistance were induded in the test. The plants 45 days after planting were inoculated through spraying with aqueous suspension of uredospores of Puccinia rccondita. Leaf rust epidemic was first observed early in February on Morocco which does not carry any known gene for resistance. The start of the disease on the cultivars carrying one or other gene (s) for resistance were delayed by one to three weeks. Similarly the rate of development of the disease per unit time was also slower on cultivars carrying a gene for resistance than on the one without any knwon gene for resistance.

Published

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26(1): 173-176,1994

Using component plating technique Macrophomina phaseolina was isolated from seed coat. tegmen!. cotyledons and embryo of pumpkin seeds. Infected seeds give rise to infected seedlings that transmit the pathogen into the fruits.

Published

Doi:
26(1): 177-180,1994

In a green house experiment soil artificially infested with a pathogenic strain of Fusarium oxysporum f.sp lycopersici suppressed the infection of Macrophomina phaseolin a, F. solani and Rhizoctonia solani on tomato and okra roots. The suppressive effect of F. oxysporum increased in the presence of Trichoderma harzianum, T. koningii, Gliocladium virens, Paecilomyces lilacinus, Bradyrhizobium japonicwn and Rhizobium meliloti against F. solani and M. phaselina. F. oxysporum induced mortality in tomato plants. Root colonization by F. oxysporum increased in F. oxysporum infested soil with reduced plant growth and less infection of M. phaseolina and R solani. T. harzianwn, T. konillgii, G. virens, P. Iilacinus, B. japonicum and R meliloti showed significant control of M. phaseolina, F. oxysporum and F. solani infection on tomato and okra both in F. oxysporum infested and uninfested natural soil, whereas T. koningii, G. virens and B. japonicum increased R solaniinfection in F. oxysporum infested soil in tomato.

Published

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26(1): 181-186,1994

The reaction of sugarcane hybrids Co.440, Co.1oo1, Co.997, OB5155, CP.36/111, CP.291116, Mex 52/29, B61208, BR.6223, BO.20/58 to Curvularia leaf-spot disease was studied in the Screenhouse. Mex 52/29 and BN61208 were moderately resistant to infection while others were moderately to highly susceptible. Increase in nitrogen levels from 80 to 240 kglha increased the severity of attack. Sugarcane leaf necrotic spots coalesced, turned brown gradually and subsequently died, resulting into significant decrease in shoot weight of sugarcane hybrid Co.1oo1.

Published

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26(1): 187-189,1994

Petiole segments and excised epidermal thin cell layers of Carica papaya N. Malir were cultured on full strength MS medium containing a range of concentrations of nephthalene acetic acid (NAA) and isopentenyl adenine (2iP) used seperately and in combination. Petiole segments and epidermal thin cell layers formed maximum callus on medium containing 2.5 mg/1 NAA plus 0.5 mgll2iP and 1 mg/1 NAA plus 1 and 5 mgll 2iP respectively. Enhanced callus growth and shoot formation occurred on half strength macro inorganic salts of MS medium containing 2.5 mg/1 NAA plus 0.5/1 mgll 2iP alongwith 15% coconut milk. Regenerated shoots produced roots on half strength macroinorgani<; salts containing MS medium supplemented with 5 g/1 glucose. The method may be useful for the mass propagation of female papaya plants for large scale cultivation.

Published

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26(1): 191-195,1994

Regeneration of plants by means of somatic embryogenesis is of utmost importance for improvement through somatic cell genetics. This is preferred over normal regeneration via organogenesis due to various advantages when used for transformation. High number of regenerants can be obtained originating from few or single cells which increases the likelihood of achieving transformed plants. Little progress has been made towards developing an in vitro regeneration system for chickpea, an important food legume crop. To date, chickpea has been regenerated only from preexisting shoot meristems (Rao & Chopra, 1989'; Rao & Reddy, 1992). This study describes the development of chickpea somatiic embryos on immature cotyledon explants.

Published

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26(1): 197-199,1994

 Dr. Sultan Ahmad, an eminent mycologist, died of heart attack on 11 th November 1983 in Lahore after a long illness. He was a chronic patient of diabetes melitus. In the later part of his life he developed retinopathy, suffered from renal failure and remained on dialysis before breathing his last. May God Almighty shower His blessings upon the departed soul and may his soul rest in eternal peace in heaven. Amen.Dr. Sultan Ahmad was born on 6th June 1910 at Ladhar, Sheikhupura, Punjab, now Pakistan. He obtained his M.Sc degree in 1932 from the University of the Punjab, Labore where he worked with Prof. S.R. Kashyap on Aithisoniella himalyensis Kash. He also obtained the B.Ed. degree from the Punjab University, Lahore in 1934 and served as a teacher in a High School in Gujrat and then as a Lecturer in Biology at Rohtak. After the creation of Pakistan in 1947, he returned to Lahore and joined the Government College, Lahore. He obtained his Ph.D. degree in 1950 for his work on Gasteromycetes of West Pakistan which he submitted under the supervision of Professor Dr. Ahmad Ali Qureshi and later D.Sc in 1957 from the University of the Punjab. Dr. Sultan Ahmad retired as Professor and Head of the Department of Botany, Government College Lahore in 1970. The University of the Punjab appointed him as Professor Emeritus in 1972 and Dr. Sultan Ahmad continued to involve himself in research work on the fungi of Pakistan.

Published

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26(2): 201-202,1994

The composition and distribution of fresh-water algae in Makkah area of Saudi Arabia were investigated. Of a total number of 107 species recorded, 37 belong to Cyanophyta, 34 to Bacillariophyta, 29 to Chlorophyta, 6 to Euglenophyta and 1 to Pyrrhophyta. The most common genera were Oscillatoria (14 spp.), Spirogyra (8 spp.), Navicula (7 spp.), Nitzschia (7 spp.), Gloeocapsa and Euglena (each with 4 spp.) where Merismopedia elegans, Oscillatoria amphibia and O. tenuiswere most widely distributed. AI-Taif locality had 64 algal species. Among the dominant algae in Makkah area, the green alga Oedogonium gracilis was chemically investigated and was characterized by having high amount of ash and protein, 17 amino acids where glutamic acid, alanine, aspartic acid and leucine were predominant.

Published

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26(2): 203-213,1994

Poropsis Kütz., is retained as a genus of its own because of smooth axes, absence of articulations and lobules.

Published

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26(2): 215-219,1994

Using ISTA techniques, 9 genera and 22 species of fungi viz., Alternaria alternata, A. tenuissima, Aspergillus candidus, A. clavatus, A. jlavus, A. fumigatus, A. niger, A. sulphureus, A. terreus, A. wentii, Aspergillus spp., Chaetomium spp., Cladosporium sp, D. state of Cochliobolus spiciJer, Fusarium equiseti, F. oxysporum, Fusarium spp., Penicillium camemberti, P. decumbens, Penicillium spp., Rhizopus sp., and Trichodenna harzianum were isolated from different parts of pistachio nuts collected from different parts of Pakistan. Of these, A. jlavus and A. niger were found predominant. The cotyledons were infected by greater number of fungi with less infection in shell, seed coat and axis (radicle and plumule). Less number of fungi were isolated by deep freezing method as compared to agar plate and blotter methods. Sterilization of seeds with 1% Ca(OCI)2 reduced the infection of Aspergillus species only.

Published

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26(2): 221-228,1994

Verticillium chlamydosporium isolated from eggs of Meloidogyne incognita, root knot nematode, inhibited the growth of Macrophomina phaseolina, Rhizoctonia solani Fusarium solani and F.oxysporum in vitro. In a field experiment v.chlamydosporium was found more or equally effective than Paecilomyces lilacinus, Talaromyces flavus and Bradyrhizobium japonicum in controlling the infection of M.phaseolina, R.solani, F.oxysporum and F.solani in chickpea. Combined use ofv.chlamydosporium and B. japonicum showed betler control of F.oxysporum than their separate use. Combined use of B.japonicum and T.flavus produced greater plant height and fresh weight of shoot in chickpea.

Published

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26(2): 229-233,1994

Pscudomonas species isolated from soils cultivated with citrus plants (204) and plant galls (46) in the Jordan Valley were physiologically and biochemically classified into fluorescent group (74) and nonfluorescent group (176). All plant gali isolates belong to fluorescent group. The soil isolates (145) and the plant gall isolates (46) were pathogenic to tobacco plants. The non-fluorescent group included: P. maltuphilia (53), P. cepaeia (41), P. avenae (21), P. solanacearun (20), P. cissicola (18), P. cattleya (8), P. paucimobilis (4), P. citrulli (3), P. mesophiliea (3), P. andmpogonis (3) and P. amygdali (2) and the fluorescent group P. syringae (62), P. fluorescens (7) and P. chlororaphis (5).

Published

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26(2): 235-240,1994

 A study was made on the seasonal fluctuations in N2-fixing (C2H2 reduction) activity and uptake hydrogenase activity of the root nodules of Coriaria nepalensis and Datisca cannabina. Nitrogenase activity of the nodules of both plants showed biphasic curves with peaks in spring and late summer. Acetylene reduction by the root nodules of Coriaria nepalensis was highest (16.4 µ mol. C2H4 g-1 fresh nodule Wt. h-1) during July while the peak acetylene reduction activity (14.8 µ mol. C2H4 g-1 fresh nodule wt. h-1) of Dansca cannabina nodules was determined in April. Less than 15% of the enzyme activity was retained by the nodules in winter. The nodules of both plant species consumed hydrogen on incubation with a gas mixture containing H2 indicating an uptake hydrogenase activity. The H2 uptake by the excised nodules of both Coriaria and Dalisca was highest (2.16 and 1.95 µ mol. H2 consumed g-1 fresh nodule Wt. h-1, respectively) in May. The presence of an uptake hydrogenase was confirmed in nodule homogenates with phenazine metasulphate as an artificial electron acceptor. Purified vesicle cluster suspensions (20 µm residue) showed highest hydrogenase activity, indicating that the enzyme is associated with the endophyte.

Published

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26(2): 241-246,1994

An actinomycete (Dc2) was isolated from the nitrogen fixing root nodules of Dalisca cannabina. The actinomycete Conned hyphae and sporangia, like typical Frankia strains but failed to infect host plants. This noninfective isolate was confirmed as Frankia by sequence analysis of 16S rRNA gene, amplified by polymerase chain reaction (PCR).

Published

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26(2): 247-251,1994

The effect of salinity on the growth of Rhizobium spp., isolated from Prosopis glandulosa and P. juliflora was studied in vitro. Growth of Rhizobium isolated from both Prosopis species increased at all salinity levels as compared with the control (0.01 %) except at 1% NaC1 level. Rhizobium sp., isolated from P. glandulosa showed a gradual decline as salinity increased from 0.3 to 1.0%; that isolated from P. juliflora showed a decline as salinity increased from 0.2 to 1.0%. Increasing salinity caused a gradual reduction in seed germination, height of the plant, number of nodules per plant and nodule size.

Published

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26(2): 253-258,1994

Salt tolerance of Pallicum antidotale Retz., was studied using gravel culture with root medium electricaI conductivity (EC) levels ranging from 3 to 20 dS/m. Salinity decreased the seed germination and plant powth. A 50% relative-to-control reduction in dry mass yield was observed at EC 15.9 dS/m. Na contents in plant shoots increased whereas K contents decreased in response to increasing salinity. Ca concentration exhibited non-significant variation over control. CI contcnt alongwith N and protein percentage increased with increasing root medium salinity.

Published

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26(2): 259-263,1994

Experiments were carried out to screen local and exotic species/accession/provenances of Prosopis species at germination and seedling stages under salinity conditions. Field trials were also undertaken to .Iuate potential species/ accessions /provenances under salt stress. Seeds of indigenous P. juliflora and P.giandulosa showed higher germination than seeds of P. cineraria and the exotic species under non.tine as well as under different levels of salinity stress with EC values of NaCl solutions ranging from 030 dS.m-1 There was a decrease in germination of all species with increasing salinity levels. Seedling anergence was completely inhibited above EC 10 dS.m -1 in P. juliflora and P. cineraria and above EC 15 dS.m-1 in P. glandulosa. Growth of 3 indigenous and 2 exotic Prosopis species/provenances in pots containing sandy soil irrigated with dilutions of sea water adjusted at ECiw : of 10, 20, 30, and 40 dS.m -1 showed that P. glandulosa did not survive beyond ECiw : of 20 dS.m-1. Among the surviving plants, P. juliflora obtained from Brazil grew at the highest salt concentration and showed minimum biomass reduction in comparision with other species. In a field experiment, seedlings of 12 indigenous and 8 exotic species/accessions/provenances of Proscpis transplanted under field conditions and irrigated with saline water (EC: 14-16 dS.m-1) showed that the indigenous species/provenances, viz., P. juliflora (D.I Khan) and P. glandulosa(Sujawal), and the exotic species/accessions, P. alba (Acc.# 0166) and 2 South American species showed better growth in terms of plant height and stem diameter under prevailing haloxeric conditions. Importance of mesquite CIItivation for providing fodder, fuelwood, timber, and checking

Published

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26(2): 265-282,1994

To produce salt-tolerant wheat germplasm through wide hybridization, 8 different salt-tolerant accessions of Ae. cylindrica were crossed with 3 hexaploid wheat cultivars: Pak-81, LU-26, and Shalimar88. Frequency of seed set ranged between 1.72% (Shalimar-88 x Ae. cylindrica acc. 38-53) and 52.6% (Pak81 x Ae. cylindrica acc. G.). The performance of wheat cultivars LU-26 and Shalimar-88 as female parent for F hybrid production was poor. Frequency of BC1 seed production ranged between 0.53% (Pak-81 x Ae. cylindrical I LU-26) and 8.92% (Shalimar-88 x Ae. cylindrical/ LU-26). BC1 plants with different chromosome numbers were selfed to produce BC1F1 derivatives. Seven BC1combinations produced selfed seeds ranging between 1 and 200. Six BC1 combinations did not produce selfed seeds and were backcrossed again with LU-26 to produce BC2 seeds, which ranged between 1 and 12 seeds per BC1 combInation. Of the 30 different BC2 seeds produced in different combinations, only 19 produced BC2F1 selfed seeds. All the BC2F 1 and BC1F2 seeds were tested for germination under saline solutions of EC 2.5 (control) 15, 20, and 25 dS/m. Salinity induced reduction and delay in seed germination; reduction in shoot and root length and in seedling fresh weight was observed with considerable variation among different salinity levels and among different genotypes at one salinity level. The results have been discussed with reference to the wide hybridization approach and its potential use in the production of Fneuc variability for polygenically controlled characters such as salt-tolerance.

Published

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26(2): 283-292,1994

The interactive effects of different salt concentrations (EC: 0, 10 and 20 dS.m-1) and waterlogging levels of 75, 100 and 125% water holding capacity on growth of Atriplex amnicola Paul G. Wilson in sandy loam and silty loam soils was studied. Plant growth in terms of shoot volume decreased in salinity treatments, with no significant differences at waterlogging treatments. There was an increase in shoot volume in silty loam soil as compared to sandy loam soil. Leaf area: weight ratio (LA:W) showed definite responces to both salinity and waterlogging treatments. Silty loam soil produced higher biomass as compared to sandy loam soil. High salt contents of EC: 20 dS,m-1at 125% WHC showed adverse effects on biomass production. In sandy loam soils, different plant parts showed non-significant variation in organic matter and ash contents for salt levels, whereas, lib contents increased and organic matter decreased at waterlogging levels. Silty loam soil exhibited low percentage of organic matter than sandy loam soils. Shoot biomass productivities correlated to both soil alinity and plant volume data. Regression equations have been calculated to determine the estimated biomass over a period of time.

Published

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26(2): 293-309,1994

Four varieties of wheat viz., C591, C273, Pak-81 and Pirsabak-85 partitioned different proportions of assimilates to the different organs having different functions. Varieties C591 and C273 grew taller, reached anthesis stage earlier and partitioned more assimilates to stem and less to spike and leaves tiling in smaller spikes, while Pak-81 and Pirsabak-85 partitioned more assimilates to spikes and leaves thus they had larger spikes than the tall varieties. Upto anthesis the 4 varieties produced about the same total biomass indicating that Pak-81 and Pirsabak-85 had lower net assimilation rate since their total green leaf areas were greater than C591 and C273.

Published

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26(2): 311-320,1994

Relationship between physical properties affecting postharvest water loss in pepper fruits wereexamined. Three pepper types viz., 'Keystone' (Bell Pepper), 'NuMex R Naky' (long green) and 'Santa AI Grande' (yellow Wax) were significantly different in their initial water content, fruit surface area, fruit surface area to volume ratio, cuticle weight and epicuticular wax content. The rates of postharvest water loss at 8,14 and 20°C were significantly different in the three pepper types. Postharvest water loss was not related to initial water content at any storage temperature or cuticle weight at 8°C. Large sized leyitone' fruits with small surface area to volume ratio and high epicuticular wax contents lost weight at significantly lower rate. No stomata on the surface of pepper fruits were found. Epicuticular wax was generally amorphous.

Published

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26(2): 321-326,1994

Field experiments were conducted at the Australian Demon stration Farm at EI-Marj Libya during the winter season 1988-89 and 1989-90 to determine the efficacy of herbicides on grassy and broad leaf weeds and grain yield of Wheat variety Mexicale. Herbicides viz., moxan, Brominal, Dicuran and Dosanex alone and in different combinations were tested. Illoxan 36 F.e. 2.2. lit + 2 lit Brominal H/ha and Illoxan 36 F.C 2.5 lit + llit Brominal H/ha increased the yield significantly over other treatments in 1988-89 while Dicuran 500 F.W 5 lit/ha and Dosanex F.L 6 lit/ha in 1989-90. The herbicide treatments showed varied response on weed control according to prevailing wecd infestation in both the years. Dicuran 500 P.W and Dosancx F.L were more phytotoxic than the mixture of Illoxan 36 F.C and Brominal-H.

Published

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26(2): 327-330,1994

Effect of contemporary rotation simulation on grain weight, protein and lysine content of four commercial cuhivars (Pavon, Sarsabz, Mehran 89 and T.J. 83). and 21 new promising strains of bread wheat was studied Late sowing decreased (P < 0.05) grain weight, but protein and lysine contents were significantly (P < 0.05) enhanced. Correlation between grain weight and development period of grain was positive (r=0.581), whereas, development period and protein (r = -0.463) and protein and grain weight (r = -0.263)was' negative. Higher temperature in the post-anthesis period oflate sown wheats probably shortened the pin filling period, which resulted in the reduced endosperm. The reduction in endosperm due to late sowing my be responsible for lower grain weight and enhanced protein content.

Published

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26(2): 331-339,1994

Response of cotton pollen to 05, 1.0, 2 and 5 kR of gammarays prior to cross pollination was determined in various cross-combinations. A low dose of 0.5 kR applied to pollen enhanced boll set and seeds per pollination, whereas pollen irradiation with higher doses of 2.0 to 5.0 kR, before cross polinations showed a sharp decline in boll set and seed production compared to control treatment. M1 generation studies showed that higher doses of 2.0 to 5.0 kR of pollen radiation decreased the emergence and survival rate whereas phenotypic and fertility changes significantly increased at 2.0 kR. Varietal response to pollen radiation was non significant for phenotypic changes but significant for fertility changes. Treatment of pollen with 0.5 to 1.0 kR of gamma-rays is suitable for inducing useful genetic ,variability in cotton.

Published

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26(2): 341-346,1994

Karyotypic analysis of Lens culinaris Medic., s.sp. Macrosperma Laird x Precoz was carried out to dcrermine the chromosomal positions. The diploid chromosome number was 14. The Karyotype characterized its seven pairs of chromosomes into 3 metacentric and 4 sub-metacentric pairs. No chromosome with secondary constriction was observed. The total chromosomal length of the diploid complement was 45.74 µm whereas, the average chromosomal length observed was 3.67 µm. The Karyotypic formula was K (n = 7) = 3 M+4Sm. A Karyogram and an idiogram was prepared for further cytogenetic studies.

Published

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26(2): 347-352,1994

Within the Triticeae, cereal crop improvement alternatively exploits use of alien genetic variation emanating from several annual and perennial species. Somatic and meiotic cytological procedures are used to diagnose the presence of alien chromosomes forms, an essential component in derived progenies. Quality somatic analytical products are achieved through a high cellular mitotic index, chromosome definition, primary and secondary constriction detail, intense nuclear staining with minimum to none cytoplasmic staining and virtually no chromosome stickiness. Meiotic preparations with similar attributes are considered to be representative of high quality, where in addition separation of multivalent associations and minimum chromosome stretching are more crucial. Such cytological results described in this technique, are anticipated to serve as the basis to further build upon with other differential heterochromatin staining and molecular cytology aspects.

Published

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26(2): 353-366,1994

This research evaluated the stability performance of sunflower cultivars in two groups of regional trials in the Northeast part of Greece. Genotype-environment interaction was measured by Ihe linear response to environmenl effects and by the deviation from linear response. The data from the two groups of cultivars showed thaI only two hybrids were stable for seed yield across the examined environments. An open pollinated variety and a hybrid that was used as checks, displayed unstable performance. The majority of sunflower cultivars followed linear response to the environmental effects. However, the unpredictable component of the genotype-environment interaction variance i.e., the deviation from the linear response, ad high variation and much more importance than the predictable component.

Published

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26(2): 367-371,1994

Polymerase chain reaction was used to detect polymorphism in 10 different salt-tolerant wheat introgression lines produced through wide hybridization, 2 cultivated hexaploid wheat varieties, a tetraploid wheat variety and salt-tolerant accession D of Aegilops cylindrica. DNAs extracted from fresh leaves by the CTAB method were amplified using 25 µ.L reaction volume in a Perkin Elmer Thermal Cycler and randomly sequenced 10 mer synthetic primers. Based on amplification reactions, all the primers were divided into 4 categories. Category A primers reacted with all the wheat lines, category B with none, category C with 10-14, and category D with 3-7 wheat lines. Of the 18 reactive primers, 11(61%) detected polymorphism in all the test material. The level of polymorphism was low and ranged from 1.2 to 22.8%. Most of the primers produced monomorphic bands including very intense, easily visible and less visible bands. Of the 9 salt-tolerant introgression wheat lines, 6 were identified on the basis of polymorphic bands. Our study indicated possibilities for using Randon Amplified Polymorphic , DNA (RAPD) markers to detect specific variations in the genome that could be used for varietal finger printing

Published

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26(2): 373-382,1994

Suspension cultures of Nicotiana tabacum cv. Virginica established from epidermal tissue-derived callus on medium supplemented with 5x10-6M NAA alone or with 5xl0-7 M kinetin when subcultured on auxin licking morphogenetic medium containing kinetin, exhibited morphogenesis. The mode of regeneration was dependent on the concentration of kinetin. Low concentrations of kinetin favoured root. and embryoIe structure development while high concentration of kinetin induced tightly aggregated clusters of shoots. The regenerated structures showed a general tendency towards a gradual increase in the number of shoots with a concomitant decrease in their size at increasing concentrations of kinetin. Histological study of the embryo-like structures revealed their resemblance with the zygotic embryos.

Published

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26(2): 383-392,1994

A protocol for excising and culturing cotyledon explants from seeds of different ages of Aegle marmelos was developed. Cotyledon explants formed callus and shoot buds on agarsolidified Murashige & Skoog (MS) medium containing several combinations of 6-benzylaminopurine (BAP), indole-3-acetic acid (IAA) and gibberellic acid (GA3). The highest frequency of adventitious bud forming explants and maximum number of shoots per explant were obtained from 110-150 days old cotyledons. BAP with lAA or GA3gave better result than BAP alone. Shoots were elongated by transferring explants with shoot buds to same basal medium containing 1.0 mg/I kinetin (kn) and 0.1 mg/I lAA. The in vitro regenerated shoots rooted when cultured on half strength MS medium containing 25 mg/I indole-3-butyric acid (IBA). Regeneration by this method may be useful for mass propagation of A. marmelos.

Published

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26(2): 393-396,1994

Trichomes from the leaves of 11 species of Pelargonium L' Herit., were examined with the S.E.M. Trichomes observed were of either non-glandular unicellular and uniseriate-type or were glandular, uniserrate stalk of different length, with a unicellular head consisting of spherical or oblong spherical terminal cell. The surface of the trichomes were smooth to granulate-tuberculate. The study revealed that trichomes of the leaf indumentum can be used as an additional aid in the identification and determination of relationship between the species.

Published

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26(2): 397-407,1994

Using Scanning Electron Microscope a micromorphological study of leaf and seed coat surfaces of all the 7 species in the genus Medicago L, from Pakistan was carried out. The seed coat sculpturing revealed 3 main surface patterns viz., verrucate, papillate and rumeniate-tugose. Leaf epidermis was found to be covered with waxy material in all taxa, exhibiting verrucate to colliculate pattern with irregular arrangement of cells. Leaf trichomes are unicellular with granulate surfaces. A key based on micromorphological characters observed has been proposed to identify the species.

Published

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26(2): 409-419,1994

Pollen morphology of 42 species belonging to 12 genera of the family Malvaceae from Pakistan were examined by light and scanning electron microscope. Pollen morphology of the family is fairly uniform. Pollen grains are generally radially symmetrical apolar, rarely isopolar (Abutilon), mostly spheroidal to oblate - spheroidal rarely sub-oblate, pantoporate or triporate zonoaperturate. Tectum uniformly echinate, medium to finely -perforated, or punctate with granules or scabrae in between spines. On the basis of various pollen characters viz., polarity, , diameter of grains, exine thickness and spines size, 6 distinct pollen types recognized areAbelmoschus crinitus - type, Abutilon indicum - type, Hibiscus aristi-valvis type, Malva parviflora - type, Senra incana - type aml Sida ovata - type.

Published

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26(2): 421-440,1994

The effect of Meloidogyne graminicola on root morphology and growth of rice and the Echinochloa colonum grass was investigated under glasshouse conditions. Invasion by nematode juveniles reduced total root length and the length of axes and laterals in both hosts, while the number of axes (nodal) in infested rice roots increased due to nematode invasion. On infested roots of both hosts, the laterals grew in clusters and appeared earlier than on uninfested roots. When a root was invaded by the nematodes and a gall formed, the growth of the root was checked and secondary laterals grew on the gall. Upto 11.6% in rice and 21:3% of total laterals in E. colonum were grrowing, on the actual galls formed due to nematode invasion.

Published

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26(2): 441-449,1994

The first three components (explaining 71.75% of the total variance) derived from principal component analysis were used to define the ecological niches of the plant populations in a desert landscape. The paper examines the niche parameters of breadth and overlap and investigates the guild structure within the assemblage. On the basis of overall (product) niche width three species Blepharis sindica, Commiphora wightii and Prosopis cineraria were shown to be generalists while five species - Prosopis juliflora, Cordia gharaf, Senna hlolosericea, Rhazya stricta and Grewia tenax appeared to be specialists. Average importance value of species was weakly positively correlated with the niche width. Pairwise niche overlaps varied considerably, ranging from 0.0886 to 0.9958 but the average overlap was high on all three niche axes. Although the niche dimensions were theoretically independent from each other, pairwise overlaps, along the axes were correlated. The extent of diffuse overlap for different species varied with the niche axes. In the three dimensional niche space, Senna holosericea experiences the least overlap while Zizyphus nummularia faces the most. Analytical study of niche packing disclosed that species were packed more closely along niche dimensions than is predicted by competition theory. The problem of interpreting overlap measures as indices of competition intensity are discussed. Analysis of guild structure revealed two major guilds each comprising of two subguilds. Coexistence of species in the face of high niche overlap is explained.

Published

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26(2): 451-465,1994

Dielectric properties of fresh leaves of Ficus benghalensis, F. elastica, F. religiosa and Morus nigra (Moraceae) and Hibiscus rosa-sinensis and Gossypium hirsutum (Malvaceae) were measured with time over a wide range of frequencies. The dielectric responses of different species belonging to the same family were qualitatively similar, whereas responses of samples belonging to different families were substantially different. The observed dielectric spectra were found to be a strong function of time. Although the overall effect of time was the reduction in sample conductance but the rate of reduction varied from species to species, which might be due to their anatomical and phytochemical properties

Published

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26(2): 467-475,1994

Astragalus (Bentham, 1865). This was maintained by Baker (1876) and more recently by Ali (1977). Rechinger f. (1957) described a new genus Kerstania Rech. f. based on K. nuristanica Rech. f. which has been shown to be conspecific with Astragalus hosackioides (Royle ex Benth.) Benth. (Ali, 1958). Rechinger f., (1984) has retained Podolotus Benth., as a separate genus whereas Polhill (1981) while discussing the genera of the tribe Loteae, has reduced Podolotus Royle ex Benth. (Astragalus sect. Podolotus (Royle) Benth.) to the synonymy of the genus. Following Polhill (1981), Astragalus hosackioides (Royle ex Benth.) Benth., is being transferred to the genus Lotus L. 

Published

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26(2): 477-477,1994

Professor Majeed Ahmad was born on May 16, 1916 at Unnao in Lucknow, India. He received his school and college education in Lucknow and obtained M.Sc. degree from Lucknow University (India) in 1938 and Ph.D. degree in 1948 from the University of Cambridge, England.

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27(1): 1-2,1995

A critical study of the genus Bryopsis Lamour., from the coast of Pakistan showed the occurrence of 16 species comprising 4 new ones viz., B. aishae Nizam. sp.nov., B. pakislanica Nizam. sp.nov., B. manorensis Nizam. sp.nov. and B. qasimensis Nizam. sp.nov., 8 new records viz., B. caespilosa Suhr, B. corticulans (?) Setchell, B. duplex De Not., B. fasligiala Kütz., B. harveyana J. Ag., B. indica A. & E.S. Gepps, B. penicillala Suhr and B. pennata Lamour., whereas the remaining 4 ones viz., B. corymbosa J. Ag., B. hypnoitks Lamour., B. pennarula J. Ag. and B. plumosa (Huds.) C.Ag. have been reported earlier.

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27(1): 3-39,1995

Five taxa including 3 species of Chlorophyta viz., Enteromorpha intestinalis (L.) Nees, E. nizamuddinii Aisha et Shameel sp. nov., E. saifullahii Aisha et Shameel sp. novo and 2 forms of Charophyta viz., Chara vulgaris L. f. atrovirens (Lowe) H. et J. Groves and C. vulgaris f. calveraensis Wood have been described from an area close to the coast of Balochistan province. All are new records of freshwater algae from Pakistan.

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27(1): 41-48,1995

A new species, Cystoseira masoudii Nizam., characterized by caespitose habit possessing smooth/spinose tophulose is described.

Published

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27(1): 49-54,1995

Effect of diurnally administered temperature regimes on the infection process of 3 Vigna spp., and 1Medicago sp., inoculated with GUS-marked (brady) rhizobial strains was examined. Conditions optimized for blue color development to indicate the presence of GUS-marked Rhizobium and Bradyrhizobium strains in the roots and nodules of inoculated plant showed significant results with 50 µg ml-1 X-gluc buffer and 3 and 5 minutes of vacuum infiltration for young and mature nodules, respectively. Root hair colonization, curling, infection thread and nodule formation were observed in all the legumes at 30°C without any temperature shock. In V. radiata, no infection thread was found even at optimum temperature of 30°C. Root hair curling and infection thread formation were not observed in the genotypes exposed to temperature stresses, except in V. unguiculata, where the infection thread aborted in the root hair. Root hair colonization was observed a day after inoculation in plants subjected to both high or low temperature stresses, indicating the survival of (Brady)rhizobium strains under temperature stress conditions. The strains were unable to nodulate the host plants due to poor root hair development.

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27(1): 55-62,1995

The performance of three green manure plant species viz., Sesbania aculeala, S. rostrata and Cyamopsis lelragonoloba was studied at different growth stages under field conditions. An the green manures upto 45 days of growth produced shoot dry biomass and shoot nitrogen contents similar to plants grown for upto 60 days. S. roslrala was found superior to other species in terms of biomass production and nitrogen contribution.

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27(1): 63-66,1995

SEM study of the fruits of Dampiera exhibit a complex morphological and micromorphological diversity providing valuable taxonomic information. The shape and surface pattern can be of high systematic significance. Ridged and non-ridged surface with colliculate to irregularly colliculate pattern are recognised. Six different fruit shapes are identified which provide a useful basis for distinguishing species at sectional level.

Published

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27(1): 67-72,1995

An investigation of leaf, calyx and nutlet microcharacters of 13 species of the genus Pogostemon found in Bangladesh was conducted using the SEM and their reliability as taxonomic markers is discussed. Leaf surfaces are mostly covered with glandular and non-glandular trichomes. Stomata are paracytic mostly levelled with epidermal surface or rarely elevated. In some species leaf surface is rough and have undulating ridges under which sessile glandular hairs are sunken. Calyx surface of all the species have trichomes. Nutlet sculpturing shows mostly reticulate or irregular shallow discoid pattern with undulating ridges.

Published

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27(1): 73-82,1995

Pollen morphology of the family Sphenocleaceae has been studied from Pakistan by light and scanning electron microscope. Pollen grains are generally colporate, small, trilobed, oblate - spheroidal with subpsilale tectum.

Published

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27(1): 83-86,1995

Pollen morphology of 3 species of the genus Bergia L., from Pakistan belonging to the family Elatinaceae has been examined by light and scanning electron microscope. Pollen grains are generally radially symmetrical, isopolar, oblate - spheroidal to prolate - spheroidal, often sub-oblate, tricolporate, l.Ono-aperturate with fossulate - reticulate tectum. On the basis of shape, colpal membrane and exine pattern, 2 distinct pollen types viz., Bergia aestivosa - type and Bergia suffruticosa - type are recognized.

Published

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27(1): 87-92,1995

Trrichodesma indicum (L.) R. Br. (Boraginaceae) flowers throughout the year. Flower was protandrous and remained in bloom for ± 3 days. Buzz-pollination was carried out stemotribically by two species of Anthophora (Apidae). Pollen - ovule ratio and breeding experiments (hand-pollination treatments) revealed it 15 a facultative xenogamous species. It is a non-apomictic species as except emasculation treatment for apomixis, all the hand pollination treatments resulted in normal fruit and seed set.

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27(1): 93-99,1995

The effect of explant source on in vitro regeneration of plants through tissue proliferation in Phoenix dactyliftra L. cv Fusli is reported.

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27(1): 101-104,1995

Suspension cultures established from hypocotyl derived calli pretreated with AS (adenine sulfate) and (NH4)2SO4, (ammonium sulfate) stimulated somatic embryogenesis in addition to root morphogenesis. All stages of embryos were produced but shoot formation was not observed. Control cultures exhibited rooting response only.

Published

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27(1): 105-109,1995

To develop early maturing and large seeded cultivars of peanut (Arachis hypogaea L) virginia type alltivars (No. 334, Banki and NC-9) were crossed with four early spanish type lines (ICGSE-4, ICGSE-130, ICGSE-147 and 'Chico') in a factorial mating design. Fl and F2 generations were evaluated in the field to clctermine the combining ability of the parents for maturity and other agronomic traits. General combining ability (GCA) estimates were highly significant for all traits except maturity index in the F1 Specific combinina ability (SCA) estimates were nonsignificant for all traits except 100 seed weight in the F2 generation. The magnitude of GCA was much greater than SCA for all the traits in both generations indicating that additive genetic variance was more important than nonadditive genetic variance. Among male parents, ICGSE130 gave highest GCA for yield per plant, maturity, and 100 seed weight, whereas ICGSE-147 gave highest GCA for 20 pod length and seed number per 50 pods. Among adapted female parents, NC 9 gave the best GCA for yield per plant, 20 pod length, seed weight, and shelling percentage.

Published

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27(1): 111-119,1995

A study was carried out to determine general and specific combining abilities of seed cotton yield, of bolls, sympodial branches, ginning outturn percent, seed and lint indices from 5x5 diallel intraI crosses. Qalandari was the best general combiner of the parents studied for seed cotton yield and of bolls followed by K-68-9. Parent Acala SJI which had the poorest general combining ability for yield and number of bolls, was the top parent for ginning outturn percent and seed and lint indices. The that formed the best general combining ability did not always form best specific combining ability with every other parents, however, Qalandri with highest general combining ability estimate also ranked first in specific combination with NIAB-78. The regression of observed vs expected values suggested the importance of specific combining ability (control of dominant genes) for seed cotton yield and seed and lint indices, "aeneral combining ability (control of additive genes) for number of bolls, sympodial branches and gining outtum percentage. The consistency in estimates of Combining ability for bolts and yield indicate that selection based on number of bolls will result in simultaneous improvement in cotton yield.

Published

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27(1): 121-126,1995

 Random Amplified Polymorphic DNA (RAPD) markers were generated in Perkin Elmer DNA Thermal Cycler using genomic DNAs extracted from different rice varieties/species and 6 synthetic 10 mer primers of series -S. Material included in the study comprised 5 cultivated and 11 wild salt tolerant and sensitive varieties/spccies with different genomes and ploidy level. The scorable DNA fragments amplified by different primers ranged between 22 and 47 fragments per primer. Of the total 212 fragments that were amplified, 99 fragments were scored as potential genetic markers to be used for cultivar identification. Of the 99 markers, 50 (51 %) were cultivar specific while 49 markers were genome specific. One marker appeared only in salt tolerant cultivated rice varietie8 while another appeared both in wild and cultivated but salt tolerant varieties. Based on these markers, 3 out of 5 cultivated and 5 out of 11wild rice species were distinguished from cach other. Inter and intraspecific variations were also detected. The markers identified in the present study can bc used to check seed quality, for fingerprinting of a specific cultivar and to detect transfer of genetic material from wild species to cultivated varieties. The results showed the potential of RAPD markers for gene lagging experiments particularly tagging genes for salt tolerance.

Published

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27(1): 127-138,1995

Effects of abscisic acid (ABA) and gibberellic acid (GA) on accumulation of Beta N-oxalylamino-Lalanine (BoAA) in leaves of Lathyrus sativus L., cvs. K 424 and K 280 under drought stress was examined. Simultaneous application of ABA and drought was inhibitory to BoAA accumulation under drought as compared to ABA application after 12 days of drought period. Simultaneous application of GA and drought was stimulatory to BoAA accumulation than that of GA applied after 12 days of drought stress. Indigenous Variety K 280 having higher BoAA content than the exotic variety K 424 showed low percentage of BoAA under drought stress. Rewatering of stressed plants of K 424 reduced BoAA whereas rewatering of K 280 increased BoAA as compared to drought stress treatment. Reduction in BoAA following simultaneous application of ABA and drought may be due to favourable effect of ABA in water conservation mechanism.

Published

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27(1): 139-141,1995

Two cultivars of mustard, Sambal and Daulat were grown in soil in polythene bags under well-watered and water-stressed conditions. Soil moisture had significant effect on total dry matter production and leaf area development. In irrigated plants more assimilates were translocated to the reproductive parts. Leaf area ratio (LAR) and leaf weight ratio (LWR) were significantly higher in the well-watered plants. Relative growth rate (RGR), net assimilation rate (NAR), relative leaf growth rate (RLGR) and specific leaf area (SLA) were not affected by soil moisture. Among the root characters, only the number of primary roots was significantly higher in the well-watered plants. Seed yield and some of its components increased by irrigation. Reasons for better performance of Daulat in the water-stressed condition are discussed.

Published

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27(1): 143-150,1995

Variations in plant growth due to changes in edaphic and climatic conditions in two halophytic species viz., Suaeda fruticosa (L.) and Tamarix indica Willd., from the saline community at Karachi University campus are reported. Growth rates of plants and regulation of Na + and C1-salts with reference to prevailing climatic and edaphic conditions were studied from mid of July to first week of November. Soil moisture content increased with soil depth in both the species studied while electrical conductivity was high in the uppennost part of the soil profile. Maximum salt accumulation was observed in ranging from EC: 110-130 dS.m-1 at soil surface of 0-5 cm. Concentrations of Na + and C1- ions in the saturated soil extract significantly corresponded to the electrical conductivities observed at different time period and at different soil depths. Stomatal conductance and transpiration rates exhibited an increase with more water availability in soil. No significant variation was evident in plant moisture content in both the species. r. indica exhibited comparatively higher organic matter and low ash as compared to S.fruticosa. Concentration of C1- remained unaffacted in T. indica. Plant volume increased with time in S. fruticosa exhibiting higher rate of increase in volume as compared to T. indica. Moisture content and soil salinity (BC) significantly affec,ed growth in both S. fruticosa and T. indica, whereas, growth of T. indica was also influenced by Na + content of soil. Percentage of both Na + and C1- ions in relation to the external medium concentrations showed higher proportion of Na + in both the species, although T. indica exhibited a relatively less absorption and accumulation of both the ions as compared to external medium.

Published

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27(1): 151-163,1995

Leaves of cotton cultivar 5-12 were acclimated at temperatures ranging from 35 to 44°C for different lime periods followed by heat stress at 45 or 46°C. The heat acclimation potential was analyzed by Chlorophyll Fluorescence technique. The recovery of Fv / Fm ratio after application of heat stress was the paramev mler for detennination of the acclimation potential. Very small fluorescence (Fv / Fm ) values were recorded after heat stress at 46°C with fairly good response when acclimated leaves were heat stressed at 4S°C.

Published

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27(1): 165-168,1995

Field experiments on seeding dates were conducted during 1990-91 and 1991-92 to determine the optimum time for sowing of wheat crop under rainfed condition. Early as well as late sowing of wheat reduced the yield. The optimum time of planting of Durum wheat variety Mexicale was found to be 4 to 21December to obtain maximum grain production.

Published

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27(1): 169-173,1995

Effect of Topsin fungicide (Methyl thiophenate) on chlorophyll, protein and phenol contents of Hibiscus esculentus and Capsicum annuum was examined. Topsin showed an increase in all the biochemical parameters with differences in response in the two test species.

Published

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27(1): 175-178,1995

The effect of foliar applied systemic fungicide propiconazole (1-[[2-2,4 dichlorophenyl) on the agronomic, seed quality, and economic response of hard spring wheat (Triticum aestivum L.) was investigated under rain-fed conditions. Propiconazole applied at Feekes growth stage (GS) 10 suppressed leaf spot disease but had no effect on grain yield or other traits measured. Percent reflectance of 800 nm wavelength radiation increased as the visually estimated leaf spot disease severity decreased following fungicide treatment, indicating that foliar reflection may be an efficient and reliable assessment of foliar disease. The use of propiconazole to control foliar diseases and maximize spring wheat production is not economically feasible under other similar enviromental conditions.

Published

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27(1): 179-186,1995

Protein content in 8 different varieties of wheat after infection with Puccinia recondira, the brown rust fungus was examined. Protein content showed an increase in resistant and moderately resistant varieties upto 3 days which later declined. In susceptible and moderately susceptible varieties no significant change in protein content was observed after 3 days, which later increased and showed maximum increase after 5 days, with a sharp decline after 7 days interval. Resistant varieties were significantly different in protein content as compared to susceptible varieties.

Published

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27(1): 187-191,1995

One hundred and two isolates of Ascochyra rabiei differing in their cultural characters were selected for pathotype analysis from a large collection of isolates obtained from chickpea growing areas of Pakistan during 1984 - 92. On the basis of pathogenicity on 11chickpea differentials, the isolates were classified into 8 pathogenic groups. Out of 102 isolates tested, only 6 were highly virulent, 8 least virulent whereas others were in between-the two extremes.

Published

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27(1): 193-199,1995

Using ISTA techniques, the seedborne mycoflora of 24 samples of tomato seeds collected from different parts of Pakistan was examined. Of the 37 species of fungi belonging to 20 genera isolated, 22 species of fungi belonging to 15 genera were found to be new records from Pakistan. Fusarium solani, F. moniliforme, Aspergillus jlavus, Allernaria allernala and Drechslera australiensis were predominant. Greater number of fungal species, both in sterilized and non-sterilized seeds, were recorded by agar plate method followed by blotter and deep-freezing method.

Published

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27(1): 201-208,1995

Species of Bipolaris, Botryodiplodia, Cephaliophora, Cephalosporium, Colletotrichum, Corynascus, Curvularia, Exerohilum, Fusarium, Macrophomiful, Melanospora, Nigrospora, Rhizoclonia, Sclerotium, Slemphylium and an unidentified basidiomycete were recorded on several new hosts from Pakistan. Cephaliophora tropica, Corynascus sp., and Exerohilum holmii are new reports from Pakistan.

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27(1): 209-216,1995

Effect of neem oil and benomyl on the growth of root infecting fungi viz., Macrophomina phaseolina, Rhizoclonia solani and Fusarium moniliforme was examined. Benomyl showed greater suppression in growth of R. solani and F. moniliforme than neem oil whereas neem oil @ 0.1 % was more effective against M. phaseolina than benomyl. Efficacy of benomyl and neem oil increased with increase in concentration. Neem oil extracted from seed samples collected from different localities showed variable suppression of growth of the test fungi.

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27(1): 217-220,1995

Colonization of Macrophomina phaseolina on roots of chickpea was higher when plants were subjected to moisture stress as compared to unstressed plants. Colonization on primary roots was greater at early stages with secondary roots infected at later stages of plant growth.

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27(1): 221-225,1995

Seed dressing of soybean with Bradyrhizobium japonicum alone or mixed with different concentration of fungicides viz., benlate, dithane, bavistin and vitavax showed significant (p < 0.001) protection of roots from infection of Macrophomina phaseolina, Rhizoctonia solani and Fusarium spp. Use of B.japonicum with benlate or bavistin against Fusarium spp., and M.phaseolina and with dithane against Fusarium spp., were more effective than their separate use. B.japonicum used with bavistin (@ 2500 a.i.) showed highest number of nodules per plant. Plant height increased over untreated control where seeds were treated with B.japonicum, benlate, bavistin or dithane or fungicides mixed with B.japonicum.

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27(1): 227-232,1995

Mean incidence of potato leaf roll virus (PLRV) in the plains of Pakistan was recorded as 44% in general, 53 % in the market or uncertified seed and 11% in certified or improved seed. The virus was successfully transmitted by side cleft grafting of infected potato to Datura slramonium and Physalis jloridana which proved useful hosts for the maintenance and propagation of the virus. The virus was purified through extraction in phosphate or citrate buffer and precipitation with polyethylene glycol followed by 2-3 cycles of differential centrifugation. The average yield of virus was 0.265 mg per kg of source tissue. The virus sedimented as single component in sucrose density gradients, reacted positively against potato leaf roll virus (PLRV) antiserum in gel immunodiffusion tests and absorbed UV light with a 260/280 ratio of I. 7. Isometric particles of 25 nm in diameter were observed under electron microscope (EM). The virus identity was also confirmed by Enzyme Linked Immunosorbent Assay (ELISA) and serological specific electron microscopy (SSEM).

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27(1): 233-241,1995

Two isolates of blackeye cowpea mosaic (BICMV) and two of cowpea aphid-borne mosaic (CABMV) potyviruses were purified by three purification procedures. Variable virus yields of each isolate of each virus were obtained with different virus-host combinations and purification procedures. Highest average virus yields of 4.6 µg and 3.4 µg per 50 g of infected tobacco leaf tissue were obtained from CABMV isolate RN7C and BlCMV isolate PU- 7B. Method-3 was most effective for purification of both viruses. Carbon tetracWoride when used in combination with chloroform as a clarifying agent improved purification of the BICMV isolates, but was harmful to CABMV isolates. Borate buffer was superior than phosphate for purification of both viruses. Addition of EDTA and Triton X-IOO in extraction and resuspension buffers circumvented virion aggregation. Leaf dip or purified virus preparations of BlCMV or CABMV isolates, examined under the electron microscope, contained elongated flexuous particles of modal length of 742 nm and 725 om for BICMV and CABMV, respectively, and confirmed particle morphology of potyvirus group.

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27(1): 243-249,1995

Bennuda grass (Cynodon dactylon (L.) Pers.) is widely distributed in Pakistan. The lawn grass at the Plant Genetic Resources Institute (PGRI) at National Agricultural Research Centre (NARC), Islamabad showed white leaf symptoms of chlorosis and adventitious branching in patches which some people related to nutritional deficiency. To identify the causal organism the diseased and apparently healthy leaves were collected and to determine the involvement of Phytoplasmas DNA was extracted from the leaves using technique as described by Nakashima et al., (1991). The extracted DNA was sent to Japan International Research Centre for Agricultural Sciences (JIRCAS) for the assay based on Polymerase Chain Reaction (PCR) amplification. The DNA of clean Bennuda grass grown in Japan and that of white leaf infected grass from Thailand, were included in the assay as references. The DNA assay was carried out using the primer (universal set) developed by Namba et al., (1993) which amplifies a segment of 16S rRNA gene specific to Mollecutes.

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27(1): 251-252,1995

Ingold (1966) reported that aquatic hyphomycetes were unable to colonize conifer needles. Since then, no report has been published on colonization of pine needles by aquatic hyphomycetes. An experiment was, therefore, carried out to see the colonization of dead needles of Quetta pine (Pinus halepensis L) by aquatic hyphomycetes in water stream near the fish house of Urak, Quetta. The stream in this area has a width of 1-2 meters, maximum depth 25-30 cm, average water temperature around 19°C, average pH 7.5 and approximate conductivity 0.9 mm/cm.

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27(1): 253-254,1995

During our investigations on the freshwater algae of the Puujab, we came across an interesting collection of Closterium spp., usually growing as planctonic in the rice fields. A gigantic form of Closterium sp., was detected which is designated as Closterium pakistani cum M-Hassan, Rasool and Nizam., sp. nov.

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27(1): 255-256,1995

The new genus Glossophorella Nizam. et Campbell is described which comprises two species viz., G. coriacea (Holmes) Nizam. Comb. nov. from Japan and the Pacific coast of U.S.A. and G. dhofarensis Nizam. et Campbell sp. nov. from the coast of the Sultanate of Oman. The genus is characterized by distromatic or polystromatic cortex and distromatic medulla throughout the thallus near the margins.

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27(2): 257-262,1995

Cystoseira wildpretii Nizam., sp. nov. is described from the coast of Canary Islands. It is characterized by procumbent, caespitose thallus bearing compressed axes and receptacles.

Published

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27(2): 263-266,1995

Occurrence of the genus Sirogonium Kütz., is a new record from Pakistan and a new species, S. khoriensis Masud-.et Nizam. sp. nov. has been described. This species is characterized by having a constant number of 3 chloroplasts and also in thickness of the exine.

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27(2): 267-27,1995

The effect of silver nitrate and gibberellic acid on 14C-IAA transport parameters was investigated in coleoptile segments of Zea mays L. Silver nitrate and GA3 enhanced the transport intensity and density without affecting absorption and the velocity. The data has been interpreted to show that these chemicals may influence abscission by increasing the relative hormone concentration at the abscission zone.

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27(2): 271-274,1995

Azolla, plant growth promoting rhizobacteria (PGPR) and chemical fertilizer alone and in different combinations were used to study the effect of nitrogen biofertilizers on rice biomass, nitrogen uptake and fertilizer-N use efficiency. 15N labelled ammonium sulphate was used to trace its uptake into rice plant and compute fertilizer-N recovery. Maximum rice biomass (straw+grain), its N yield and fertilizer-N recovery were obtained in the treatment where PGPR inoculum with 30 KgN/ha was used followed by treatment where in addition to PGPR and fertilizer-N, Azolla cover was also present. Use of biofertilizers alongwith a low input of chemical fertilizer-N soils was useful for increasing rice biomass, N uptake and fertilizer-N recovery in rice grown in saline soils.

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27(2): 275-281,1995

The effects of salinity (BC: 0, 10 and 20 dS.m-l) and waterlogging levels of 75, 100 and 125 % of soil water holding capacity on some physiological processes and ionic regulation were studied in Atriplex amnicola Paul G. Wilson in sandy loam and silty loam soils. Stomatal conductance of plants grown on sandy loam soil exhibited significant variations under the waterlogging treatments of 10 and 20 dS.m-1 salinity levels. At low waterlogging level (75 % WHC), significant differences were recorded at different salinity levels for stomatal conductance, transpiration rate and quantum yield. In silty loam soil, non-significant variation was observed for both salinity and waterlogging treatments when analyzed one day after irrigation, but after three days, there were significant variations in stomatal conductance and transpiration rate in different salt treatments. Sodium showed maximum accumulation in leaves followed by roots and minimum in stem in both sandy and silty loam soils at different salinity and waterlogging levels. Concentration of Na + varied with time and exhibited higher amount after 8 weeks as compared to 4 weeks growth period. Chloride also showed the same pattern, however, plants grown on silty loam soil exhibited higher amount as compared to sandy loam soil. Salinity did not have any pronounced effect on the oxalate content, whereas, waterlogging did affect the oxalate concentration after 4 weeks of growth with non-significant effects after 8 weeks growth. Increase in salt concentration of the irrigation medium increased the electrical conductivity of both sandy and silty loam soils at different growth periods and with different waterlogging levels.

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27(2): 283-295,1995

Comparative effects of different salt levels (EC: 4-24 dS.m-1) on the morphology and anatomy of four cotton cultivars viz., B-557, Niab- 78, Sarmast and Qalandri was studied. A decrease in stomatal density under salt stress was compensated by an increase in stomatal size and mesophyll surface area. Adaptation to saline environment was adjusted by increasing mesophyll surface area to ensure normal exchange of gases and photosynthetic activities. In order of their salt tolerance, the cultivars studied can be rated as Niab- 78 > B-557 > Qalandri > Sarmast.

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27(2): 297-303,1995

Seed fatty acid composition in the wild form and cultivars of Laurocerasus officinalis are reported. C18:l and C18:2 chain length pattern were the dominant fatty acids in seeds of all species. C18:l values in L. officinalis cultivars was higher than wild form whereas C18:2 value was higher in wild forms.

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27(2): 305-308,1995

Rate of emergence of seedlings from the uppermost 2 cm layer of soil from different habitats of the desert of North, South-West and South-East of Riyadh City in the Central Region of Saudi Arabia was examined. In most of the sites the emergence of the seedlings started after one week. The number of individual plants that emerged at the end of the experiment ranged from 44 to 2660 plants m2. A number of 59 species of plants were identified. Biomass of the emerged seedlings ranged from 0.356 to 308.524 per sq metre.

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27(2): 309-319,1995

The soil seed reserves of different summer weeds were studied in the fields of different rainfall zones of Punjab, Pakistan. Composite soil samples collected from fields comprising of very low (150-300 mm), low (300-500 mm), medium, (500-1000 mm) and high (1000-1500 mm) annual rainfall areas were kept in trays of uniform size in the green house at National Agricultural Research Centre, Islamabad. An environmental condition was provided for germination of weed seeds. Seedlings emerging over a period of three years were identified, recorded and removed at intervals. The seed reserves of different zones differed from each other in tenus of weed seed composition, seed number by species and total number of seeds in the soil. The species diversity and number of seeds in the soil remained lowest in very low rainfall area. With the increase in annual rainfall, both the parameters also increased with highest values in the high annual rainfall area.

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27(2): 321-326,1995

Pollen morphology of 49 species representing 20 genera of family Boraginaceae from Pakistan has been cxamined by light and scanning electron microscope. Boraginaceae is a eurypalynous family and pollen morphology of the family is significantly important at tribal and subfamiliallevel, such as the tribes Edtrichicae and Cynoglosseae of subfamily Boraginoideae and subfamily Heliotropioideae,. respectively, are characterized by heterocolpate pollen which is rare in angiosperm. However, in the other tribes of subfamily Boraginoideae (Trigonotideae and Lithospermeae except Myosotis) and subfamily Ehretioideae have homoapcrturate pollen (colpate, colporate), ora mostly endocingulate, elliptic-rectangular in equatorial view, with or without constriction at the equator, circular or hexagonal in polar view. Tectum usually psilate or sub-psilate. However, combination of other tectum types i.e., reticulate-rugulate, fossulate or foveolate are also found. On the basis of size, shape, apertural configuration and exine sculpturing 11distinct pollen types viz., Anchusa arvensis - type, Amebia benthamii - type, Buglossoides arvensis - type, Ehretia obrusifolia - type, Gastrocotyle hispida - type, Heliolropium subulalum - type, Undelojia longilfora - type, Nonea caspicatype, Onosma hispida - type, Sericosloma pauciJIofUm - type, Trichodesma indicum - type are recognized.

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27(2): 327-360,1995

cp DNA variations were examined in 5 genera of the tribe Polygonatae, for 60 probe-enzyme combinations, to study Disporum-Prosartes generic separation problem. The shared fragments were counted, index of similarity and distance matrix was calculated. The distance within the genus Prosartes was 0.033, while it differed from Disporum in 0.34-0.342. The difference of Prosartes from Streplopus was 0.217, while between Disporum and Uvularia was 0.164-0.171. The data was examined using Neighbour Joining (NJ) and Fitch-Margoliash methods. The divergence between Disporum and Prosartes was greater than that between Disporum and Uvularia or Prosartes and Streplopus. Within the genus Prosartes, P. maculala was different from the rest of the Prosartes species. rbcL gene sequence data revealed that north American Prosartes and Asian Disporum species differed by 90-96 substitution (100d= 6.92-7.41). The base substitution between Disporum and Prosartes is much greater than that between Prosartes and Streplopus (14-16, 100d= 1.03-1.18) or that between Disporum and Uvularia (23-26, 100d= 1.70-2.01). The results support recent morphological, karyological and molecular arguments of the restoration of genus Prosartes as an independent genus. The results also indicate that Uvularia is closly related to Dispomm while Streplopus is closer to the genus Prosartes.

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27(2): 361-369,1995

A microcomputer program package which prints herbarium labels, retrieves and edits information has been developed. Individual labels consist of a maximum of 12 lines, each with 40 character spaces. Required number of labels are automatically printed and the label information is stored on a computer file. The paper suggests how data presented on herbarium labels might be improved and made suitable for retrieval. The program-package is portable and can be implemented on a variety of machines using different dialects of BASIC. However, due to memory and speed constraints the program is suitable for small herbaria. The advantages of computer application as related to herbarium procedures are discussed.

Published

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27(2): 371-383,1995

GA3 and 2,4-D @ 10-5 and 10-3M used as foliar spray on date palm (Phoenix dactylifera L) cv. Khedri 3 seedlings affected the length of root and the anatomical characteristics of thick root. GA3 at low concentration increased the differentiation of fibre, xylem strands and number of vessels in each xylem strand while at high concentration the number, size of lacunae and the number of vessels in each xylem strand decreased. 2,4-D at low concentration increased lacunae, fibre and xylem strands but decreased the number of vessels in each xylem strand, which at high concentration decreased the number of fibre, xylem strands and number of lacunae but increased the xylem vessels in each xylem strand.

Published

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27(2): 385-397,1995

Of the 10 exotic rose cultivars evaluated for their performance and adaptability in the D.l. Khan, Magic Carrousel, Paradise, Pink Delight, Yankee Doodle, and Love were found most promising as compared to Green Sleeves, Oregold, Peer Gynt, Razzle Dazzle and Revenue. Magic Carrousel was dwarf, dense with small sized fragrant flowers and bore maximum flowers per plant per month. Paradise was tallest and produced large sized flowers without fragrance. Pink Delight had maximum flower vase life (8 days) and persistence, in both spring and summer months, with slight fragrance. During spring, 91 petals per flower were counted in Yankee Doodle, while Love produced 47 petals per flower in Summer. Both cultivars were slightly fragrant.

Published

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27(2): 399-403,1995

Mature embryos, excised from the soaked peanut seeds, when cultured on MS medium supplemented with BA and 2,4-0 each @ 0.5 mg/I induced, callus. Regeneration occurred when this callus was subcultured on to MS containing BA and kin each @ 1.0 mg/I. Similarly, development of callus followed by regeneration was noticed in mature embryos in MS medium containing 0.5 mg/l kin and 1.5 mg/l NAA. Direct regeneration was also observed on MS containing 1.0 mgll each of BA and kin. All the regenerated shoots when transferred to the rooting medium (1/2 MS) supplemented with 0.1 mg/I NAA showed development of root.

Published

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27(2): 405-409,1995

Rapid propagation of carnation (Dianlhus caryophyllus L) was achieved in vitro. Multiple shoots were induced from nodal explants on MS medium supplemented with 1.0, 2.0 or 3.0 mg/l of BAP. For further proliferation the multiple shoots were transferred to MS medium containing different concentrations of BAP and GA3alone or in combination. Maximum number of plantlets per flask were produced on medium enriched with 5.0 mg/l BAP. Rooting was stimulated by subculturing the proliferated shoots on 1/2 MS, 3% sucrose and I % agar. Rooted plantlets were successfully raised in pots filled with soil.

Published

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27(2): 411-415,1995

An intervarietal chromosome banding polymorphism in 8 botanical varieties of Hordeum vulgare viz., convar. hexastichon vars: coelesle and ingrum; convar. distichon vars: inerme, pallidum and nulans; convar. vulgare vars: coelesle, horsfordianum and dwndarbeyi was studied by Giemsa N-banding technique. Chromosomes were numbered according to the wheat homoeologue groups. The classification of the bands was in accordance to the generalized cytological nomenclature of cereal chromosomes (GCNCC). Majority of bands recognized in all varieties were centromeric or interstitial. Band polymorphism was observed on all chromosomes except 1H, which exhibited typical banding pattern in all varieties.

Published

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27(2): 417-423,1995

Combining ability analysis was conducted for yield and its primary components in Gossypium hirsutum L. The results indicated that variance due to GCA and SCA were significant for all the characters except ginning percentage. The additive gene action was more important than non-additive. Highly significant GCA effects were found in lines S-12 for all traits and CRIS- 7 A for seed weight, lint weight and seed cotton yield and testers CYTO-127 for seed weight, lint weight and seed cotton yield and CYTO-130 for seed weight and seed cotton yield. The crosses S-12 x Cyto-127 and BH-36 x CRIS-54 for all characters except ginning percentage, while NH-26 x CYTO-130 and CRIS-7A x CYTO-130 for lint weight and seed cotton yield per plant exhibited significant SCA effects.

Published

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27(2): 425-429,1995

Combining ability analysis was conducted for yield and yield components in line x tester involving 5 lines and 3 testers. Combining ability variances for GCA of lines and SCA variances were highly significant for boll number and seed cotton yield per plant, suggesting the importance of additive and non-additive type of gene action for these traits. The cultivar BH-36, CIM-240 and CYTO-129 exhibited significant GCA effects for boll number and S-12 and CYTO-129 for seed cotton yield. The female parent CYTO-129 proved to be good general combiner for boll number and seed cotton yield per plant. SCA effects of the crosses S-12 x CRIS-52, CIM-240 x CYTO 129 and NH-26 x NIAB-78 were considerably high for number of bolls and seed cotton yield per plant. Hence, while breeding varieties for high yield these crosses should be considered

Published

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27(2): 431-434,1995

Combining ability and genetic analysis was conducted in a four parent complete diallel for seed weight in lentil. Additive type of gene action predominantly governed by recessive genes was observed for the expression of this character. Thus, simple selection in late generations, when genes are fixed, is recommended to pick the desired transgressive segregants in the hybrids involving Mansehra-89 and Flip-8638L as one of the parents.

Published

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27(2): 435-439,1995

On the bases of morphology, cultural and biochemical characteristics, 50 indigenous clinical pseudomonads were identified as Pseudomonas aeruginosa. Resistance patterns of antibiotics upto 500 µg mL-1 and inorganic metallic ions upto 3 mg m-1 were determined by medium incorporation method. Five of the isolates lost their resistance to erythromycin after curing for plasmid elimination with 5 mg mL-1 of acridine orange, thereby indicating the extrachromosomal location of the resistance determinants. Agarose gel electrophoresis using 'Mini prep' method for plasmid isolation revealed that six isolates harbour plasmids of different molecular weights (5-28 kb) with Hind III digest of λ DNA as ladder. Some of the pseudomonad isolates were able to transfer their resistance to Escherichia coli BU 40 by in vivo gene transfer plasmid conjugation.

Published

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27(2): 441-446,1995

Relative aggressiveness of eight strains of Xanthomonas campestris pv. citri was tested on detached citrus leaves at 22°C and of another seven at 24°C. An the strains showed variability in their relative aggressiveness as measured through development of lesions. Number of lesions produced by any strains was significantly affected by the strain: cultivar interaction thus indicating host parasite specificity for this character. Three levels of aggressiveness i.e. high, intermediate and low aggressiveness were noticed among the strains.

Published

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27(2): 447-450,1995

Use of growth promoting becterium Pseudomonas aeruginosa, strain Pa6 and Pa12 significantly (p <0.05) reduced the infection of Macrophomina phaseolina and Rhizoctonia solani on chickpea. P.aernginasa strain Pa12 was found effective against F.oxyspornm and Pa6 against F.solani. Combined use of Bradyrhizobium sp., (TAL 480) and P.aernginosa showed complete control of R.solani and F.oxyspornm infection. Use of bradyrhizobia with P. aeruginosa also showed better control of F.solani infection than either used alone. Greater number of nodules per plant were produced where bradyrhizobia was used with strains of P. aernginosa as compared to bradyrhizobia used alone.

Published

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27(2): 451-455,1995

In March 1983, a spineless variety "Thori-78" of Safflower (Carthamus tinctorius L) growing at the experimental plot of National Agricultural Research Centre, Islamabad showed symptoms of wilting. Base of the stem was covered with white cottony mycelium associated with 2-10 mm large black sclerotia round to irregular in shape. Sclerotia were only observed in severely affected plants having shredded stems. Incidence of the disease ranged from 2-25 %. The fungus was identified as Sclerotinia sclerotiorum (Lib.) de Bary [Syn. Whetzelinia sclerotiorum (Lib.) Dork & Dumont] after reference to Willetts & Wong (1980)

Published

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27(2): 457-458,1995

Complete bunt of wheat is an important and destructive disease of wheat in the upland areas of Pakistan where an incidence as high as 25 % has been recorded (Hafiz., 1996; Hassan, 1971) with losses up to 33% in individual fields (Kausar, 1955). Two allied species of Tilletia viz., T. laevis Kühn (syn, T. foetida (Wall.) Liro) and T. tritid (Bjerk.) Winter (syn. T. caries (Dc.) Tul., have been reported by Malik & Virk (1968), Hassan (1971) and Mirza & Qureshi (1978) whereas only T. tritici has been mentioned as the cause of bunt of wheat in Pakistan by Hafiz (1986). An extensive survey of upland areas of Balochistan, NWFP and the Punjab was therefore carried out to determine the present status of complete bunt of wheat caused by T.laevis and or T.tritici.

Published

Doi:
27(2): 459-460,1995

Generic limits in Gentiana L. (s.l.) from Pakistan and Kashmir was evaluated chemotaxonomically. Forty four taxa belonging to 8 genera were delimited into three broad groups on the basis of their flavonoid patterns where Rutin and Quercetin were the most widely distributed compounds present in 79 % and 76 % of the taxa respectively. The observations and results also suggested that the genera Aliopsis, Gentianopsis, Aloitis, Comastoma and Jaeschkea are advanced than Ciminalis, Gentianodes and Qaisera in evolutionary sequence.

Published

Doi:
28(1): 1-8,1996

Numerical technique has been used to construct the cladogram to depict the natural relationships among the species of the genus Sibbaldia. The cladistic analysis of the genus is presented with a discussion of characters used and the result suggest the exclusion of S. micropetala from the genus Sibbaldia. The transfer of S.adpressa by Juzepczuk (1941) to the monotypic genus Sibbaldianthae is rejected

Published

Doi:
28(1): 9-19,1996

Pollen morphology of 2 species of the genus Myriophyllum L.. from Pakistan belonging to the family Haloragaceae has been examined by light and scanning electron microscope. Pollen grains are generally radially symmetrical, isopolar, sub-oblate to oblate, 4-zonocolpate, colpi short, elliptic. Tectum scabrate - punctate.

Published

Doi:
28(1): 21-24,1996

Andromonoecy is being reported for the first time in Glossonema varians (Stocks) Hook. f. and in the family Asclepiadaceae. Each inflorescence has 2 perfect and 2-6 male flowers. Both type of flowers have similar qualitative characters. However, perfect flowers can easily be recognized due to relatively large size of their component parts, trullate corona lobes, corpusculum partially covered by anther flap, presence of stigmatic chambers, anther wings, normal styles and ovaries and male flowers on the basis of relatively smaller size of their component parts, obtrullate corona lobes, corpusculum not covered by anther flap, rudimentary styles and ovaries, absence of stigmatic chambers and anther wings.

Published

Doi:
28(1): 25-29,1996

The anatomy of the seedling of Tessaria absinthioides was studied by the use of serial cross sections. Continuous with the diarch vascular system of the root there are bundles of two types in the hypocotyl: double bundles formed by two lateral groups of phloem and one of protoxylem, that will become the cotyledonary traces and intercalary collateral bundles formed by one median group of phloem and one group of metaxylem, going to the protophylls. T. absinthioides has unilacunar one-trace cotyledonary and protophyll nodes and trilacunar three-trace nomophyll nodes.

Published

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28(1): 31-36,1996

Meristan tip culture of potato (Solanum tuberosum L) were established on MS medium containing BA and NAA and multiplied on hormone free MS medium. Potato culture survival and growth was significantly influenced by storage period and the incubation temperature, whereas, stress levels significantly affected shoot growth where its effect on survival was non-significant. A temperature of 25°C and longer storage period adversely affected the culture survival.

Published

Doi:
28(1): 37-40,1996

Mutant lines of Arabidopsis thaliana resistant to either spermine (a polyamine), naphthalene acetic acid (an auxin), or benzyl adenine (a cytokinin) were isolated by screening for growth of seedlings in the presence of growth inhibitory concentrations of the respective growth regulator. In addition to growth regulator resistance, mutant lines displayed distinct developmental phenotypes including alterations of the stature, seed dormancy, hypocotyls, roots, leaves, flowers and pods. Genetic evidence indicated that the mutant phenotype in 19 mutant lines was due to single recessive nuclear mutations.

Published

Doi:
28(1): -49,1996

Random amplified polymorphic DNA markers were generated in a diploid and two tetraploid salt-tolerani accessions of wild rice species Oryza punctata, O. sativa cuitivars Basmati - 198, IR-6 and F1 hybrids between Basmati-198 and IR-6 with three accessions of O. punctata used as male parent. The PCR mediated DNA amplification profiles produced with different 10 mer primers were generally reproducible and differendsled tetraploid accessions from diploid and the hybrids from their parents. Of the total 263 markers that were generated with II different primers, 164 markers (62 %) were exhibited by 5 parents and 102 markers (38 %) by 3 different F1 hybrid combinations. In 2 of the 3 hybrids, frequency of the markers inherited from O. punctata was above 70%, as most of the primers amplified in the hybrid, DNA fragments inherited from O. punctata (male parent). Most of the markers transferred from the male parent to the hybrids were of the same intensity while those transferred from the female parent (IR-6 and Basmati-198) were of low intensity compared to their intensity in the female parent itself. The detection of the male and female parent specific fragments in the hybrids was primer dependent. Our study indicated the reproducibility and reliability of the RAPD markers in identification of wild and cultivated rice varieties and their F1 hybrids. The significance of RAPD markers in monitoring specific characters transferred from the wild parents to the cultivated rice varieties is discussed.

Published

Doi:
28(1): 51-59,1996

Genotype X environment interactions and relative stability for grain yield were studied in four durum wheat, one bread wheat and one triticale genotype grown at 5 locations. The yield ranking of the varieties varied across the environments. Both linear and non-linear components of genotype X environment interactions were significant, indicating genetic differences among 6 genotypes for both linear and non-linear response to varying environments. D-88678 and Wadanak-85, being high yielding with unit regression and non-significant non-linear deviation from regression were identified to be most stable and adaptable genotypes.

Published

Doi:
28(1): 61-65,1996

A study was undertaken to estimate correlation coefficient between seed size, starch content and its composition together with the estimation of genetic variability in a range of chickpea genotypes. Among the 15 chickpea genotypes of diverse origin analyzed highly significant differences which ranged from 191 mg to 496 mg were found for weight per seed. Relatively small differences from 38-45 % of seed dry weight were found for total starch whereas values for amylose and amylopectin percentage of starch varied from 32-42 % and 58-68 % respectively. Within genotype variation for starch content and amylose percentage was insignificant which could be due to experimental error. However, there were considerable differences within genotype for seed sIze in almost all the lines. The correlation between seed size and starch content and compsition was negligible although positive and there was no association between starch percentage and amylose percentage of starch.

Published

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28(1): 67-73,1996

A pot experiment was conducted to study the effect of N-Serve (nitrification inhibitor) and Baythroid (an insecticide with strong inhibitory effect on nitrification in soil) on dry matter yield and N uptake of rice (Oryza sativa L). N-Serve was applied @ 1.1, 4.4 mg kg-1 soil and Baythroid @ 1.6 and 6.4 mg kg-1 soil, either alone or together with 15 N-labelled (NH4 )2 SO4 @ 200 mg kg-1 soil. Both N-Serve and Baythroid caused an increase in the dry matter yield of root and shoot portions, with significant decrease in the grain weight. There was no significant effect of either inhibitor on total dry matter yield and N uptake. Nitrogen yield and dry matter yield were significantly correlated in different treatments.

Published

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28(1): 75-84,1996

Effect of nitrogen in the form of urea @ 0, 10, 20, 30, 40, and 50kg N ha-1 by broadcast application, on the growth of Sesbania bispinosa (Dhancha) was studied. An increase in plant height at 15, 30, 45, and 60 days after germination was observed with maximum @ 50 kg N ha-1 in the first cutting and @40 kg N ha-1 in the last three cuttings. Maximum increase in air dry and oven dry weight was found at harvesting where 50 kg N ha-1 was used.

Published

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28(1): 85-89,1996

A controlled conditions study on sunflower grown in root medium with a pH range of 4.5 to 8.5 revealed a consistent growth improvement with the rise in root medium pH. Similarly, the sulphate concentration of root and shoot consistently increased with the increase in root medium pH. The same trend was observed in the total sulphate uptake by sunflower shoot. A significant positive correlation between biomass accumulation and sulphate uptake by sunflower shoot indicated the distinct role of sulphur in optimum growth of this non conventional oil seed crop of Pakistan.

Published

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28(1): 91-95,1996

Lettuce (Lactuca sativa var. Great Lakes) grown in soil irrigated with water of different salinities maintained with 0-72mM NaCI showed greater leaf area, shoot / root ratio and dry weight when kept at 92/100% night and day R.H., as compared to 62/82% R.H. No significant difference'in the rate of assimilation or stomatal conductance was found in plants grown at high and low R.H.

Published

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28(1): 97-102,1996

Ten different wheat varieties viz., Rohtas-90, Pirsabak-90, Mehran-89, Chakwal-86, Inqalab-91, Sutlaj86, Sariab-92, LU-26, Rawal-87 and Yecora- 70 were compared for 'water imbibition for 0, 2, 4, 6, 8, 10 and 12 hours and germination. Chakwal-86 showed maximum water imbibition during first two hours of soaking with Sutlaj-86 the least. Drying the seeds after soaking improved the germination potential. Germination Rate Index in Yecora - 70 was maximum both in soaked and conditioned seeds. Soaking time did not affect the GRI but after conditioning, six hours soaking proved the best treatment for better germination.

Published

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28(1): 103-108,1996

Soil amendment with Prosopis juliflora, P.glandulosa, P. cinererea and neem cake significantly (p<0,05) controlled the infection of Macrophomina phaseolina, Rhizoctonia solani and Fusarium solani on okra roots. Combined use of Prosopis spp., with Verticillium chlamydosporium and Paecilomyces lilacinus showed better control of root infecting fungi than their separate use. Greater plant height and fresh weight of shoot was produced by V. chlamydosporium used with neem cake. P. cinererea used alone also significantly (p < 0.05) increased plant height and fresh weight of shoot. Prosopis spp., can therefore, be exploited for the control of root infecting fungi.

Published

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28(1): 109-113,1996

More than 300 taxa of the rust fungi (Uredinales) have been reported from Pakistan. (Ahmad, 1956 a,b, 1969, 1976; Jorstad & Iqbal, 1967; Gjaerum & Iqbal, 1969; Mirza & Qureshi, 1978; Khalid et al., 1993, 1995; Masood et al., 1995; Khalid & Iqbal, 1996; Okane et al., 1992; Ono, 1992; Ono & Kakishima, 1992; Kakishima, 1992; Kakishima et al., 1993 a,b; Kaneko, 1993). Four taxa of the rust fungi viz., Puccinia caricis-flicinae Barclay, P. crepidicola Syd., P. sessilis W.G. Schneider var. sessilis and Uromyces fragilipes Tranz., are reported as new records for Pakistan.

Published

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28(1): 115-117,1996

Loose smut of wheat caused by Ustilago tritici (Pers.) Rostr., is one of the major diseases of wheat in wheat growing countries of the world. Upto 7 % losses in wheat variety Kalyansona have been recorded in India (Joshi et al., 1973) whereas, an incidence of 1-2% has been reported in Pakistan (Kamal & Moghal, 1968; Hafiz, 1986; Khan et al., 1992). In 1981-82, the severity of loose smut in "some fields of Pakistan reached upto 15% (Khanzada & Aslam, 1982). Bhutta & Ahmed (1991) recorded upto 0.2 % infection of loose smut in some areas of Punjab and suggested treatment of seed lots for the production of disease-free certified seeds. Seed dressing with fenufuran (Panoram) and tridimenol (Baytan) @ 2 to 4 g/kg seed provided complete control of loose smut of wheat while carboxin (Vitavax) did not show consistent results (Khanzada & Mathur, 1983). The present report describes the comparative efficacy of 3 systemic fungicides used at different dosage for the control of loose smut of wheat.

Published

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28(1): 119-120,1996

Plants have the capacity to adjust under variable environmental conditions. Water is generally considered as one of the limiting factors which affects the physiological and biochemical processes affecting crop productivity (Boyer, 1982). Nucleic acid metabolism has a major role in the overall performance. Experiments were therefore carried out to study the nucleic acid metabolism in drought tolerant / susceptible wheat genotypes grown under water stress conditions.

Published

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28(1): 121-123,1996

Prof. Hafiz was born on April 14, 1937 at Lahore. When he was only 9 years old he joined "Madrassa Zia-ul-Uloom, Faiz Bagh", at Lahore where he learned the Holy Quran by heart at the age of 11 years. He passed the Matriculation examination from Islamia High School, Sheranwala Gate, Lahore in 1955 and Intermediate in 1957. He obtained the B.Sc. degree (1959) and M. Sc. degree (1962) from the University of Punjab. The University awarded him the Gold Medal for securing first position in the M.Sc. examination. He also obtained M.S. degree in Genetics and Plant Breeding from the University of Wales, U.K. and a diploma in German Language from Germany. During his stay in Germany he was elected as President ofIslamic Society for 1973-74 session.

Published

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28(2): 125-126,1996

Stypopodium shameelii Nizam. et Aisha sp. nov., has been described from the coast of Pakistan. It is characterized by regular tiers of central cells both in cross as well as in longitudinal sections, surfaces of the distal and proximal portions of the frond are elevated and smooth respectively, sporangia scattered in between the hair-lines on both surfaces and restricted to the distal portion of the frond or blade. Vegetative growth occurs by simultaneous transverse and longitudinal segmentations of the apical cells. The genus Srypopodium Kütz., is also emended. The validity of S. tubruqense Nizam. & Godeh is also discussed.

Published

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28(2): 127-141,1996

The mangrove stand of Kalmat Khor, situated in the middle of the Balochistan coastline, is poor most probably due to intensive cutting and lopping for fuel and fodder and absence of any significant source of freshwater. The trees are small with decumbent branches touching the muddy substrate and belong to only one species Avicennia marina (Forssk.) Vierh. The zonation pattern is disturbed most probably because of indiscriminate harvesting of trees.

Published

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28(2): 143-149,1996

Pollen morphology of the family Salvadoraceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally radially symmetrical, isopolar, 3-zonocolporate rarely 4zonocolporate, prolate-spheroidal to sub-prolate. Tectum reticulate. Pollen morphology of the family is significantly helpful for delimiting the species.

Published

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28(2): 151-154,1996

Seed oil content and fatty acid composition of seed lipids in 4 species of Consolida viz., C. oriemalis, C. armeniaca, C. glandulosa and C. hoheneckeri of the family Ranunculaceae are reported. The oil ranges from 44.5 to 53.1 % by dry weight. The 18:1 chain length pattern was dominant fatty acid in seed lipids in all the 4 species examined. Among the total 7 fatty acids, 18:2 was the next abundant lipid component whereas pattern 16:1 and 20:0 were minor constituents in all the four species.

Published

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28(2): 155-159,1996

Effect of sugar concentration on in-vitro pollinium germination in 8 members of Asclepiadaceae viz., Calotropis procera ssp. hamiltonii, Corallima edlllis, Carollima tuIberculata, Ceropegia bulbosa, Glossonema varians, Leptadenia pyrotechnica, Pentatropis nivalis and Perglliaria daemia was studied. Although pollinia of each taxa germinated in a wide range of sucrose concentration (Le. 5-40%) but each taxa showed a specific sucrose concentration at which optimal pollinium germination occurred. In P. nivalis and Per. daemia, coiling and beading of pollen tubes occurred at 20-40% sucrose concentrations while in other taxa at 5-15% concentrations. Optimal sucrose concentration required for in-vitro pollinium germination was similar to the average sugar concentration observed in the floral nectar of the studied taxa except in P. nivalis where maximum pollinium germination occurred at 10% sugar concentration as compared to 24% sugar concentration in its floral nectar.

Published

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28(2): 161-165,1996

Alfalfa (Medicago sativa L. cv Regen SY) plants were regenerated from roots induced by inoculation of leaf discs with Agrobacterium rhizogenes containing the vector p35S GUS INT. The DNA transformed to the plant genome with T-DNA based vector contained genes which encoded neomycin phosphotransferase (NPT II), that confers resistance to kanamycin and intron containing ß-D glucuronidase (GUS) gene. Histochemical staining for all the tested kanamycin resistant plants exhibited GUS activity and some differences in the phenotypic characters were also noted in the transformed and untransformed plants.

Published

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28(2): 167-172,1996

Electrophoretic profiles of native seed protein of 26 species of the genus Vicia representing sections Australe, Vicilla and Cracca in subgenus Vicilla and sections Hypechusa, Peregrinae and Faba in subgenus Vicia have been revealed by PAGE. Numerical analysis of the results indicated that the delimitation of the majority of the examined species agree with their previous classification based on morphological characters. However the grouping of some species i.e., V. dasycarpa, V. haeniscyamus, V. dichronanrha and V. peregrina was found to be anomalous to earlier classifications. V. michauxii is also clearly delimited from the other species.

Published

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28(2): 173-182,1996

Acacia nilotica seeds collected from Cholistan desert, Bahawalpur, Pakistan, exhibited poor germination profiles both at 37°C and at natural day and night alternating temperature cycle (25/16°C), At 37°C an erratic gennination of 40±10% was obtained with a spread of germination from 6 to 17±2 days, while at alternating temperature cycle (25/16°C) it was 37±7% and 7 to 20±3 days, respectively. A number of physico-chemical treatments failed to improve these germination profiles, Imbibition at 37°C for a specific period followed by a cold shock, a drop in temperature for 14 h, significantly improved germination of seeds.

Published

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28(2): 183-189,1996

Bayleton showed adverse effects on seed germination of Vigna radiala as compared to Topsin-M. Fungicides also affected root growth as compared to shoot growth. An increase in phenolic content of seedling was also recorded.

Published

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28(2): 191-193,1996

Plant tops are considered as both sink and source of various N gases and other air pollutants which therefore, may influence the gaseous N content of the environment. Five varieties each of wheat (Triticum aestivum L. and T. durum L.) viz., Pak-81, LU-26, Sarsabz, Durum and M-143 and rice (Oryza sativa L.) viz., 8as-370, Bas-385, DM-25 , Kashmir Basmati and IR-6, were compared for NH3 absorption and its correlation with leaf area and N content of the plants. Eight week old plants grown in plastic pots were exposed to 15NH3 for 24 h in an air-tight canopy able to provide a limited supply of CO2 . Labelled NH3 was generated by reacting 15N-labelled ammonium sulphate with NaOH in the canopy. Total N and 15N content of the dried and powdered plant material was then determined. Upto 44% in rice and 50% in wheat of the 15NH3 generated in the canopy was assimilated by the plants. Varietal differences in foliar absorption of NH3 were observed. No correlation was obtained between leaf area and the amount of 15NH3 absorbed by different varieties indicating that NH3 absorption was not solely dependent on leaf area and/or photosynthetic activity, of the plants.

Published

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28(2): 195-202,1996

A procedure was developed which allows high frequency adventitious shoot regeneration from radicle tissues of Aegle marmelos. Adventitious buds were initiated on Murashige & Skoog's (MS) medium containing various combinations of benzyl adenine (BA) and naphthaleneacetic acid (NAA). The medium containing 1.0 mg/1 BA and 0.2 mg/1 NAA produced highest number of shoots per explant with maximum frequency of regeneration. Shoots were elongated by transferring explants with shoot buds to a medium with a low concentration (0.1 mg/1) of BA. The shoots grown in medium containing 25 mg/l indolebutyric acid (IBA) for one week, when transferred to basal medium produced adventitious roots. Maximum rooting (80%) with 3-6 roots per shoot was achieved.

Published

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28(2): 203-206,1996

Shoot apices of Bougainvillea spectabilis cv. Texas Dawn were excised and cultured on MS .modified medium containing different concentrations and combinations of plant growth regulators for shoot growth, multiplication and root induction. Shoot development was observed where BAP 0.25 + NAA 0.25 mg/l were used. Medium containing NAA 0.1 + BAP 2.0 + glutamine 250 mg!l induced maximum number of multiple shoots with higher percentage (70%) of rooting where IBA 5.0 + NAA 5.0 mg/l were added to the medium. The system will provide a means for rapid clonal propagation future.

Published

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28(2): 207-211,1996

Artificial inoculation with a spore suspension of Ascochyta rabiei showed highest leaf and branch infection in Aug424 followed by Pb-1 with maximum resistance in ILCI91 followed by CM72. Histological studies showed that thickness of stem epidermis was significantly higher in ILCI91. Thickness of stem hypodermis was also greater in ILCI91 and CM72 as compared to Pb-1 and Aug424 , with minimum thickness of cortical region in Aug 424. The fungus caused severe damage to different tissues of Aug424 and Pb-1 soon after infection as compared to CM72 and ILCI91.

Published

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28(2): 213-217,1996

Seaweed viz., Sargassum lenerrumum, S.swartzii and S. wighlii bused as soil amendment alone or with Pseudomonas aeruginosa, Bradyrhizobium japonicum and Paecilomyces Iilacinus significantly (p <0.05) reduced infection of Macrophomina phaseolina and Fusarium solani on sunflower. Seaweeds were found less effective or increased Rhizoclonia solani infection. Combined use of seaweed with P.lilacinus and B.japoni cum showed better results against M.phaseolina and F.solani than their separate use. Greater plant height was produced where P.aeruginosa was used with S.swarlzii. Use of P.aeruginosa with S.lenerrumum and P. lilacinus with S.swartzii produced greater fresh weight of shoot than other treatments.

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28(2): 219-223,1996

Using agar plate, blotter and deep freezing method, 11 genera and 23 species of fungi were isolated from walnut (Juglans regia) seeds. Agar plate method yielded greater number of fungi. Of the fungi isolated, Aspergillus niger and Penicillium spp., were found preponderant. Greater number of fungi were isolated from cotyledons followed by shell and axis. .Component plating was helpful in detecting the depth of infection which may be used to determine the disease free seeds and their suitability for human consumption.

Published

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28(2): 225-230,1996

Among the pathogenic fungi, Fusarium moniliforme Sheld., has been found widely distributed in seeds of different rice cuItivars in Pakistan causing wilt of seedlings (Khan et aI., 1974). Using blotter or agar plate methods, it has been usually difficult to detect and isolate F. moniliforme in pure culture due to the growth of other seedbome fungi such as Alternaria spp., Curvularia spp., Drechslera spp., and Fusarium spp., on rice seeds (Khan et al., 1988). A comparative study was therefore carried out to find more suitable method by which F. moniliforme could be detected and isolated in pure culture from rice seeds.

Published

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28(2): 231-232,1996

Fenugreek (Trigonellafo.enum-graecum L) used as a condiment is well known for its alkaloids trogonelline, cholesterin, lecithin and choline. Fenugreek has also been used as a green manure for the control of Verticillium dahliae, wilt of cotton (Askarova & Golovchenko, 1962). In the present study, the seed-borne mycoflora of fenugreek has been examined and compared with that given in the Annotated List of Seed-borne Diseases (Richardson, 1979, 1981, 1983) and that of Hashmi (1988) and Khan et al. (1974) where a total of 11 genera and 16 species of fungi have been reported.

Published

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28(2): 233-234,1996

Galphimia gracilis Bartl. (Malpighiaceae) is a shrub or a small tree upto 10' in height with yellow flowers. It is a native of Mexico which has since been introduced in Pakistan. During an excavation of root systems of some leguminous herbs growing under the canopy of Galphimia gracilis plants forming a hedge near the faculty of Pharmacy, University of Karachi, ectomycorrhizal associations on the roots of Galphimia gracilis were observed.

Published

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28(2): 235-237,1996

A monographic study of the genus Sibbaldia (Rosaceae) is carried out. A total of 10 species are recognized of which 9 are dominantly Asian species whereas 1 species (Sibbaldia procumbens) is distributed in Asia, Europe and North America. Taxonomic criterion, key to the closely related genera and species along with distribution, ecological notes, speciemen citation, synonyms and nomenclatural notes are also given.

Published

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28(1): 1-38,1997

Pollen morphology of the family Neuradaceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally heteropolar, oblate, 3-aperturate with reticulate tectum.

Published

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28(1): 39-42,1997

Anatomical features of wood of 15 coniferous species viz., Abies pindrow Royle., Cedrus deodara (Rex. ex Lamb.) G. Don., Cupressus arizonica Greene., C. funebris Endl., C. sempervirens L., C. torulosa D. Don., Juniperus polycarpos C. Koch., Araucaria cookii R.Br., Pinus gerardiana Wall. ex Lamb., P. halepensis Mill., P. roxburghii Sargent., Picea smithiana (Wall) Boiss; P. wallichiana A.B. Jackson; Taxus baccata Zucc., and Thuja orientalis L.. have been described. Wood characteristics such as variation in growth rings, thickness of early wood and late wood tracheids, presence or absence of parenchyma and its distribution, characteristics of rays and nature and distribution of resin canals in the wood have been presented.

Published

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28(1): 43-73,1997

A broad vegetation analysis has been carried out in one of the prominent Rawdhats (Rawdhat Khorim) in the Central region of Saudi Arabia. The vegetation of the study site which is protected from off road traffic is unusually rich, compared to the surrounding areas, with the influence from the sand dunes on one side and calcareous desert on the other side. The study showed that the silt basin is dominated by ephemerals and their distribution and density varies each year, depending on the amount of rain fall. The perennial vegetation. represented by few stands, constitutes less than 10% of the total vegetation cover. An inventory of 112 species. consisting of 4 life forms (trees, shrubs, perennial herbs and annual herbs) alongwith the ecological and meteorological data have been provided. Qudrat studies have also been coonducted on 8 transect lines to verify the average abundance, frequency and density of each species.

Published

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28(1): 75-88,1997

The magnitude of genotype-environment interaction and the stability parameters of 21 F6 Near Isogeneic Lines (NILs) of wheat developed from 4 indigenous inbred lines and 2 exotic lines were estimated over 6 seeding dates for 5 morphological yield traits. The NILs were considered as different genotypes and the seeding dates were treated as different environments. Highly sigilificant GE interaction alongwith their significant linear component for all the traits, except the grains/ear and grain yield/plant, predicted the feasibility of the genotypes under different environments. Linear relationship with the environment was found to be predominant in most of the cases compared to that of non-linear relationship. For the estimation of stability parameters the genotypes 10-12 and 16 for SE 3, 10 and 11 for GE and GY proved to be most stable and suitable performer in any environment and couJd be used for future breeding programme. On the other hand. the genotypes 7, 17 and 18 for most of the traits would be stable and suitable performer under unfavourable environments. Thus, the yield potency might be increased by developing the stable and good performer with either specific or general photothermal adaptation under adverse environments.

Published

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28(1): 89-95,1997

Studies on genotypic and phenotypic variance, heritability and expected genetic advance for G.O.T. %, staple length, lint index, fibre strength, fibre fineness and seed cotton yield in 10 genotypes of Gossypium hirsutum L, indicated that these estimates varied considerably within traits studied. The magnitude of genetic and phenotypic variance ranged between 0.032 (fibre fineness) to 407.34 (seed cotton yield). Heritability in broad sense showed high estimates (ranging from 89.75 % to 99.74%) for all the characters, indicating the involvement of additive type of gene action. G.O.T %, staple length and fibre fineness exhibited low genetic advances irrespective of their high heritability estimates, probably due to non-additive gene (dominance and epistasis) effects.

Published

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28(1): 97-101,1997

Agro-morphological response of two maize (Zea mays L.) cultivars viz., Neelum and Akbar to water stress at their different development stages was studied at the agronomic research area, University of Agriculture, Faisalabad. Each cultivar was subjected to water suess either throughout vegetative development, throughout reproductive development or during tasseling and silking only. Water suess enhanced plant maturity and plant sterility substantially compared to control but decreased significantly crop growth rate, number of fertile plants m-2, cobs plant-1, grains cob-1, l000-grain weight, grain yield and harvest index. Water stress during vegetative development delayed tasseling and silking significantly. Both maize cultivars were statistically similar to each other in all parameters except grain yield and harvest index which Were significantly greater in Neelum than Akbar. Neelum grown without water stress produced maximum grain yield of 5.74 t ha-1, while Akbar subjected to water stress throughout vegetative development gave the minimum of 2.96 t ha-1

Published

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28(1): 103-111,1997

Leaves, roots and seeds of soybean and cotton were subjected to a series of temperature stress of 30, 34,38, 42, 46 and 50°C to measure the ion efflux from the cell. Soybean leaves leaked more electrolytes at 313 µS/cm than cotton leaves which recorded the electrical conductivity of 143 µS/cm at 50°C. Below the stress at 42°C relatively less ions were effluxed as compared to 42°C or above where severe damage to cell membrane occurred and more than 50% electrolytes leaked from leaves, seeds and roots of both crop plants.

Published

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28(1): 113-117,1997

A field experiment was conducted at the Marfa Mwar field station, Univesity of Wales Aberystwyth, UK. on a sandy loam soil during 1993 to evaluate the seed density and row spacing effects on the growth rhythms of linseed cv. Antares. The treatments comprised of four seeding densities (250, 500, 750 and 1000 seeds/m2) and three row spacings (12, 15, and 20 cm). Crop growth rate (CGR) was not affected by seed density during early growth period, while lower seed density gave higher CGR later in the season. A progressive reduction in relative growth rate (RGR) was observed with the age of the crop, giving the lowest values during maturity. A higher net assimilation rate (NAR) was observed with lower desnities, however the magnitude of difference was smaller at later growth stages. Row spacing effects and interactions remained statistically non-significant.

Published

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28(1): 119-123,1997

Growth srudy of mustard (Brassica juncea L. cv. cutlass) was srudied under (triple, double and single) irrigation regimes and dry conditioned treatment in the field during 1991 and 1992. In triple application treatment, water was applied at 10% flowering, pod formation and ripening @ 5-hectare centimetres per application in the double application, water was applied at 10 % . flowering and pod formation @ ,5- and 10hectare centimetres, respectively and in single irrigation at 10% flowering @ 15-hectare centimetres. Above ground plant material harvested at 7-day intervals showed a substantial increase in the amount and distribution of dry matter of the plant, panicularly in triple-irrigation treatment. Leaf-area index (LAI) reached a maximum just after the stan of flowering and then declined. Triple application increased leaf and pod areas in maximizing crop-growth rate (CGR) which increased to a maximum near early flowering and then declined. Changes in net-assimilation rate (NAR) during the life cycle were associated with concomitant changes in CGR. The contribution of assimilates from leaves during the seed ripening was related to leaf-area duration (LAD) which was strongly affected by water supply. Triple application enhanced NAR, improved leaf and pod areas during seed development.

Published

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28(1): 125-134,1997

Sustained embryogenesis in data palm (Phoenix dactylifera L. cv. Dhakki) were induced which were then induced to form plants. These plants after acclimatization were transferred to field in D.I. Khan where they have shown good perfonnance.

Published

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28(1): 135-141,1997

Meristematic tip with two pairs of leaf primordia from 5 clones of dessert banana (Musa spp.) viz., GN60A, SH3362, William, Highgate and Basrai were evaluated for in-vitro propagation. Rapid shoot proliferation cultures were established in MS medium with 20 mu M BAP. Clone GN60A produced highest tillers followed by clone SH3362, with lowest number of tillers produced by Clone Basrai. Shoots were easily rooted on MS medium with 4% sucrose. Oxidation of phenolic compounds was controlled by addition of 40 mg/l cystein HCl.

Published

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28(1): 143-150,1997

Five species of fresh water red algae viz., Audouinella hermannii Roth, Barrachospermum cf. arcuartum Kylin; Compsopogon coeruleus (Balbis) Montagne; Composopogon cf. prolijicus Yadava et Kumano and Thorea hispida Desvaux were found growing in the water effluents of a thermal power house located at Jamshoro, Sindh, Pakistan. Of these A. hermannii and C. coeruleus were found preponderant during January and April.

Published

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28(1): 151-160,1997

Biodiversity among 25 strains of Xilnthomonas campestris pv cirri isolated from different localities of Pakistan was distinguished through Immunodiffusion tests. Two serovars were detected based on the presence of a sharp band or faint band in gel diffusion plates. Antisera XC.91 and XC-93 formed a very strong precipitin band with strain XC-58, XC-91, XC-93, XC-lOO, XC-1O1, XC-105, XC-107, XC-114 and XC-125 with a faint band with XC-92, XC-94, XC95, XC-96, XC-1O2, XC-103, XC-1O6, XC-1O9, XC-11O, XCIll, XC-I13, XC-115 and XC-12l. Three strains viz., XC-97, XC-98 and XC-99 did not give any reaction against either of the two antisera and thus appeared to be non specific.

Published

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28(1): 161-166,1997

Using component plating technique, 7 genera and 16 species of fungi were isolated from almond seeds collected from different localities of Pakistan. Most of the fungi were located on seed coat followed by cotyledons, shell and axis. The cotyledons were more infected by Fusarium moniliforme and Aspergillus flavus. Surface disinfection reduced the infection of Aspergillus spp., with increase in Alternaria sp. Component plating technique could be used to determine the depth of infection and the suitability of dry fruits for human consumption.

Published

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28(1): 167-170,1997

Karnal or partial bunt of wheat caused by Tilletia indica Mitra (Syn. Neovossia indica (Mitra) Mundkur) is an important disease of wheat in the Punjab and North West Frontier Province of Pakistan, where an incidence of 2-10% and upto 20% in some fields has been reported (Khan et al., 1992) as compared to 89% in some wheat samples from India (Joshi et al., 1983). The disease is transmitted through air borne inoculum (Bedi et al., 1963). Freshly collected teliospores due to their dormant state has either shown no germination (Mitra, 1935) or low % of germination (Bansal et al., 1983) with highest germination in one year old teliospores (Mathur & Ram, 1963). In the present study, germination of the teliospores were tested on different media in order to produce sporidia in culture which could be used for artificial inoculation of wheat germplasm for testing their resistance potential against partial bunt of wheat.

Published

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28(1): 171-172,1997

The leaf curl disease of cotton (Gossypium hirsutum L.) was first observed in Pakistan during 1967 from Multan area. The disease remained in low intensities or was ignored until 1987 when it erupted as an epidemic. The cause of the disease was established in 1992 as a whitefly-transmitted geminivirus with the properties of cotton leaf curl virus (CLCuV) (Hameed et al., 1994). On the basis of departmental reports, the disease was found to be restricted only in the Punjab area and the cotton crop in Sindh was considered disease free. Keeping in view the magnitude of the disease in Punjab and whitefly (Bemisia tabaci) as its vector, a program of monitoring virus diseases with emphasis on geminiviruses including CLCuV in Sindh was initiated in late 1996. Hyderabad, Sanghar and Nawabshlj.h districts were surveyed during September, 1996 and the districts of Ghotki, Sukkur, Khairpur and Naushehro Feroze during January, 1997. CLCuV-like symptoms showing curling, cupping upward/downward and shortening of leaves, thickening of veins and development of enations on underside of leaves were observed in cotton fields around Obaro in district Ghotki, the area not far from Punjab border, where the disease incidence in two fields was about 10%. According to local farmers, such symptoms in cotton were also observed during the 1995 season also. Disease symptoms were also observed on other wild and ornamental plants around Mirpur Mathelo and Ghotki.

Published

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28(1): 173-174,1997

Pollen morphology of the family Paeoniaceae from Pakistan has been examined by light and scanning electron microscope. Pollen grains are generally radially symmetrical, isopolar prolate-spheroidal, 3 zonocolporate, colpi long. Tectum rugulate-striate.

Published

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28(2): 175-178,1997

A new taxon Codium shameelii Nizam., characterised by coxcomb-like tenninal proliferations has been described from the coast of Pakistan.

Published

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28(2): 179-184,1997

The vegetative, anatomical and reproductive structures of the Pakistani populations of Gelidiurn pusillurn (Stackhouse) Le Jolis have been investigated. The plants showed distinctive features with turf or cushion forming habit; upto 11 mm in length and appear distinctly segmented in microscope; primary erect fronds tereto-compressed below becoming flat in the upper half; random arrangement of surface cells as well as tetrasporangia; tetrasporangia borne in stichidia-like structures as well as on the tips of branch fronds; sexual plants not found; and abundance of rhizines.

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28(2): 185-190,1997

Twenty one species of algae were found growing as epiphytes on the pneumatophores of mangrove Avicennia marina (Forssk.) Vierh. They appear to be new reports as epiphytes on mangroves of Pakistan except for Chaetomorpha gracilis Kutzing, Enteromorpha torta (Mert.) Reinbold, Lyngbya majuscula Gomont, Polysiphonia abscissa J. Hooker et Harvey. Most species occupied middle position on the pneumatophores indicating avoidance from both long-term exposure and submergence.

Published

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28(2): 191-197,1997

Conidial appendages have been used as a taxonomic criteria in Coelomycetes. A modified conidial appendages classification has been proposed.

Published

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28(2): 199-205,1997

Fifteen isolates of Ascochyta rabiei causing blight of chickpea (Cicer arietinum) were collected from Pakistan and analyzed for esterase, acid phosphatase, alcohol dehydrogenase, lactate dehydrogenase, malate dehydrogenase, glutamate dehydrogenase and fumarase. Only two enzymes viz., esterase and acid phosphatase produced qualitative as well as quantitative differences among the isolates of A. rabiei. Six electrophoretic phenotypes were developed in case of acid phosphatise, whereas isoelectric focusing of the protein extracts revealed simpler banding patterns for the esterase activity on gel. No correlation between isozyme patterns and the pathogenic groups were established on the basis of aggressiveness.

Published

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28(2): 207-216,1997

Out of 16 genera and 28 species of fungi isolated from soil, at least 7 genera and 10 species of fungi were isolated from root, stem, leaves and seeds of infected plants of bell pepper (Capsicum annuum) as compared to 7 genera and 11 species from red pepper (C. frutescens). Alternaria altemata, Cephalosporium acremonium, Fusarium anthophilum, F. moniliforme, F. oxysporum, F. proliferatum, F. solani, Macrophomina phaseolina, Pythium aphanidermotum and Rhizoctonia solani were found predominant in plants showing symptoms of wilting in Mirpur Khas District, Sindh, Pakistan.

Published

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28(2): 217-222,1997

Axenic soil base VAM cultures of 6 different Glomus spp., viz., Glomus fasiculatum, G. macrocarpum, G. monosporum, G. mosseae, G. radiatum and G. warcupii extracted from the soil of wheat field and stored separately in pots at 5 and 10 (±l)°C or kept under natural conditions showed a gradual loss in viability in 2 yeats. Loss in viability of spores was significantly higher (p < 0.001) when the axenic culture of Glomus spp., were stored under natural condition with temperature ranging from 10-25°C during winter and 22-38°C during summer season. G. macrocarpum retained highest viability (p<0.001) after 2 years.

Published

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28(2): 223-227,1997

Pathogenicity of Fusarium moniliforme, F. graminearum and Macrophomina phaseolina isolated from stalk rot disease of corn were tested on a susceptible com cv. Shaheen in different seasons and at different stages of plant growth at the National Agricultural Research Centre (NARC), Islamabad, Pakistan. F. moniliforme and M. phaseolina in combination produced 77.9 and 89.0% infection with respectively 21.7 and 25.9% reduction in grain yield during spring and summer seasons of 1988, whereas F. graminearum produced 32.8 and 49.4 % disease severity with 0.9 and 1.4 % reduction in grain yield during the same spring and summer seasons.

Published

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28(2): 229-234,1997

Analyses of cellular fatty acids (FAs) were used to identify bacterial leaf streaking pathogen(s) infecting foxtail and pearl millet in Colorado, USA. Isolates from both hosts were identified as unknown pathovar(s) of Xanthomonas campestris. To detennine any similarity the most discriminatory FA profiles of the US isolates were compared with those of X. campestris. pv. pennamericanum infecting pearl millet in Africa and 11 other X. campestris pathovars infecting members of the Poaceae family. The US isolates were different from X. campestris. pv. pennamericanum and the other X. campestris pathovars but similar among themselves. When a dendogram of the millet isolates was constructed with 35 other X. campestris pathovars, the different nature of the US isolates was further clarified. However, this evidence was not enough to give the American isolates a separate pathovar status.

Published

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28(2): 235-241,1997

Based upon their ability to produce auxins (indole-3-acetic-acid equivalents), 11 isolates of rhizobacteria were selected to evaluate their growth promoting activity. Seeds of 2 wheat cvs. Inqlab and LU 26S inoculated with these isolates were sown in the field under optimum fertilization (NPK @ 150-75-50 kg ha-1). Inoculation with rhizobacteria showed an increase in grain yields of cv. Inqlab and LU 26S by upto 15.3% and 18.5%, respectively, as compared to uninoculated control. Inoculation with rhizobacteria also significantly increased the number of tillers, straw weight and lOoo-grain weight in both cultivars. Plant height was increased only in case of wheat cv. LU 26S.

Published

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28(2): 243-248,1997

Glycine max (L) Merrill genotypes (Bossier, Hampton, Improved Pelican and Clark-63) were planted at 15 days interval (1st June, 15th June, 1st July, 15th July, 1st August and 15th August) at Agricultural Research Institute, Tando Jam during summer, 1993. Seed yield and yield components varied significantly (P<0.0I) due to change in sowing time and genotype. All genotypes yielded more when planted on 1st June, while decreased for each delay in planting beyond 1st June. Among genotypes Bossier yielded more over rest of the genotypes tested. Genetic analysis depicted that plant height and seed yield/plant had greater genetic advance, whereas heritability was more in plant height, seed yield/plant, branches/plant, seed index, effective pod filling period and pods/plant. Correlation of yield was significant and positive with plant height, branches/plant, nodes/plant, pods/plant, seeds/pod, and seed index. Flowering days exhibited significant and positive association with effective pod filling period. Plant height had positive and significant relationship with nodes/plaut and pods/plant. The correlation of branches/plant was positive and significant with nodes/plant, seeds/pod and seed index. Nodes/plant displayed positjve and significant correlation with pods/plant, while pods/plant depicted positive and significam association with seeds /pod and seed index whereas seeds/pod had positive and significam association with seed index.  The path coefficient analysis reveals that pods/plant, plant height and seed index had high positive direct effect on yield, while maturity days displayed high negative direct effect on yield. The multiple regression analysis suggested that pods/plant and seed index contributed significantly towards yield and could be used for future plant breeding programme of soybean.

Published

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28(2): 249-262,1997

Karyomorphological and micromorphological observations of different collections of the species Girardinia diversifolia show enough evidences to the existence of 2 or more ecotypes in the species.

Published

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28(2): 263-269,1997

The population structure, intraspecific competition and phasic development of growth in a population of Urochondra setulosa (Trin.) C.E. Hubb., in a dry salt marsh of Hawkes Bay, Karachi, Pakistan, are described. Density and cover values averaged 26000 plants/ha and 1951 sq. m /ha, respectively. Size class distribution was asymmetrical (X-2 = 37.62, p < 0.001) as 84.8% of the population concentrated in initial classes of plants smaller than 50 cm crown diameter. The crown size data fined best (P < 0.001) to the negative power/ logarithmic equation indicating decreasing rate of mortality with age. Drawn to scale, crown outline diagrams indicated that when a hummock reaches to a critical size of around 60 cm in diameter begins to undergo degeneration and consequent hollowing in crown develops which increases with age. Among various developmental phases, mature hummocks dominated (40%) the frequency distribution, followed by building ones (23%). The frequency of seedlings + seedlings intergrading to pioneer was more or less equal to the frequency of degenerate and eroded phases. The phenomenon of phasic development is cyclic in time though quite incoherent in space. The spatial pattern of the population was contagious as determined through rest of fitness of Poisson series and the magnitude of variance mean quotient (2.58). Bivariate Simple Linear Correlation analysis for multiple nearest neighbours measurements indicated significant competitive influence of reference plants extending upto the third neighbour only. Multivariate Canonical Correlation Analysis (CANCOR), however,indicated intense competition only between the reference plant and the second and third nearest neighbours. The first nearest neighbour appeared to exhibit substantially lower competitive interaction with reference plant. The results are discussed in view of population structure, pattern and the biological characteristics.

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28(2): 271-287,1997

Kallar grass [Leptochloa fusca (L) Kunth] and Kochia indica Wight were grown in mono-cultures and mixed-cultures under different soil salinity and water conditions. K. indica suppressed growth of kallar grass in all salinity and watering treatments; the reduction in biomass yield of the latter species was more pronounced in low watering treatment at both salinity levels. In contrast, K. indica gave increased yield when intercropped with kallar grass as compared to that in mono-cultures suggesting its competitive superiority. Nutrient (N ,P,K, Ca and Na) concentrations in shoots of a species grown in mono- and mixed-cultures under a particular treatment were similar. However, the total uptake of nutrients differed significantly and K. indica removed proportionately higher amounts of nutrients when grown in mixed-cultures compared to corresponding mono-cultures. The significance of competition by K. indica is discussed with regard to its invasion and spread in kallar grass stands.

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28(2): 289-297,1997

Salinity/Water stress commonly cause leaf yellowing due to changes in chlorophyll, reduction in endogenous cytokinins as well as an enhancement in abscisic acid (AbA) contents. Since cytokinin (CK) and abscisic acid (AbA) levels are known to differentially influence the senescence process, their effect(s) on chlorophyll contents of salinity stressed wheat (Triticum aestvium L.) seedlings showed that chlorophyll degradation was reduced by CK, benzylamino purine, BAP, but not by other treatments.

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28(2): 299-303,1997

Experiments were undertaken to see the prospects of using saline/sodic water for irrigation. The brackish water was amended with biological ameliorants like sesbania, pressmud or poultry manure or used with good quality canal water in blended or cyclic modes. All the organic manures were almost equally effective in sustaining the yield. Cyclic use of canal and brackish water showed better results than the blend use. These studies suggested a possibility for using saline/sodic water for irrigating crops under specified management conditions.

Published

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28(2): 305-311,1997

The effects of adding K, P and Ca to saline nutrient solutions on K/Na ratio and salinity tolerance in tomato (Lycopersicon esculentum Mill) in five tomato cultivars viz., Tropic, Marikit, Montecarlo, Strain B and Pearson was studied. Addition of K, K+P and K+P+Ca to saline nutrient solutions significantly increased K/Na ratios in the leaf, stem and root as well as fruit yield by 25-35 %, whereas addition of Palone significantly reduced K/Na ratio in the stem but not in the leaf and root with a increase in fruit yield by 9%. Two types of physiological mechanism conferring salinity tolerance to tomato cultivars based on their respective K/Na ratios were detected where Marikit exhibited a typical halophytic characteristic while Tropic, Montecarlo, Strain B and Pearson showed typical glycophytic response, reaction

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28(2): 313-318,1997

During the growth of rice crop upto 7-54% of fertilizer N is generally lost from soil plant system. Using 15N labelling technique, the balance of vegetative N between anthesis and maturity in 3 rice cultivars showed a loss of 7-21 % from foliar parts. Grain yield of the plants was dependent on the efficiency of plants to utilize vegetative N assimilated before anthesis, a factor that plays a significant role in N fenilizer economy of crop plants.

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28(2): 319-322,1997

Vigna ambacensis plants grown hydroponically in a Hoagland nutrient solution with either nitrate or ammonia as a source of nitrogen and NaCI a 0,40, 80 and 160 mM concentrations showed reduction in all growth parameters where ammonia was used as compared to nitrate as a nitrogen source. Salt decreased the growth of plants. Plants grown in nitrate were more salt tolerant as compared to ammonia especially at 80 and 160 roM NaCilevel. High salinity conditions reduced calcium and potassium contents in shots with a increase in sodium which was higher (80 m µl) in NH+4-N as compared with NO-1 3-N source.

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28(2): 323-330,1997

Water soluble sugar and sugar alcohol composition in fruits of Laurocerasus officinalis cvs. Oxygemmis, Globigemmis and wild form of L. officinalis Roem., have been examined. Gas chromatography-mass spectrometry studies exhibited that the main sugars in L. officinalis and related cultivars are fructose, glucose and sorbitol and sorbitol and mannitol as sugar alcohols. Fructose, glucose and sorbitol were in significantly higher levels in cultivars and the wild form with highest value 74.4% of dry weight of total water soluble sugar in Oxygemmis and the highest level of sugar alcohol (42.6%) in the wild form with least in Angustifolia (19.9% of dry weight).

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28(2): 331-336,1997

A series of experiments were conducted in pot and lysimeter conditions to evaluate net photosynthesis and water-use-efficiency as breeding criteria for drought resistance. Six drought resistant and 6 drought susceptible genotypes were used. Net photosynthesis decreased under drought which was caused mainly by non stomatal factors. Genotypes with the same stomatal conductance had different net photosynthesis under suggesting that genotypes with high water-use-efficiency can be tailored. Measurement of net photosynthesis and water-use-efficiency can thus be used as breeding criteria for drought resistance.

Published

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28(2): 337-346,1997

In homoeopathic system of medicine, the use of small ,doses of potentised substances by succession or trituration and dilution excites the curative force of the substances. When substances are diluted beyond 10-24, the original substances do not exist in the solution, still the biological activity of these substances could be demonstrated at much higher dilutions (Boyd, 1954; Khan et al., 1991). Effect of homoeopathic remedies on the growth of fungi (Kumar & Kumar, 1980), wheat coleoptiles (Khan et al., 1991) and young wheat seedlings (Jones & Jenkins, 1981) have shown promising results. Information on the effect of homoeopathic remedies on cell division seems to be lacking. The present report describes the effect of Pyrogenium potencies on cytological changes and root growth in the meristem of Allium cepa.

Published

Doi:
28(2): 347-349,1997

Gradual and shock treatments of NaCI salinity to wheat (Abdullah et al., 1978) and cotton plant (Abdullah & Ahmed, 1986) are reported to decrease the viability and germination of pollen grain. Sharma et al., (1985) also studied the pollen sterility in two varieties of grapes under different levels of soil salinity and found that increase in salinity from 2 to 8 mmhos/cm decreased the percent viability of pollens by upto 50%. Similarly, an increased spikelet sterility was also found by Murty & Rao (1968) in rice grown under saline conditions. Akbar et al., (1972) are of the opinion that sterility in rice panicles is due to some physiological disorders. The present study describes the in vitro effect of seawater and NaCI salinities on germination of pollen and tube growth of Catharanthus roseus (L) G. Don.

Published

Doi:
28(2): 351-354,1997

Extensive studies have been conducted on Leptochloa fusca (L.) Kunth (kallar grass) regarding its salinity/sodicity tolerance, nutrition and productivity on saline lands (Malik et al., 1986). This grass easily propagates from root-stock and stem cuttings, thus information regarding its seed production and germination is scanty in the literature. Sinha et al. (1982) reported that germination of kallar grass seeds was adversely affected by osmotic tension but not by alkalinity; the viability of seeds used was very low (ca. 20%), and suggested the need for improving seed fertility/ viability of this promising species. The present paper reports some observations on germination of kallar grass seeds.

Published

Doi:
28(2): 355-357,1997

Alternaria padwickii (Ganguly) M.B. Ellis (Syn., Trichoconis padwickii Ganguly) is an important seed-borne fungus which causes stackbum disease of rice (Noble & Richardson, 1968). The fungus occurs widely in the rice-growing countries of the world (Ou, 1985; Khair et al., 1988; Rodriguez et al., 1988; Shetty & Shetty, 1992). A. padwickii has also been found widely distributed as a common seed-borne fungus in different rice cultivars in Pakistan (Kamal & Moghal, 1968; Khan et al., 1974). Using blotter and agar plate methods, it has been usually difficult to detect and isolate T. padwickii in pure culture due to the growth of other seedbome fungi such as Pyricularia oryzae, Drechslera oryzae and species of Curvularia, Drechslera and Fusarium on rice seeds (Neergaard, 1977; Khan et al., 1988). A comparative study of various methods was therefore, carried out to find more suitable method by which A. padwickii could be detected and isolated in pure culture from rice seeds

Published

Doi:
28(2): 359-361,1997

Published

Doi:
30(1): 1-2,1998

Pollen morphology of the family Cistaceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally tricolporate, triangular, prolate-spheroidal with striate rugulate tectum.

Published

Doi:
30(1): 3-6,1998

Euastrum oblongum, E. verrucosum var. rhomboideum, Micrasterias americana, M. denticulata. M. rotata, Staurastrum pilosum and Spondylosium planum are recorded for the first time from Turkey.

Published

Doi:
30(1): 7-13,1998

Vaucheria geminata (Vaucher) de Candole var. geminata was found preponderant in the beta-mesosaprobic riverine pond in winter and V. longicaulis Hoppaugh in eusaprobic pond in Hyderabad, Sindh, Pakistan throughout the year.

Published

Doi:
30(1): 15-18,1998

Methanolic (MeOH) extract of Chara corallina var. wallichii (A. Br.) R. D. Wood has been analysed for its fatty acid and sterol compositions. Using GC-MS technique 23 fatty acids viz., 7 saturated, 6 monoenoic, 5 dienoic and 5 trienoic acids were identified as methyl esters, where 63.5 % were unsaturated and 36.5 % as saturated acids. With the exception of heptanoic and pentacosenoic, the acids ranged from C 10 to C18; longer-chain and polyunsaturated acids beyond trienoic ones were not detected. Hexadecadienoic acid occurred in greatest amount (23.7%), and pentadecylic and palmitic acids appeared to be the major saturated acids. Besides, 4 sterols have been identified by spectroscopic techniques, where ß-sitosterol was 76.8 % while cholesterol, c1erosterol and stigmasterol were 6.4-8.7 %. The alga resembled in certain characters of fatty acid and sterol compositions with cWorophytes and in others with higher plants. The MeOH extract, its EtOAc-soluble part and four isolated sterols showed bioactivity against 10 species of bacteria and 10 species of fungi and phytotoxicity against Lernna minor. ß-Sitosterol was least active in its bioactivity as well as phytotoxicity.

Published

Doi:
30(1): 19-31,1998

A study was conducted to assess the mutagenic and recombinogenic potential of 10 commonly consumed spices and condiments viz., bay leaves, black pepper, cardamom small, caraway, red chilies, cinnamon, coriander, fennel, garlic and curry powder in the diploid yeast Saccharomyces cerevisiae. Aqueous extracts of these spices were tested for the induction of mitotic gene conversion and reverse mutation in the diploid strain D7 of the yeast. All except cinnamon failed to induce detectable recombination and mutations in the growing cells of the yeast without exogenous metabolic activation. Treatments with an aqueous extracts of cinnamon significantly increased the rate of gene conversion and reverse mutation. Cinnamon caused cells death and inhibition of cell division. Ethyl methane sulphonate (EMS) used as a positive control exhibited recombinogenic and mutagenic effects.

Published

Doi:
30(1): 33-38,1998

The effect of physical parameters like temperature, flooding duration and soil type on the incidence of root and collar rot disease of chillies was examined. The disease incidence increased from 0-100% with rise in temperature from 15-30°C producing maximum canker length (4.5 cm) and girdling index (4 em). Gradual increase of flooding period from 0-48 hours enhanced the disease development from 25-100 % with maximum Canker length (3.66 cm) and girdling index at 48 h flooding period. Heavy soils showed 83.3% disease as compared to light medium soil which respectively showed 50 and 66.7% of disease incidence.

Published

Doi:
30(1): 39-43,1998

Soil amendment with neem seed cake, cotton seed cake, Datura fastuosa and Steochospermum marginatum significantly (p<0.05) reduced Fusarium solani whereas neem seed cake and cotton seed cake were effective against Macrophomina phaseolina and Rhizoctonia solani, while Steochospermum marginatum and D. fastuosa against Rhizoctonia solani infection on sunflower roots. Pseudomonas aeruginosa, the plant growth promoting bacterium significantly controlled root rot disease of sunflower caused by M. phaseolina, R. solani and F. solani. Use of P. aeruginosa with neem seed cake and S. marginatum produced greater fresh weight of shoot and plant height respectively as compared to their separate use.

Published

Doi:
30(1): 45-50,1998

Number of nuclei and the nature, arrangement and number of appendages in 8 genera of Coelomycetes viz., Kellermania, Alpakesa, Seimatosporiopsis. Parahyalotiopsis. Hyalotiella. Hyalotiopsis. Robillarda and Pseudorobillarda has been described and illustrated.

Published

Doi:
30(1): 51-68,1998

Bradyrhizobium sp., with Benlate or Bavistin and Rhizobium meliloti isolates with Captan or Topsin-M showed better control of Fusarium solani infection on chickpea roots than their separate use. Bradyrhizobium sp., (Mungbean isolate) with Bavistin showed complete control of Macropbomina phaseolina infection, whereas Captan was found more effective against Rhizoctonia solani infection when used alone or with rhizobia. Maximum number of nodules per plant was produced by Bradyrhizobium sp., (TAL-620, chickpea isolate) used with Benlate or Bavistin. Some rhizobial isolates also significantly (p<0.05) enhanced plant height when used with Benlate, Bavistin or Topsin-M.

Published

Doi:
30(1): 69-74,1998

A pot experiment was conducted to observe the growth, nodulation and ion accumulation of salt tolerant and salt sensitive cultivars of soybean (Glycine max L.) when grown in symbiotic association with rhizobium in the absence of mineral nitrogen at different salinity levels (0.05, 0.1 and 0.2 % NaCl). The rhizobium strains pre-tested for salt tolerance were found more. tolerant than the host plants. Plants were inoculated with a mixture of rhizobial strains at the time of sowing in sterilized sand. Salts showed a greater inhibitory effect on nodulation at 0.1 % NaCI with decreased nodule number and weight than the plant growth. Soybean cultivar ICAL-132 showed better growth and produced more nodules by keeping low sodium in the shoot as compared to sensitive cultivar Loppa which failed to survive at 0.2 % NaCI. Salinity decreased potassium concentration in all cultivars tested, but this reduction was also less in ICAL-132. K:Na ratios showed similar trends. A highly positive correlation was observed between nodules and shoot dry weight.

Published

Doi:
30(1): 75-81,1998

Effects of soaking seed with plant growth regulators viz., Indole acetic acid (IAA), Abscisic acid (ABA) and Kinetin each at 10-6 M on Glycine max (L) cv. NARC-1 was studied. Kinetin was found to be most effective in increasing the yield, oil as well as ash contents. Greater seed oil content were found in ABA and Kinetin treatment. Maximum ash contents and seed weight were found in Kinetin treated seed as compared to control. The absorbance for ethylene at 412 om of nodules was found to be significantly different from that of the control with maximum value recorded in Kinetin and minimum in IAA treated seeds.

Published

Doi:
30(1): 83-86,1998

A study using 21 cultivars of wheat (Triticum aestivum L) and a salt tolerant barley (Hordeum vulgare L) showed significnat variation in ∆ (discrimination against 13C during photosynthetic CO2 - uptake) among cultivars and salinity levels. Salinity reduced straw, grain weight and the average value of ∆ in all the cultivars. The reduction caused by salinity varied among cultivars. Barley had larger values of ∆ than did wheat and there was a positive correlation between ∆ and production of straw (r = 0.36), grain (r = 0.44) and total biomass (r = 0.47).

Published

Doi:
30(1): 87-93,1998

The expressivity of H2 gene of hairiness (pilose) and L° gene of leaf shape in cotton (Gossypium hirsutum L) was studied in F1 and F2 generations of four crosses involving a female Okra Pilose strain (HR-Velvet Okra) and four broad leafed and semi/sparsely hairy varieties/strains of cotton. Both pilose and okra leaf shape of cotton plant were partially dominant in Fl generation. The F2 generations of all the four crosses segregated into four classes of hairiness as well as that of leaf shape. The summation of the two intermediate classes of leaf hairiness and shape helped to fit the segregating classes of three crosses to the theoretical 1 :2: 1 ratio of partial dominance. The two homozygous extreme classes of both the characters were easily distinguishable however, the heterozygous condition for hairiness was highly influenced by the genetic background i.e., modifying gene effect. It was perceptible from the study that hairiness and leaf shape in cotton though monogenically inherited, their phenotypic expressions especially in heterozygous conditions were affected by a complex.of modifier genes (genetic background) especially that for pubescence. Hairiness, as compared to leaf shape was more influenced by the minor (modifier) gene effect. Homozygous condition for both H2 and L° genes, however, imparts pilose hairiness and narrow okra leaf shape, respectively, without the aid of modifier genes. A significant level of genetic association (linkage) existed between H2 and L° genes in two crosses; HRVO x S-12 and HRVO x S-14, which was indicative of the higher number of velvet okra combi lation in the advance segregating generations of these crosses.

Published

Doi:
30(1): 95-100,1998

Karyological studies in Hordeum species viz., H. bogdanii (2x), H. brachyantherum ssp, californicum (2x), H. brevisubulatum (4x), H. brevisubulatum ssp. nevskianum (2x), H. brevisubulatum ssp. turkestanicum (4x), H. bulbosum (4x), H, chilense (2x), H. comosum (2x), H. depressum (4x), H. jubatum (2x), H. marinum (2x), H. murimum ssp, leporinum (4x), H. lechleri (6x), H. roshevitzii (2x), H. secalinum (4x), H. stenostachys (2x) and H. vulgare ssp. agriocrithon (2x) were made using aceto-orcein staining technique. Detailed morphological observations of chromosomes included total length, arm ratio and presence of satellites. The cytological technique employed gave good spread of chromosomes, an important prerequisite for karyotype analysis.

Published

Doi:
30(1): 101-115,1998

External morphological, anatomical and physilogical studies on Galanthus ikariae Baker and G. rizehensis Stem (Amaryllidaceae), the bulbous perennial plants collected from Trabzon, Turkey are described.

Published

Doi:
30(1): 117-131,1998

Three different plastic collectors of seeds of 18 x 23 x 4.5 cm from an isolated plant of Eryngium paniculatum (Apiaceae-Saniculoideae) were placed at 5 and 75 cm heights from the ground to test their efficiency. Plastic nets placed at 5 cm above the ground showed better results.

Published

Doi:
30(1): 133-140,1998

Presowing treatment of dry wheat seeds to a constant magnetic field of 30 mT was found to promote the elongation of 24 hrs old wheat coleoptile tips. The growth of apical and basal segments of wheat coleoptiles were also promoted by 30 mT magnetized sucrose and maltose.

Published

Doi:
30(1): 141-144,1998

Sodium chloride is known to inhibit the mitotic activity (Kuliava et al.

Published

Doi:
30(1): 145-149,1998

Phytophthora crown and root rot disease of apple is widespread in most apple growing areas of Malakand Division, Pakistan where Phytophthora cactorum and Phytophthora spp., have been reported from infected plants of apple orchards and nurseries (Jahangir et al.

Published

Doi:
30(1): 151-,1998

Geriachia oryzae (Hashioka & Yokogi) W. Gams (Syn. Rhynchosporium oryzae Hashioka & Yokogi), a dematacious fungus is wide spread in the rice growing areas of the world (Baker & Miah

Published

Doi:
30(1): 153-154,1998

Published

Doi:
30(1): 1-2,1998

Pollen morphology of the family Cistaceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally tricolporate, triangular, prolate-spheroidal with striate rugulate tectum.

Published

Doi:
30(1): 3-6,1998

Euastrum oblongum, E. verrucosum var. rhomboideum, Micrasterias americana, M. denticulata. M. rotata, Staurastrum pilosum and Spondylosium planum are recorded for the first time from Turkey.

Published

Doi:
30(1): 7-13,1998

Vaucheria geminata (Vaucher) de Candole var. geminata was found preponderant in the beta-mesosaprobic riverine pond in winter and V. longicaulis Hoppaugh in eusaprobic pond in Hyderabad, Sindh, Pakistan throughout the year.

Published

Doi:
30(1): 15-18,1998

Methanolic (MeOH) extract of Chara corallina var. wallichii (A. Br.) R. D. Wood has been analysed for its fatty acid and sterol compositions. Using GC-MS technique 23 fatty acids viz., 7 saturated, 6 monoenoic, 5 dienoic and 5 trienoic acids were identified as methyl esters, where 63.5 % were unsaturated and 36.5 % as saturated acids. With the exception of heptanoic and pentacosenoic, the acids ranged from C 10 to C18; longer-chain and polyunsaturated acids beyond trienoic ones were not detected. Hexadecadienoic acid occurred in greatest amount (23.7%), and pentadecylic and palmitic acids appeared to be the major saturated acids. Besides, 4 sterols have been identified by spectroscopic techniques, where ß-sitosterol was 76.8 % while cholesterol, c1erosterol and stigmasterol were 6.4-8.7 %. The alga resembled in certain characters of fatty acid and sterol compositions with cWorophytes and in others with higher plants. The MeOH extract, its EtOAc-soluble part and four isolated sterols showed bioactivity against 10 species of bacteria and 10 species of fungi and phytotoxicity against Lernna minor. ß-Sitosterol was least active in its bioactivity as well as phytotoxicity.

Published

Doi:
30(1): 19-31,1998

A study was conducted to assess the mutagenic and recombinogenic potential of 10 commonly consumed spices and condiments viz., bay leaves, black pepper, cardamom small, caraway, red chilies, cinnamon, coriander, fennel, garlic and curry powder in the diploid yeast Saccharomyces cerevisiae. Aqueous extracts of these spices were tested for the induction of mitotic gene conversion and reverse mutation in the diploid strain D7 of the yeast. All except cinnamon failed to induce detectable recombination and mutations in the growing cells of the yeast without exogenous metabolic activation. Treatments with an aqueous extracts of cinnamon significantly increased the rate of gene conversion and reverse mutation. Cinnamon caused cells death and inhibition of cell division. Ethyl methane sulphonate (EMS) used as a positive control exhibited recombinogenic and mutagenic effects.

Published

Doi:
30(1): 33-38,1998

The effect of physical parameters like temperature, flooding duration and soil type on the incidence of root and collar rot disease of chillies was examined. The disease incidence increased from 0-100% with rise in temperature from 15-30°C producing maximum canker length (4.5 cm) and girdling index (4 em). Gradual increase of flooding period from 0-48 hours enhanced the disease development from 25-100 % with maximum Canker length (3.66 cm) and girdling index at 48 h flooding period. Heavy soils showed 83.3% disease as compared to light medium soil which respectively showed 50 and 66.7% of disease incidence.

Published

Doi:
30(1): 39-43,1998

Soil amendment with neem seed cake, cotton seed cake, Datura fastuosa and Steochospermum marginatum significantly (p<0.05) reduced Fusarium solani whereas neem seed cake and cotton seed cake were effective against Macrophomina phaseolina and Rhizoctonia solani, while Steochospermum marginatum and D. fastuosa against Rhizoctonia solani infection on sunflower roots. Pseudomonas aeruginosa, the plant growth promoting bacterium significantly controlled root rot disease of sunflower caused by M. phaseolina, R. solani and F. solani. Use of P. aeruginosa with neem seed cake and S. marginatum produced greater fresh weight of shoot and plant height respectively as compared to their separate use.

Published

Doi:
30(1): 45-50,1998

Number of nuclei and the nature, arrangement and number of appendages in 8 genera of Coelomycetes viz., Kellermania, Alpakesa, Seimatosporiopsis. Parahyalotiopsis. Hyalotiella. Hyalotiopsis. Robillarda and Pseudorobillarda has been described and illustrated.

Published

Doi:
30(1): 51-68,1998

Bradyrhizobium sp., with Benlate or Bavistin and Rhizobium meliloti isolates with Captan or Topsin-M showed better control of Fusarium solani infection on chickpea roots than their separate use. Bradyrhizobium sp., (Mungbean isolate) with Bavistin showed complete control of Macropbomina phaseolina infection, whereas Captan was found more effective against Rhizoctonia solani infection when used alone or with rhizobia. Maximum number of nodules per plant was produced by Bradyrhizobium sp., (TAL-620, chickpea isolate) used with Benlate or Bavistin. Some rhizobial isolates also significantly (p<0.05) enhanced plant height when used with Benlate, Bavistin or Topsin-M.

Published

Doi:
30(1): 69-74,1998

A pot experiment was conducted to observe the growth, nodulation and ion accumulation of salt tolerant and salt sensitive cultivars of soybean (Glycine max L.) when grown in symbiotic association with rhizobium in the absence of mineral nitrogen at different salinity levels (0.05, 0.1 and 0.2 % NaCl). The rhizobium strains pre-tested for salt tolerance were found more. tolerant than the host plants. Plants were inoculated with a mixture of rhizobial strains at the time of sowing in sterilized sand. Salts showed a greater inhibitory effect on nodulation at 0.1 % NaCI with decreased nodule number and weight than the plant growth. Soybean cultivar ICAL-132 showed better growth and produced more nodules by keeping low sodium in the shoot as compared to sensitive cultivar Loppa which failed to survive at 0.2 % NaCI. Salinity decreased potassium concentration in all cultivars tested, but this reduction was also less in ICAL-132. K:Na ratios showed similar trends. A highly positive correlation was observed between nodules and shoot dry weight.

Published

Doi:
30(1): 75-81,1998

Effects of soaking seed with plant growth regulators viz., Indole acetic acid (IAA), Abscisic acid (ABA) and Kinetin each at 10-6 M on Glycine max (L) cv. NARC-1 was studied. Kinetin was found to be most effective in increasing the yield, oil as well as ash contents. Greater seed oil content were found in ABA and Kinetin treatment. Maximum ash contents and seed weight were found in Kinetin treated seed as compared to control. The absorbance for ethylene at 412 om of nodules was found to be significantly different from that of the control with maximum value recorded in Kinetin and minimum in IAA treated seeds.

Published

Doi:
30(1): 83-86,1998

A study using 21 cultivars of wheat (Triticum aestivum L) and a salt tolerant barley (Hordeum vulgare L) showed significnat variation in ∆ (discrimination against 13C during photosynthetic CO2 - uptake) among cultivars and salinity levels. Salinity reduced straw, grain weight and the average value of ∆ in all the cultivars. The reduction caused by salinity varied among cultivars. Barley had larger values of ∆ than did wheat and there was a positive correlation between ∆ and production of straw (r = 0.36), grain (r = 0.44) and total biomass (r = 0.47).

Published

Doi:
30(1): 87-93,1998

The expressivity of H2 gene of hairiness (pilose) and L° gene of leaf shape in cotton (Gossypium hirsutum L) was studied in F1 and F2 generations of four crosses involving a female Okra Pilose strain (HR-Velvet Okra) and four broad leafed and semi/sparsely hairy varieties/strains of cotton. Both pilose and okra leaf shape of cotton plant were partially dominant in Fl generation. The F2 generations of all the four crosses segregated into four classes of hairiness as well as that of leaf shape. The summation of the two intermediate classes of leaf hairiness and shape helped to fit the segregating classes of three crosses to the theoretical 1 :2: 1 ratio of partial dominance. The two homozygous extreme classes of both the characters were easily distinguishable however, the heterozygous condition for hairiness was highly influenced by the genetic background i.e., modifying gene effect. It was perceptible from the study that hairiness and leaf shape in cotton though monogenically inherited, their phenotypic expressions especially in heterozygous conditions were affected by a complex.of modifier genes (genetic background) especially that for pubescence. Hairiness, as compared to leaf shape was more influenced by the minor (modifier) gene effect. Homozygous condition for both H2 and L° genes, however, imparts pilose hairiness and narrow okra leaf shape, respectively, without the aid of modifier genes. A significant level of genetic association (linkage) existed between H2 and L° genes in two crosses; HRVO x S-12 and HRVO x S-14, which was indicative of the higher number of velvet okra combi lation in the advance segregating generations of these crosses.

Published

Doi:
30(1): 95-100,1998

VAHIDY, A.A. AND B. JAHAN

Published

Doi:
30(1): 101-115,1998

External morphological, anatomical and physilogical studies on Galanthus ikariae Baker and G. rizehensis Stem (Amaryllidaceae), the bulbous perennial plants collected from Trabzon, Turkey are described.

Published

Doi:
30(1): 117-131,1998

Three different plastic collectors of seeds of 18 x 23 x 4.5 cm from an isolated plant of Eryngium paniculatum (Apiaceae-Saniculoideae) were placed at 5 and 75 cm heights from the ground to test their efficiency. Plastic nets placed at 5 cm above the ground showed better results.

Published

Doi:
30(1): 133-140,1998

Presowing treatment of dry wheat seeds to a constant magnetic field of 30 mT was found to promote the elongation of 24 hrs old wheat coleoptile tips. The growth of apical and basal segments of wheat coleoptiles were also promoted by 30 mT magnetized sucrose and maltose.

Published

Doi:
30(1): 141-144,1998

Sodium chloride is known to inhibit the mitotic activity (Kuliava et al.

Published

Doi:
30(1): 145-149,1998

Phytophthora crown and root rot disease of apple is widespread in most apple growing areas of Malakand Division, Pakistan where Phytophthora cactorum and Phytophthora spp., have been reported from infected plants of apple orchards and nurseries (Jahangir et al.

Published

Doi:
30(1): 151-,1998

Geriachia oryzae (Hashioka & Yokogi) W. Gams (Syn. Rhynchosporium oryzae Hashioka & Yokogi), a dematacious fungus is wide spread in the rice growing areas of the world (Baker & Miah

Published

Doi:
30(1): 153-154,1998

Pollen morphology of the family Coriariaceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally porate, prolate - spheroidal with scabrate tectum.

Published

Doi:
30(2): 155-157,1998

While revising the genus Fagonia from Pakistan, a new species: Fagonia elliptica Thbassurn, Orner & Qaiser sp. nov., is recognized, whereas one new status is also proposed.

Published

Doi:
30(2): 159-160,1998

To elucidate the phylogeny of the endemic North American genus Uvularia and related taxa, the chloroplast gene rbcL was sequenced in all the 5 species of the genus. The rbcL sequence data of 12 other genera viz., Tricyrtis. Disporum. Prosartes. Streptopus. Clintonia, Polygonatum, Medeola, Gloriosa. Colchicum. Veratrum. Dioscorea and Scilla representing different orders of Liliflorae were also analyzed to assess phylogenetic relationships among genera.

Published

Doi:
30(2): 161-172,1998

The genus Silene L.. (Caryophyllaceae) from Turkey have been studied for their seed morphology. A total of 19 species of which 3 are endemic belonging to 12 sections were studied. The seeds show variation in their morphology. The seed morphology as studied show section specific observations.

Published

Doi:
30(2): 173-188,1998

Seed bank and morphological characteristics of Arthrocnemum macrostachyum population along an inundation gradient are described. The seed density increased substantially from lower marsh (2987 seed m-2) to upper marsh (141,509 seed m-2) The seed bank contained only dominant species in the lower marsh, however, the number of species in the seed bank increased towards the upper marsh. A. macrostachyum constituted about 97 % of the seed bank. Density and height of plants were higher in the middle marsh. Plant cover and number of branches were lowest in lower marsh and increased substantially in next zone, with no significant differences among other zones. Dry weight accumulation was highest in lower-middle marsh.

Published

Doi:
30(2): 189-197,1998

Field experiments were conducted to study the nitrogen fixing potential of cultivars and breeding lines of chickpea (Cicer arietinum) where 20 chickpea genotypes were compared using the 15N isotope dilution technique, acetylene reduction assay (ARA) and yield parameters such as biomass, grain and total nitrogen. Great differences in nitrogen fixation were observed between and within the experiments. Proportion of nitrogen fixed from air (Pfix) and nitrogen derived from air (Ndfa) ranged from 23-68 % and 4-61 kg ha-1 for the first year and 37-62 % and 24-60 kg ha-1 for the second year, respectively. There was highly significant correlation between yield and N2 -fixation but these were non-significantly correlated with nodulation data and ARA. The nodulation and ARA data were not good for field evaluation of chickpea cultivars suggesting that simple yield parameters like grain and total nitrogen yield could be used to screen a large gerrnplasm in field as compared to highly expensive and laborious 15N dilution technique.

Published

Doi:
30(2): 199-207,1998

A study was undertaken to estimate the level and pattern of correlation between various plant characters including grain yield, separately in 28 Fls and 18 homozygous parental genotypes of chickpea grown under similar conditions. The correlation coefficients were partitioned into direct and indirect effects through path analysis. Highly significant genetic differences were recorded for all the characters studied both in F1 and parental lines. A comparison between F1 populations and parental lines revealed that the ranges of genotypic variations in F1 were greater than their corresponding ranges in parental lines. Study of correlation coefficients revealed that genetic correlation's in F1's as well as in parental lines were higher than phenotypic correlations. Positive and highly significant genetic correlation of grain yield in parental genotypes was observed with number of primary and secondary branches per plant, pods per plant, l00-seed weight and biologkal yield per plant, whereas in F1 highly significant and positive correlation of grain yield was noted only with number of secondary branches, pods per plant and biological yield per plant. However, F1 and parental genotypes appeared to be similar with respect to the pattern of correlation of grain yield with other plant characters except 100 seed weight. The correlation of l00-seed weight with grain yield in F1 was negative and highly significant, whereas it was positive and highly significant in the case of parents. The study of correlation coefficients between yield components showed that the pattern of correlations between plant height and secondary branches, primary branches and l00-seed weight, biological yield and l00-seed weight and between harvest index and l00-seed weight were dissimilar in F1 and parental genotypes. The results of path analysis showed harvest index and biological yield to have maximum direct effect on grain yield respectively in parental lines and F1 genotypes. These results showed that the pattern and level of association between various plant characters in F1 and parental genotypes were not similar for all the cases. However, the level and pattern of correlation of grain yield with number of secondary branches, number of pods and biological yield per plant were similar in both the sets of genotypes.

Published

Doi:
30(2): 209-219,1998

A series of field experiments were conducted on sandy loam soil at Cereal Crops Research Institute, Pirsabak (Nowshera) NWFP, to study the effect of sowing time, crop density and weed control on heading and maturity of bread wheat. The data revealed that planting dates viz., October 15, November 15 and December 15 had significant effects on days to heading and days to maturity. Maximum days to heading and days to maturity were observed in November 15 planting. Further data indicated that maximum days to heading and maturity were in planting density of 100 and 150 kg per hectare seeding which was statistically at par with 100 kg seeding per hectare for days to maturity only. The results further demonstrated significant difference between weed control methods for days to maturity only. Maximum days to heading and maturity were found in no weeding plots whereas minimum days to maturity were found in chemical weeding and hand weeding plots.

Published

Doi:
30(2): 221-225,1998

Two hundred and eighty five blackgram germplasm accessions, collected from different parts of Pakistan were evaluated for morphological and agronomical traits. The evaluation results based on basic statistics and correlation studies blazed good hope for blackgram improvement through simple selection for maturity, branches, pods, biomass, grain yield and harvest index. Classification of quantitative traits showed some outstanding accessions with unique traits which could be exploited directly or be included in hybridization programme for blackgram improvement. Data analyzed on the basis of harvest index revealed that the genotypes within 25 to 40% harvest index exhibited better performance for most of the yield contributing traits. As a result of these findings

Published

Doi:
30(2): 227-238,1998

The effect of aqueous sprays of salicylic acid (SA), acetylsalicylic acid (ASA) and methyl-2,6 dichloroisonicotinic acid (INA) , which mimics SA action, was investigated and compared with naphthaleneacetic acid, Ag and Co ions sprayed on juvenile fruits at pea size (5-6 mm) and two weeks later when they had attained marble size (10-15 mm). All the chemicals significantly (P(0.05) enhanced harvestable fruits in all the three cultivars tested. Considering the cost, easy availability and convenience of preparing aqueous solution, use of soluble ASA is suggested.

Published

Doi:
30(2): 239-243,1998

Gennination and growth inhibiting activity of water soluble extract of Washingtonia filifera fruits was investigated. Paper chromatographic separation of the extract revealed the presence of two inhibiting zones of germination and growth. The fast moving beta - inhibitor was further separated by TLC into four components, one of which appears to be abscissic acid ( ABA) and the rest phenolic substances. Gibberellic acid (GA3) was found to neutralize the gennination and growth inhibiting ability of the inhibitor beta-complex. Besides these, a slow moving inhibitory zone of gennination and growth was due to the presence of phenolic substance.

Published

Doi:
30(2): 245-252,1998

Two sugarcane clones viz., AEC81-8415 and BL4 were tested for in vitro mutagenesis using irradiation doses of 0

Published

Doi:
30(2): 253-261,1998

In order to determine the mode of inheritance of resistance to blackeye cowpea mosaic virus in 6 cowpea lines, direct, reciprocal and back crosses were attempted between resistant and susceptible parents. The data from F1 populations suggested the dominant nature of susceptibility. The number of resistant and susceptible plants in F2 progenies of each cross segregated in a ratio of 1 resistant: 3 susceptible. The observed ratios were compared with the expected monogenic recessive model for goodness of fit using chisquare test. Based on the results obtained from F1, F 2 and back crosses, it is concluded that the resistance in the 6 cowpea lines viz., IT86F-2089-5, IT86D-880, IT90K-76, IT86D-1010, IT86F-2062-5 and BPICP3 is conditioned by a single homozygous recessive gene. The symbol for this gene is proposed as "bcm" (blackeye cowpea mosaic).

Published

Doi:
30(2): 263-270,1998

Seimatosporiella salvadore gen. et sp. nov., is proposed for a species found on Salvadora oleoides. It has pycnidial to eustromatic conidiomata. Conidia brown, cylindrical to fusiform to clavate, minutely verruculose, straight or curved with 3 transversely eusepta, apical cell conic, brown, rarely hyaline; basal cell hyaline tapered towards the truncate base. The genus is compared with Exosporiella, Bactrodesmium, Endocoryneum, Seimatosporium, Pestalotiopsis and Neohendersonia. Nature of appendage in Exosporiella is illustrated and discussed and compared with appendaged bearing related genera.

Published

Doi:
30(2): 271-278,1998

Use of Bradyrhizobium spp.. (chickpea isolate and mungbean isolate) and Rhizobium trifolii (berseem isolate) with or without fungal antagonists viz., Paecilomyces lilacinus. Memnoniella echinata. Trichoderma harzianum and Stachybotrys atra significantly (p<0.05) controlled Macrophomina phaseolina. Rhizoctonia solani and Fusarium solani infection on sunflower and chickpea. Use of rhizobia with fungal antagonists showed better results in the control of root infecting fungi with enhancement in plant growth.

Published

Doi:
30(2): 279-286,1998

Infection and colonization of Macrophomina phaseolina increased significantly (p<0.05) with the increase in sclerotial population in soiL No significant difference in shoot length was observed in different treatments. In seed inoculation experiment, size of inoculated plants was significantly smaller than the uninoculated plants (p<0.001). Infection of root by M. phaseolina was significantly greater in treated plants as compared to control (p<0.05) which showed significant increase with the increase in time (p<0.001).

Published

Doi:
30(2): 287-290,1998

Sunflower seeds inoculated with toxigenic strain of Aspergillus flavus showed a reduction in seed germination whereas seed treattnent with fungicides viz., Captan, Bay tan and Benomyl significantly increased seed germination and decreased infection of A. flavus. Seed treattnent with fungicides before inoculation with A. flavus was found more effective in reducing infection by A. flavus and aflatoxin production.

Published

Doi:
30(2): 291-294,1998

A software was developed in order to help the management of reference collections when microhistology is used to determine herbivorous diet. This software represents a useful tool in the redetermination of the epidermis and comparisons of similar epidermis. Microsoft Fox Pro 2.6 for Windows was used to create the databases and programs because it supports several types of data such as numeric, alphanumeric and digitalized images. Running the program does not need high amounts of memory, so it can be executed in conjunction with other programs, without causing any trouble, even though the Diet program is image user.

Published

Doi:
30(2): 295-300,1998

During a survey of the marine algal flora, a variety of forms attributed to the genus Scinaia Bivona-Bernardi (Galaxauraceae, Bonnemaisoniales) were found growing along the coast of Pakistan (Shameel et al.

Published

Doi:
30(2): 301-303,1998

Although comprehensive lists of saprophytic and plant parasitic fungi from Pakistan are available, the Oomycetes are among the less studied group of fungi where 8 genera comprising of 35 species have been recorded from Pakistan (Ahmad

Published

Doi:
30(2): 305-306,1998

Pollen morphology of the family Coriariaceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally porate, prolate - spheroidal with scabrate tectum.

Published

Doi:
30(2): 155-157,1998

While revising the genus Fagonia from Pakistan, a new species: Fagonia elliptica Thbassurn, Orner & Qaiser sp. nov., is recognized, whereas one new status is also proposed.

Published

Doi:
30(2): 159-160,1998

To elucidate the phylogeny of the endemic North American genus Uvularia and related taxa, the chloroplast gene rbcL was sequenced in all the 5 species of the genus. The rbcL sequence data of 12 other genera viz., Tricyrtis. Disporum. Prosartes. Streptopus. Clintonia, Polygonatum, Medeola, Gloriosa. Colchicum. Veratrum. Dioscorea and Scilla representing different orders of Liliflorae were also analyzed to assess phylogenetic relationships among genera.

Published

Doi:
30(2): 161-172,1998

The genus Silene L.. (Caryophyllaceae) from Turkey have been studied for their seed morphology. A total of 19 species of which 3 are endemic belonging to 12 sections were studied. The seeds show variation in their morphology. The seed morphology as studied show section specific observations.

Published

Doi:
30(2): 173-188,1998

Seed bank and morphological characteristics of Arthrocnemum macrostachyum population along an inundation gradient are described. The seed density increased substantially from lower marsh (2987 seed m-2) to upper marsh (141,509 seed m-2) The seed bank contained only dominant species in the lower marsh, however, the number of species in the seed bank increased towards the upper marsh. A. macrostachyum constituted about 97 % of the seed bank. Density and height of plants were higher in the middle marsh. Plant cover and number of branches were lowest in lower marsh and increased substantially in next zone, with no significant differences among other zones. Dry weight accumulation was highest in lower-middle marsh.

Published

Doi:
30(2): 189-197,1998

Field experiments were conducted to study the nitrogen fixing potential of cultivars and breeding lines of chickpea (Cicer arietinum) where 20 chickpea genotypes were compared using the 15N isotope dilution technique, acetylene reduction assay (ARA) and yield parameters such as biomass, grain and total nitrogen. Great differences in nitrogen fixation were observed between and within the experiments. Proportion of nitrogen fixed from air (Pfix) and nitrogen derived from air (Ndfa) ranged from 23-68 % and 4-61 kg ha-1 for the first year and 37-62 % and 24-60 kg ha-1 for the second year, respectively. There was highly significant correlation between yield and N2 -fixation but these were non-significantly correlated with nodulation data and ARA. The nodulation and ARA data were not good for field evaluation of chickpea cultivars suggesting that simple yield parameters like grain and total nitrogen yield could be used to screen a large gerrnplasm in field as compared to highly expensive and laborious 15N dilution technique.

Published

Doi:
30(2): 199-207,1998

A study was undertaken to estimate the level and pattern of correlation between various plant characters including grain yield, separately in 28 Fls and 18 homozygous parental genotypes of chickpea grown under similar conditions. The correlation coefficients were partitioned into direct and indirect effects through path analysis. Highly significant genetic differences were recorded for all the characters studied both in F1 and parental lines. A comparison between F1 populations and parental lines revealed that the ranges of genotypic variations in F1 were greater than their corresponding ranges in parental lines. Study of correlation coefficients revealed that genetic correlation's in F1's as well as in parental lines were higher than phenotypic correlations. Positive and highly significant genetic correlation of grain yield in parental genotypes was observed with number of primary and secondary branches per plant, pods per plant, l00-seed weight and biologkal yield per plant, whereas in F1 highly significant and positive correlation of grain yield was noted only with number of secondary branches, pods per plant and biological yield per plant. However, F1 and parental genotypes appeared to be similar with respect to the pattern of correlation of grain yield with other plant characters except 100 seed weight. The correlation of l00-seed weight with grain yield in F1 was negative and highly significant, whereas it was positive and highly significant in the case of parents. The study of correlation coefficients between yield components showed that the pattern of correlations between plant height and secondary branches, primary branches and l00-seed weight, biological yield and l00-seed weight and between harvest index and l00-seed weight were dissimilar in F1 and parental genotypes. The results of path analysis showed harvest index and biological yield to have maximum direct effect on grain yield respectively in parental lines and F1 genotypes. These results showed that the pattern and level of association between various plant characters in F1 and parental genotypes were not similar for all the cases. However, the level and pattern of correlation of grain yield with number of secondary branches, number of pods and biological yield per plant were similar in both the sets of genotypes.

Published

Doi:
30(2): 209-219,1998

A series of field experiments were conducted on sandy loam soil at Cereal Crops Research Institute, Pirsabak (Nowshera) NWFP, to study the effect of sowing time, crop density and weed control on heading and maturity of bread wheat. The data revealed that planting dates viz., October 15, November 15 and December 15 had significant effects on days to heading and days to maturity. Maximum days to heading and days to maturity were observed in November 15 planting. Further data indicated that maximum days to heading and maturity were in planting density of 100 and 150 kg per hectare seeding which was statistically at par with 100 kg seeding per hectare for days to maturity only. The results further demonstrated significant difference between weed control methods for days to maturity only. Maximum days to heading and maturity were found in no weeding plots whereas minimum days to maturity were found in chemical weeding and hand weeding plots.

Published

Doi:
30(2): 221-225,1998

Two hundred and eighty five blackgram germplasm accessions, collected from different parts of Pakistan were evaluated for morphological and agronomical traits. The evaluation results based on basic statistics and correlation studies blazed good hope for blackgram improvement through simple selection for maturity, branches, pods, biomass, grain yield and harvest index. Classification of quantitative traits showed some outstanding accessions with unique traits which could be exploited directly or be included in hybridization programme for blackgram improvement. Data analyzed on the basis of harvest index revealed that the genotypes within 25 to 40% harvest index exhibited better performance for most of the yield contributing traits. As a result of these findings

Published

Doi:
30(2): 227-238,1998

The effect of aqueous sprays of salicylic acid (SA), acetylsalicylic acid (ASA) and methyl-2,6 dichloroisonicotinic acid (INA) , which mimics SA action, was investigated and compared with naphthaleneacetic acid, Ag and Co ions sprayed on juvenile fruits at pea size (5-6 mm) and two weeks later when they had attained marble size (10-15 mm). All the chemicals significantly (P(0.05) enhanced harvestable fruits in all the three cultivars tested. Considering the cost, easy availability and convenience of preparing aqueous solution, use of soluble ASA is suggested.

Published

Doi:
30(2): 239-243,1998

Gennination and growth inhibiting activity of water soluble extract of Washingtonia filifera fruits was investigated. Paper chromatographic separation of the extract revealed the presence of two inhibiting zones of germination and growth. The fast moving beta - inhibitor was further separated by TLC into four components, one of which appears to be abscissic acid ( ABA) and the rest phenolic substances. Gibberellic acid (GA3) was found to neutralize the gennination and growth inhibiting ability of the inhibitor beta-complex. Besides these, a slow moving inhibitory zone of gennination and growth was due to the presence of phenolic substance.

Published

Doi:
30(2): 245-252,1998

Two sugarcane clones viz., AEC81-8415 and BL4 were tested for in vitro mutagenesis using irradiation doses of 0

Published

Doi:
30(2): 253-261,1998

In order to determine the mode of inheritance of resistance to blackeye cowpea mosaic virus in 6 cowpea lines, direct, reciprocal and back crosses were attempted between resistant and susceptible parents. The data from F1 populations suggested the dominant nature of susceptibility. The number of resistant and susceptible plants in F2 progenies of each cross segregated in a ratio of 1 resistant: 3 susceptible. The observed ratios were compared with the expected monogenic recessive model for goodness of fit using chisquare test. Based on the results obtained from F1, F 2 and back crosses, it is concluded that the resistance in the 6 cowpea lines viz., IT86F-2089-5, IT86D-880, IT90K-76, IT86D-1010, IT86F-2062-5 and BPICP3 is conditioned by a single homozygous recessive gene. The symbol for this gene is proposed as "bcm" (blackeye cowpea mosaic).

Published

Doi:
30(2): 263-270,1998

Seimatosporiella salvadore gen. et sp. nov., is proposed for a species found on Salvadora oleoides. It has pycnidial to eustromatic conidiomata. Conidia brown, cylindrical to fusiform to clavate, minutely verruculose, straight or curved with 3 transversely eusepta, apical cell conic, brown, rarely hyaline; basal cell hyaline tapered towards the truncate base. The genus is compared with Exosporiella, Bactrodesmium, Endocoryneum, Seimatosporium, Pestalotiopsis and Neohendersonia. Nature of appendage in Exosporiella is illustrated and discussed and compared with appendaged bearing related genera.

Published

Doi:
30(2): 271-278,1998

Use of Bradyrhizobium spp.. (chickpea isolate and mungbean isolate) and Rhizobium trifolii (berseem isolate) with or without fungal antagonists viz., Paecilomyces lilacinus. Memnoniella echinata. Trichoderma harzianum and Stachybotrys atra significantly (p<0.05) controlled Macrophomina phaseolina. Rhizoctonia solani and Fusarium solani infection on sunflower and chickpea. Use of rhizobia with fungal antagonists showed better results in the control of root infecting fungi with enhancement in plant growth.

Published

Doi:
30(2): 279-286,1998

Infection and colonization of Macrophomina phaseolina increased significantly (p<0.05) with the increase in sclerotial population in soiL No significant difference in shoot length was observed in different treatments. In seed inoculation experiment, size of inoculated plants was significantly smaller than the uninoculated plants (p<0.001). Infection of root by M. phaseolina was significantly greater in treated plants as compared to control (p<0.05) which showed significant increase with the increase in time (p<0.001).

Published

Doi:
30(2): 287-290,1998

Sunflower seeds inoculated with toxigenic strain of Aspergillus flavus showed a reduction in seed germination whereas seed treattnent with fungicides viz., Captan, Bay tan and Benomyl significantly increased seed germination and decreased infection of A. flavus. Seed treattnent with fungicides before inoculation with A. flavus was found more effective in reducing infection by A. flavus and aflatoxin production.

Published

Doi:
30(2): 291-294,1998

A software was developed in order to help the management of reference collections when microhistology is used to determine herbivorous diet. This software represents a useful tool in the redetermination of the epidermis and comparisons of similar epidermis. Microsoft Fox Pro 2.6 for Windows was used to create the databases and programs because it supports several types of data such as numeric, alphanumeric and digitalized images. Running the program does not need high amounts of memory, so it can be executed in conjunction with other programs, without causing any trouble, even though the Diet program is image user.

Published

Doi:
30(2): 295-300,1998

During a survey of the marine algal flora, a variety of forms attributed to the genus Scinaia Bivona-Bernardi (Galaxauraceae, Bonnemaisoniales) were found growing along the coast of Pakistan (Shameel et al.

Published

Doi:
30(2): 301-303,1998

Although comprehensive lists of saprophytic and plant parasitic fungi from Pakistan are available, the Oomycetes are among the less studied group of fungi where 8 genera comprising of 35 species have been recorded from Pakistan (Ahmad

Published

Doi:
30(2): 305-306,1998

Pollen morphology of the family Frankeniaceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally colpate, sub-oblate. Tectum densely rugulate with scabrate.

Published

Doi:
31(1): 1-3,1999

Isozyme peroxidase (Pox), shikimic dehydrogenase (Sdh), superoxide-dismutase (Sod), esterase (Est), phosphoglucoisomerase (Pgi) and catalase (Cat) were standardised for different varieties of cotton (Gossypium hirsutum) and one variety of G. arboreum using stacking and resolving polyacrlyamide gel electrophoresis (PAGE). Isozymes were extracted in different buffers using fresh leaves collected from different cotton cultivars growing in the field. Isozyme shikimate dehydrogenase and esterase have been smdied in different varieties of G. hirsutum in addition to the remaining isozymes which have been reported only for G. arboreum and G. herbaceum. The objectives of the study were to standardize different isozyme systems for G. hirsutum varieties using material collected from field. identification of an isozyme system through which inter and intravarietal differences and genetic changes occurring in the plant growing under stress condition can be detected, and detection of a polymorphic locus which can be correlated with the stress prevailing in the area (s) of cotton cultivation. Electrophoretic profiles of isozymes showed generally monomorphic patterns for isozymes esterase and superoxide dismutase and thus detected minor inter and/or intravarietal differences. The remaining isozyme systems appeared polymorphic and differentiated different plants of a variyty and different varieties from each other. Most of the isozymes appeared to be controlled by one or two loci except peroxidase for which 7 different loci were identified. Possibilities of using the observed isozyme polymorphism in persuing the prescribed objectives are discussed.

Published

Doi:
31(1): 5-20,1999

Total activity of peroxidase and its isozymic profiles in the explants of soybean during the process of dedifferentiation was investigated. The explants obtained from aseptically germinated seedling were transferred to callusing medium containing MS salts supplemented with 9.0 uM (2.0 mgl-1) 2,4-D and 6.9 uM (1.5 mgl-1) Kinetin. Total activity of peroxidase increased in hypocotyl (0.75 to 1.80), cotyledon (0.55 to 1.20) and internode (0.31 to 1.00) during dedifferentiation process with a peak of activity observed prior to callus initiation. In leaf however, there was a sharp decline in enzyme activity (1.42 to 0.30) after excission with a moderate increase (0.96) prior to callus initiation. Electrophoretic pattern of peroxidases were organ specific. The explant of hypocotyl internode and leaf had three band each but with different Rf values. The expant of cotyledon showed only one isozyme. In all the explants marked changes were associated with the process of dedifferentiation. Once the meristematic activity was triggered no further qualitative changes took place in the isozymes. Calluses of all the four explant had only two bands and these persisted during successive subcultures.

Published

Doi:
31(1): 21-29,1999

Adventitious shoot regeneration from hypocotyl explants was examined in Citrullus lanatus Thunb. Hypocotyl explants of 2,3.4,5 and 6 week old seedlings when cultured on LS medium containing BA, Kn, Zip with or without 0.5-1.Q mg/l IAA showed that 1.0 mg/l BA and 1.0 mg/l IAA proved ideal for shoot differentiation from 2 week old hypocotyl explants. Shoots elongated on the medium with 0.5 mg/l GA3 and 0.1 mg/l BA and later rooted on half-strength MS medium containing 1.0 mg/l IBA.

Published

Doi:
31(1): 31-35,1999

The relative morphogenetic response of internodal segments of tomato hybrids viz., Bornia and Royesta was studied at varying concentration of BAP, Kn, NAA and IAA. NAA @ 3 uM/I proved to be better than IAA @ 3 uMI in combination with different PGR regimes of both BAP (0, 3, 6, 9 uM/I) as well as Kn (0, 6

Published

Doi:
31(1): 37-40,1999

An investigation was carried out to estimate genetic variability and level of association of grain yield with its various components, separately in 18 parental lines

Published

Doi:
31(1): 41-53,1999

Photosynthetic pigments, TAN (Titrable Acid Number), proteins, polyphenols and tannin con leaves of 9 species of mangroves viz., Acanthus ilicifolius, A. ebracteatus, A. volubilis, Brownlowia tersa, Bruguiera cylindrica, B. gymnorrhiza, Ceriops tagal, Rhizophora apiculata and Xylocarpus mekongensis found in the mangrove forests of Bhitarkanika and Mahanadi delta of Orissa were estimated chlorophyll content varied from 0.16% in B. tersa to 1.05 % in A. volubilis. Calculated chlorophyIl a:b ratio was minimum (1.23) in C. rugal and maximum (3.85) in A. ilicifolius. The carotenoids as accessory pi also varied from 0.08% in B. rersa to 0.76% in A. ilicifolius. Analysis of variance showed inti interspecific variations in photosynthetic activities. TAN values revealed appreciable variations from 2 32.86 in B. gymnorrhiza and A. ilicifolius, respectively. TAN values showed negative correlatio chlorophyll band carotenoids but highly significant positive correlation was noted with chlorophyIl a among the species. Total buffer soluble protein content in leaf varied significantly from 13.26 % B. cylindrica to 21.05% in X. mekongensis. The quantitative analysis of tannin and polyphenols from the of mangroves showed significant variation ranging from 14.56% to 40.11 % in X. mekongensis and C. tagal and 15.65 % to 38.64 % in A. volubilis and C. tagal, respectively. Statistical analysis of the endogenous polyphenols and tannins showed no interdependence with leaf proteins.

Published

Doi:
31(1): 55-62,1999

Rice (Orya sativa 1. cv. IR-30) was grown hydroponically in growth chambers at 28/23°C day/night temperatures with 14-h photoperiod and quantum irradiance of 450 umol m-2 S-l. Sucrose phosphate ;ynthase (SPS) activity in desalted extracts from 21 days old leaves was measured in saturating and "limiting" ( Pi included) substrate conditions. Evidence is presented that SPS activity via UDP estimation underestimates !the enzyme activity in rice. Substrate UDP-Glc and Fru-6-P saturation curves in presence of G1c-6-P were hyperbolic with apparent Km(UDP-G1c) of 2.7 mM and SO.5 (Fru-6-P) of 1.2 mM. G1c-6-P activated SPS rand apparent Kact was 3.2 mM. Diel SPS profiles indicated that rice SPS was activated in light and this activation was more marked under "limiting" assay conditions. Pi inhibition of SPS was dependent upon suubstrate conditions; being more pronounced in "limiting" conditions. Mannose and Pi feeding experiments rindicated that rice SPS was activated by mannose in darkness and the activated enzyme was not sensitive to Pi. In contrast, SPS from leaves fed with Pi was substantially inhibited when Pi was included in the assay medium. The data suggests that rice SPS may exist in different forms. It may also be possible that P insensitive form is more active in light while Pi sensitive in the dark.

Published

Doi:
31(1): 63-77,1999

Cotton (Gossypium hirsutum L) Cv. MNH-93 was tested to see the differences in rates of cell division betWeen slow-growing and fast-growing roots by maesuring the (Me-3H) thymidine incorporation into DNA. At early 24 and 36 h germination times, the incorporation of (Me-3H) thymidine into DNA was more in long than in short roots. At germination times after 36h, the incorporation was almost the same in the tips of roots of all lengths. Thymidine incorporation values were markedly higher in younger (24-48h) roots than in older (60-96h) roots.

Published

Doi:
31(1): 79-84,1999

Effect of phosphorus deficiency on PMEase activity in cotton, wheat and rice was investigated. Seedlings grown with and without phosphorus added to the growth medium using pNPP substrates at different pH levels showed that PMEase activity in cotton seedlings was 68-69% higher in without and 55-56% with phosphorus added to growth medium than rice and wheat seedlings in pNPP substrate, whereas in 4-MUP substrate PM Ease activity in cotton seedlings was 68-70% higher than those of rice and 61-62% in wheat seedlings. All plant species displayed higher PMEase activity when grown in growth medium without phosphorous than the plants grown in growth medium with phosphorus.

Published

Doi:
31(1): 85-91,1999

Use of Dipterex insecticide showed a decrease in carbohydrate, RNA and DNA contents of Vigna radiata and Vigna mungo with more adverse effects on V. radiata specially at higher concentration of insecticide. An increase in total phenolic content was however recorded in the two test species.

Published

Doi:
31(1): 93-96,1999

An experiment was conducted to study the effects of methanol on the growth and productivity of tomato (Lycopersicon esculentum Mill.) in a sandy soil during 1996 and 1997. Plants were transplanted in the field and sprayed with methanol to run off at 5,10,15 and 20% concentrations at two different intervals starting from the first week followed by a second application after two weeks. MeOH showed no significant effects on plant height, number of branches and leaf area and plant productivity in total yield, fruit mass, fruit volume and total soluble solids. Since methanol had similar or adverse effect on tomato growth and productivity, it should not be recommended as a growth promoter.

Published

Doi:
31(1): 97-101,1999

A field experiment was conducted to evaluate the effect of sowing dates and row spacings on yield and yield components of different soybean genotypes under rainfed conditions. The newly developed test genotypes NARC-V and NARC-III produced significantly higher yield of 4264 and 4262 kg per hectare, respectively, at 45 cm apart rows. The check genotype William-82 gave smallest grain yield. Highest number of pods per plant were observed in NARC-IV and NARC-V, when planted on early date and gradually decreased as the sowing was delayed. The genotype NARC-IV and NARC-V produced highest number of pods when planted at 45 cm apart rows. Number of pods decreased as the spacing was decreased. William82, being a taller genotype, produced taller plants when planted early. Delayed plantings and closer spacings produced smaller plants.

Published

Doi:
31(1): 103-108,1999

Effect of drought simulation (terminal, preanthesis, postanthesis and full irrigation) on grain weight, protein and lysine content in different strains of bread wheat viz., Chakwal, Pavon, AZS-4 and AZS-17 was studied under field conditions. Water stress especially terminal and postanthesis decreased (P< 0.05) grain weight. whereas protein and lysine content significantly (P < 0.05) increased. Correlation between grain weight and protein content was negative and highly significant (r = -0.672, n= 16). Reduction in endosperm due to water deficit could be the probable cause for lower grain weight and enhanced protein content.

Published

Doi:
31(1): 109-114,1999

Cotton leaf curl disease in Pakistan is associated with two whitefly-transmitted geminivirus species named cotton leaf curl virus Pk1 (CLCuV-Pk1) and cotton leaf curl virus Pk2 (CLCuV-Pk2). PCR is a highly specific and reliable technique for the detection of geminiviruses. A protocol has been developed for rapid isolation of a suitable template for PCR. The method is based either on the adsorption of DNA template from cleared lysate on PCR tubes or a rapid minipreparation of total DNA by CTAB method. Similarly, a simplified protocol is used for the isolation of total DNA from individual whitefly which is suitable for PCR amplification. Primers have been designed in such a way that the two geminivirus species are amplified in a single tube by multiplex PCR. In this PCR virus sense primer is common to both viruses in the rep gene whereas the complementary sense primer is specific for either of the two viruses. For CLCuV-Pk1, the reverse primer is designed at the start of C4 ORF gene whereas for CLCuV-Pk2 the primer is designed at the start of rep gene. The two PCR products of about 360 bp (CLCuV-Pk1) and 510 bp (CLCuV-Pk2) are resolved on an agarose gel. A rapid profIle for multiplex PCR was used and completed in 2 hr. The whole process of template preparation, PCR and the detection of PCR product by agarose gel electrophoresis is completed in a single day. The protocol has been used reliably for the detection of cotton geminiviruses in plant and whitefly samples collected from the field.

Published

Doi:
31(1): 115-123,1999

Spontaneous deletion was detected in read-through domain of potato mop-top furovirus (PMTV) RNA 3 of isolate T by reverse transcription-polymerase chain reaction (RT-PCR). PCR amplification of readthrough of PMTV-T and comparison with PMTV-S, a full-length isolate, indicated 700 nucleotides difference in size but no difference in coat protein gene. Sequence analysis of the 5'-end of the read-through gene of PMTV-T relative to that of PMTV-S occurs in 3' -half of the gene and is associated with loss of transmission by the fungus vector, Spongospora subterranea f. sp. subterranea. A mono-fungal S. subterranea f. sp. subterranea was unable to acquire and transmit PMTV-T which had 700 nucleotides deletion in 5'-half of read-through domain of PMTV RNA 3, while PMTV-S with full-length read-through gene was efficiently acquired and transmitted by the same fungus cultures. These results indicated that readthrough gene encoded on RNA 3 is involved in acquisition and transmission of PMTV by its fungal vector, S. subterranea f. sp. subterranea.

Published

Doi:
31(1): 125-136,1999

Cynodon dartyton (L.) Pers., Desmostachya bipinnata (L.) Stapf, Kochia indica Wight, Polypogon monspeliensis (L.) Desf., Sporobolus arabicus Boiss., and Suaeda fruticosa (L.) Forssk. established in well defined patches in saline fields planted with Kallar grass (Leptochloa fusca (L.) Kunth). Water extracts, shoot material of different species decomposing in soil and leachates from soils amended with shoot materials inhibited seed germination and/or growth of Kallar grass to varying degrees. Each species showed allelopathic potential against Kallar grass in one or more tests. Six allelochemicals viz., benzoic, ferulic, caffeic, p-OHbenzoic, vanillic and syringic acids were identified in water and/or hydrolysis extracts of different species. Four of these compounds (present in all species) inhibited seed germination and seedling growth of Kallar grass. Allelopathic influence of invading species and autotoxicity are important factors causing elimination of Kallar grass from weed patches and its decreased productivity in older stands.

Published

Doi:
31(1): 137-149,1999

Relative toxicity of five phenolic compounds and 2,4-D herbicide on seed germination and early seedling growth of Pennisetum americanum (L.) Schumann and the degree of leaching of 2,4-D and benzoic acid in clay loam and sandy soil was studied. 2,4-D @ 10 and 50 ppm caused greater reduction in seed germination and root and shoot growth than the phenolic compounds. The phenolic compounds reduced seed geemination percentage in the order: benzoic acid > p-coumaric > catechol > chlorogenic acid > gallic acid. A similar trend was observed with respect to root and shoot growth. 2,4-D in conjunction with pcoumaric acid and catechol exhibited synergistic effect on the process of germination and seedling growth. In the leaching experiment, greatest toxic effect was observed in the first 2 cm depth and lowest at 6 cm depth. Greater leaching of both 2,4-D and benzoic acid occurred in sandy soil compared to clay loam.

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31(1): 151-161,1999

Arthrocnemum macrostachyum is a stem succulent halophyte commonly found in the intertidal communities in the, tropics and subtropics. The effect of density on the growth of a population of A. macrostachyum in various zones at the Arabian Sea coast was studied. Above ground biomass was low in lower swamp and a change in density has little affect in all zones. Below ground biomass showed a considerable reduction in the upper swamp in comparison to the middle and lower swamp. Height of the plant remained unaffected by density but was substantially reduced in lower swamp. Number of branches and basal area of the plants decreased with increasing density while middle swamp plants showed high basal area and branching.

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31(1): 163-172,1999

Frankia strains isolated from actinorhizae of 7 Casuarina/Allocasuarina species were screened for nodulation and nitrogen fixing ability on Casuarina glauco and C. obesa plants under controlled environmental conditions. Five out of 13 strains were found to induce root nodules on C. glauco with none on C. obesa. Similarly various rhizobial strains were screened for nodulation and nitrogen fixation on 4 Acacia species. Frankia strains CcOI and CcI3 and Rhizobium strains Abal, Ar2-1 and PMA63/1 were checked for sodium chloride tolerance in vitro. Frankia strain CcDI showed tolerance for upto 500 mM NaCI concentration (Ec47 dSm-1 approx.), whereas strain Cc13 was sensitive to even 100 mM NaCI concentration (Ec 9 dSm-fapprox.). The 3 rhizobial strains showed tolerance upto 300 mM NaCI concentration (Ec 28 dSm-le approx.). A morphological and dry weight analysis for the initiation and development of sporangia in Frankia strains CcO1 and Cc13 grown on modified basal propionate medium showed increase in dry weight and number of sporangia fonnation.

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31(1): 173-182,1999

Estimates of nitrogen concentration in cultivated and wild species of 115 leguminous plants of Sindh are reported. The main aim of this investigation was to find relationship between nitrogen contents of nodulated versus non-nodulated legumes, between wild and cultivated legumes and between herbs, shrubs and tree legumes. Nitrogen concentrations of nodulated plants were found significantly higher (p<0.05) than nonnodulated plants. Nitrogen concentrations of cultivated plants were marginally better (p<0.l) when compared with wild plants. Nitrogen contents of herbs and shrubs showed a significant correlation (p < 0.05). This relationship was non-significant between herbs and trees and between shrubs and trees. Nitrogen concentrations of the leguminous plants were also correlated with soil texture, soil pH and nodulation frequency. Nodulation frequency did not bear significant correlation with soil textural type but showed a significant correlation with soil pH (p<0.0l). Nitrogen concentration showed a significant relationship with soil pH (p<0.0l) and with nodulation frequency (p<0.0l). The significance of wild legumes growing in natural ecosystems of Sindh is discussed.

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31(1): 183-192,1999

Codium eiongatum, Cauierpa texijlora and Viva lactuius (green algae) were collected from Karachi coast. High Molecular Weight Crude Elicitor Preparation (HMWCEP) of these plants were obtained by sequential extraction of H2O, dilute NaOH and HCl, ethanol precipitation and freeze drying. Results showed hat yields were high in NaOH extracts ranging from 4.3 - 69.6%. These HMWCEP were chemically anaysed for total sugar, protein, SO4 group and uronic acid content. Elicitor activity was determined in terms of induced browning in Cicer arietinum (chickpea) tissues. Amongst the three algae HMWCEP of Codium elongatum was found the most active elicitor and produced maximum browning after 24 hour incubation at 25°C.

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31(1): 193-198,1999

Of a total of 41 genera and 66 species of red, green and brown seaweeds collected from the rocky shore of Buleji during August

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31(1): 199-210,1999

Melanothamnus afaqhusainii Shameel is characterised by large size of thallus (up to 80 cm) with 7-14 celled thick cortical zone, bearing conical (spindle shaped) propagule-like bodies, up to 365 um long x 100 um broad, consisting of up to 21 tiers of cells and borne only on Polysiphonia-like dwarf branches. It differs from S. somalensis in all these characters.

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31(1): 211-214,1999

Codium saifullahii Nizam., sp. nov., is characterized by flattened thallus and a great variation in shape size of utricles as well as gametangia.

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31(1): 215-218,1999

Amphisolenia Stein is a warm water marine planktonic dinoflagellate (Taylor

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31(1): 219-220,1999

A new combination Phloeosporella salvodorae (Prasad, Singh & Bhatnagar) Abbas, Sutton & Ghaffar is proposed based on Septogloeum salvadorae Prasad, Singh & Bhatnagar.

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31(1): 221-225,1999

TLC technique and plug method were used for the detection of aflatoxin in almond seed. Of the 25 seed samples examined, 5 were found to be contaminated with aflatoxin B1 (5.8-140 ug/kg) which included 2 samples that showed the presence of B2 (7.0-140 u/kg) also. Out of 29 isolates of A.flavus tested, 9 showed the presence of aflatoxin B1 with 1:2 ratio of toxigenic and non-toxigenic strains.

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31(1): 227-230,1999

Sunflower seeds inoculated with Aspergillus flavus reduced seed geemination with greater production of aflatoxin during storage. Use of ammonia gas although reduced seed germination but infection of A. flavus decreased with consequent reduction in aflatoxin production. Use of ammonia gas for 15 minutes was fonnd optimum for significant supression of the production of aflatoxin B1 and 5 minutes for aflatoxin B2.

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31(1): 231-235,1999

Use of Pseudomonas aeruginosa with or without Badyrhizobium sp., significantly reduced Macrophomina phaseolina, Rhizoctonia solani and Fusarium solani infection on mashbean (Vigna mungo (L.) Hepper under green house conditions. P. aeruginosa also enhanced plant growth and showed greater nodulation in mashbean plants.

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31(1): 237-242,1999

Pollen morphology of the family Betulaceae from Pakistan has been examined by light and scanning electron microscope. Pollen grains are generally 3-5-porate, oblate or sub-oblate with scabrate tectum.

Published

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31(2): 243-246,1999

Scarification of seeds of Ducrosia anethifolia (DC.) Boiff., in concentrated sulphuric acid was found most effective than boiling water or ethanol treatment to break seed dormancy. Germination percentage at optimum temperature of 30 °C for seed germination decreased at 1 M NaCI salinity level from 65 to 8 %, this decrease in germination was also observed in the other temperature and salinity treatments giving a lower percentage of germination compared to the optimum. No germination was recorded at 1 M NaCI salinity level at lowest 10 °C and highest 40 °C temperature and also at 0.5 M and 0.1 M NaCl levels. Significant effect of temperature, salinity and their interaction was found on seed germination.

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31(2): 247-252,1999

The importance of seed size in germination, emergence, growth and survivorship was assessed. Seed weight of Acacia nilotica subsp. indica varied from 0.1104 to 0.2490 g per seed with a coefficient of variation of 19.56 %. Larger seeds showed greater rate and final germination percentage compared to medium and small size seeds. Survivorship curves for all three seed size categories approached Deevy type II curves but the curves for medium and small-sized seeds were slightly steeper. Final surviving percentage of seedlings after 120 days was higher for large seeds compared to that of medium and small seeds. Seedling fresh and dry weights after 120 days of growth were greater for the ones developed from large seeds. It is concluded that variation in seed size produces variation in seedling fitness.

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31(2): 253-263,1999

Effect of light and different concentrations of m- and p- isomers of 1-nitrophenyl indole-2-carboxylic acid (NPICA) has been investigated on the germination of Cenchrus ciliaris seeds. Light not only delayed germination of the seeds but also reduced the germination by >62 %. Presence of 15 to 45 ppm of either 1m- or 1-p-NPICA in the germination medium showed a negative effect on seed germination whereas, presence of 30 ppm of either of the two isomers improved germination, albeit slightly and only in the presence of light.

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31(2): 265-270,1999

Heat stress tolerance was studied in cotton (Gossypium hirsutum L.). Callus cultures of two cotton cultivars viz., Coker 312 (cotyledonary-derived) and Acala SJ2 (leaf and petiole-derived) showed significant stimulation in growth at stress temperature of 44 °C for 2 hours after 2 days of pre-incubation at 28 °C followed by 26 days of incubation at 28 °C. Reduction in callus growth at 47 and 50 °C was higher in Acala SJ2 compared to Coker 312. Petiole-derived callus exhibited more heat tolerance than leaf-derived callus. At 50 °C callus tissue turned brown. The relative significance of increases in growth rate at 44 °C and drastic reduction in growth rate at temperatures above 44 °C is discussed in the light of heat induced production of proline, glycinebetaine, heat-shock proteins and killing of some viruses which have been reported to protect plant tissues from damage caused by heat stress.

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31(2): 271-281,1999

Various combinations of plant hormones were tested for canogenesis in different explants of microsperma lentil cultivar Masoor-85. Callogenesis was observed under dark conditions. Calli could regenerate bud primordia and a few buds developed into shoots with leaves when transferred under light conditions. Elongated shoots were cut from the base and adventitious rooting was induced to develop these into pod bearing plants in the field.

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31(2): 283-292,1999

Protoplasts were isolated both from leaf mesophyll tissue as well as from compact globular white embryogenic callus of mesophyll origin in sugarcane (Saccharum spp. hybrid cv. COL 54). Totipotent protoplasts with an yield of 1x106 and1x105 ml-1 with 72 and 68% viability were obtained respectively from mesophyll and embryogenic callus cultures. A heterogeneous population of protoplasts (30-60µm Ø) was obtained from both sources. Protoplasts isolated from compact globular white embryogenic callus were less heterogeneous (30-40µm Ø)and cytoplasmically dense. Of the several protoplast culture methods tried, the best results were achieved using protoplast embedding in agarose-solidified medium. Medium P9 proved good for somatic embryogenesis from mesophyll-derived protoplasts in which further differentiation of somatic embryos was not possible. Protocallus formation from protoplasts isolated from embryogenic callus cultures was achieved in dark using agarose-solidified KPR medium in 16 weeks. Shoot formation was achieved from such protocalluses by further transferring to MS basal medium containing 9µmol (2 mg-1) 2,4D for 8 weeks under 16h photoperiod condition. Transfer of such proliferated callus masses to MS basal medium containing 9.29µmol (2 mg-1) Kinetin + 5.37µmol (1.0 mg-1) NAA and 200 mg-1 activated charcoal for 10 weeks resulted in shoot formation.

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31(2): 293-300,1999

Original chromosome observations of seven species of the genus Centaurea (Sect. Acrocentron) are reported. Of these, counts for 3 taxa viz. C. irritance 'Wagenitz., C. persica Boiss, and C. sosnovskyi Grossh., are new 10 science. Meiotic behaviour of chromosomes and chiasmata frequency are noted here for the first time Basic chromosome numbers for section are x = 10 and x = 11.

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31(2): 301-305,1999

The distribution of heterochromatin on the chromosomes of Vicia hybrida L. (2n= 12), V. hirsuta (L.) S. F. Gray (2n= 14). V. tetrasperma (L.) Schreb, Spic. (2n = 14) and V. sativa L. subsp. nigra (L.) Ehrh._n= 12) have been established with the aid of the C-banding technique.

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31(2): 307-313,1999

Karyotype analysis of four Lilium L (Liliaceae) species viz., L. candidum L. L. martagon L. L.ciliatum P.H. Davis and L. carniolicum subsp. ponticum. (C.Koch) Davis & Henderson distributed in North East Anatolia, Turkey, was carried out. The chromosome number was found to be 2n = 24 in all taxa. The karyotype analysis showed that the karyotypes of these taxa consist of median, submedian, subterminal and terminal chromosomes.

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31(2): 315-321,1999

Studies were carried out to detennine the inheritance and heritability of early maturity and yield traits where 2 high yielding virginia types (No. 334 and 'NC 9') were crossed with an early maturing spanish type (lCGSE-4) of peanut (Arachis hypogaea L.). A field trial with eight generations per cross (P1, P2, Fl, F2, BC11, BC12, BC11S, BC12S) was conducted at two locations in North Carolina during 1989. Analysis of generation means indicated that additive genetic effects were important for yield per plant, maturity index and seed weight in both crosses. Dominance effects were also important for yield per plant, maturity index, seed number and shelling percentage in cross 1but only for maturity index in cross 2. Epistasis was not important for the desired traits in either population. Significant additive effects suggest that effective selection for early maturity, seed weight and yield is possible. Selection for seed weight could be accomplished in the F2 generation in both crosses. Selection for early maturity would be more effective in later generations. Narrow sense heritability (h2) was estimated using variance components in F2 generation and two backcrosses.2 Narrow sense heritability estimates were fairly high for seed number (0.83) and pod length (0.43) in cross 1 and for all the traits except yield/plant in cross 2. The results suggested that selection for seed number, pod length and seed weight is possible in early segregating generations in both the crosses while for early maturity it is possible in cross 2 only. For yield selection would be more effective in later generations. Correlations of maturity with seed number and shelling percentage were positive and highly significant in both the crosses. Maturity was negatively correlated with pod length and seed weight in cross 2. Positive and highly significant correlations for yield per plant with seed number, seed weight and shelling percentage indicated that selection based on any of these traits could indirectly increase yield.

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31(2): 323-335,1999

Nitrogen application at 3 different times using 2 methods was used for increasing nitrogen use efficiency of maize in terms of above ground dry matter and grain yield. Side-drilling with 245 g N/plot at sowing and 123 g N/plot soil-dressed at silking significantly improved the vegetative and reproductive growth of maize except number of grains per cob and harvest index. Nitrogen use efficiency in above ground dry matter yield was positively related to plant height, cob length and above ground dry matter, whereas, nitrogen use efficiency in grain yield showed positive relationship with cob bearing plants per plot

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31(2): 337-341,1999

An appreciable amount of uranium was accumulated by Raphanus sp. growing on heap piles of uranium mine wastes and overburdens in the mining area. About 40 % of the plant samples contained > 5 µg U3 O8 / g on dry weight basis. The descending order of average U content in various plant parts was: leaves > roots > stems.

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31(2): 343-346,1999

Isozyme peroxidase was studied in different varieties of cotton (Gossypium hirsutum) growing at three different locations to detect possible variation in the activity of peroxidase within a variety growing at three different locations, between different cotton varieties growing at a particular location and to identify possible reason(s) of the observed (if any) variation in Pox. activity as measured by the intensity of isozyme bands observed in the extract of the material collected from different areas. Significant differences were observed in peroxidase activity within the plants of a variety growing at a particular location, between different varieties growing at one location, within a variety growing at three locations and between different loci of a variety growing at all the three locations. Isozymic phenotypes of varieties growing at locations III were significantly different from those growing at other two locations. Locus 4b expressed fully at location I and II while it did not show any activity at location III. Also, locus 3b showed maximum activity in varieties growing at location III while there was no activity at this locus in varieties growing at locations I and II. Prevalence of cotton leaf curl virus (CLCuV) disease at location III could be one of the reasons of observed isozymic variation. It was inferred that instead of different varieties, if similar varieties growing simultaneously at all the three locations were studied, it would have been possible to [rod a locus and/or loci which may show effect of CLCuV. Possibilities of success in such studies and their utilization in breeding cotton varieties having resistance agaist cotton leaf curl virus disease are discussed.

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31(2): 347-359,1999

Isozymes of the enzyme peroxidase was studied in different resistant, tolerant and susceptible varieties of cotton growing at a location known as a hot spot for cotton leaf curl virus disease. Plant material used for extraction was collected from the field in the month of September when leaf curl virus disease its peak and the results were compared with those obtained in July when disease intensity stays in 50 to 80%. Significant differences were observed in the Pox. activity (as measured by the intensity;) exhibited by different loci in different varieties while among different varieties, variation in mean activity of 7 loci was generally not significant. In most of the cases, Pox. activity increased with in virus intensity from July to September. The differences due to locations in Pox. activity exhibited specific locus in a variety were mostly non-significant in September compared to July when they were not. When differences in mean Pox. activities of 3 varieties growing simultaneously at three locations onth of July and September were compared, significant increase in the activity was observed at locus 1 in varieties growing at location-1 while locus 7 exhibited progressive decrease in the activity at location 111. The mean varietal Pox. activity increased in all the varieties and at all the 3 locations but the differences were not significant. Prevalence of cotton leaf curl virus at location-Ill appeared to be positively correlated JS 4a and 6 under low to medium virus intensity while under high virus intensity, locus 2 appeared to lated with increased Pox. activity. Possibilities of using Pox. activity as marker for selection of to be cultivated under the areas of high disease intensity are discussed.

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31(2): 361-370,1999

The circumscription of Gelidium pusillum (Stackhouse) Le Jolis has been discussed and a new taxon G. pusillum var. pakistanicum Afaq-Husain et Shameel is described. The vegetative, anatomical arid reproductive structures of the Pakistani populations of this species have been investigated in detail. The new variety showed distinctive characters as turf or cushion forming habit, the primary erect fronds being teretocompressed below and becoming flat in the upper half, plants up to 11 mm in length appearing distinctly segmented under microscope, random arrangement of surface cells as well as of tetrasporangia borne on stichidia-like structures as well as on the tips of branch fronds, presence of rhizines in abundance and sexual plants not being present. This species has also been compared with G. usmanghanii Afaq-Husain et Shameel.

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31(2): 371-382,1999

A new species. Codiurn gerloffi has been described from the coast of Pakistan, which differs from other species of the genus in being unusually flat in form.

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31(2): 383-386,1999

A pot experiment was conducted to study the tolerance induced by vesicular arbuscular mycorrhizal fungi (VAM) and effective microorganisms (EM) in chick pea (Cicer arietinum L.) against allelopathic stress caused by aqueous leaf extract of Syzygium cumini (L.) Skeels. The adverse impact due to aqueous leaf extract on plant vegetative and reproductive growth and shoot nitrogen content was significantly reduced by the application of EM and VAM, Co-inoculation of EM and VAM was found more effective than inoculation with either alone. However, reduction in shoot phosphorus content due to allelopathic stress could only be compensated by VAM inoculation alone. VAM colonization was stimulated by EM application.

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31(2): 387-396,1999

Efficacy of three strains of Pseudomonas aeruginosa multiplied on wheat bran, rice husk and saw dust evaluated in the control of soil-borne root infecting fungi under screen house and field conditions. Wheat was found as a good substrate for mass multiplication of the bacterium as compared to saw dust and rice husk, Wheat bran inoculum of P. aeruginosa strains significantly (p < 0.05) controlled infection of Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani on cotton under green house and also on sunflower, soybean, uridbean and cotton under field conditions with enhancement in plant growth. Bacterial antagonists showed better biocontrol and growth promoting effects in the screen house as compared to their use in the field.

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31(2): 397-405,1999

Ten new species of Coniothyrium on Salvadora spp. viz., Coniothyrium pakistanicum, C. oblongatum, undulatum, C. maqsoodii, C. ismailii, C. suttonii, C. sultanii, C. sivanesanii, C. punithalingamii; C. truncatum and an already reported Coniothyrium salvadorae are described, illustrated and compared with related taxa.

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31(2): 407-436,1999

During a three year survey (1996-99) of betelvine fields in Karachi and Thatta districts of Sindh and area of Balochistan

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31(2): 437-443,1999

Mustard (Brassica campestris L) is an important oil seed crop of Pakistan cultiated over 3,53,900 ha giving an yield of 2,85,600 tonnes annually (Anon.

Published

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31(2): 445-446,1999

On a loam soil having pH of 8.0., water requirements, dry matter accumulation, yield performance, water use efficiency (WUE) and economics of mashbean (Vigna mungo) were studied during kharif 1992 and 1993, at the National Agricultural Research Centre, Islamabad. Water requirement for mashbean growth cycle varied depending upon season, potential evapotranspiration (ETo) and crop coefficients. It ranged from 332.8 mm to 357.8 mm from sowing upto its maturity during 1992 and 1993, respectively. Overall under agroecosystem of Islamabad, rainfall was surplus than water requirements of mashbean. Dry matter (DM) accumulation vs days after planting (DAP), showed sigmoid response curve, Maximum crop growth rates were 15.8 g m-2 d-1from 50 DAP to 79 DAP during 1992 and 21.4 g m-2d-1 from 58 DAP to 77 DAP during 1993, Mashbean produced seed yield of 1147 kg ha-1 (Average of two seasons). Mean water use effeciency of both seasons was 3.4 kg/ha/mm. Net monetary benefits of Rs. 5788 per hectare could be obtained by sowing mash bean under rainfed ecology.

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31(2): 447-454,1999

A pot experiment was conducted to study the effect of water stresses on the growth features of maize (Zea mays L.) cultivars viz., Amper pop, Bomali, Suvra, Sadaf and Sayar II. The treatments were with soil moisture (control), constant drought, constant saturated soil moisture and waterlogged conditions of soil. The growth features were plant height, base diameter, leaf number and total life span of the plants height, base diameter, leaf number and total life span were severely affected by drought and waterlogged conditions in all the test cultivars with significant effect in drought than under waterlogged. There were little adverse effects in saturated soil moisture condition. Within the treatment, different cultivars suffered at different magnitude. Amper pop was more resistant to both drought and waterlogging as compared to other cultivars.

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31(2): 455-460,1999

A.H, KHAN, S.M. h-.11JJTA4BAA ND B. KHANZADA

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31(2): 461-468,1999

Ionizing radiation was successfully utilized to develop the mutant variety Jajai 77-30 with reduced plant height and high grain yield from a commercially grown aromatic variety Jajai 77. About 22 % reduction in plant height was recorded in the mutant variety Jajai 77-30 compared with its parent variety. The data of zonal and national trials indicated that the mutant variety Jajai 77-30 had significantly higher (P< 0.05) grain yield than the commercial varieties viz., Jajai 77, Basmati 370 and Basmati 385. The mutant variety Jajai 77-30 yielded 3781 kg/ha during 1990 and 4232 kglha during 1991 in the National Uniform Rice Yield Trials, securing second and first positions, respectively. This mutant has been named as "KHUSHBOO 95" and also released as a rice variety in 1996 for general cultivation in the province of Sindh.

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31(2): 469-474,1999

A pot experiment was conducted using six rice varieties viz., NR-I, IR-6, NIAB-6, KS-282, Basmati 370 and Basmati-385 to determine their yield potential and quality under non-saline (1.7 dS m-1) and saline condition (10 dS m-1) by adding appropriate amount of NaCI salt. Basal dose of NPK and ZnSO4 respectively was applied. On an average, the grain yield of rice varieties was reduced by 30% with salinized soil over the normal soil whereas, protein content in rice grain was greater on salinized soil. Among the varieties, NIAB-6 gave better performance with improved grain yield as well as protein contents of both straw and grain.

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31(2): 475-479,1999

Research on Plant Viral Diseases in Pakistan - Bibliography and Abstracts. 1999. Compiled by: Saif Khalid. Plant Virology Programme, National Agricultural Research Centre, Islamabad 45500, Pakistan. e-mail: saif@pvirol.sdnpk.undp.org ISBN 9969-8497-00-5. viii+215 pp. Price (including postage): Rs. 300 (in Pakistan), $ 20 (outside Pakistan).

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31(2): 481-,1999

Pollen morphology of the family Flacourtiaceae has been examined from Pakistan by light and scanning electron microscope. Pollen grains are generally radially symmetrical, isopolar, tricolporate, zonoaperturate, prolate with reticulate tectum.

Published

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32(1): 1-3,2000

Pollen morphology of Galanthus e/wesii Hooker (Amaryllidaceae) was examined by light, scanning and transmission electron microscopy. It was compared with that of members of Galanthus ikariae Baker and G. rizehensis Stem.

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32(1): 5-6,2000

cp DNA variations were examined in 16 species of 7 genera of the tribe Polygonatae for 50 probe-enzyme combinations to study phylogenetic relationship among genera and species. The shared fragments were counted, index of similarity and distance matrix calculated. The study supports the idea against mono-phyly of Polygonatae sensu lato. The results suggest that there are three monophyletic groups within Polygonatae sensu lato. Group I with genera Maianthmum, Smilacina and Disporopsis; group11with Uvularia and Disporum and group III with genera Prosartes and Clintonia. The differences between each group (estimated F value x 100 were 5.88-7.8 for group I and 11, 4.8-6.6 for I and III and 3.4-5.61 for II and III. The distance within the genus Prosartes was 0.33-0.84, while it differed from Disporum in 3.4-5.52. The difference of Prosartes from Clintonia was 2.2, while between Disporum and Uvularia as 1.63-0.171. The RFLP studies turned out to be concordant to morphological data. The present findings support lumping of Smilacina in Maianthemum.

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32(1): 7-14,2000

AFAQ-HUSAIN S, SHAMEEL M

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32(1): 15-26,2000

Ten species of Discomycetes viz., Bulgaria inquinans Fr. , Geopyxis alpina Fr. , Helvella atra Holmskj ex Fr., H. cupuliformis Dissing & Nanuf., H. elastica Bull. ex St. Amnas, H. villosa (Hedw. ex Kze.) Dissing & Nanuf., Humaria hemisphaerica (Wigg ex. Gray) Fckl., Sarcoscypha occidenta lis (Schw.) Sacc., Scutellina scutellata (Fr.) Lambotte, Trichophaea cupulata Paut., are described and illustrated from Himalayan moist temperate forests of Pakistan. Of these, B. inquinans, G. alpina, H. cuputaformis and Trichophaea cupulata are new records from Pakistan. Discomycetes, the cup fungi, are the most common type of fleshy ascomycetes. At least 175 species of Discomycetes are known from Pakistan (Ahmad

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32(1): 27-34,2000

A new species of Sphaeropsis karachiensis from Salvadora oleoides is described, illustrated and compared with allied taxa.

Published

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32(1): 35-39,2000

A new species of Sphaeropsis karachiensis from Salvadora oleoides is described, illustrated and compared with allied taxa.

Published

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32(1): 35-39,2000

Anthracnose disease of betelvine caused by Colletotrichum capsici was more frequently detected in Karachi as compared to Thatta and Hub regions of Pakistan. Colletotrichum gloeosporioides was isolated only from infected plant samples collected from Karachi. Use of Benomyl and Topsin-M significantly reduced anthracnose disease.

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32(1): 41-44,2000

Two Polymerase Chain Reaction (PCR) specific primers, ASCO1 and ASCO2 were developed for the detection of Ascochyta lentis from infected lentil seeds. PCR amplification with primers ASCOI and ASCO2 resulted in amplification of an approximately 400bp product with A. lentis and A. rabiei isolates but not with A. fabae and other lentil pathogens viz. , Sclerotinia sclerotiorum, Stemphylium botryosum and Colletotrichum lindemuthianum. The specific primers were amplified with the whole DNA of the A. lentis infected seeds but not with healthy seeds suggesting that the specific primers will provide a valuable tool for accurate and quick detection of A. lentis in lentil seeds.

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32(1): 45-56,2000

Eleven R plasmids isolated from enteric bacteria were studied for their transfer and stability in plant associated bacteria to use them as vehicles for In vivo genetic engineering. The bacteria of plant origin viz., Xanthomonas, Erwinia, Citrobacter, Rhizobium, Agrobacterium and Pseudomonas used as recipients and the R plasmids used included pFK2, pFK6, pFK7, pFK8, pFK20, pAS72, pNJ15, pNJ18, pFK5a, pFK17 and pFK18. The R plasmids which carried resistance to one or five different antibiotics were tested for their conjugal transmission from enteric bacteria to the bacteria of plant origin. Two of these R plasmids viz., pFK6 and pFK7 could be conjugally transmitted to four different bacteria of plant origin whereas, pFK2 could be transmitted to three and the rest could be transmitted to two or one plant associated bacteria. Most of the R plasmids were found to be stably maintained after their transmission into the bacteria of plant origin indicating that they could be used as vehicles for In vivo genetic engineering of these bacteria.

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32(1): 57-64,2000

Field studies were conducted in 1997 at Central Cotton Research Institute, Sakrand to evaluate useful heterosis in seven hybrids derived from glandless cotton varieties crossed with local advance strains against two commercia! varieties NIAB-78 and CRIS-9 in respect of seed cotton yield per plant, number of bolls per plant, boll weight, ginning outturn percent, staple length and uniformity ratio. Six hybrids yielded more seed cotton and number of bolls per plant than both commercial checks NIAB-78 and CRIS-9, All hybrids produced heavier bolls and five gave more ginning outturn percent than both the check varieties. As regards staple length and uniformity ratio, all the hybrids measured longer staple and produced more uniform fiber than both the checks. The maximum heterosis for seed colton yield per plant of 39.7 % was observed against NIAB-78 and 32.8% against CRIS-9.

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32(1): 65-68,2000

Four population of maize drived from a broad based population CIMMYT 31 on the basis of silking and black layer formation after four breeding cycle were evaluated for 10 quantitative characters. Significant improvement alongwith expected transgressive segregants for maturity and yield potential was observed and suggested to be exploited for maize production. Major emphasis was given to develop different populations on the basis of maturity phases and correlation of BLF with other physiological and agronomic charaters revealed significant association of BLF with silking in EE, EL and LE populations but insignificant correlation in LL. The characters like Kernels per row, grain weight, kernels per plant, grain yield and leaf area did not exhibit any significant association between BLF and other yield contributing characters which might be due to linkage among genes responsible for phenotypic expression of these characters which can be broken by using selective diallel following recurrent selection. There was a reduction in grain yield in early population whereas, high variance observed in LE population alongwith early maturity suggested a potential source for earliness and high yield which could be attained by repeating more breeding cycles and finally to develop a composite variety within each population especially in LE population.

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32(1): 69-75,2000

Homogeneous seeds of Oriental mustard cv. Agati Sarhein (Brassica juncea Coss.) were treated with different doses of gamma rays (750 to 1250 Gy) to induced genetic variability for the selection of genotypes with improved agronomic traits. Seventy-five useful mutants selected from M2 generation were tested in progeny rows to confirm the stability of genetically altered economic traits in M3 generation. Thirteen mutants with promising performance for yield and yield components were evaluated in preliminary yield trial. Five mutants produced significantly (P<0.05) higher yield than parent.

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32(1): 77-83,2000

The stability for yield performance and genotype x environment (GxE) interaction was studied in 12 wheat genotypes grown at 13 contrasting sites (12 in Sindh and one in NWFP) over two years. The combined analysis of variance over all environments revealed a highly significant (P< 0.01) difference for genotypes, environments and genotype x environment interaction. An adaptation analysis was applied to estimate the b, s.e. (b) and deviation from regression coefficients (S 2d) for each genotype. The genotype SI90157 produced the highest mean yield over all the environments showing wide adaptation and stability. Genotypes PN90111; Anmol 91, SP89126 and SH8921 gave the lower mean yield over all environments with high value of s.e. (b) and s2d. The line SI88126 gave higher yield particularly in high yielding environments showing weak stability. The utilization of stable genotype SI90157 in the breeding programme for the evolution of new high yielding variety has been suggested.

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32(1): 85-91,2000

A declining trenld in per hectare yield of sugarcane in Nawahshah is being observed since 1992. Soil samples collected from Nawabshah, Padedan and Sakrand when analysed for soil properties and some macro and micro nutrients showed that the soil is highly deficient in organic matter (X = 0.35% ) and phosphorus (X = 6.2 ppm). Soil pH was found to be 8.35 inldicating its alkalinily. Sodium was found to be the dominant cation (X =950 ppm) affecting electrical conductivity (7.71 millimohs/cm). Mean exchangeable sodium percentage and sodium absorption ratio were 5.4% and 9.5 millimol / L respectively. The soils were found to have sufficient potassium (X = 500 ppm), calcium (X = 10500 ppm) and magnesium (X = 3500).

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32(1): 93-100,2000

NAZIR A. DAHAR, M.H. KHANZADA AND RAZIULLAH KHAN

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32(1): 101-104,2000

From the chloroformlic extract of Gentiana olivieri plant, two alkaloids gentianine and gentianadine were isolated and their structures established on the basis of spectral data and by comparison with the known compounds. Brine shrimp (LC50) bioassay of the crude extract and the pure compound was found to be nontoxic.

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32(1): 105-109,2000

Exogenous and endogenous abscisic acid (ABA) play a preventive role in the germination of seeds (Bewley & Black

Published

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32(1): 111-114,2000

Wheat seeds of two different cultivars viz., Inqalab and Pasban, pretreated in water for 2, 6

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32(1): 115-119,2000

Changes in carbohydrate content in olive during fruit ripening in on and off years showed that contents of fruit soluble sugars during fruit development increased up to 90 days after fruit set and then decreased during fruit ripening up to 120 days. A marked temporary increase was evident at the beginning of fruit color changes. The content of reducing sugars in fruit were considerdbly higher than that of non-reducing ones. In leaves the amount of non-reducing sugars was higher than that of reducing ones. During on-year, content of soluble sugars decreased after a primary increase whereas during off-year a different pattern was observed. Glucose, fructose and mannitol, main sugars df soluble fraction of fruits were in decreasing order. Changes of glucose and fructose content were contrary to each other up to 135 days after fruit set, thereafter concom- itant to decrease of glucose and fructose, mannitol content increased. In leaves, mannitol, glucose and fructose are the major components of soluble sugars, with different pattern during on-and off-years where the content of mannitol in off-year was lower than that of on-year. Insoluble sugars of fruit and leaf in off-year were higher than that of on-year. The main constituents of this fraction after hydrolysis were glucose, rham- nose, arabinose, fructose, galactose, ribose, xylose and mannitol, in different amounts. Glucose was the major sugar of fruits in most cases.

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32(1): 121-129,2000

Mucilage content and its sugar composition in leaflets of 15 species of Astragalus from Iran were examined. The mucilage content of different species varied from 3.44 to 23.56% dry weight. Mucilage content in some of the species of this genus is comparable with that of the richest sources of mucilage. The mucilages obtained from different species, all showed the presence of glucose, galactose, arabinose, xylose, fucose and rhamnose but in different amounts. In mucilages of 1.2 species glucose was the major monosaccharide and in 3 species galactose was the main constituent. The uronic acids were detected in 12 of the 15 species.

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32(1): 131-140,2000

Floral parts of Crocus sativus L., were cultured on MS medium supplemented with various concentrations of kinetin and naphthalene acetic acid. Excised explants from style, perianth, stamen filament and ovary showed different reactions in vitro. Stigma-Iike structures appeared at different frequencies directly or indirectly through meristematic tissue on colourless style and perianth explants. Direct stigma-Iike structures were frequently produced in the form of bunched groups and intensely pigmented at the basal cut ends of colourless style and perianth explants. Indirect stigma-like structures usually regenerated in large numbers on the surface of the calli and up to 100 per explant were obtained on colourless style explants in medium containing 5 mgl-1 of kinetin and 5 mgl-1 of naphthalene acetic acid. After successive subculturing or continuous cultures on solid media, complete or incomplete neoformed floral buds formed on colourless style and perianth explants in media with high concentrations of kinetin. At higher concentrations of both kinetin and naphthalene acetic acid many indirect stigma-Iike structures were also produced on stamen filament and colourful style explants.

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32(1): 141-150,2000

Avicennia marina is the most dominant species among mangroves found in the lndus delta, Pakistan, alongwith a few populations of Aegiceras corniculata, Rhizophora mucronata and Ceriops tagal. Propagules of Avicennia marina collected from the lndus delta were grown in pots containing sandy soil that were subirrigated with 0

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32(1): 151-169,2000

Variation in composition, strucrure, plant biomass and net primary productivity was analyzed in a grass dominated sandy desert community of Lasiurus scindicus Henr., and Cenchrus setigerus Vahl., situated within the campus of University of Karachi. Pakistan. Life form indicated a thero-hemi-cryptophytic/geophytic flora. Phytosociological parameters of vegetation were srudied at monthly interval from June 1990 to June 1991. The density as well as live biomass-based diversity of the community was generally low and dominance high. The live-biomass-based diversity varied seasonally and was the function of precipitation and soil moisture. On the advent of rain in August with the increase in diversity, the relative abundance pattern tended to approach log-normal distribution which was otherwise geometric. The density-based diversity declined after August rains largely due to very high density of Tragus roxburghii (1327 plants.m-2), a small graminoid, which created the condition of very high dominance concentration.

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32(1): 171-210,2000

Fecundity of three Rhynchosia minima populations was compared. The old-field population exhibited highest fecundity as well as average reproductive output weight, followed by the population existing in a vacant lot while the population in a natural undisturbed shrub-dominated community showed lowest fecundity and average output weight. Variation in seed weight within and between populations was demonstrated. The implications of seed size variation are discussed. Seeds have water impermeable seed coats and thus they have physical dormancy. Physical scarification with sand paper was more effective in breaking seed dormancy than chemical scarification with hydrochloric acid. Dry heat treatment (50oand 70oC) markedly increased the germination percentage. Under field conditions dry heat during summer apparently breaks seed dormancy thereby allowing the seeds to germinate in considerable numbers after rain showers. Greater germination percentage was observed in light compared to dark. Final germination percentage varied with temperature (25o- 40oC) with the optimum at 35o. Significant inhibition of germination occurred at 6, 7, and 8 bar NaCI salinity, while in polyethylene glycol (PEG 4000) germination was reduced at 7 and 8 bar. At iso-osmotic concentrations PEG 4000 caused lesser inhibitory effect compared to NaCI salinity.

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32(1): 211-226,2000

Gawatar Bay located at Pakistan-Iranian border facing Gulf of Oman serves as a connection between mangroves of the Gulf area and N.E. Arabian Sea of Pakistan. It forms the westernmost part of the coastal belt of Pakistan, the climate of which is maritime desert type. Only one species Avicennia marina (Forssk.) Vierh, prevails in the Bay as in the Arabian Gulf and the adjacent Kalmat Khor. Their vertical zonation pattern of different size groups is not regular but disturbed, The major problem facing the mangroves is excessive harvesting, which stems from the socio-economic set up of the local people residing in the area.

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32(1): 227-234,2000

Algal specimens collected from Hawkesbay sandy beach and Buleji rocky coast of the Arabian sea, 40-50 km from the Karachi University Campus showed the presence of a new cylindrical species of Codium which is described as Codium islamii Nizamuddin and named after Prof. Dr. A.K.M. Noorul Islam of the Department of Botany, University of Dhaka, Bangladesh for his devotion and contribution in the field of Phycology.

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32(2): 235-238,2000

Camarosporiopsis Abbas, Sutton & Ghaffar gen. nov, and C. cuppuridis (Ahmad) Abbas, Sutton & Ghaffar com nov., on Capparis decidua, based on Camarosporiopsis capparidis Ahmad are described, illustrated and compared with related taxa.

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32(2): 239-246,2000

Septoria salvadorae Abbas. Sutton & Ghaffar sp.nov., on Salvadora persica is described,iIllustrated and compared with related taxa.

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32(2): 247-250,2000

Of the 17 species of fungi, Macrophomina phaseolina, Fusarium moniliforme, Rhizoctonia solani and maize stem borer Chilo partellus, were found predominantly associated with stalk rot disease of com in different parts of Pakistan The bacterium Erwinia chrysathemi pv. zeae was found only in samples collected from Punjab and N.W.F.P areas of Pakistan.

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32(2): 251-253,2000

The present study is concerned with the optimization of different cultural conditions for the production of L-DOPA from L-Tyrosine by surface culture technique. Of the 12 different isolates of Aspergillus oryzae tested, for production of mycelium, strain ISB-9 was found to give maximum yield of L-DOPA (0.34 mg/ml) L-DOPA production was maximum at pH 3.0 of the reaction mixture, 50oC, 50 minutes and 2.5 mg/ml, optimum temperature, time and L- Tyrosine concentration, respectively.

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32(2): 255-258,2000

Anatomical investigations on 8 cultivars of rice (Oryza sativa L.), four from each of the traditional (local) and modem (high yielding) cultivars, were carried out to study the variation among the cultivars. The epidermis is single layered having cuticle of varying thickness. The number of hypodermal layer is more in modem cultivars compared to traditional ones. The vascular bundles are of two types, outer (small) and inner (large), in all the cultivars except Madhabshail-boro where additional median (medium) type is present in between outer and inner bundles The number, position and arrangement of vascular bundles vary among the cultivars. The outer vascular bundles are embedded in the hypodermis and found to push outwards forming outgrowth of different shapes in all the cultivars except BR7 and BR3 where the wavy appearance in outer circumference of the stem is present. Some of the inner vascular bundles are attached or nearer to the 11 hypodermis while the rest are away from it. The hollow pith is found to be smaller in modern cultivars compared to traditional ones. The higher number of mechanical tissues (hypodermal cells and inner vascular bundles) in modern cultivars imparts resistance to lodging.

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32(2): 259-264,2000

Effects of NaCI salinity at different growth and developmental stages on ions accumulation in two wheat cultivars were studied in greenhouse conditions. Concentrations of Na + in leaves and roots of Ghods, a salt-sensitive cultivar, were more than that of Boolani, a salt-resistant cultivar. K+ and Ca2+ contents were found to be less under NaCl treatments. This loss increased with increasing salinity and was markedly higher in Ghods than in Boolani There were significant differences between the cultivars with respect to ion absorption and translocation indicating that the cultivars may give genotype dependent responses under salinity stress conditions.

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32(2): 265-271,2000

The germinable seeds in the seed bank in the uppermost two centimeter layer of the soil of Rawdhat Khorim in the Riyadh region of Central Saudi Arabia was studied using 1250 cm2 soil samples collected in winter season from three line transects. The seed bank composition was determined using germination experiment. Most of the seedlings emerged in the first three weeks. The final number of seedlings ranged from 18 to 1190/m2. The floristic composition of the emerged seedlings consisted of 56 plant species. There was a compositional difference in the emerged seedlings between sites having different soil texture. Biomass of the emerged seedlings ranged from 2.14 to 51.8 g/m2 depending on the seedling density and soil texture.

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32(2): 273-282,2000

Eryngum paniculatum (Apiaceae-Saniculoideae) is of great importance in the north region of Argentina where it is invading abandoned fields. The studies evaluate the dispersion of the species and present spatial orientation for the collectors of seeds of this species.

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32(2): 283-288,2000

A experiment was carried out to detennine the relationship between the seed weight and the distance they fall from the mother plant when they disseminate There was an inverse relationship between the number and weight of seed and the distance from the mother plant. Greatest weight were registered between 0.25-0.40 m and there were no seeds further from the mother plant inspite of them being smalll and easy to disseminate.

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32(2): 289-292,2000

Cousinia mozaffariani is described as a new species from southern Iran. This species is related to Cousinia barbeyi from middle Zagros (Saverz Mountains) in Iran.

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32(2): 293-294,2000

Pollen morphology of 6 endemic taxa in the genus Helichrysum Gaertner (Compositae) has been investigated using light and scanning electron microscopy. The pollen grains of all the Helichrysum taxa are similar in that they are tricolporate with spines and rugulate ektexine sculpturing. They are spheroidal, prolate-spheroidal or oblate-spheroidal in shape.

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32(2): 295-301,2000

Pollen grains of 12 species and 3 varieties of the genus Ebenus L., (Leguminosae: subfamily papilionoideae have been examined using light microscopy (LM) and scanning electron microscopy (SEM). Pollen description of each taxon has been given. Pollen grains of Ebenus L., species examined are radially symmetrical, isopolar, tricolpate, prolate rarely perprolate, Their ornamentations are reticulate. The exine structure are similar, ektexine thicker than endexine. The pollen morphology seems to be very similar to each other.

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32(2): 303-310,2000

Cytological study of 8 Iranian species of Cousina section Cynaroideae (Asteraceae) was carried out. The basic chromosome number is x =12 and all of the studied plants were diploid. The western parts of Iran seems to be the center of diversity and origin of Cousinia section Cynaroideae.

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32(2): 311-316,2000

The wild wheats of Iran are considered as original genetic sources that could be used for improvement of the cultivated wheat Triticum boeoticum ssp, thaoudar (syn. Triticum thaoudar) and its associates, as one of the best living collection of the wild wheats, could play a major role in this regard. The distribution of Triticum thaoudar and its associates are described.

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32(2): 317-322,2000

Genetic selection indices were studied for six productive traits in two varieties (S-9 and S-95) of Brassica juncea and four varieties (Canola-l,II,III and Canola standard) of B. napus. Correlation analysis indicated that seed yield/plant had strong positive association with plant height, branches/plant, siliqua/ plant, seeds/siliqua and dry matter yield/plant. Path analysis and selection indices also confirmed that all the traits contributed significantly towards seed yield/plant. The direct and indirect effects were found to be regulating the character association in all the traits. Magnitude of genetic and phenotypic variance ranged between 0.555 (seed yield/plant) to 960.63 (siliqua/plant), respectively. Heritability (b.s) showed high estimates (ranging from 97.70% to 60.24%) for all the traits, indicating the involvement of additive gene action. Dry matter yield/plant, seeds/siliqua and plant height exhibited low genetic advance irrespective of their high heritability estimates, probably due to non-additive gene (dominance and epistasis) effects. On the basis of selection indices, it is concluded that branches/plant and siliqua/plant are the most important yield components, therefore, selection based on these traits could be exploited for the improvement of yeild in present genotypes.

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32(2): 323-330,2000

A new species Foveostroma salvadorae on Salvadora oleoides is described, illustrated and compared with related taxa.

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33(1): 1-6,2001

A field trial was conducted at NIA experimental farm, Tandojam, Pakistan to study the effect of different Rhizobial strains on the survival and growth of two Australian Acacias viz., Acacia ampliceps and Acacia stenophylla under saline condition. Inoculation of tree seedlings improved survival and growth of both Acacia species as compared to uninoculated ones. A. stenophylla showed higher survival as compared to A. ampliceps, whereas the over all performance of A. ampliceps was much better. A. ampliceps inoculated with rhizobial strain no. 63/1 showed greater plant height, stem diameter and plant canopy followed by 403/1 and 399/1. Performance of tree seedlings with the application of 100 mg N/kg of soil alone were better as compared to two strains of Rhizobia. A. stenophylla, inoculated with strain no. 403/1 proved better for its symbiotic partner followed by 63/1. The uptake of nitrogen by plant also increased in inoculated plants but the values for N-content in seedlings without N application were higher.

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33(1): 7-11,2001

Morphology of pollen grains of 13 species (3 of which are endemics in Turkey) belonging to nine sections of the genus Silene L., (Caryophyllaceae), collected from Northwest Anatolia in Turkey, was investigated using light, scanning electron (SEM) and projectina screen scale microscopy. The pollen grains were pantoporate, spheroidal and semitectate with perforations, spinulose exine. S. rhynchocarpa Boiss., with highest number and S. otites (L.) Wibel with lowest number of pores have the right taxonomical positions. The taxonomical position of S. compacta Fischer and S. dichotoma Ehrh. subsp. sibthorpiana (Reichb) Reich., which have flowers forming heads and are monochasial is disputed because they have lower pore number in relation to the other taxa, although they have other phylogenetically advanced characteristics.

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33(1): 13-25,2001

The genus Eryngium has about 230 species distributed in temperate and subtropical zones of Europe and America. In South America the genus is presented in Bolivia, Paraguay, Uruguay, Brazil and Argentina. In the northwest of Argentina and specially in Tucumán province, Eryngium elegans Cham. et Schlecht is one of the aggressive weed that affects pasture areas as well as economically important crops like sugarcane. E. elegans is a diploid species with regular meiosis and fertile seeds so that it can easily colonize different ecological areas. The objective of this work was to identify the different populations through the use of isoenzyme patterns of esterases and peroxidases and the application of cluster analysis. Discontinuous vertical polyacrylamide gel electrophoresis was utilized and Jaccard' Similarity Coefficients was used for making the dendrogram. Profiles of peroxidases, showed a characteristic and distinct pattern in all samples, which explains in part, the phenotypic variation found in the population. This was confirmed by the low value of similarity index showed by the dendrogram. In esterases, a common wide band, of different colour intensity was observed according to the locality. Through the difference in the pattern of peroxidases it was thus possible to determine intraspecific variations in the populations which can be used for characterization of samples.

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33(1): 27-34,2001

In vitro shoots of Solanum tuberosum cv 'Spunta' were subcultured on liquid MS media containing 0.0, 0.5

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33(1): 35-41,2001

The green fluorescent protein (GFP) from the jellyfish (Aequorea victoria) has become a vital reporter not only to identify and screen transformed organisms including bacteria, animals and plants but also to study gene expression. A modified form of the green fluorescent protein was expressed in tobacco (Nicotiana tabacum var. Samsun) chloroplasts using both the bacterial as well as chloroplast specific promoters. A number of species-specific promoters have been used to express foreign DNA in chloroplasts, but there is no such report where DNA has been expressed in chloroplasts from bacterial promoters. This is the first report of stable expression of reporter gene (gfp) in chloroplasts using bacterial promoter. The GFP fluorescence was detected only in transformants where the trc promoter used to regulate gfp. In transformants where gfp was under the control of the chloroplast rrn promoter, fluorescence was comparable to controls without an introduced gfp gene. The transformed seedlings gave a green fluorescence after illumination with long-wave UV light. Fluorescence excitation and emission spectra of leaf extracts from the transformed plants confirmed the presence of GFP. Analysis of high expressing lines was carried out using Confocal Laser Scanning Microscopy. Gfp was found as a versatile and sensitive reporter and can be used to study promoters. The bacterial trc promoter appeared to be stronger than the chloroplast rrn promoter in E. coli as well as in chloroplasts of tobacco.

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33(1): 43-52,2001

A new taxon Scinaia moniliformis J. Agardh var. pakistanensis Afaq-Husain et Shameel is described. The vegetative, anatomical and reproductive structures of the Pakistani populations of this red alga have been investigated in detail. The new variety showed distinctive characters as thalli up to 22.5 cm long; deeply constricted into 4-26 mm long ´ 2.0-5.5 mm broad segments; branching di- to subdi-chotomous, from every segment in proximal and at 2-5 segment distances in the distal part of plants; utricles 30-38 mm long ´ 16-21 mm broad; hypodermal cells 5-15 mm broad; carpogonia conical distally, up to 10´4.5 mm; cystocarps up to 320 mm broad. These specimens were found to differ from S. moniliformis growing in Australia and India and, therefore, given the status of a new variety.

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33(1): 53-68,2001

The taxonomy and distribution along with environmental parameters of seven species of the genus Gonyaulax Diesing (Harmful Algal Bloom organisms) including four new records from the Northeastern Arabian Sea have been described from Korangi creek, Manora channel and continental shelf of Pakistan.

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33(1): 69-75,2001

Using the Braun-Blanquet approach

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33(1): 77-91,2001

Development of early maturing and high yielding cultivars of peanut (Arachis hypogaea L.) is a major objective of groundnut breeding programme. To select the best combining parents, three high yielding virginia type cultivars No. 334, Banki and NC-9 were crossed with four early spanish type lines ICGSE-4, ICGSE-130, ICGSE-147 and Chico in a factorial mating design. F2 and F3 generations were evaluated in the field to determine the combining ability of the parents for maturity and other agronomic traits. General combining ability (GCA) estimates were significant for all traits except maturity index in F2 and F3 generations and seeds per 50 pods in F3. Specific combining ability (SCA) estimates were non-significant for all the traits except oil contents in F 2 and pod length in F3 generations. The magnitude of GCA was much greater than SCA for all traits in both the generations indicating that additive genetic variance (GCA) was more important than nonadditive genetic variance (SCA). Among male parents ICGSE-147 gave highest GCA for 20 pod length, seeds per 50 pods while Chico gave best GCA for maturity index. Among adapted female parents NO. 334 gave best GCA for seeds per 50 pod and maturity index while NC-9 gave best GCA for 100 seed weight.

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33(1): 93-99,2001

Pattern of distribution of Na+ and Cl- ions were examined in four moderately salt-tolerant Sorghum bicolor accessions (Double TX, Giza 114, INRA 353 and INRA 133) grown in salinized sand-culture. Analyses for ion content were made on each leaf, pseudostems and roots. Ion content of leaves of different ages differed but not consistently among accessions. Double TX and Giza 114 had the lowest Na+ and Cl- concentration in young leaves and these increased with leaf age. In INRA 353 leaf Na+ and Cl- decreased in older leaves. The Na+ content of pseudostems of Double TX and Giza 114 were similar to those in leaves but in INRA 133 and INRA 353 Na+ ions were markedly higher than in leaves and considerably higher than in Double TX and Giza 114. Pseudostems contained the highest concentrations of Cl- and were similar in the four accessions. Root Cl- concentrations were similar to those in leaves in the four accessions. In terms of relative grain yield, INRA 133 and INRA 353 were found superior accessions than Double TX and Giza 114, and therefore, their potential may be exploited through selection and breeding of plants to effect further improvement in salinity tolerance in sorghum.

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33(1): 101-107,2001

A survey of weed communities was carried out in wheat fields of district Sukkur during 1999-2000. Forty-five weed species belonging to 16 angiospermic families are reported from the study area. Five weed communities viz:1) Lathyrus-Fumaria-Melilotus in Bhit of Noor Shah

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33(1): 109-115,2001

Effect of different salts viz., sea salt, NaCl , CaCl2, NaNO3, MgSO4, MgCl2 and KCl was studied on in vitro growth of Fusarium solani by food poison method. Growth of F. solani was enhanced as compared to control in potato sucrose agar (PSA) medium containing sea salt @ 20,000 ppm but suppressed where sea salt was used @ 60,000 ppm or more. No conidia were produced in 100,000 ppm of sea salt. Similarly, F. solani showed enhanced growth in NaCl at 10,000 and 20,000 ppm and declined with increasing conc. from 30,000 to 100,000 ppm. Growth of F. solani also increased significantly with increasing conc. of MgSO4 up to 40,000 ppm but declined thereafter. Use of NaNO3 @ 10,000 to 70,000 ppm showed significant increase in growth with massive cottony white mycelium as compared to control. Growth of F. solani declined gradually compared to control with increasing conc. of MgCl2 from 20,000 ppm to 100,000 ppm. Similarly, use of KCl @ 20,000 to 40,000 ppm showed gradual decline in growth of F. solani whereas @ 50,000 ppm or more, growth started after 7-days of inoculation. Amendment of PSA with CaCl2 showed gradual decline in growth of F. solani with increasing conc. of CaCl2. Chlamydospores were produced only where NaNO3 was used @ 10,000 to 40,000 ppm.

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33(2): 117-124,2001

A protocol was established for isolation of sugarcane protoplasts, cell wall regeneration and cell division. Protoplast were isolated from cell suspension initiated from fresh leaf calli and produced on agar medium by enzymatic treatment, 4% cellulase

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33(2): 125-132,2001

Quantitative, qualitative and multi-state morphological characters on 350 herbarium specimens from 35 Iranian populations of Hordeum murinum s.l. were examined. Based on the results of this study, the followings were chosen as diagnostic characters: fresh leaf colour, inflorescence density, inflorescence colour at anthesis and maturity, pedicel presence in central spikelet and central floret, ratio of the length of the central spikelet (excluding awn) to that of the lateral ones, shape and colour of the lateral spikelets rachilla prolongation, central spikelet lodicules margin vestiture, ratio of the anther length of the central floret to those of the lateral ones, central and lateral florets anther colour, central floret anthers situation at anthesis, and lateral florets palea vestiture. Regarding morphological diversity, the idea that this group has three distinct species is confirmed. Moreover, Hordeum murinum L., is recorded for the first time from Iran from Bandar-e Abbas and Bandar-e Lengeh. Using morphological characters, two taxonomic keys are provided for the taxa in Hordeum murinum s.l.

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33(2): 133-141,2001

The seed characters of 10 species of Veronica in Iran are described. Six distinct types based on seed features such as shape, surface ornamentation and cell shape are distinguished. A diagnostic key for determination of these taxa is provided. One of the examined species i.e., Veronica davisii, is recorded for first time from Iran. This species is compared with its closest relatives within sect. Veronicastntrum.

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33(2): 143-152,2001

Through selecting new epitypes for incomplete type material of both A. cryptocarpos and A. rechingeri the systematic position of Astragalus cryptocarpos is clarified. It was confirmed that the latter must be reduced under synonymy of the former. Scaning-electron microscopy showed that A. cryptocarpos belongs to A. sect. Acanthophace.

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33(2): 153-155,2001

This study was carried out during the field trips for Turkey's endemic plant seeds collection project where 48 taxa presented in this study were interesting in terms of being known from the type-gathering, their collection long years ago and as topotype, their distribution in very small area, providing data of unknown morphological characteristics in the Flora of Turkey. They are also presented with their threatened categories.

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33(2): 157-166,2001

Karyotype structure of two Iris L., species viz., Iris galatica Siehe and Iris kerneriana Ascherson & Sint ex Baker collected from Central Black Sea Region of Turkey have been analysed. Chromosome number determined is I. galatica 2n=24, I. kerneriana 2n=18.

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33(2): 167-171,2001

A comparative study of total seed storage protein was carried out by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to characterize oilseed mustard [Brassica juncea (L.) Czern. & Coss.] germplasm from Pakistan. Oilseed collections from Pakistan as well as oilseed cultivars from diverse origin were not differentiated from each other nor were vegetable cultivars found to be distinct from one another on the basis of their seed protein patterns. Eight types of protein were recognized based on the banding patterns of 52 accessions. Relative inter-type relationships of protein patterns were estimated using Jaccard's similarity index and a dendrogram showing the hierarchical clustering was constructed by unweighted pair-group method with arithmetic averages (UPGMA). The clustering of eight protein types generally agreed with our previous classification and the limited data already available on inter-accession relationships in oilseed mustard based on morphological traits and RAPD analysis. The differences between the profiles of accessions 'PAK-85835', 'PAK-85839' and 'PAK-85910' supported the idea that they were separate species from B. juncea. The results showed that the technique of SDS-PAGE applied to seed proteins was not feasible to distinguish the closely related oilseed collections and cultivars from each other as they were characterized by the same banding pattern and formed a common gene-pool. However, seed proteins were useful to discriminate B. juncea and B. campestris. It was also possible to distinguish the oilseed mustard from the vegetable form. Future studies should involve a greater number of local accessions of oilseed mustard from other parts of Pakistan, and those of vegetable and condiment forms to further elucidate the situation.

Published

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33(2): 173-179,2001

Inheritance of three isozymes i.e., Leucine aminopeptidase-1, Phosphoglucoisomerase-1, and Phosphoglucomutase-2 in lentil was investigated. The plants were grown in greenhouse and the isozyme analysis was done by starch gel electrophoresis. X2 procedure was applied to test the goodness-of-fit for the observed and hypothesized ratios. All the three isozymes showed a monogenic inheritance pattern with co-dominant alleles for fast and slow allozymes. Heterozygous plants can be recognized at early stages and selfed plants may be discarded immediately. Their use in lentil improvement has been discussed.

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33(2): 181-186,2001

Twelve genotypes of mungbean (No. 7-2, NCM 201, NCM 209, No. 1, NCM 205, AEM 6/20, NM 18, AEM 30/20, NM 93, NM 90, NM 121-25, M 20-24) were evaluated for stability of grain yield under seven diverse environments of Pakistan. The interaction between the genotypes and environments (G X E interaction) was used as an index to determine the yield stability of genotypes under all the environments. The G X E interaction was highly significant and both linear as well as non-linear components were equally important for determining the yield stability. The genotype "NM 90" gave the highest yield with above average regression value and non-significant standard deviation, showing consistently better performance in favorable environments. The genotype "NCM 209" also had high mean yield over the environments and did extremely well under less favorable conditions. The genotypes "No.1" and "NM 18" responded well under favorable conditions as compared to unfavorable conditions. The genotypes "NCM 201", "M 20-24" and "AEM 30/20" had below average yield, whereas their stability parameters revealed above average stability with specific adaptation to unfavorable environments.

Published

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33(2): 187-190,2001

Ten promising genotypes of groundnut were evaluated for their adaptiveness and stability performance at eight different locations during 1997. The G x E interaction was highly significant. The regression coefficients (b) ranged from 0.76 to 1.17 and deviations from regression (S2d) ranged from 0.06 to 0.82. BM-28 and ICGV-86550 showed above average performance, unit slop and non significant deviation from regression and thus are suitable for wide range of environments. Four genotypes, Gori, ICG-7326, CINA and Chinese 68-4 possessed b < 1 and mean performance was also below average hence are suitable for poor environment. Out of all the tested genotypes, ICG-4993 had greater than unit regression coefficient (bi=1.14) and highest significant (S2d) (0.82) indicating its unsuitability for wider cultivation.

Published

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33(2): 191-196,2001

Experiments were conducted to determine the level of ABA, K+ and Ca2+ mineral content and mannitol in the leaves of two lines of wheat (Triticum aestivum L.) under field condition in order to find any relationship between them and the tolerance of the plant against drought stress and to know if we can use one or more of them in determining tolerant or sensitive plant. The resistance of the plants was affected by the studied factors and all of them changed under drought conditions. Both K+ and Ca2+ have an important role in determining the stomatal situation, however, the ratio of K+/Ca2+ may regulate the position of stomata in different conditions. The existence of an inverse relation between this ratio and the rate of mannitol confirms the validity of this hypothesis. When the ratio is low, stomata are closed and when it is higher than the control, the stomata are open. Thus we could suggest this ratio to determine tolerant and sensitive lines, as well as the tolerant or sensitive stages of the plant development.

Published

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33(2): 197-202,2001

Plant transformation is now a routine practice in many laboratories around the world. However it has been observed that sometimes the introduced gene becomes inactive. This inactivation could be reversible or irreversible. In this study the genetic behavior of an inactive transgene was observed. For this purpose a wild type chlorophyll gene CH-42 was introduced into a pale (ch-42) mutant Arabidopsis by Agrobacterium mediated transformation. After transformation most of the plants showed green wild type phenotype. However, some transgenic lines did not show the phenotype of the CH-42 transgene and appeared pale in color. Four transgenic lines showing inactive CH-42 transgene were selected to study the segregation of the inactive transgene in the next generations. These transgenic lines with inactive insert were crossed to the wildtype and the CH-42 mutant plants. The F1 plants produced from these crosses were allowed to self fertilize and some of the seeds of these F1 were germinated for analysis of the F2 generation. The results of the reciprocal crosses of all four inactive lines were similar. The inactivation of transgene CH-42 was irreversible and the cellular gene at the CH-42 locus did not have any effect on the expression of the transgene.

Published

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33(2): 203-209,2001

Thirty four Citrus cultivars were studied for nucellar embryogenesis and for the extent of polyembryony per seed. Ovule weight had no correlation with the number of nucellar embryos. Also seed weight had no correlation with the number of embryos per seed. The maximum and minimum number of embryos per nucellus were in cvs. Kinnow (7.75) and Baramashi (2.23), respectively. Secondary somatic embryogenesis was also studied which was maximum in cv. Kinnow (8.40) and minimum in cv. Baramashi (2.90). Maximum and minimum polyembryony were in cultivars Minneola (7.50) and Orlando (2.75), respectively which indicated that nucellar embryogenesis was cultivar dependent. The soil survival after two months hardening process was maximum in cvs. Minneola (100 %), Shamber (100 %), Foster (100 %), Gada dehi (100 %) and minimum in cv. Baramashi (10.00%).

Published

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33(2): 211-215,2001

A survey of betelvine fields in Karachi and Thatta districts of Sindh and Hub area of Balochistan was conducted during 1996 to 1999 where 38 funfal species belonging to 25 genera were isolated from root and stem of diseased betelvine plants. Of the fungi isolated

Published

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33(2): 217-219,2001

Dr. Abdul Hafiz , an eminent agricultural scientist died of heart attack in Karachi on April 8

Published

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33(3): 221-222,2001

Pollen morphology of 6 species belonging to a single genus Polygala of the family Polygalaceae has been investigated using light microscope and scanning microscope. It is a stenopalynous in nature. Pollen grains usually radially symmetrical, isopolar, prolate-spheroidal to oblate-spheroidal or sub-prolate, polycolporate. Tectum psilate to subpsilate or scabrate often punctate. On the basis of polar length

Published

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33(3): 223-227,2001

A new species of Cytostagonospora yousufii Abbas, Sutton & Ghaffar is described, illustrated and compared with 4 species of Cytostagonospora.

Published

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33(3): 229-232,2001

Somatic hybridization studies were performed using leaf mesophyll as well as homogeneous cell suspension-derived protoplasts. The optimum results were achieved when leaf mesophyll protoplasts from cv. CP-43/33 and homogeneous cell suspension-derived protoplasts from cv. CoL-54 (at 2.0x10 5 ml-1 final density) were used. Polyethylene glycol (PEG) at 35% level was found optimum for maximum protoplast agglutination (32%). Maximum heterokaryon formation (17%) was obtained employing 50 mM l-1 CaCl2.2H20 at pH 10.5 as an eluting solution. The hybridized protoplasts were cultured to monitor the divisions and further growth.

Published

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33(3): 233-238,2001

Eighty eight genotypes of Vigna mungo (L.) Hepper selected on the basis of source/origin were evaluated for agronomic traits and analyzed on the basis of three geographic parameters i.e., provinces, agro-ecological zones and altitude. The differences according to geographical regions proved its validity in substantiating the postulated regions of diversity or gene centres. Migration of landraces into new regions, followed by some degree of contamination by mixture or out crossing with other landraces were observed which might be due to frequent exchange of germplasm or transportation of grains from one place to others. The areas with a high level of stress will present interesting tolerance to environmental stresses, but homogeneous mixtures, and hence needs less extensive sampling for genetic resources for conservation purposes. The study confirmed the existence of a wealth of phenotypic divergence in the local blackgram germplasm. The variation within the country appears largely attributable to different provinces rather than smaller units of crop-ecological zones and altitude intervals. Further collecting missions to main blackgram growing areas with greater diversity could concentrate efforts on sampling as many geographically and ecologically distinct areas as possible rather than collecting extensively from fields close to motorable roads within individual province. The germplasm with high mean values along with medium to high genetic variance should be exploited through simple selection.

Published

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33(3): 239-249,2001

Pea germplasm consisting of 69 pure-lines from diverse origin was evaluated under screen-house and field conditions for 2 years for their resistance against powdery mildew and yield potential. The genotypes viz.

Published

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33(3): 251-255,2001

Somaclonal variation is one of the possible sources of variation in plant breeding. To evaluate the usefulness of somaclonal variation for creating variation in some Iranian cultivars of wheat, changes in proteins and oxidative enzymes in regenerated and seed-produced plants of wheat were studied. Three populations of each plant were used each of which belong to one embroyogenic callus or one ear. Immature embryos from three cultivars of wheat (Alamout, Hyrmand and Maroon),14 days after anthesis were cultured on solid MS medium with 1mgl-1 2,4-D. The embryogenic calli obtained were then transferred to solid hormone-free MS medium to produce plantlets. Seeds of these three cultivars of wheat were also cultured on solid hormone free MS medium. Plantlets obtained from the two above sources were collected and used for the study of proteins, peroxidases, polyphenoloxidases and superoxidedismutases. There was no significant difference in the banding pattern SDS-PAGE and PAGE systems.Comparison of proteins between different regenerated or between different seed plants and the resulting dandrogram showed that the plants derived from seed culture belong to one group and those derived from tissue culture belong to another group. The level of peroxidase isozymes were lower in regenerated plants while superoxidedismutase represented additional isozyme in regenerated plants. Polyphenoloxidase had equal isozymes in both kinds of plant.

Published

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33(3): 257-266,2001

Results of the studies on olive trees from four regions of Iran (Roudbar, Gilvan, Gorgan, and Zanjan) indicate that soluble protein content as well as the activity of peroxidase and polyphenoloxidase in the leaves and fruits increases and continues to do so until complete ripening of fruits. After ripening, protein content and enzyme activities don't change or slightly decrease until the harvest of fruits. The trend seems to be similar in the "on" and "off" years, but in the "off" years the protein content and enzyme activity in the leaves and fruits are greater reflecting the various metabolic status of the plant during floral induction and fruit ripening.

Published

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33(3): 267-277,2001

Water relations of four guar genotypes viz., S-807, Esser, Brooks and S-1183 under different water regimes at pre-flowering, post-flowering and terminal drought were studied in cemented tanks under natural conditions. Water deficit reduced yield relative water content (RWC), leaf osmotic potential (OP), leaf water potential (WP), turgor potential (TP) in all four guar genotypes used. However, the genotypes S-807 and Esser had comparatively higher yield RWC, turgor potential under all water stresses than Brooks and S-1183. Maximum reduction in all parameters were recorded under terminal drought. The differences between pre- and post-flowering stresses were non-significant in case of yield and RWC but significant in other parameters. Genotypes with higher RWC and turgor potential had higher seed weight.

Published

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33(3): 279-287,2001

Maximum plant height and spread were observed in Central Leader System of training in Double Red Lebanon cultivar of apple. Maximum fruit size index (83.00 mm), fruit weight (259.20 gm), number of fruits per plant (200) and yield (51.84 kg/plant) were recorded in plants trained as Modified Leader System followed by Open Centre System, while all the above mentioned parameters were found minimum in Central Leader System during both years of studies. Stock and scion girths and Total Soluble Solids (TSS) did not respond at all with various training techniques. All the tested training techniques had no profound effect on blooming period and maturity of Double Red Lebanon apple cultivar. The fruit harvested from the plants trained as Central Leader System and Open Centre System had deep red color with red streaks while in modified leader system the color of the fruit was shining red with red streaks.

Published

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33(3): 289-292,2001

Litter fall and nutrient return in a deciduous Quercus cerris L. var. cerris forest which constitutes the "étage supra-mediterranéen pré-pontique" vegetation layer in the Central Black Sea Region of Turkey were investigated. Total annual input of litter was 681.90 g m-2 of which 64% was leaf litter fall, followed by 27, 7 and 2% wood, reproductive and miscellaneous litter fall, respectively. The annual nutrient return through litter fall was 42.70 kg ha-1 N

Published

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33(3): 293-303,2001

The seasonal variation of a seed bank was studied along an inundation gradient in a coastal marsh community dominated by Arthrocnemum macrostachyum (Moric.) C. Koch (Syn: Arthrocnemum indicum (Willd.) Moq.; Chenopodiaceae;) near Karachi, Pakistan. The distance from the Avicennia marina edge to mean high tide line (110 m) was divided into five zones. Density and height of the plants were higher in the middle marsh than in other areas. Plant cover and number of branches were lowest in the lower marsh and increased substantially in the next zone and there was no significant difference among other zones. Dry weight accumulation was highest in the lower-middle marsh. The size and composition of the seed bank was determined by monthly counting and identifying the seeds extracted from soil samples. A persistent seed bank flora was dominated by A. macrostachyum. The upper, upper-middle and middle marsh had seeds of five additional species viz., Atriplex stocksii Boiss., Suaeda fruticosa (L.) Forssk., Halopyrum mucronatum (L.) Stapf., Aeluropus lagopoides (L.) Trin. Ex Thwaites, Urochondra setulosa (Trin.) C.E. Hobbard and Cressa cretica L. from adjacent communities. Seed bank size was one of the largest in the samples collected immediately following dispersal ranging from 40,760 ± 123 seeds m-2 in March to 917,135 ± 567 seeds m-2 in July. Seed density then declined rapidly over two to three months. Size and diversity of the seed bank progressively increased from the lower to the upper salt marsh.

Published

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33(3): 305-314,2001

Eight new species of Verbascum L., from Saudi Arabia viz., Verbascum abyadicum F.M. AI-Hemaid, V asiricum F.M. AI-Hemajd, V chaudharyanum F.M. AI-Hemaid, V hema-figranum F.M. AI-Hemaid, V medinecum F.M. AI-Hemaid, V sheilae F.M. AI-Hemaid, V shiqricum F.M. A1-Hemaid and V tabukum F .M. AI-Hemaid are described along with their relationship, habitats and key to the eight new species.

Published

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33(4): 315-328,2001

The pollen morphology of 45 species

Published

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33(4): 329-355,2001

Seventeen species of green, brown and red seaweeds collected from Manora, Buleji and Paradise Point near Karachi coast of Pakistan were analyzed for their elemental composition with the help of Perkin Elmer 3100 Atomic Absorption Spectrometer. Several significant elements e.g., Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Na, Pb and Zn were detected quantitatively. Ca, Fe, K, Mg and Na were found in large amounts (223.79-13129.56 ppm), Cr, Cu, Pb and Zn were present in small quantities (1.27-10.49 ppm), while Cd and Co were detected in extremely small amounts (0.39-1.10 ppm). The average quantity of Na was found to be the highest among these algae (13129.56 ppm), followed by K (11655.71 ppm) and Ca (4242.17 ppm) with low quantity of Cr (1.27 ppm), Co (1.10 ppm) and Cd (0.39 ppm).

Published

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33(4): 357-363,2001

Cystotrichiopsis gen.nov., and C. salvadorae sp.nov., on Salvadora oleoides is described, illustrated and compared with related taxa.

Published

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33(4): 365-368,2001

Spore germination of Uromyces striatus, the cause of leaf rust on lucerne was significantly reduced on tap water agar (TWA) pieces containing different doses (1

Published

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33(4): 369-371,2001