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Pak. J. Bot., 47(4): 1225-1230, 2015. |
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Updated: 18-08-15 | ||||
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DOSE-RESPONSE BEHAVIOUR OF WATER SCARCITY TOWARDS GENETICAL AND MORPHOLOGICAL TRAITS IN SPRING WHEAT (TRICTICUM AESTIVUM L.)
IJAZ RASOOL NOORKA*AND SABA TABASUM
Abstract: Combining ability was studied in a Line × Tester mating fashion in wheat (Tricticum aestivum L.). Significant differences were observed for all the yield and yield contributing traits. GCA and SCA components of variation were found significant for most of the traits. Under water stressed conditions among lines the genotype Kohistan-97 revealed significant GCA effects for all the traits except spike length. Among testers, the genotype V08172 showed significant effects for the traits spike length, 1000-grain weight and flag leaf area. Based on desirable SCA effects and mean performance the cross combinations Kohistan-97 × V08172, Chakwal-86 × Punjab-81, Fsd-2008 × Punjab-81, Sehar-2006 × V08172 and Chakwal-86 × V08172 behaved best combiner to tolerate the water stress. Results of genetic analysis offered over dominance type of gene action that remained unchanged with the change in water provision for the traits like 1000 grain weight and economic yield. Similarly additive gene action was observed for the trait plant height under both normal irrigation and water stress conditions. However the cumulative genetic effects to control the expression of yield and yield components was shifted due to the changed environments. The study was concluded that due to presence of additive variance, selection could be practiced in early generation whereas in the presence of recessiveness the selection may be delayed up to the later generations. Plant traits associated with water stress tolerance having high heritability and with additive gene action may be used as indirect selection criteria for early selection of water stress tolerant genotypes. The information generated as a result of this study on genetic analysis of important economic traits of wheat under contrasting water availability positions will be of great value to the wheat breeders to design future breeding programmes.
Key words: Association, Wheat breeding, Crop production, Economic yield, Water stress.
Department of plant breeding & Genetics, University College of Agriculture, University of Sargodha, Pakistan *Corresponding author e-mail: ijazphd@yahoo.com |
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