Pak. J. Bot., 40(3): 1319-1328, 2008. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
EFFECT OF MOISTURE STRESS ON COMBINING ABILITY VARIATION FOR BIRD RESISTANCE TRAITS IN SUNFLOWER (HELIANTHUS ANNUUS L.) SAEED RAUF1*, H.A. SADAQAT1 AND A. NAVEED2
Abstract: Experiments on sunflower were carried
out under 2 moisture level in the field to study their modifying effect on
phenotypic expression and combining ability of bird resistant traits i.e.,
degree of head shape (DHS), degree of achene compactness (DAC), degree of
stem orientation (DSO) and degree of head orientation (DHO). Genotypes
indicated substantial shift in their relative morphology for all traits
related to bird resistance over moisture regimes. All traits exhibited
larger proportion of non additive gene action under both conditions and
showed an increase in proportion of non-additive genetic variation under
moisture stress condition. Intermating and recurrent selection procedures
could be useful breeding procedures for accumulating favorable genes
responsible for better bird resistance traits and may produce superior
recombinants in segregating progenies under both conditions. Under moisture
stress condition, only drought tolerant parents showed peculiar morphology
of traits leading to bird attack resistance. Relative sensitivity of these
traits to the moisture stress has indicated their potential of acting as
morphological marker for selection of drought tolerant genotypes. Among bird
resistant traits, degree of head shape showed significant negative
relationship with achene yield suggesting the possibility of improving yield
through selection of highly concave genotype under drought stress condition 1Oil seeds Research Laboratory, Department of Plant Breeding & Genetics University of Agriculture, Faisalabad-38040, Pakistan 2Directorate of Research, University of Agriculture, Faisalabad-38040, Pakistan Corresponding author: saeedbreeder@hotmail.com, Fax+92-041-9200161 |
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