Genetic analysis of grain yield, days to flowering and maturity in oilseed rape (B. napus L.) using diallel crosses.

Abstract

Abstract Twenty one F 2 progenies derived from a 7×7 diallel crosses along with parents were evaluated for grain yield, flowering and maturity time. Due to significant genotypic effects for all traits, genetic analyses were performed on F 2 progenies including analyses of combining ability and genetic components. The Analysis of variance revealed that both additive and non-additive genetic effects were involved in controlling these traits. GCA/SCA ratios were 0.91 for days to flowering, 0.95 for days to maturity and 0.83 for grain yield which indicated that the additive gene effects were more important than non-additive gene effects for all these traits. Narrow-sense heritability was high for days to flowering (73.12%) and days to maturity (81.99%) and low for grain yield (30.15%). Heterosis in hybrids seemed to be largely determined by complementary epistasis as well as genetic distance between the parents. The spring-type varieties Tower and Regent appeared as the best parents for earliness whereas winter-type varieties D.R. and Ceres were best parents for high grain yield. It could be concluded from the study that S 1 recurrent selection would be effective to improve the performance of these genotypes for grain yield, flowering and maturity time. The selected S 1 lines from each cycle can be used in a pedigree-breeding program to identify superior genotypes