Study of heritable variation and genetics of earliness in mungbean (Vigna radiata L. Wilczek)

Abstract

Fifty-five mungbean lines were evaluated for days to maturity and grain yield per plant. This material showed considerable range of variability for the target traits. Eight genetically diverse parents were selected and used for a full diallel set of crosses to study the mode of inheritance for earliness related parameters (days to flowering, days to maturity and length of reproductive phase) during summer 2005. The F1 generation of these crosses was sown during the spring of 2006 and the selfed seeds were used to raise the F2 generation during kharif season. The data recorded from two generations were subjected to genetic analysis. The formal ANOVA showed the significance of both additive and dominance effects for all the traits in both generations. Significance of D, H1 and H2 components also confirmed the contribution of both additive and dominance effects in controlling the inheritance of these traits. The estimates of narrow sense heritability were low to moderate except higher estimates for days to maturity in F2 generation, while the broad sense heritability estimates were relatively higher. Seasonal and environmental effects were also found to be significant. In view of the complex nature of gene action for earliness, it is suggested that breeders should look for transgressive recombinants of earliness and other desirable attributes in later segregating generations to gain higher genetic advance. The variety NM92 was found to be the best source of earliness in mungbean breeding.