Genetic analysis of some yield attributes in Indian mustard (Brassica juncea L.)

The present investigation on Brassica juncea L. genotypes is an attempt to study variations and to generate variability through hybridization and also to obtain genetic information on some yield attributes for selection in segregating generations. Eight promising genotypes were selected and crossed in all possible combinations under complete diallel system. Data was recorded for seed yield and some important yield attributes. Analysis of variance showed significant differences for all the traits and therefore further analyzed using Hayman’s approach, which showed existence of both additive and dominance gene effects governing all the traits. However, estimates for genetic components of variation revealed that additive effects were more important for seeds per siliqua and 1000-seed weight indicating possibility of selection for these traits in early segregating generations. Dominance effects were more prominent with presence of over-dominance for plant height, number of primary branches per plant, number of siliqua per plant, siliqua length and seed yield per plot, thus suggesting that selection could be effective in latter generations. Only siliqua length showed the presence of directional dominance, while asymmetrical distribution of dominant genes among the parents was identified for all the traits.   Key words: Indian mustard, genetic analysis, gene action, yield attributes, complete diallel.