Combining Ability Analysis for Yield and its Components in Indian Mustard (Brassica juncea L. Czern and Coss)

The combining ability analysis of 10 parents and their 45 F₁s generated through diallel system of mating revealed that significant differences existed for general and specific combining ability for all the characters. Gca and sca variances were highly significant for all the characters indicating importance of both additive and non-additive gene effects in controlling the expression of various characters. Vardan, Krishna and Pusa Bahar were found to be good general combiners for seed yield and some of its component traits. Twenty crosses exhibited good combining ability for seed yield. Yield was found to be controlled predominantly by non-additive gene action. The crosses with high sca effects did not always had parents with good gca effects. Such a relationship between gca and sca indicates the importance of epistasis and the crosses are expected to produce desirable transgressive segregants if the additive genetic system of good general combiner and the complementary epistatic effect of F₁ act in the same direction to maximize the desirable yield attribute