Heterosis and combining ability for seed yield and its components in Brassica juncea L.

The heterosis and combining ability of six Indian mustard (Brassica juncea L.) genotypes were estimated using 6 × 6 diallel crosses. The analysis of variance indicated significant differences among parents and their hybrids in the F1 generation for all the traits studied. The cross combinations namely CR-5 × RAS 3189, DP 7-91 × INDIA III, RAS 3189 × DP 7-91, RAS 3189 × 0714-A and RAS 3189 × INDIA III exhibited significantheterosis for most of the studied traits thus may be exploited using heterosis breeding. The parent INDIA III and DP 18-9 was best general combiners for majority of traits. The cross combination DP 7-91 × INDIA III proved best specific combiner for plant height, number of siliquae per plant, number of seeds per siliquae and seed yield per plant. The GCA and SCA mean squares significance determined the presence of both additive and nonadditive gene action that execute role for the expression of these traits.