Combining ability analysis for seed yield and its attributes in Indian mustard [Brassica juncea (L.) Czern and Coss]

The hybrids were developed by adopting diallel mating design excluding reciprocals involving ten diverse Indian mustard genotypes during rabi 2007-08. The resultant 45 hybrids along with their parents were evaluated in a Randomized Block Design with three replications under four environments viz., timely sown at Sardarkrushinagar (E1) and Ladol (E2), and late sown at Sardarkrushinagar (E3) and Ladol (E4), during rabi 2008-09. Combining ability analysis on pooled basis, revealed importance of both additive and non-additive genetic variances for the control of various traits. However, the ratio σ2 gca/σ2 sca indicated preponderance of non-additive gene action for days to 50% flowering, days to maturity, seed yield/plant and oil content, while additive gene action was preponderant for rest of the traits. The parents RK 9501, GM 1 and GM 2 were good general combiners, whereas, the crosses 'RK 9501 x GM 2', 'GM 1 x GM 3' and 'GM 3 x SKM 139' were found to be the best specific combinations for seed yield/plant and some of the important yield contributing traits. However, on the basis of per se performance, exploitable heterosis and significant sca effects for seed yield/plant and some of its important components, the above hybrids were considered to be the most promising for exploitation of heterosis.