Estimation of combining ability of blackgram [Vigna mungo (L.) hepper] genotypes for grain yield and component traits

Combining ability for grain yield and its component traits were assessed utilizing line × tester method by involving three lines and six testers. For all the nine traits under study, the ratio of GCA (general combining ability) to specific combining ability (SCA) was less than unity as the relative estimates of variance due to GCA were lower than SCA, thereby reflecting the predominance of non-additive gene action. On the basis of per se performance and GCA estimates of the parents, Mash 114, RUG-46 and KU-99-21 were found to be the good general combiners for grain yield per plant. Based on SCA estimates, six hybrid combinations were found to be promising. They were: KUG 503 × KU 99–21, Mash 114 × VBN-6 and Mash 479 × RUG-46 with high × low/low × high general combiners, KUG 503 × KU 9921, Mash 479 × KU 99–21 with low × medium and KUG 503 × TU 94-2 with low × low general combiners. As the presence of high proportion of non-additive gene action was found to be pronounced, the breeding procedures such as pedigree method, bi-parental mating(s) or selection in later generations are suggested for expecting transgressive segregants on employing the promising parents and cross combinations.