Combining Ability for Seed Yield in Indigenous and Exotic Brassica napus Genotypes

Combining ability was estimated for seed yield using biplot approach in fifteen parental genotypes following 11× 4: line × tester fashion. The resultant 44 F1 hybrids along with parental genotypes were evaluated under field condition in a replicated trial for seed yield plant^-1 performance. Differences among the parental lines, testers, F1 hybrids and line × tester interaction for found significant (P 0.01) for the studied parameter. Promising genotypes for seed yield i.e. L-4, L-5, L-7 and T-4 were identified as best parents as they outclassed all other genotypes by producing maximum seed yield per plant of 28 g. Since, the line × tester source was significant, hence data was further subjected to combining ability analysis. For the inheritance of the studied trait (seed yield plant^-1), additive as well as non-additive genetic mechanisms were found important due to significant effects for both components i.e. General Combining Ability (GCA) and Specific Combining Ability (SCA) effects. Maximum GCA was shown by L-7 and T-1; whereas high SCA was noted for L-6 and L-7 with good ability to combine with T-3 and T-1 respectively, and could be utilized as genetic material in future breeding programs. Overall the biplot approach was found much cooperative in elaborating the genetic parameters of the data on the basis of its high explanatory aptitude and graphical demonstration.