Combining ability and heterosis for seed yield and its attributes in sunflower

The analysis of combining ability and heterosis was studied through line x tester for ten sunflower inbreds. Significant mean squares due to males and females for various characters indicated the presence of substantial variability among the lines selected. An over all evaluation of GCA effects of parents for different characters revealed that among the lines SA, 9A and 10A and testers 21R were found to be the good general combiners for majority of the yield components besides seed yield. Further observed that the seed yield and its components are governed predominantly by non-additive gene action. The crosses 9AK x 21 R, 10A x 21R and 8A x 22R were found to be superior anq exhibited highest SCA effects and heterosis. Majority of the heterotic crosses involved parents with low x low GCA or high x low GCA effects. This suggests that a single high general combiner, in the cross combination will results in best specific combinations.