Heterosis and Combining Ability Analysis for Oil Yield and Its Components in Castor (Ricinus communis L.)

Twelve castor (Ricinus communis L.) genotypes consisting four lines and eight testers were crossed in a line × tester mating design. The analysis for combining ability revealed significant mean sum of squares of both general combining ability (GCA) and specific combining ability (SCA) for all the characters which indicated the presence of both additive and non-additive gene actions. The ratio of GCA variance and SCA variance ratio revealed the predominance of nonadditive gene action for all the traits except for days to 50 per cent flowering, days to 50 per cent maturity and oil content. VP1, SKP 84, ANDCM 2, ANDCI 9 and ANDCI 10-4 were good general combiner for most of the characters including seed yield. Cross JP 65 x JC 22 was a good specific combiner for seed yield per plant and for other yield component. In general for yield and other yield attributing traits the promising hybrids with high heterosis were VP1 xANDCM 2 and SKP 84 x ANDCM 2 having high mean, high heterosis (over better parent as well as standard hybrid). These cross combinations could be utilized for further use in breeding programme for improvement in yield of castor.