Study of combining ability and gene action for seed yield and its component traits in castor (Ricinus communis L.)

The experimental material includes four lines, ten testers of castor, their forty hybrids developed by line × tester design and standard check (GCH- 9) were evaluated by the use of RBD with three replications. Mean sum of squares of both general and specific combining ability were significant for all traits when analysis of variance for combining ability tested, which signified presence of additive gene action and non-additive gene action were pivotal in the inheritance of these traits. The variance ratio lesser than unity of both general and specific combining ability were exhibited that the non-additive gene action was primary for the expression of most of the traits studied but variance ratio greater than unity of both general and specific combining ability were exhibited that the additive gene action for length of primary raceme(cm), plant height up to primary raceme and effective length of primary raceme (cm), Parents; IPC 30, JI 518, JI 531 and 532, were found good general combiner for seed yield per plant that is revealed by gca effects. The estimates of sca effects of crosses signified that crosses IPC 30 × JI 533, IPC 31 × JI 532 and SKP 126 × JI 532 displayed maximum significant and sca effects are positive for seed yield per plant.