Studies on combining ability for seed yield and yield components in castor, Ricinus communiis L.

Combining ability for 11 characters was studied using line X tester mating design involving 5 diverse pistillate lines and 8 inbred lines in castor. Combining ability analysis revealed that gca variances were significant for days to 50% flowering, plant height, number of nodes up to primary raceme and 100-seed weight, whereas, sca variances were significant for ail the characters, reiterating the preponderance of non-additive gene action in the inheritance of these characters. The study also revealed that JP 65 and VP 1 among females while JI 35, I 21 and VI 9 among males were superior and consistent general combiners for seed yield and majority its yield contributing characters. VP 1, GC 2 and EB 16 were found to be good general combiners for days to 50% flowering, days to 50% maturity of primary raceme, plant height and number of nodes upto primary raceme. Good general combiners for oil content were VP 1 among females and SKI 283 amongst the males. The per se performance of crosses is not correlated with the sca effects of the crosses. The study also suggested the involvement of at least one good general combiner as parent result in better yielding cross. A parallel behavior was observed between per se performance and general combining ability effects of parents. The bestthree hybrids recorded maximum significant positive sca effects for seed yield were ACP 1 X SPS-44-1, VP 1 X GC 2 and SKP 4 x EC 38538.