Heterosis and combining ability studies in Indo-African crosses of pigeonpea

Forty five hybrids derived from 10 diverse parents in diallel mating design were evaluated to study the magnitude of heterosis and combining ability effects in pigeonpea. There were significant genotypic differences among the parents and hybrids for all the traits. Mean squares due to parents vs hybrids were significant for all the traits except seeds per pod and 100seed weight, revealing significantdifferences in the performance of parents and crosses in F₁ generation. Out of 45 crosses studied, 30 and 19 crosses evinced significant positive heterobeltiosis and standard heterosis for seed yield per plant, respectively. Ten best crosses viz., GT 100 with ICP 12116, ICP 12161, Banas and ICP 11912; Banas with ICP 9140 and ICP 11488; GT 101 with ICP 12161 and ICP 12116; ICP 12161 with ICP 9135, and ICP 13555 with ICP 9135 exhibited significant desirable standard heterosis for seed yield per plant as well as other important yield components. The mean squares due to general and specific combining ability effects were significant for all the characters except seeds per pod, evincing importance of both additive and non-additive gene actions with preponderance of non-additive type of gene effects in the expression of all the traits except days to 50% flowering, days to maturity and pod length. The top three heterotic combinations for seed yield per plant involved African germplasm as males i.e., ICP 12116 and ICP 12161 from Tanzania and ICP 9135 from Kenya. However, in females, no such trend was observed.