Combining Ability and Index Selection in F₂ Generation of Pigeon Pea Crosses

An F₂ diallel analysis involving 45 crosses and the ten parents was carried out. The parents chosen for the crosses furnished adequate diversity for plant type, duration, flowering habit, seed size, length of pod bearing region, pod number and yield. The studies indicated.

(1) Analysis of F₂ means revealed significant differences, between parents, crosses and parents vs crosses. Of the various groups of crosses, the E × L, M × L and M × M groups appeared more productive and of greater selective value. The E × L group in particular exhibited significant differences for most characters and could offer maximum scope for selection.

(2) The yield levels of crosses belonging to different maturity groups indicated that yield increases were almost linear from E × E to E × M E × L and M × M; the E × L, M × M and M × L groups being the most promising.

(3) Combining ability analysis revealed that the estimates of variance due to sca was several times that of gca for most characters indicating the importance of non-additive gene action in influencing most characters in Cajanus. Both F₁ and F₂ analyses are in agreement.

(4) An examination of the gca effects of the various parents indicated that Prabhat among earlies, 4651 among medium duration parents and 1609, 2889 and 2894 among lates are desirable. Hy-3A provides choice for recombining plant type. Grosses involving these parents, particularly between different maturity groups, could be rewarding.

(5) Plant height, seed weight, length of pod bearing region and number of pod bearing branches furnish criteria for selection.