General and specific combining ability in varieties of Leucaena leucocephala (Lam.) de wit

Abstract

A diallel series of intervarietal crosses in Leucaena leucocephala was used to estimate general and specific combining ability for length of main stem and stem number in four varieties of contrasting growth habits. Reciprocals were not included. Significant differences were found between varieties for variation due to general combining ability, for both characters, and for variation due to specific combining ability for length of main stem, but not for stem number. Peru and Guatemala were superior to Hawaii and El Salvador in general combining ability for length of main stem. Peru and Hawaii were superior to El Salvador and Guatemala in general combining ability for stem number. Peru and El Salvador had much higher specific combining ability variances for length of main stem than Guatemala and Hawaii. An evaluation of parents and crosses based on F₁ performance and the estimates of combining ability has been made, and compared with the subsequent performance of the crosses in later generations.