Diallel Analysis of Certain Yield Traits Related to Cowpea Seed ( Vigna unguiculata (L.) Walp)

Abstract

Cowpea is a major food legume in West Africa, but its yields remain low in Côte d’Ivoire despite its recognized nutritional value and agronomic importance. This study aims to evaluate the agronomic performance of F1 hybrids from diallel crosses and to determine the genetic parameters of interest. To do this, three parental accessions (NBO04, NKO03, and NFE011) showing the best agro-morphological and nutritional characteristics were selected and crossed according to a 3 × 3 diallel design. The traits studied were the number of seeds per pod, seed length, 100-seed weight, and seed yield. These parameters were analyzed using an ANOVA test. The determination of genetic diversity parameters (heterosis, potency ratio) as well as the diallel analysis (General combining ability, specific combining ability, and the General combining ability/specific combining ability variance ratio) were then carried out. The results showed that the three parental genotypes NBO04, NKO03, and NFE011 are phenotypically divergent from each other for the traits number of seeds per pod, 100-seed weight, and seed yield. Heterosis (%) and the hybrid vigor ratio of F1 hybrids indicate that only the NBO04 × NFE011 hybrid (9.12%) compared to the mid-parent and reciprocal cross, NFE011 × NBO04 hybrid (11.58%) compared to the better parent show positive heterosis for yield. General combining ability (GCA) and specific combining ability (SCA) are significant for all traits. The GCA/SCA variance ratio confirms the predominance of additive effects over non-additive gene effects in the inheritance of quantitative traits. The results obtained provide breeders with indications on the mechanisms of trait transmission, with the main objective of better guiding the selection of the best parents when establishing a hybridization program.