Heritability and gene effects for incorporating pubescence into cowpea (Vigna unguiculata (L) Walp.) from V. rhomboidea Burtt. Davy

Abstract

Cowpea, an important subsistence pulse crop in the tropics and subtropics is susceptible to several insect pests that seriously limit its yield potential. Pubescence (hairiness) on the parts of some of its wild relatives has been reported to reduce the damage caused by some of the insect pests. A generation mean analysis was conducted between a cowpea variety IT82D-716 and two accessions of Vigna rhomboidea to investigate the gene effects and heritability for incorporating pubescence into cultivated cowpea from V. rhomboidea. The additive-dominance model that was adopted in the analysis was observed to sufficiently explain the mode of inheritance of leaf and stem pubescence with the additive effect being more important than the dominance effect. A six-parameter model with epistatic gene interactions was adequate for explaining the inheritance of pod pubescence. Heritability estimates, in the narrow sense were high for pubescence density and pubescence length. Inheritance of pubescence in crosses between cowpea and V. rhomboidea was governed by one and two genes. Significant and higher additive gene effects and high-heritability suggest that backcross selection schemes should be responsive in the development of pubescent cowpea lines.