Abstract

General combining ability (GCA) describes the general usefulness of the parental form in terms of the concerned trait, whereas specific combining ability (SCA) indicates importance of the joint action of the genes of parental forms. Such information is useful to identify the best combiners which may be hybridized to build up favourable genes. This present investigation aimed to determine the GCA and SCA effects of cowpea (Vigna unguiculata (L.) Walp.) genes resistance to aphids (Aphis craccivora Koch). The experimental design consisted of twenty-eight entries comprising of seven parents and their 21 hybrids in a Randomized Complete Block Design with three replications. The study was conducted in two locations: Kamboinse and Farakoba in Burkina Faso. The study focused on plants survival rate (SR) and degree of infestation (DI). Results showed that the survival rate is under control of additive and non-additive genes action. Additive genes are involved in the expression of the degree of infestation. Fourteen crosses capable of producing transgressive segregants were selected. The low values of the narrow sense heritability indicate high influence of environment in the expression of the traits; suggesting the need of improved methods to select in early generation. The results also showed significant genotype by environment interaction (G×E), GCA by environment interaction (GCA×E), and SCA by environment interaction (SCA×E).

Key words: General Combining Ability (GCA), specific combining ability (SCA), additive, non-additive.