Inheritance and the Allelic Relationship of Resistance to Cowpea Aphid Borne Mosaic Virus (CABMV) in Two Cowpea Genotypes, KVX640 and KVX396-4-5-2D, in Burkina Faso

Abstract

Cowpea (Vigna unguiculata (L.) Walp.) is a grain legume crop cultivated in all the agro-ecological zones of Burkina Faso. It plays an important role in human nutrition due to its richness in protein and it enormous agronomic, sanitary and economic potentialities. However, several virus originated diseases negatively affect it production, the most important being cowpea yellow mosaic transmitted by aphid or cowpea aphid-borne mosaic virus (CABMV). One of the controle meseasures of this disease, which causes yeild losses, is the use of resistant varieties. This study consisted at determining the inheritance and the allelic relationship of the resistance to CABMV in two cowpea genotypes KVx640 and KVx396-4-5-2D. Plants were evaluated in pots under green house at Saria research station in Burkina Faso. The inheritance and allelic relationship studies showed that the resistance is governed by two dominant genes in the two varieties, each variety contributing for a resistant gene. Therefore, the resistance is monogenic. There was not any allelic relationship between the two resistant cowpea varieties, KVx640 and KVx396-4-5-2D, to CABMV. The identification of the nature of the gene governing the resistance to CABMV was done through a screening of F1 individuals derived from crosses between one resistant parent (KVx396-4-5-2D) and a susceptible check (Gorom local). The F1 hybrids were uniform; therefore, the resistance is conferred by a dominant gene.