Determination of inheritance of aphid resistance in cowpea genotypes and identification of single sequence repeat markers linked to resistance genes

Abstract

An understanding of the mode of inheritance is fundamental to plant breeding. The choice of an appropriate selection method considers the number of genes involved and their modes of action. In plant breeding, markers can overcome the false resistance that may arise from greenhouse screening. The goal of this study was to facilitate the better use of cowpea genotypes resistant to aphids. Specifically, we sought to determine the number of genes involved in the ability of cowpeas to survive aphid infestation and identify single sequence repeat (SSR) markers linked to aphid resistance genes. Two pairs of parents (Tiligre  KVX295-124-2-99 and Tiligre  IT97K556-6) were used to generate two F 2 populations. Each of these populations was screened with aphids to determine the mode of inheritance of resistance to aphids in cowpeas. SSR markers were used to screen parent, F 1 , and F 2 individuals to locate polymorphic markers and markers linked to the genes involved in resistance to aphids. The results showed that the ability to survive under aphid infestation in KVX295-2-124-99 and IT97K556-6 is controlled by two nonallelic genes. The markers MA61 and MA70 were found linked to aphid resistance in cowpea.