Genetic Analysis and Identification of Linked SSR Markers for Erectness in Forage Cowpea [Vigna unguiculata (L.) Walp.]

Abstract

Background: Cowpea is an important fodder legume crop due to its high protein content and fast growing nature. Cowpea can be grown as sole crop or it can also be grown as intercrop with some non legume such as maize, pearl millet or sorghum. Mostly the farmers prefer erect or semi erect high yielding cowpea varieties as an intercrop because they are easy to harvest. The transfer of erectness along with other forage traits can be done with proper knowledge of gene action controlling that particular trait. Methods: To improve the fodder yield, two sets of crosses along with their segregating generations were analysed for erectness along with other forage traits to estimate the type of gene action through generation mean analysis. Identification of SSR primers associated with erectness was also carried out in F2 population of a Cross (C-88 x TNFC 6926). Result: The scaling test showed significant results for most of the traits indicating the presence of epistatic interactions. The six-parametric model test was performed and the results indicated the significant overall mean and traits were inherited quantitatively. The high magnitude of additive x additive gene effect for green fodder yield suggests the pedigree method is most suitable breeding programme for development of fodder cultivars with better quality traits. Out of 151 SSR primers, 15 SSRSs showed polymorphism between two parental lines. Out of these 15 SSR primers, three primers showed linkage with erectness.