Characterization of the genetic diversity of breeding Cowpea Lines (Vigna unguiculata L.)

Abstract

Abstract Cowpea (Vigna unguiculata L.) is a legume widely produced and consumed globally, with grains possessing significant nutritional value and diverse applications. Despite its production potential and broad variability and adaptability to adverse conditions, it remains a crop with limited research in the areas of genetics and plant breeding. Therefore, the objective of this study was to evaluate the genetic variability of 10 cowpea lines originating from the University of Córdoba using eight ISSR markers. The results indicated that polymorphism ranged from 20% (AC) to 58.3% (ACA). Cluster analysis grouped the lines into two clusters based on their genetic similarity rather than their origin. This was corroborated by genetic parameters such as expected heterozygosity (He = 0.16), the diversity index (I = 0.24), and the coefficient of genetic differentiation (Gst = 0.16), which demonstrate low genetic variability but with gene flow among the lines (Nm = 2.70) and greater variation within (91%) than between them. The results demonstrate the efficiency of SSR markers in determining genetic diversity within germplasm exhibiting a narrow genetic base. In contrast, Caupicor 50 exhibites greater genetic divergence and may represent a useful parental source for broadening the genetic variability of future breeding change for populations. Despite the reduced variation attributed to breeding processes and recurrent self-pollination, desirable agronomic traits are fixed. These traits can be selected in breeding programs aimed at developing promising genotypes that are adapted, resistant to biotic and abiotic factors, and possess good productivity and nutritional quality, thereby offering a food security alternative for many Andean regions.