Diversidade genética de progênies de feijão-caupi utilizando marcadores ISSR e SSR

Abstract

Cowpea (Vigna unguiculata (L.) Walp.) is a crop of great socioeconomic and nutritional importance in Brazil, particularly in the Northeast region, due to its excellent adaptability to diverse environmental conditions and its high nutritional value. However, crop productivity remains limited in some regions, highlighting the need for advances in cowpea breeding programs. In this context, the assessment of genetic variability is an essential step for identifying and selecting superior and genetically divergent parents, contributing to the development of populations with greater genetic variability and, consequently, improving the efficiency of breeding programs. Therefore, the present study aimed to confirm the hybridization of F1 progenies, evaluate the genetic diversity of F1 and F2 cowpea populations using ISSR molecular markers, and assess the potential of multiplex PCR associated with capillary electrophoresis using SSR markers. Seven parental genotypes, eight F1 progenies, and 97 individuals from the F2 population were evaluated. Genomic DNA was extracted from young leaves and subsequently subjected to PCR amplification using ISSR and SSR markers. The hybrid status of five previously selected F1 progenies was confirmed using seven ISSR markers, which enabled the identification of polymorphic bands inherited from the male parent and the discrimination of true hybrids from potential self-pollinated individuals. The formation of distinct clusters in the F2 population revealed the existence of genetic variability among the individuals. Four individuals exhibited the greatest genetic divergence compared with the remaining materials evaluated, indicating their potential for advancement in subsequent selection generations. In addition, multiplex PCR associated with capillary electrophoresis showed potential for allele identification in cowpea, although methodological adjustments and optimization of the experimental conditions are still required to improve the efficiency and standardization of the analyses. Overall, ISSR markers proved to be effective for molecular characterization, genetic diversity assessment, and hybrid confirmation in cowpea, highlighting the potential of the F2 population as a valuable source of genetic variability for cowpea breeding programs.