Exploring the Genetic Diversity of Common Bean Germplasm: An Important Food and Nutritional Security Legume Crop in Kenya

Abstract

Common beans is an important legume crop used as a source of protein, vitamins and other beneficial nutrients among resource poor populations in Kenya. Despite its nutritive and economic value, very little information is available on the genetic diversity of Kenyan common bean germplasm using molecular markers. Evaluation of genetic diversity among Kenyan common bean germplasm could provide useful information for genetic improvement. The aim of this study was to characterize and evaluate the genetic diversity of common bean germplasm from different geographical regions of Kenya using start codon targeted (SCoT) markers. A total of 30 common bean accessions were used. A set of 36 SCoT primers were tested of which 17 primers gave reproducible amplification which were further used for diversity analysis. The 17 SCoT primers generated a total of 224 amplification bands, of which 95% were polymorphic, indicating high genetic variation among the tested accessions. Polymorphism information content ranged between 0.60 and 0.85 with an average of 0.73 indicating that all the primers were informative. Pair-wise genetic similarity values ranged between 0.264 and 0.734 with a mean of 0.515. The principal component analysis (PCA) and Un-Weighted Pair Group Method with arithmetic mean (UPGMA) showed that the germplasm divided into 2 main clusters. Analysis of molecular variance showed a significant difference across accessions with a high within population variation. This study revealed genetic variation among the studied accessions, which can be exploited for common bean improvement in breeding programs.