Genetic diversity in field bean as revealed with AFLP markers

Assessment of genetic diversity is a prerequisite in any crop improvement programme. In order to obtain an overview of the genetic diversity present in Indian field bean genotypes in addition to few Kenyan genotypes, 40 field bean genotypes were analyzed at DNA level using AFLP markers. Four AFLP primer combinations (E-CAT/M-GTG, E-CAG/M-GTG, E-CAT/M-GCC & E-CAA/M-GCC) were used, which amplified a total of 223 bands of which 200 bands were polymorphic (89%). The number of amplified bands ranged from 36 (E-CAA/M-GCC) to 88 (E-CAT/M-GTG). Out of four primer combinations, two primer combinations (E-CAT/M-GCC & E-CAA/M-GCC) produced good polymorphism of 97% and 94%, respectively. The dendrogram and principal component analysis (PCA) based on AFLP data showed one major cluster in which all 39 genotypes were placed and one genotype (GL 103) was placed separately. Dendrogam and principal component analysis indicated pattern of clustering was not according to location from which they were collected. The Kenyan genotypes GL 84 and GL 92 were grouped along with Indian genotypes indicating these genotypes are genetically related to Indian genotypes. The genetic distance values based on AFLP data ranged from 2 to 142 (per cent dissimilarity varies from 0.8 to 63) suggesting a higher genetic diversity among field bean genotypes used for the study.