AFLP markers were used for evaluating genetic diversity, population substructure, species relationships, and gene flow among eighty-five accessions belonging to the mungo-radiata group of section Ceratotropis of subgenus Ceratotropis of genus Vigna. Twelve preselected AFLP primers generated 1869 polymorphic amplification products. The number of fragments for each primer pair ranged from 44 to 296, showing 100% polymorphism. An analysis of the mungo-radiata group from different phytogeographical regions across India revealed a high level of genetic diversity. The six species of the mungo-radiata group were assembled into three groups namely, Radiata, Mungo, and Hainiana. The highest total diversity as well as within accession diversity was obtained for the Hainiana group and minimum for the Mungo group. Genetic differentiation values for Mungo and Radiata group was 0.158 and 0.212, respectively. Also, high gene flow was detected within each group. For mungo-radiata-hainiana relatives, Fct, Fsc and Fst estimates were 0.089, 0.120, and 0.034 respectively all Vigna species combined the fixation indices Fsc, Fst and Fct were 0.068, 0.120, and 0.034 respectively. A tree with a star-shaped topology was obtained, in which the accessions from all the species are intermingled. This kind of tree topology that isgrouping of individuals from different populations in the same cluster of the tree further substantiates gene flow between populations.
Keywords: AFLP, Asiatic Vigna, Ceratotropis, population substructure, gene flow.