Analysis of population substructure, genetic differentiation and phylogenetic relationships among selected Asiatic Vigna Savi species

Random amplified polymorphic DNA markers were used to study sub-structure and genetic differentiation amongst 31 populations (seven cultivated and 24 wild populations) belonging to 14 Asiatic Vigna species. Ten pre-selected RAPD primers generated 152 polymorphic amplification products. Estimates of polymorphism indices were higher for the wild taxa in comparison to the cultivated forms. F(ST) values between populations ranged from 0.111 to 0.801 and Nei's genetic diversity values between and within species varied from 0.26 to 0.70 and 0.04 to 0.56 respectively. The high F(ST) and F(CT) values indicated strong subdivision of populations and high differentiation among species. Analysis of molecular variance was performed by grouping the populations conforming to specific species. AMOVA was also performed separately to better resolve the differentiation of species within mungo-radiata complex. Molecular phylogenetic relationships amongst the species of radiata-mungo complex; namely, black gram (V. mungo (L.) Hepper), green gram (V. radiata (L.) Wilczek), V. radiata var. sublobata, V. radiata var. setulosa, V. mungo var. silvestris and V. hainiana, were studied through cluster analyses. Two distinct groups were recognized within the complex, with population samples of V. hainiana forming one cluster. Further, V. hainiana appeared to be equidistant to both V. radiata and V. mungo.