Genetic differentiation of Vigna species by RAPD,URP and SSR markers

Seventy genotypes belonging to 7 wild and cultivated Vigna species were genetically differentiated using randomly amplified polymorphic DNA (RAPD), universal rice primer (URP) and simple sequence repeat (SSR) markers. We identified RAPD marker, OPG13 which produced a species-specific fingerprint profile. This primer characterized all the Vigna species uniquely suggesting an insight for their co-evolution, domestication and interspecific relationship. The cluster analysis of combined data set of all the markers resulted in five major groups. Most of the genotypes belonging to cultivated species formed a specific group whereas all the wild species formed a separate cluster using unweighted paired group method with arithmetic averages and principle component analysis. The Mantel matrix correspondence test resulted in a high matrix correlation with best fit (r = 0.95) from combined marker data. Comparison of three-marker systems showed that SSR marker was more efficient in detecting genetic variability among all the Vigna species. The narrow genetic base of the V. radiata cultivars obtained in the present study emphasized that large germplasm collection should be used in Vigna improvement programme.