Genetic relationships among Vigna mungo (L.) Hepper and its close wild relatives using microsatellite markers

Genetic relationships of two wild Vigna species, Vigna mungo var. silvestris andVigna hainiana, with accessions of a cultivated species, V. mungo known as urdbean or blackgram was studied with a view of using them as a donor of alien stress resistance genes in future breeding. POPGENE analysis conducted on a total of 375 individuals of 25 accessions using sequence tag microsatellite markers (STMS) revealed effective number of alleles varying from 3.0 to 1.7. The mean values of observed and expected heterozygosity were 0.084 and 0.335, respectively. Average Wright’s fixation indices were: FIT = 0.710, FST = 0.840 and FIS = -0.84, indicating high level of outcrossing and genetic differentiation with limited gene flow between and within the three taxa studied. The Nm value for the accessions was found to be negligible, suggesting no gene flow within populations. For the groups, Nm value for V. mungo was 0.464, which was more than that of both V. radiata var. silvestris and V. hainiana. Since V. mungo is a cultivated species, it showed the highest within-species gene flow. Ewens-Watterson test for neutrality was done using 1000 simulated samples. All the loci were neutral to selection pressure as their observed F value was between lower and upper 95% limit.   Key words: Species relationships, Vigna mungo, microsatellite marker, blackgram.