Evaluation of black gram (Vigna mungo (L.) Hepper) genotypes for coastal saline tolerance using microsatellite markers

Black gram is one of the important legume crops cultivated in the world, particularly in India mainly for protein requirements. It is grown mostly as a fallow crop in rotation with cereals. However, under saline stress conditions, the growth of the plants is reduced, ultimately resulting in a reduction in yield. The present investigations were carried out to evaluate the extent of genetic divergence and character association in 48 black gram genotypes for eleven biometric characters. In addition, the saline-tolerant genotypes were assessed in vitro. The analysis of variance revealed significant differences present in all the genotypes and showed a considerable amount of saline tolerance in the genotypes. Genetic diversity analysis using microsatellite markers revealed that out of a total of 21 SSR markers, 13 were polymorphic which revealed 47 alleles in forty-eight black gram genotypes with an average of 3 alleles per locus. Cluster analysis revealed that among the 21 markers used, 13 were found to be polymorphic with a transferability rate of 83%. From the present study, three genotypes, namely AUB 9, AUB 14 and AUB 20, were identified as saline-tolerant and were also confirmed by biometric and molecular analysis.