Assessment of molecular divergence using microsatellite markers linked to drought-yield QTLs of rice (Oryza sativa L.)

The drought stress is the major limitation for the production and yield stability in the rice (Oryza sativa L.) growing areas particularly under rainfed conditions. The assessment of genetic diversity among the rice genotypes using molecular markers linked to drought-yield QTLs will help in the selection of divergent parents to produce superior recombinants and transgressive segregants to develop high yielding cultivars for drought conditions. So the current study was conducted to estimate the genetic diversity among the set of twenty four advanced drought tolerent rice genotypes and commercial checks using SSR markers linked to major drought-yield QTLs. A total of 31 alleles were detected by 13 polymorphic markers across 24 rice genotypes with a mean of 1.94 alleles per polymorphic marker. Among the polymorphic markers, 11 markers formed 2 alleles each, 2 markers have produced 3 alleles each. The PIC value observed in the contemporary study ranged from 0.239 to 0.499 with an average PIC value of 0.346. The dendrogram displayed a total five clusters on the basis of dissimilarity coefficient values, the cluster II had maximum ten genotypes followed by cluster IB-a with five genotypes and clusters IA-a, IA-b, IB-b with three genotypes each. IR 82475-110-2-2-1-2 and IR92937-178-2-2 (R-155) were found to be the most divergent genotypes.