Author(s): V. Kumar, N. K. Rastogi, R. R. Saxena and S. N. Mandal

Abstract: Molecular characterization of genotypes gives precise information about the extent of genetic diversity. In the present study, a total of 25 polymorphic SSR markers were used across 24 aromatic rice genotypes from India and abroad for their characterization and discrimination. The allelic richness per locus ranged from 2 to 4 alleles with an average of 2.44 alleles. A total of six rare alleles were identified at six loci among 25 microsatellite loci. The polymorphism information content (PIC) values ranged from 0.278 to 0.642 with an average of 0.465. The PIC values revealed that RM527 might be the best marker for identification and diversity estimation of aromatic rice genotypes followed by RM1, RM22565 and RM207 markers. At a 40% level of similarity, the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) cluster dendrogram showed three major clusters (I, II and III) with additional sub-clusters, except cluster III. The cluster III had only one genotype Bas 837 which showed 63% dissimilarity with rest of the genotypes. At below sub-cluster level, about half of the genotypes exhibited more than 70% genetic similarities between genotypes which itself explains the existence of narrow genetic base among aromatic rice genotypes. The low to high degree of similarity among studied genotypes indicated high level of genetic diversity, and also the possibility of using these genotypes in breeding programmes targeted at improvement of elite aromatic rice varieties.

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