Genetic Diversity Studies on Indigenous Boro (summer) Rice (Oryza sativa L.) Genotypes of Assam using SSR Marker

The present study was designed to find out the genetic variations among 44 rice genotypes using SSR markers. Out of one hundred ten SSR primers screened, fifty two SSR primers were found to be polymorphic and generated 158 alleles with 100 per cent polymorphism. The dendrogram classified the 43 boro (summer) and one winter rice (Ranjit) into two main clusters, namely A and B. The similarity coefficient ranged from 0.026 to 0.731, indicating no true duplicates. The maximum similarity was observed between Jhum kamranj and TN6, and Jhum mycin and Mohi shaludhan (73.10%), suggesting close genetic relatedness. The lowest similarity (26.00%) has been observed between EC268181 and PSB RC 68, showing how genetically divergent these two are. The number of alleles detected by a single marker ranged from 2 to 4 with an average of 2.65 alleles per locus. The highest PIC (0.768) was recorded in RM 316 of chromosome number 9 and the lowest PIC (0.363) was recorded in RM 541 of chromosome number 6. The average PIC for the 52 SSR primers was 0.615. The SSR marker data revealed no true duplicates among the genotypes, indicating genetic divergence of the cultivars under the study. The result of the present investigation would be valuable to identify genetic variation among the different boro genotypes and could be used as baseline information for future rice breeding programme.