Genomic DNA Diversity Analysis of Some Accessions of Oryza sativa L. for Breeding and Conservation Strategies

Abstract

Molecular characterization provides basic vital information on the degree of genetic diversity among genetic materials which guides development of breeding programme and inform strategies on genetic conservation of important accessions. A total of 21 SSR markers were used to characterize 25 rice genotypes. The 21 microsatellite markers were highly polymorphic and allele number per locus ranged from 3 alleles (RM 224, RM 229, RM 256, RM 413, RM 3, RM 276, RM 219, RM 88 and RM 349) to 5 alleles (RM 247 and RM 288), with a mean of 3.67 alleles through the 21 loci obtained in the study. The content value of the polymorphic information ranged from 0.372 in RM 88 to 0.503 in RM 256 with overall average of 0.422 in all the 21 loci. PIC values indicated that RM 256 was the best marker for the identification of the rice genotypes. The main allele frequency at each locus ranged from 54.5% (RM 219) to 69.3% (RM 229). The pairwise genetic dissimilarity co-efficient showed that the highest genetic distance was obtained between NERICA 2 and MR 220; NERICA 2 and MR 263; and finally between WITA 4 and NERICA 2 (76.0%). The lowest genetic dissimilarity was between NERICA 6 and NERICA 8 (19.0%) followed by WITA 4 and NERICA L 34; BW 348-1 and IWA 10 (24.0%). Intercrossing far related genotypes could yield hybrids of high heterosis using SSR marker. Cluster analysis revealed reasonable levels of locational groupings among the genotypes.