Evaluation of Genetic Diversity in Iranian Rice (Oryza Sativa) Cultivars for Resistance to Blast Disease Using Microsatellite (SSR) Markers

Rice plays an important role in feeding the world's population, especially the people who live in developing countries. More than 90% of the world's rice is produced and consumed in Asia. Blast disease caused byMagnaporthe Oryzaeis one of the most important diseases of rice in the world. This study evaluated the power of 10 blast-specific SSR markers in the determination of genetic diversity among 30 cultivars ofIndicarice. The phenotypic evaluation was also performed usingM. Oryzaeat the stage of three or four leaves. A total of 23 effective alleles with an average of 2.21 alleles per locus were found. A total of 28 alleles were also observed per locus with an average of 2.8. Also, the average of Polymorphic information content (PIC) for the studied markers was estimated as 0.42. RM204 and RM413 showed the highest (0.60) and the lowest (0.081) PIC, respectively. The UPGMA-based dendrogram obtained from the binary SSR data divided 30 studied genotypes into three groups. In phenotypic testing, the observed phenotypic similarities corresponded to those in UPGMA-based dendrogram with some intermixing. The phenotypic evaluation also divided the population into three groups. According to Student'sttests for comparing the phenotypic and genotypic data, SSR markers RM277 and RM8225 were found to be linked to semi-susceptible and resistant phenotypes, respectively.