Evaluation of genetic diversity in rice using simple sequence repeats (SSR) markers
The genetic diversity of 64 rice genotypes using 20 SSR primers on chromosome number 7-12 was investigated. DNA was extracted by modified cetyl trimethyl ammonium bromide (CTAB) method. The banding pattern was recorded in the form of 0-1 data sheet which was analyzed using unweighted pair group method with arithmetic mean (UPGMA) based on Jaccard's similarity coefficient. The results revealed that out of twenty, eight primers showed distinct polymorphism, indicating the robust nature of microsatellites in revealing polymorphism. The cluster analysis showed higher level of genetic variation among the genotypes. Similarity coefficients ranged from 0.40 to 0.96. The dendrogram revealed 8 major distinct clusters. Higher range of similarity values for related genotypes using simple sequence repeats (SSR) provides greater confidence for the assessment of genetic diversity and relationships. The polymorphism information content (PIC) value for the SSR loci ranged from 0.36 to 0.98. Higher PIC values were associated with higher level of polymorphism. The information obtained from the DNA fingerprinting studies helps to distinctly identify and characterize the various genotypes. Such information can be used in background selections during backcross breeding programs.
Key words: Genetic diversity, simple sequence repeats (SSR) marker, dendrogram.