Genetic diversity analysis of groundnut genotypes using microsatellite markers

A set of groundnut microsatellite markers were utilized in 23 elite groundnut genotypes to assess the genetic diversity. A total of 13 alleles were detected at 3 loci using the PM3, PM50 and PM238 microsatellite primer pairs. The number of alleles ranged from 4 to 5 with an average of 4.33 alleles per locus. The allele sizes for all loci in 23 genotypes ranged from 137 to 217 bp and the frequency of SSR allele ranged from 0.022 to 0.500. The genetic distance for all possible 253 pairs of groundnut genotype combination ranged from 0.000 to 2.093 with an average of 0.92. The values of polymorphic information content (PIC) ranged from 0.617 to 0.701 and according to the result the primer PM3 was found to be the most polymorphic. The UPGMA dendrogram was constructed based on Nei's (1972) genetic distance delineated the above groundnut genotypes into two major clusters (I and II). Cluster I had two sub-clusters la and lb and cluster II consisted of two genotypes namely, ICGV 94165 and ICGV 00340 were unique and diversed from all other genotypes belonging to cluster I. Regarding 3 primer pairs, 4 specific alleles (PM3/195, PM50/146, PM50/137 and PM238/171) were able to distinguish a maximum of 6 genotypes and finally 2 (ICGV 94165 and ICGV 00340) from the above 23 groundnut genotypes. This approach will be useful for exploiting SSR markers for detecting polymorphism leading to genotype identification and conservation of commercially developed groundnut varieties through DNA fingerprinting and for estimating genetic diversity