Genetic structure of different strains of ornamental barb (Puntius tetrazona) by microsatellite markers

The genetic structure, diversity and population kinship of four strains of ornamental barb, Puntius tetrazona, viz. tiger, green, albino and rose barb, was studied through microsatellite markers. Genomic DNA was extracted from dorsal fin tissue of 160 individuals (40 per strain) using kit and its protocol from Denazist Co. PCR amplification was performed using four pairs of microsatellite primers (Sm17, Sm25, Ma106 and Ma109). PCR products were electrophoresed on 8% acrylamide gel and stained with silver nitrate. The results showed that all loci were polymorphic. A total of 21 alleles for four markers in four strains was found. The mean number of alleles per locus at the population level was 5.25, and the number of alleles per polymorphic locus varied between 3 and 6. Average number of the observed alleles in tiger, green, albino and rose barb strains were 3.25, 3.25, 4 and 3.25, respectively. The observed and expected heterozygosity averages were 0.24 and 0.49, respectively. Most cases significantly deviated from Hardy-Weinberg equilibrium (p≤0.01). The analyses of molecular variance showed high genetic diversity (97%) within populations. The Fst value was 0.03 which indicates the low genetic differentiation between populations. UPGMA cluster analysis based on Nei genetic distance showed two different populations inhabiting the regions. Therefore, the microsatellite markers used in this study were found suitable for the different strains, and the degree of diversity was very low between strains, indicating a high degree of kinship.