Molecular analysis revealed genetic decline in hatchery-produced Cyprinus carpio

Abstract

Population genetic structure of cultured fish species is vital for improving the fisheries management and stock enhancement programs. The genetic variability and population genetic structure at fourteen microsatellite loci of a total 210 individuals of Cyprinus carpio from six selected hatcheries were analyzed. The data obtained through microsatellite markers showed a low- to-moderate level of genetic diversity in terms of allele numbers (Na), allelic richness (Ar), effective allele numbers (Nae) and observed heterozygosity (Ho) in all the populations. At the examined loci, 32 out of 84 possible tests were observed to be significantly (P<0.05) deviated from the Hardy-Weinberg equilibrium. Maximal gene flow (Nm) and lower population differentiation (FST) was experienced among populations. However, significant (P<0.05) differentiation was observed among some populations. An analysis of the distribution of genetic variation indicated within individual was very high (69.07%), while, among individuals within populations and among populations was low (29.56% and 1.37%, respectively). Recent bottleneck was detected with the shifted mode. Phylogenetic neighbor joining tree analysis showed the two distinct clusters. The inferences of this study would be helpful for setting up effective management strategies for the better conservation of genetic integrity in the hatchery stocks of C. carpio.