Monitoring the genetic effects of broodstock enhancement of silver carp (Hypophthalmichthys molitrix) in middle Yangtze River based on cytb gene and D-loop sequences

Abstract

In this study, we first evaluated the genetic effects of the stock enhancement program of silver carp (Hypophthalmichthys molitrix) on wild populations in the middle Yangtze River using the sequences of the mitochondrial Cytochrome b gene and control region (D-loop). 129 cytb individuals and 135 D-loop individuals were sequenced successfully, and the results obtained by two markers were similar. T test results showed that there was no significant difference in haplotype diversity (Hd) values and nucleotide diversity (Pi) values before and after release. The exact test result of population differentiation based on haplotype frequencies was consistent with no significant change in haplotype frequency after release. Pairwise genetic differentiation index (FST) and gene flow (Nm) revealed no genetic differentiation among four populations. Results of the Bayesian clustering analysis performed with STRUCTURE and analysis of molecular variance (AMOVA) confirmed that the genetic component did not change after release. In summary, there was no significant genetic effect of broodstock enhancement of silver carp on wild populations in the middle Yangtze River.