Assessment of genetic differentiation in the large yellow croaker, Pseudosciaena crocea Richardson, and its first hybrid filial generations with AFLP markers

The genetic diversity (the digital characteristics) of four populations (120 individuals) of breeding large yellow croakers, Pseudosciaena crocea Richardson, was analyzed with amplified fragment length polymorphism (AFLP) markers. Ten primer combinations amplified 248 bands, of which 39.52% were polymorphic. Shannon's information index of the Daiqv (DQ) population was higher than that of the Minyu (MY) population, at 0.2167 and 0.2074, respectively. Additionally, the Shannon's information index value for the minus-hybrid (DQ population♂ × MY population♀) first hybrid generation was higher than the value for the plus-hybrid (MY population♂ × DQ population♀) first hybrid generation at 0.1687 and 0.1613, respectively. The FST of the parental generation was lower than that of the filial generation at 0.0329 and 0.0891, respectively. Gene flow was very high according to Fst values in both parental and filial generations. The UPGMA clustering analysis based on genetic similarity organized the four populations into three groups. The minus-hybrid stock was the most distinct as compared to the other populations.Reciprocal cross hybridization was an effective method in improving the genetic diversity of the large yellow croaker, and the minus-crossing methods were especially improved as compared to plus-crossing.