Abstract:16S rRNA and COI fragments from two mitochondrial genes of Portunus trituberculatus sampled from three sites (Hokkaido of Japan, the east coast of South Korea and Huichang, Jimo of China) were amplified and sequenced. The variable sites, nucleotide diversity, average number of nucleotide differences and nucleotide diversity index were calculated, and the sequence differences and genetic diversity levels among three different populations were compared. The results show that levels of genetic diversity of Chinese wild population are low. The molecular phylogenetic tree of 16S rRNA was different with that of COI gene, which was constructed using NJ method with software MEGA 4.0. Their main difference was in the classification relationship with Charybdis. The phylogenetic tree of 16S rRNA gene sequences show that Portunidae are clustered into two branches: different haplotypes of P. trituberculatus clustered first, then with P. pelagicus and P. sayi; the three kinds of Scylla clustered first, then with Charybdis japonica. In this study, 19 haplotypes were obtained, and Huichang, Hokkaido and east coast of South Korea populations possessed shared haplotypes, indicating that these three wild P. trituberculatus populations had similar genetic background. These findings are expected to provide molecular biological basis for the protection and utilization of P. trituberculatus resources in China..
