浙江近海三疣梭子蟹群体遗传结构的初步分析

Study on population genetic structure of Portunus trituberculatus offshore Zhejiang

对我国浙江近海4个采样点(长江口、嵊泗群岛、舟山群岛、洞头群岛)的147个三疣梭子蟹个体的线粒体DNA 16S rRNA部分序列进行了测定和分析,获得其基因片段长度为991 bp,共发现14种单倍型,11个核苷酸多态性变异位点。长江口、嵊泗群岛、舟山群岛、洞头群岛4个地方群体的平均核苷酸多样性和单倍型多样性分别为0.000 89和0.565。其中,嵊泗群岛群体的遗传多样性水平最高(核苷酸多样性0.001 27,单倍型多样性0.754),长江口群体最低(核苷酸多样性0.000 34,单倍型多样性0.322)。长江口与嵊泗群岛群体之间的遗传分化指数最大(0.102 26),舟山群岛与洞头群岛群体之间遗传分化指数最小(0.025 75);舟山群岛和洞头群岛群体之间的基因流最大(9.46),长江口与嵊泗群岛群体之间基因流最小(2.19)。

The partial sequences of mtDNA 16S rRNA of 147 Portunus trituberculatus individuals sampled from the coastal waters of the East China Sea in Zhejiang Province （ Changjiang estuary, Shengsi islands, Zhoushan islands, Dongtou islands） were sequenced and analyzed. A fragment of 991 base pairs of P. trituberculatus mtDNA 16S rRNA gene was amplified, and 11 polymorphic sites and 14 distinct haplotypes were defined in our study. The mean sequence divergence values between nucleotide and haplotypes diversity was 0.000 89 and 0.565, respectively. Shengsi islands population had the highest genetic diversity （ π= 0. 001 27, h = 0. 754） , and Changjiang estuary population possessed the lowest （ π = 0. 000 34, h = 0. 322）. The coefficient of genetic differentiation between Changjiang estuary and Shengsi islands populations was the highest （0. 102 26）, and the lowest between Zhoushan and Dongtou islands populations（0. 025 75 ）. The largest gene flow was detected between Zhoushan and Dongtou populations （9.46）, and the lowest between Changjiang Estuary and Shengsi islands populations（2.19 ）.