中华绒螯蟹长江、黄河和辽河水系野生和养殖群体的遗传多样性

中华绒螯蟹(Eriocheirsinensis)是中国最重要的淡水养殖蟹类,广泛分布于东亚地区,养殖区域主要集中在长江、黄河和辽河流域。本研究基于线粒体DNAD-loop区评估辽河野生群体(LW)和养殖群体(LC)、黄河野生群体(HW)和养殖群体(HC)及长江野生群体(YW)和养殖群体(YC)的遗传多样性和种群结构。结果显示:(1)用于本研究的D-loop基因片段长度为477 bp,共包含234个变异位点和131个简约信息位点, 6个群体的262个个体中共有110个单倍型,包括90个独有单倍型和20个共享单倍型;(2)6个种群的单倍型多样性指数(Hd)范围为0.88889～0.96522,核苷酸多样性指数(π)范围为0.00887～0.01602,养殖和野生群体遗传多样性水平依次为:HCYCLC及HWLWYW;(3)6个群体的遗传距离(Da)范围为0.0119～0.0173,不论是养殖群体还是野生群体,辽河群体和长江群体之间的遗传距离均最小,且6个群体间遗传分化指数FST为0.12938。对6个群体进行中性检验显示Tajima’s D和Fu’s Fs的值均为负值。综上,基于线粒体D-loop基因的研究结果表明,三水系养殖和野生群体均具有较高的遗传多样性,且辽河和长江水系中华绒螯蟹的亲缘关系相对较近,该研究为中华绒螯蟹的种质资源评估、保护和开发提供了参考。

Genetic diversity analysis of wild and cultured Eriocheir sinensis populations from the Yangtze River, Yellow River, and Liaohe River based on the mitochondrial D-loop gene

The Chinese mitten crab, , is one of the most important aquaculture species in China, and is widely distributed in Eastern Asia. This study was conducted to evaluate the genetic diversity and genetic structure of cultured and wild populations of River, and Liaohe River based on the mitochondrial DNA D-loop region. The results showed that the length of the D-loop gene segment used in this study was 477 bp, which contained a total of 234 variation sites and 131 parsimony information sites for all tested samples. The 262 samples from six populations had 110 haplotypes, which consisted of 90 unique haplotypes and 20 shared haplotypes. The haplotype diversity index () of the six populations ranged from 0.88889 to 0.96522, and the nucleotide diversity index () ranged from 0.00887 to 0.01602. The genetic diversity levels of cultured populations were HC > YC > LC, whereas the levels of wild populations were HW > LW > YW(LC and LW indicate cultured and wild population of Liaohe River respectively, HC and HW indicate cultured and wild population of Yellow River respectively, YC and YW indicate cultured and wild population of Yangtze River respectively). The genetic distance () ranged from 0.0119 to 0.0173 for the six populations. Regardless of their wild or cultured status, the genetic distance between the Liaohe and Yangtze populations was the smallest among three rivers. The genetic differentiation index () was 0.12938 among the six populations. A neutral test of the six populations showed the values of Tajima''s were negative. The population''s Tajima''s value test showed that these groups have a complex population history, and it is speculated that has had a large-scale group expansion event. The genetic distances of the six populations were analyzed. It was found that the overall genetic distance was not large. The results of genetic differentiation showed that there was no significant difference between the LW and YC, and YC and YW populations. The results of the AMOVA analysis of the six populations showed that population genetic differences mainly occurred in the six population. The phylogenetic trees may have resulted from of a certain degree of confounding caused by the cross-regional introduction of the Chinese mitten crab population in the Liaohe River system. These results provide valuable information for the evaluation, protection, and exploitation of resources.