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长江水系中华绒螯蟹是我国最重要的河蟹养殖群体,通常认为长江野生大眼幼体在成蟹阶段具有一定的生长优势,但是长江流域河蟹增殖放流和养殖群体逃逸可能对其野生大眼幼体遗传多样性造成一定的影响,尚未见相关报道。因此,本研究利用29对微卫星标记对河蟹长江水系野生和人工繁殖大眼幼体的亲缘关系及遗传多样性进行了分析。两群体大眼幼体均表现出较高的杂合水平,两个种群Ho分别为0.729 9和0.750 0,无显著差异(p>0.05)。两群体总近交系数(Fit)为0.171 2,群体内近交系数(Fis)为0.165 9,群体间分化系数(Fst)为0.006 4;分子方差分析(AMOVA)显示,99.7%的遗传变异来自种群内个体间,0.3%来源于种群间的变异,遗传分化程度较低;各位点的基因流Nm平均值为38.739 9,说明两种群基因交流频繁;群间平均遗传距离仅为0.106 7。瓶颈效应和遗传结构分析显示,两个群体近期经历过瓶颈效应,群体间间遗传混杂,不能分出有效理论种群数。综上所述,长江口河蟹野生大眼幼体的SSR遗传多样性稍高于人工繁殖群体,两者的遗传分化程度较低,这暗示两群体间存在基因交流。
The Yangtze River Eriocheir sinensis is the most important crab culture group in China. It is generally believed that the Yangtze River wild giant eyed larvae have some growth advantages in the crab stage, but the crab population excretion and escape from the Yangtze River may have genetic effects on the wild giant eyed larvae Diversity has a certain impact, but no relevant reports. Therefore, the genetic relationship and genetic diversity of 29 pairs of microsatellite markers in the wild and artificial reproductive magnocapacids of the Yangtze River crab were analyzed in this study. Both groups showed higher heterozygosity levels in the macroscopically larvae, and the two populations, Ho, were 0.729 9 and 0.750 0, respectively, with no significant difference (p> 0.05). The total inbreeding coefficient (Fis) of the two groups was 0.171 2, the inbreeding coefficient (Fis) of the two groups was 0.165 9, and the coefficient of variation (Fst) between the two groups was 0.006 4. The molecular variance analysis (AMOVA) showed that 99.7% Among the individuals within the population, 0.3% originated from the variation among populations and had a low degree of genetic differentiation. The average Nm of gene flow at each locus was 38.739 9, indicating that the two populations exchanged frequently and the average genetic distance between the two populations was only 0.106 7. Bottleneck effect and genetic structure analysis show that the two groups have recently experienced the bottleneck effect, the genetic heterogeneity among the groups can not be divided into effective theoretical population. In conclusion, the SSR genetic diversity of the wild large-eyed larvae in the Yangtze River Estuary was slightly higher than that in the artificial propagation population, indicating a low degree of genetic differentiation between the two groups, suggesting that there is gene exchange between the two populations.