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中华绒螯蟹(Eriocheir sinensis)的生命周期通常为两年,繁殖结束生命也就终止。在理论上,相邻两个年份中华绒螯蟹群体间不存在遗传婚配或基因交流,而存在奇年与偶年两个系谱之分。为检验长江野生中华绒螯蟹奇、偶年份群体的遗传差异,应用18对微卫星引物,对2004-2011共7年采集的中华绒螯蟹长江口天然繁殖群体进行了遗传分析。结果表明:(1)偶年群体(2004、2006、2008、2010)的观测杂合度和期望杂合度显著高于奇年群体(2007、2009、2011),P<0.05;(2)奇、偶年群体间的遗传分化差异显著(P=0.024);(3)基于遗传距离的NJ聚类关系树表明:奇、偶年群体形成较为明显的两个遗传聚类;(4)主成分分析(PCA)和STRUCTURE遗传聚类分析均表明:奇、偶年类群的分化明显,但两群体间存在一定程度的遗传渐渗与基因交流;(5)两个偶年(2004、2006)和两个奇年(2007、2011)群体检测到显著的遗传瓶颈效应。研究结果综合表明:长江天然中华绒螯蟹群体存在较明显的奇年与偶年差异,但两者间也存在一定程度的基因交流。
The life cycle of Eriocheir sinensis is usually two years, and the end of life ends. In theory, there is no genetic marriage or gene exchange between two populations of Chinese mitten crab (Eriocheir sinensis) in the two adjacent years, but there are two genealogies of odd and even years. In order to test the genetic diversity of the wild crab population in Yangtze River, we analyzed the genetic diversity of natural population of Yangtze River Eriocheir sinensis collected from 2004-2011 for seven years with 18 pairs of microsatellite primers. The results showed that: (1) The observed heterozygosity and expected heterozygosity of adolescents (2004,2006,2008,2010) were significantly higher than those of the odd year population (2007,2009,2011), P <0.05; (2) odd and even (P = 0.024). (3) NJ clustering tree based on genetic distance showed that two or more genetic clusters were formed in odd and even adolescents groups. (4) Principal component analysis PCA) and STRUCTURE genetic clustering analysis showed that the differentiation of odd and even perennial groups was obvious, but there was a certain degree of genetic introgression and gene exchange between the two groups; (5) Two occasional (2004, 2006) and two Bizarre (2007, 2011) groups detected significant genetic bottleneck effects. The results of the comprehensive study show that there are obvious differences between the odd and even years in natural Yangtze Eriocheir sinensis population, but there is also a certain degree of gene exchange between the two populations.