安徽三大水系入侵物种克氏原螯虾的种群遗传格局  

Genetic patterns of an invasive Procambarus clarkii population in the three river basins of Anhui Province

作　　者：曹玲亮[1] 周立志[1] 张保卫[1] 

机构地区：[1]安徽大学生命科学学院生物多样性与湿地生态研究所,安徽省生态工程与生物技术重点实验室,合肥230039

出　　处：《生物多样性》2010年第4期398-407,共10页Biodiversity Science

基　　金：安徽省教育厅重点科研项目(KJ2009A179);安徽大学人才培养项目

摘　　要：克氏原螯虾(Procambarus clarkii)是长江中下游地区较为常见的外来物种,目前已经扩散到安徽境内的主要水系。我们采集了安徽境内长江、淮河和新安江三大流域的4个地区9个地点的182个样本,利用9对微卫星分子标记,通过PCR扩增和微卫星分型,分析了其种群遗传多样性水平和遗传结构,构建了地方种群的遗传距离格局。结果表明本研究区域克氏原螯虾种群遗传多样性处于较高水平,总的期望杂合度(HE)和观测杂合度(HO)分别为0.78和0.36。望江种群遗传多样性最高(期望杂合度为0.76),肥西种群遗传多样性最低(期望杂合度为0.56)。克氏原螯虾种群显示了极强的杂合子缺失,人为捕捞可能是造成其种群私有等位基因数目较多和杂合子缺失的主要原因。地方种群分化系数(Fst)与地理距离呈显著正相关(r=0.33,P<0.05),望江种群和城东湖种群存在明显的跳跃性扩散(jump dispersal)。因此,水系间的交流是种群扩散的主要途径,人为贸易促使克氏原螯虾种群在不同地区的交流,对其种群扩散也有一定的作用。Procambarus clarkii is an alien invasive crayfish species that occurs in the major river basins along the middle and lower reaches of the Yangtze River.To understand genetic diversity and population structure of the species in the region,we collected 182 individuals from nine sites in four regions in the Yangtze,Huaihe,and Xin＇anjiang River basins in Anhui Province.Using nine pairs of microsatellite markers,we studied the genetic differentiation,genetic structure and genetic clustering pattern of these P.clarkii populations.The expected heterozygosity（HE） was 0.78 while the observed heterozygosity（HO） was 0.36.Of the nine populations,the highest expected heterozygosity（0.76） was in the Wangjiang population,and the lowest（0.56） was for the Feixi population.Using a Bottleneck Test,we found a significant signal of heterozygote deficiency,indicating a recent decline in these populations.Our studies also showed that there were high levels of gene flow among populations,and a significant correlation found between genetic distance and geographic distance（r = 0.33,P 0.05）.We detected evidence of a significant jump dispersal event between the Xin＇anjiang and Chengdonghu populations,thus indicating that human-mediated dispersal has played an important role in the present genetic structure of Procambarus clarkii population.

关 键 词：PROCAMBARUS CLARKII 微卫星 遗传结构 生物入侵 物种扩散 

分 类 号：Q958[生物学—动物学]