梭鱼(Liza haematocheila) 4个野生地理群体遗传多样性的微卫星分析

Analysis of Genetic Structures of Four Wild Geographoic Populations of Mullet Liza haematocheila by Using Microsatellite Marker Technique

中文关键词: 梭鱼  地理群体  微卫星  遗传多样性

英文关键词: Mullet Liza haematocheila  Geographical population  Microsatellite  Genetic diversity

中文摘要:

      利用14对微卫星引物，对采捕于辽宁葫芦岛、山东青岛、江苏连云港以及浙江舟山附近海域的梭鱼(Liza haematocheila) 4个野生地理群体进行群体遗传多样性分析。结果显示，14对微卫星引物均能扩增出清晰的条带且具有一定的多态性，4个野生群体的多态性百分率分别为92.86%、92.87%、100.00%和85.71%。4个群体共扩增出61个等位基因，4个群体的等位基因数为3.786−4.000，有效等位基因数为2.673−2.899，观测杂合度为0.359−0.389，期望杂合度为0.503−0.561，多态信息含量为0.465−0.513，说明4个群体遗传多样性处于中等多态水平。运用SPSS软件对杂合度期望值进行Kruskal-Wallis检验，其结果(H=0.187，df=3，P=0.980)表明，4个群体间的遗传多样性差异无统计学意义(P>0.05)，各群体大部分微卫星位点偏离Hardy-Weinberg平衡(P<0.05)。另外，研究发现，葫芦岛和舟山均出现两个位点呈现杂合子过剩，其他两群体均出现3个位点呈现杂合子过剩(Fis<0)，表明近期可能出现过瓶颈效应。所有群体间遗传分化系数为0.148，基因流值为1.444，群体间出现中度遗传分化，群体间出现一定程度基因流。两群体间的遗传相似性系数为0.623−0.818，遗传距离为0.202−0.473，青岛和葫芦岛的遗传距离最近(0.202)，而连云港和舟山的最远(0.473)，这可能与梭鱼幼体的扩散能力及近海沿岸生态环境及群落结构有关。采用UPGMA法对4个群体进行聚类分析，结果显示，4个地理群体按其地理位置由北向南依次聚为一类。

英文摘要:

      In this study, fourteen markers were analyzed to assess the genetic diversity of four wild geographical populations of Liza haematocheila from the adjacent waters of Huludao, Qingdao, Lianyungang, and Zhoushan. The results showed that there was a certain degree of polymorphism in the four populations and the percentages of polymorphic loci were 92.86%, 92.87%, 100%, and 85.71% respectively. A total of 61 alleles were detected in the four populations, and the average number of alleles was between 3.786 and 4.000 for each population and the effective number of alleles was from 2.673 to 2.899. The average values of observed and expected heterozygosity ranged from 0.359 to 0.389 and from 0.503 to 0.561 respectively. The mean polymorphic information contents were from 0.465 to 0.513. These results suggested that there was a moderate genetic diversity among the four populations, however, the Kruskal-Wallis test (SPSS software) indicated no significant difference in the genetic diversity among the four populations (H=0.187, df=3, P=0.980). The majority of loci in each population were found to deviate from the Hardy-Weinberg equilibrium (P<0.05). Moreover the Huludao and Zhoushan populations were found to have two loci with heterozygote excess (Fis<0), while the other two populations had three loci with heterozygote excess. This was probably caused by recent bottleneck effect. The values of genetic differentiation coefficients and gene flow were 0.148 and 1.444 respectively, which suggested a medium level of genetic differentiation and a certain degree of gene flow between the four populations. The genetic similarity coefficients of the four populations ranged from 0.623 to 0.818 and the genetic distance was between 0.202 and 0.473 among the populations. The genetic distance was the nearest between Huludao and Qingdao, and was the farthest between Lianyungang and Zhoushan. These results could be related to the diffusion of the mullet larvae, the inshore coastal ecological environment, and the community structure. Cluster analysis with the UPGMA method showed that the four geographic populations could converge into one cluster according to their distribution from north to south.