菲律宾蛤仔不同地理群体生化遗传结构与变异的研究

Biochemical genetic structure and variation in different populations of Ruditapes philippinarum

采用聚丙稀酰胺凝胶电泳技术对福建平潭岛、浙江象山港、江苏海州湾和辽宁辽东湾4个海区菲律宾蛤仔(Ruditapes philippinarum)野生群体的生化遗传特征进行了分析。结果表明,菲律宾蛤仔4个群体的多态位点比例为62.5%～75.0%,平均杂合度观测值在0.2743～0.3387之间,与平均杂合度期望值相近;平均有效等位基因数在1.4891～1.6325之间,遗传变异水平较高;杂合子缺失不显著。比较群体间的遗传分化指数和群体每代迁移数发现,平潭岛、象山港和海州湾3个群体间的遗传分化不显著,而辽东湾群体与3个群体间出现遗传差异。聚类分析同样表明,平潭岛群体首先与象山港群体聚类,再与海州湾群体相聚,最后与辽东湾群体相汇。讨论了杂合子缺失不显著原因和群体间遗传分化机制。

The biochemical genetics in four populations of Ruditapes philippinarurn, which were collected from Pingtan Island, Haizhou Bay, Xiangshan Harbor, and Liaodong Bay, were analyzed by polyacrylamide gradient gel vertical electrophoresis. The results showed that the percentages of polymorphic loci （P. 95） of the four populations varied from 62. 5% to 75.0% , the average heterozygosities ranged from 0. 274 3 to 0. 338 7. The mean effective numbers of alleles in loci varied from-0. 066 7 to 0. 026 0, and the populations of R. philippinarum demonstrated a high genetic variability. Based on the coefficient of genetic differentiation and the number of migrants per generation, the genetic divergence between the populations of Pingtan Island, Haizhou Bay and Xiangshan Harbor was infinitesimal, while the genetic divergence between the three populations and the population of Liaodong Bay was slightly evident. Clustering analysis also showed that the populations of Pingtan Island and the population of Xiangshan Bay were clustered with priority, then the population of Haizhou Bay joined, finaly the population of Liaodong Bay joined the group. The genetic differentiation mechanism of populations and the cause of indistinctively heterozygosity deficiency were also discussed in the paper.