牙鲆野生群体与养殖群体的遗传多样性分析

The Genetic Diversity of Wild and Farmed Japanese Flounder Populations

利用AFLP技术对荣成野生群体和养殖群体牙鲆进行遗传多样性分析和比较。实验采用 7对引物组合在 2个群体中共扩增出 797个位点 ,其中多态位点数为 43 3个 ,占总位点数的 5 4.2 7%。各引物组合在 2个群体中的扩增位点数目和多态位点比例有较大不同 ,但养殖群体的总扩增位点数和多态位点比例均低于野生群体 ,野生群体和养殖群体的平均多态位点率分别为 46.18%和 40 .0 7% ,其中 ,E3 8M 5 0引物组合在两群体中扩增的多态位点比例差异显著 (P <0 .0 5 )。养殖群体中低频位点明显减少而隐性纯合基因位点显著增加。群体遗传结构分析表明 ,两群体间的遗传距离比较小 ,群体遗传结构相似 ,说明养殖群体尚没有形成自己独立的遗传结构。

The genetic diversity of cultured and wild populations of Japanese flounder, Paralichthys olivaceus, were analyzed and compared using AFLP. The wild population was collected from the coastal area of Rongcheng, Shangdong Province and the cultured population was hatchery-reared offspring of wild caught individuals from the same area. A total of 797 loci were generated with 7 primer combinations, of which 433 (54.27%) were polymorphic loci. Variations in the ability to detect genetic diversity among different primer combinations were observed in both wild and culture populations. However, the cultured population showed smaller numbers of total loci and lower percentages of polymorphic loci. The average percentages of polymorphic loci in the wild and cultured populations were 46.18% and 40.07%, respectively. The noticeable decrease in the number of rare loci and the increase in the number of homozygous recessive loci in the cultured population suggested a considerable loss of rare alleles in the cultured population. This may have resulted from small effective population sizes during artificial seed production.