塔玛亚历山大藻遗传多样性的微卫星分析

Genetic Diversity among Populations of the Toxic Dinoflagellate Alexandrium tamarense Revealed by Microsatellite Markers

摘要:

应用12个微卫星标记对9株来自欧洲和中国等不同海域的塔玛亚历山大藻(Alexandrium tamarense)进行了遗传多样性分析，探讨了不同地理藻株之间的遗传分化程度和基因流水平，分析了我国沿海塔玛亚历山大藻的遗传多样性。结果表明：9株塔玛亚历山大藻共检测出26个等位基因，其中9个位点具有多态性，多态比率75%。有效等位基因数1.3243～3.2667，平均为1.8774。塔玛亚历山大藻种内基因多样性为0.3630。9株塔玛亚历山大藻大致可以分为3个进化支，进化支与藻株的地理位置相关联。其中，中国海域的塔玛亚历山大藻至少可分为2个进化支。不同地理分布的塔玛亚历山大藻的遗传分化水平较高，达0.7522。种群间的基因流估算水平较低，提示3个种群间可能不存在基因交流。

Abstract:

Alexandrium tamarense was a wide-spread species of dinoflagellate causing harmful algal blooms and paralytic shellfish poisoning around the world. The genetic diversity of 5 European and 4 Chinese strains of A. tamarense was analyzed by using microsatellite markers. Relative low genetic diversity was revealed in the 9 strains of A. tamarense, with effective number of alleles of 1.3243~3.2667 and gene diversity of 0.3630. Based on the markers, the 9 strains of A. tamarense were divided into three lineages with genetic differentiation of 0.7522, which related to their geographic origins. Chinese samples could be divided into two lineages, and the European strains belong to another lineage. High genetic differentiation among the three populations suggested the lack of gene flow.