缢蛏6个群体遗传结构的ISSR分析

ISSR Analysis on Genetic Structure of Six Sinonovacula constricta Populations

采用ISSR分子标记对采自福建宁德(ND)、浙江台州(TZ)、上海崇明(CM)、山东海阳(HY)、天津汉沽(HG)和辽宁庄河(ZH)的缢蛏6个野生群体进行遗传多样性和遗传关系分析.筛选出10条ISSR引物对6个群体共216个样品进行扩增,共得到138个清晰的扩增位点,其中多态性位点135个,多态位点百分率为97.83%,在物种水平上的遗传多样性较为丰富.群体遗传多样性分析结果表明,6个群体的多态位点百分率在61.59%～72.46%之间,基因多样性指数和Shannon’s信息指数分别在0.1043～0.1766和0.1789～0.2808之间,其中ND群体的多样性指数最低.群体间遗传分化、遗传距离和聚类结构显示,ND群体和TZ群体亲缘关系最近,首先聚为一支,之后依次与CM群体及HG群体和HY群体聚类,最后与ZH群体聚在一起,表明地理位置较远的群体,遗传距离也较远.

The genetic structure of six geographic populations of the razor clam Sinonovacula constricta along the coast of China was investigated by the inter-simple sequence repeat （ISSR）. The six populations were named as ND in Ningde City of Fujian, TZ in Taizhou City of Zhejiang, CM in Chongming Island of Shanghai, HY in Haiyang City of Shandong, HG in Hangu District of Tianjin and ZH in Zhuanghe City of Liaoning. Of the 138 ISSR loci tested, 135 （97.83%） were polymorphic with 10 ISSR primers. The number of alleles （N）, effective number of alleles （N）, Shannon＇s information index （I）, mean Nei＇s gene diversity （H）, percentage ofpolymorphic bands （PPB）, average values of lit, H, and Gst for pairwise subpopulations were analyzed with POPGENE. The results showed that the values of PPB, I and H were 61.59%-72,46%, 0.104 3-0.176 6 and 0.178 9-0.280 8, respectively for the six populations with the lowest values in ND population. The UPGMA tree based on the Nei＇ genetic identity showed that ND was clustered with TZ into one clad, then with CM, HY and HG, and finally with ZH.