提要 利用RAPD技术对栉孔扇贝(Chlamys farreri)的四个自然群体(大连、烟台、青岛、韩国)的遗传多样性进行了分析。12个随机引物在四个群体中共检测到123个位点,其中多态位点109个,多态位点比例为88.62%;四个群体中均未检测到各群体特有的扩增带。韩国、烟台、大连、青岛四个群体的遗传多样性指数(Shannon指数)分别为0.2557、0.2557、0.2344和0.2249,以韩国和烟台群体遗传多样性较高,其次为大连群体,青岛群体最低,但它们之间无明显差异。不同群体的遗传多样性指数的平均数Hpop为0.2427,整个栉孔扇贝自然群体的遗传多样性指数Hsp为0.2503。遗传多样性剖分显示,绝大多数(97%)的遗传多样性是由群体内不同个体间的差异造成的,只有很小部分(3%)的遗传多样性与群体间的遗传分化有关。而采用基于单倍型(等位基因)之间的进化距离的AMOVA分析得到的这两个数据则分别为99%和1%,中值为0.010,且P=0.05,表明群体间遗传分化明显程度位于临界值。
Genetic diversity of four wild populations of Zhikong scallop Chlamys farreri collected from Dalian (DL), Yantai (YT), Qingdao (QD) and Korea (SK) were examined using RAPD technique. Thirty oligonucleotide primers were screened, and then 12 were selected to amplify genomic DNA from 80 samples representing the four populations. A total of 123 loci were scored for these samples and 109 were polymorphic. The mean percentage of polymorphic loci over the four populations was 88.62%. No population-specific bands were detected in any population. Shannon index of phenotype polymorphism was used to quantify polymorphisms. The indexes of genetic diversity of the four populations were 0. 2344 (DL) , 0. 2557 (YT), 0. 2249 (QD) and 0. 2557 ( SK), respectively. Partitioning analysis of genetic diversity in Shannon index indicated that 96.97% of genetic variation was distributed within populations and 3.03% from between populations. The same analysis with AMOVA presented 99% and 1% for the two categories of variation resources, respectively, with Ф=0.010 and P=0.05, indicating significance magnitude of genetic divergence at critical point.