野生和养殖牙鲆(Paralichthys olivaceus)遗传差异的RAPD和ISSR研究

RAPD AND ISSR ANALYSIS ON GENETIC DIVERSITY FOR WILD AND CULTURED OLIVE FLOUNDER PARALICHTHYS OLIVACEUS

利用RAPD和ISSR两种分子标记技术,分析了山东威海近海野生和养殖牙鲆的遗传多样性差异。结果表明,用10个RAPD引物对两个样本各30个个体的基因组DNA进行扩增,共获得110个重复性好且带谱清晰的扩增位点,片段大小在200—2500bp之间,野生样本和养殖样本的多态位点比例分别为59.09%和60·91%,Shannon多样性值分别为16·563和16·917,野生样本内平均遗传距离为0·17427,养殖样本为0·17553,样本间遗传距离为0·17419。用6个ISSR引物共在两样本中检测到161个位点,野生样本有111个(68·94%)为多态位点,养殖样本有112个(69·57%)为多态位点,野生和养殖样本的样本内平均遗传距离分别为0·19996和0·20007,样本间遗传距离为0·20002,Shannon多样性值分别为29·254和29·688。平均位点多态率显著性检验标明,无论是利用RAPD还是ISSR技术,两群体间平均位点多态率皆差异不显著,说明第一代养殖群体的遗传结构尚未发生明显变化。

Randomly Amplified Polymorphic DNA （RAPD） and Inter-Simple Sequence Repeat （ISSR） systems were used to detect the genetic diversity in wild and cultured populations of the olive flounder, Paralichthys olivaceus. Thirty individuals from each population were used. Of the 40 RAPD primers screened, 10 generated clear and reproducible bands. A total of 110 reproducible loci ranging from 200 to 2500bp were amplified from all the 60 individuals. The average percentages of polymorphic loci in wild and cultured populations were 59.09% and 60. 91% , while the Shannon＇s diversity indices of the two populations were 16.563 and 16. 917, respectively. The intra-population genetic distance was 0. 17427 in wild population and 0. 17553 in cultured population. Statistic analysis in terms of average percentage of polymorphic loci revealed no significant difference between the two populations （μ = 0. 274 〈μ0.05 - 1.96）. The genetic distance between the two populations revealed by RAPD analysis was 0. 17419. In ISSR analysis, 60 primers were screened and 6 were finally selected for further research. A total of 161 loci were obtained from all the 60 individuals, of which 111 （68.94%） in wild population and 112 （69.57%） in cultured population were polymorphic. The Shannon＇s diversity indices were 29. 254 in wild population and 29. 688 in cultured population, respectively. The intra-population genetic distances in wild and cultured populations were 0. 19996 and 0. 20007, respectively. The genetic distance between the two populations revealed by ISSR analysis was 0. 20002. No significant difference in the average percentages of polymorphic loci between the two populations was detected （μ = 0. 103 〈μ0.05 = 1.96）. The RAPD and ISSR systems produced similar results that the cultured population used in the present study did not show marked decrease in genetic diversity compared with the wild one. Because the cultured population in this study is the first generation offspring of wild caught parents.