【摘要】 利用ISSR(InterSimpleSequenceRepeate)技术对文蛤(Meretrixmeretrix)江苏和辽宁两个地理种群进行了PCR扩增.从100条ISSR引物中筛选出引物13条,每条引物检测出位点数1到8.平均每条引物可检测到位点数4 6个.实验结果表明:江苏文蛤的位点多态性(80 7%)高于辽宁文蛤的位点多态性(68 4%);种群内平均遗传距离分别为0 3105±0 090和0 2658±0 044,江苏文蛤也高于辽宁文蛤.从筛选得到的引物可以发现,文蛤简单重复序列中A、G碱基含量较高.通过对不同实验条件的对比,对ISSR PCR反应体系进行了优化.更多还原

【Abstract】 The technique of Inter-Simple Sequence Repeates （ISSR） was applied to study on the genetic variations of two populations of Meretix meretrix. Thirteen ISSR primers were selected from 100 ones offered by University of British Columbia. Each primer yeilded 1 to 8 bands with the average of 4.6 bands. By comparing the differnet reaction conditions, the ISSR-PCR reaction system was improved. The reactions composed of 0.2?μmol/L primer,2.5?mmol/LMg²⁺,1.5?U Taq polymerase, 20?ng templete DNA; The optimized programs were predenaturation at 94℃ for 5?min, then 45 cycles containing denaturation 45?s at 94℃,annealing 45?rs at 52℃,and enlongation 1.5?min at 72℃; at last holding 10?min at 72℃. The optmimized con ditions culd result in satisfactory specificity and reproducibility of ISSR-PCR amplification patterns bands.The study through preanalysised two kinds of two stocks of Meretix meretrix （Meretix meretrix of Liaoning and Meretix meretrix of Jiangsu）demonstrated that the genetic polymorphism of Jiangsu’s （80.7%） was higher than Liaoning’s（68.4%）, and its average genetic distance in the Jiangsu’s population（0.310?5±0.090） was bigger than that of Liaoning’s（0.265?8±0.044） as well. It was found by the selected primers that the simple sequence tandem repeats （STRs） of Meretrix meretrix were mainly composed of AG dinucleotedes. Compering Meretrix meretrix of Liaoning, Jiangsu’s have larger genetic improving potential. The results showed that ISSR-PCR technique have application potential in study of genetic polymorphisms and germplasm of shellfishes.更多还原