3个德国镜鲤养殖群体遗传变异的微卫星分析

The microsatellite analysis of genetic variability for 3 domesticated populations of German mirror carp

利用10个多态微卫星标记对我国北方不同地区3个德国镜鲤（Cyprinus carpio L．mirror）群体（绥化，BL；哈尔滨，BZ；天津，TJ）的遗传多样性及群体间的亲缘关系进行研究。结果显示，3个养殖群体在10个位点上表现出较高的多态性，其中9个位点表现为高度多态（PIC〉0．5）；平均杂合度为0．6293；10个位点共检测出144个等位基因；BL与TJ群体的总体变异水平高于BZ群体。Nei氏DA遗传距离分析显示，BL与TJ群体的遗传距离最近，而与BZ群体的遗传距离最远；群体间遗传分化微弱（Fst=0．0315），群体内变异占总变异的96．85％，3个群体各自特有的等位基因频率普遍较低（0．0125～0．1500），群体共有的等位基因频率相对较高。上述结果表明，3个德国镜鲤养殖群体仍保持着较高的遗传多样性，群体间未产生明显的遗传分化。

Nowadays, the selective German mirror carp （Cyprinus carpio L. mirror） is one of the excellent breeds adapted to pond conditions in the North area of China. In China, however, the information on their genetic variability is unavailable. Here, to evaluate the genetic diversities and relationships among 3 populations （BL, BZ and TJ ） located at Suihua, Harbin and Tianjin of China respectively, 10 polymorphism microsatellite markers were used. The results demonstrated that 3 populations showed high polymorphism in 9 loci （PIC 〉 0.5 ）, and the average heterozygosity degree per locus was 0. 629 3. Meantime, 144 alleles were detected in all examined loci. Among them, BL and TJ populations had higher genetic variation than BZ population. The analyses of Nei ＇ s DA genetic distance indicated the closest relationship was between BL and TJ, and the largest distance was observed between BL and BZ. Only little genetic differentiation was detected among the 3 populations （Fst = 0. 031 5）, and the internal variation was 96.85% of the total variation. Furthermore, the own alleles frequencies of each population were commonly lower （0. 012 5 -0. 150 0）, but the shared alleles frequencies of total populations were relatively higher. Therefore, it is concluded that the selective populations of German mirror carp in different regions of China still kept high genetic diversity, and the genetic differentiation among populations was not significant.