细鳞鱼三个野生种群的遗传多样性AFLP分析

细鳞鱼是我国一种珍贵的淡水经济鱼类，在人类和环境因素的影响下数量急剧下降。本文采用扩增片段长度多态性（Amplified Fragment Length Polymorphism, AFLP）技术对牡丹江（Mudanjiang River, MD）、鸭绿江（Yalujiang River, YL）和乌苏里江（Wusuli River, WSL）的三个细鳞鱼野生种群共72个个体进行了遗传多样性分析。结果显示，12对选择性扩增引物共扩增得到559个位点，其中多态性位点541个，多态性百分比为96.78％。文中对3个群体的Shannon多样性指数，Nei氏基因多样性等参数进行了分析。其总基因多样性Ht平均值为0.3512±0.0208；种群内基因多样性Hs平均值为0.2137±0.0152；群体间的基因多样性Dst为0.1375。基因分化系数Gst为0.3914，种群内的基因多样性占总群体的60.85%，种群间为39.15%，而基因流系数Nm 为0.7776。分子方差分析（AMOVA）表明：群体平均遗传分化系数Fst为0.55336，变异来源有44.84%来自群体间，55.16%来自群体内。三个群体中牡丹江群体的细鳞鱼种内多态性比例最高，而乌苏里江群体最低。

Assessment of Genetic Diversities in Three Wild Brachymystax lenok Populations by AFLP Markers

Lenok (Brachymystax lenok), which was a famous endemic fish in China, had undergone a dramatic decline for the impacts of human and environment. In this paper, the genetic diversity of the seventy-two individuals, which from the three wild populations of Mudanjiang River (MD), Yalujiang River (YL) and Wusuli River (WSL) respectively, were analyzed using the AFLP method. In total, 541 polymorphic loci of 559 were amplified with 12 primer pairs and the percentage of polymorphic loci was 96.78 %. The Shannon information index of the MD, YL and WSL populations was 0.3988±0.2913, 0.3254±0.3037, 0.2125±0.2862, respectively. And the Nei's gene diversity index was 0.2737±0.2062, 0.2229±0.2129, 0.1446±0.1985, respectively. The average Ht was 0.3512±0.0.0208 and Hs was 0.2137±0.0152. Among the three populations the average genetic distance (Dst) was 0.1375. The gene differentiation coefficient (Gst) of 0.3914 indicated that there was genetic differentiation of a certain degree among the populations. The genetic diversity was 60.85% within population and 39.15% among the population. The gene flow index (Nm) was 0.7776. The AMOVA analysis indicated that the average Fst was 0.55336. 44.84% of variance was among populations and 55.16% within populations. The MD group showed the highest polymorphism ratio and the lowest in WSL group.