散鳞镜鲤两个保种群体的遗传多样性

利用20个微卫星标记分析国内仅存的两个散鳞镜鲤（Cyprinus carpio）保种群体（SP、CJ）的遗传多样性。结果表明：共检测到147个等位基因，平均值为7.35，有效等位基因数（Ae）、期望杂合度（He）以及多态信息含量（PIC）的平均值分别为2.7828、0.6041和0.5386。SP群体的Ae、He以及PIC值分别为3.1126、0.6479和0.5948，大于CJ群体（2.4529、0.5602和0.4823）。在两个群体中，群体特有等位基因共53个，其中9个为低频等位基因。对20个引物在两个群体中等位基因的显著性分析表明：其中有16个引物可以作为区分两个群体的特异性分子标记。瓶颈效应分析结果显示：2个群体均经历了瓶颈效应。同胞率检测结果（SP 97.5%；CJ 96.7%）偏高说明群体内近交压力较大。哈迪-温伯格平衡检测表明：两个群体大部分位点偏离平衡并处于杂合子过剩状态。两个群体间的遗传距离（D）为0.5625，SP和CJ群体的个体均各聚为一支。群体间的遗传分化指数（Fst）为0.1138，Nm值为1.9462。该研究表明：散鳞镜鲤群体遗传多样性水平较高，其中SP群体的遗传多样性水平高于CJ群体，两群体处于中度遗传分化。

Microsatellite Marker Analysis of Genetic Diversity in Two Scattered Scale Mirror Carp Populations

Twenty polymorphic microsatellite markers were used to evaluate the genetic diversities in two scattered mirror carp （Cyprinus carp i o） populations sampled from Heilongjiang River Fisheries Research Institute （SP） and Yangtze River Fisheries Re-search Institute （C J）. The estimation of genetic variability indicated that a total of 147 alleles were detected with average of 7.35 at each locus. The average of effective number of alleles （Ae） was found 2.7828, expected heterozygosity （He） 0.6041, and polymor-phism information content （PIC） 0.5386. The SP population had Ae value of3.1126, He of 0.6479 and PIC of 3.1126, higher than CJ population （2.4529, 0.5602 and 0.4823 ） did. A total of 53 frequencies of private alleles were detected in the two scattered mirror carp populations, with low frequency alleles of 9. Significance analysis showed that there were 16 primers as specific molecular markers to distinguish the two populations. Bottleneck analysis illustrated that the two populations had experienced bottleneck effect recently. High Compatriots rate showed a high inbred pressure. Hardy-Weinberg equilibrium~ showed that the two populations were in disequilibrium mode. The genetic distance between the two populations was 0.5625 and the genetic similarity index 0.4375. Individu-al clustering showed that all SP individuals converged in the right branch of topology tree, and the 30 individuals of CJ population con-verged in the left branch. The values ofpairwise and gene flow were also estimated for the two populations, with pairwise Fst value of 0.1138, and Nm of 1.9462. The findings indicated that there were rich in polymorphism information content and large genetic diversity in the two scattered mirror carp populations, the level of genetic diversity of SP population being higher than CJ population, indicating that SP and CJ populations have a moderate level of differentiation.