Xu Gefeng

用微卫星分析细鳞鲑( Brachymystax lenok )连续3代选育群体的遗传结构

本研究拟利用微卫星标记分析细鳞鲑（Brachymystax lenok）连续3代选育群体的遗传结构及差异。通过筛选出的22对细鳞鲑微卫星引物，利用PCR进行扩增后进行毛细管凝胶电泳，利用GeneMapper V4.1软件进行图像收集和数据分析。在3代共96个样本中共检测到181个等位基因，各标记检测的等位基因数为2—26个，平均为8.227个；3代平均等位基因数（Na）为6.500—6.773，平均有效等位基因数（Ne）为3.356—3.649，3代间Na和Ne差异均不显著；3代平均观测杂合度（Ho）为0.462—0.530，平均多态信息含量（PIC）为0.459—0.525，平均期望杂合度（He）为0.494—0.566；F2和F3的Ho、He、PIC 3项遗传多样性参数均显著低于F1（P＜0.05）；Hard-Weinberg平衡检验结果表明细鳞鲑3代选育群体整体保持了遗传平衡状态，但经Bonferroni校正后，尚有2个标记在F1和F3极限著偏离遗传平衡（P＜0.0005），3个标记在F2极限著偏离遗传平衡（P＜0.0005）。细鳞鲑在选育过程中通过群体选育等方法注重了对稀有等位基因的保护，在细鳞鲑多代选育过程中保持了较高的多态性水平，但在选育过程中某些等位基因出现了富集现象，3代间的遗传分化也较小，仅1.49%的遗传变异来自群体间，表明细鳞鲑群体尚具有持续选育的潜力。

Assessing genetic diversity in three wild Brachymystax lenok populations using AFLP markers

The genetic diversities of 72 individuals from three wild Lenok populations of Mudanjiang River (MD), Yalujiang River (YL) and Wusulijiang River (WSL) in the northeast of China were analysed using amplified fragment length polymorphism (AFLP) markers. The results showed that 541 polymorphic loci out of 559 were amplified by 12 primer pairs and the percentage of polymorphic loci was 96.78%. Shannon indices for the MD, YL and WSL populations were 0.3988±0.2913, 0.3254±0.3037, 0.2125±0.2862, respectively, and Neis gene diversity indices were 0.2737±0.2062, 0.2229±0.2129, 0.1446±0.1985, respectively. The average total genetic diversity ( H t ) was 0.3512±0.0.0208 and the average genetic diversity within populations ( H s ) was 0.2137±0.0152. Among the three populations, the average genetic distance ( D st ) was 0.1375 and the gene differentiation coefficient ( G st ) was 0.3914. The genetic diversity was 60.85% within populations and 39.15% among populations. The gene flow index ( N m ) was 0.7776. The analysis of molecular variance (AMOVA) indicated that the average fixation index ( F st ) was 0.55336. The variance was 55.16% within populations and 44.84% among populations. The highest polymorphism ratio was in the MD group and the lowest in the WSL group.