基于AFLP分析的乌江四川裂腹鱼种群遗传结构及多样性研究

AFLP analysis of genetic structure and diversity in population of Schizothorax kolzovi from the Wujiang River

中文关键词: 乌江  四川裂腹鱼  种群  AFLP  遗传多样性

英文关键词: Wujiang River  Schizothorax kolzovi  Population  AFLP  Genetic diversity

中文摘要:

      本研究采用扩增片段长度多态性(AFLP)分子标记技术，以筛选出的7对引物，对采自贵州乌江的30尾四川裂腹鱼(Schizothorax kolzovi)的遗传结构和多样性进行分析。结果显示，用7对引物获得的扩增片段数为5~73，扩增片段长度范围为69~500 bp，共检出扩增位点856个。其中，多态位点796个，占扩增总位点数的92.99%。该种群含30个基因型，其观测等位基因数(Na)、有效等位基因数(Ne)、Nei多样性指数(H)、Shannon信息指数(I)平均值分别为1.933 6、1.338 8、0.212 2和0.338 7。个体之间遗传距离为0.169 1~0.531 9，平均为0.306 8。根据遗传距离，采用UPGMA法和NJ法得到了拓扑结构相似的30个个体的系统树，该系统树由2个分支组成。其中，个体1为一个分支，而其余29个个体聚为另一个分支。乌江四川裂腹鱼种群具有较丰富的遗传多样性。然而，受水电站建坝、河流污染和酷渔滥捕的影响，该种群分布区已缩小，种群数量减少，处于生态受威胁状态，需要开展对乌江四川裂腹鱼种群及种质资源的保护。

英文摘要:

      Schizothorax kolzovi, which belongs to Cypriniformes, Cyprinidae and Schizothoracinae, is a wild fish species of high economic value, distributed in the Jinsha, Yalong, and upper Wujiang Rivers of the Yangtze River system and the Beipan River in the Pearl River system in China. To assess the genetic diversity and germplasm resources of S. kolzovi in the Wujiang River, Guizhou, the genetic structure and diversity were analyzed in the 30 individuals of the species from the river by the methods of amplified fragment length polymorphism (AFLP). With 7 pairs of selected primers through the pre-experiment, 5~73 DNA fragments were amplified in the 30 individuals, ranging from 69 to 500 bp. A total of 856 loci were detected, including 796 polymorphic loci accounting for 92.99% of the total. The population contained 30 genotypes, and the mean values of the observed number of alleles (Na), effective number of alleles (Ne), Nei diversity index (H), and Shannon information index (I) were 1.933 6, 1.338 8, 0.212 2, and 0.338 7, respectively. The genetic distance between individuals ranged from 0.169 1 to 0.531 9, with an average of 0.306 8. The unweighted pair group method with arithmetic mean (UPGMA) and neighbor-joining (NJ) phylogenetic trees of the 30 individuals contained 2 branches and had the similar topological structure. The S. kolzovi population in the Wujiang River contained rich genetic diversity. However, hydropower station dams, river pollution, and overfishing have reduced the distribution of S. kolzovi, and its population size has declined. Therefore, this species is ecologically threatened, and the population and germplasm resources of S. kolzovi in the Wujiang River needs to be protected.