Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan Hubei 430072, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Zool Res. 2019 Sep 18;40(5):427-438. doi: 10.24272/j.issn.2095-8137.2019.027.
Small populations with low genetic diversity are prone to extinction. Knowledge on the genetic diversity and structure of small populations and their genetic response to anthropogenic effects are of critical importance for conservation management. In this study, samples of , an endemic cyprinid fish from the upper reaches of Yangtze River, were collected from five sites to analyze their genetic diversity and population structure using mitochondrial cytochrome gene and 14 microsatellite loci. Haplotype diversity, nucleotide diversity, and expected heterozygosity indicated that the populations had low genetic diversity, and decreased heavily from 2001 to 2016. Significant genetic differentiation was found among different populations in the cyt gene and SSR markers based on the genetic differentiation index ( ), whereas no differentiation was found in 2001. Haplotype genealogy showed that eight out of 15 haplotypes were private to one population. The SSR STRUCTURE analysis showed that there were four genetic clusters in the samples, with each population forming a single cluster, except for the Chishui River (CSR) and Mudong River (MDR) populations, which formed a common cluster. Therefore, loss of genetic diversity and increased genetic differentiation were found in the populations, which could be attributed to dam construction, overfishing, and water pollution in the upper Yangtze River. It is therefore recommended that the government should ban fishing, control water pollution, increase river connectivity, and establish artificial breeding and stocking.
小种群通常具有较低的遗传多样性，因此容易灭绝。了解小种群的遗传多样性和结构及其对人为影响的遗传响应，对于保护管理至关重要。本研究从长江上游五个地点采集了特有鲤科鱼类 的样本，利用线粒体细胞色素 b 基因和 14 个微卫星标记分析其遗传多样性和种群结构。单倍型多样性、核苷酸多样性和预期杂合度表明， 种群遗传多样性较低，且自 2001 年以来急剧下降。基于遗传分化指数（ ），在细胞色素 b 基因和 SSR 标记中发现不同种群之间存在显著的遗传分化，而在 2001 年并未发现分化。单倍型系统发育表明，15 个单倍型中有 8 个是一个种群所特有的。SSR STRUCTURE 分析表明，在 样本中存在 4 个遗传群，除赤水河（CSR）和木洞河（MDR）种群外，每个种群形成一个单独的群，其余种群形成一个共同的群。因此， 种群遗传多样性丧失，遗传分化增加，这可能是由于长江上游筑坝、过度捕捞和水污染造成的。因此，建议政府禁止捕捞、控制水污染、增加河流连通性，并建立人工养殖和放养。
