Abstract: In this study, 149 Himalayan marmot individuals from 13 populations were sampled from eastern Qinghai and genotyped at 11 microsatellite loci. Then the genetic diversity and genetic structure of these populations were analyzed using different population genetics methods. As the results showed, a total of 97 alleles were detected in all 11 SSR loci. The average observed heterozygosity and expected heterozygosity for each population ranged from 0.58 and 0.60 to 0.82 and 0.79, representing a relatively high level of genetic diversity. The genetic structure analyses demonstrated that the marmot populations in eastern Qinghai exhibited a strong genetic structure, where 13 geographical populations were allocated into 3 genetic clusters. Surprisingly, such three genetic clusters are in perfect accordance with the geographical units divided by the trunk stream of the Huangshui river and the head trunk stream of the Huanghe river. Therefore, we conclude that these two rivers act as natural barriers to the dispersal and gene-flow between the marmot populations in different units. Meanwhile, as suggested by the STRUCTURE analysis, there was still obvious gene-flow between the three genetic clusters, and the AMOVA analysis also showed that the percentage of the variance between genetic clusters was 6.60%, slightly higher than that between different populations within clusters (4.51%) and far lower than that within populations (88.90%), indicating a low degree of differentiation between the genetic clusters. All such results implied that the Himalayan marmots may cross over the rivers by some bridges or in low water periods to disperse and exchange. These results can provide scientific information for the monitoring and management of marmot populations and even plague control in this region.

Key words: Genetic diversity, Genetic structure, Marmot, SSR

摘要： 本研究利用11个微卫星标记对采自青海省东部地区的13个喜马拉雅旱獭（Marmota himalayana）种群149个个体进行了基因分型，并运用种群遗传学方法对其遗传多样性和遗传结构进行分析。结果显示，11个微卫星标记位点共计检测到97个等位基因，各种群的平均观测杂合度和期望杂合度范围分别为0.58~0.82和0.60~0.79，种群遗传多样性水平相对较高；遗传结构分析表明，青海省东部地区的喜马拉雅旱獭种群具有显著的遗传结构，13个地理种群形成了3个遗传聚类群，且3个遗传聚类群与湟水河和黄河上游干流所划分出的地理单元完全一致，因此我们认为湟水河和黄河上游干流是阻碍该地区喜马拉雅旱獭种群进行迁移扩散和基因交流的天然屏障。同时，STRUCTURE分析结果还显示3个遗传聚类群间仍有明显的基因流，AMOVA分析也显示3个聚类群间变异百分比为6.60%，仅略高于聚类群内种群间的变异（4.51%），而远低于种群内变异水平（88.90%），表明三个聚类群间的分化程度并不是很深。这说明喜马拉雅旱獭可能通过桥梁或在枯水期等穿越河流进行基因交流。以上结果为该地区的旱獭种群监控和鼠疫防控提供了科学的理论基础。

关键词: 旱獭, 遗传多样性, 遗传结构, 微卫星