人为干扰和景观格局导致秦岭川金丝猴遗传分化机制的研究

The habitat fragmentation restrict the exchange of individuals and genes between populations, reduce the genetic diversity, aggravate the genetic differentiation and influence the survival of species. Due to the limitation of analysis methods and the difficulty of genetic sampling, previous studies make effort to explain the phylogeographic structure of species with long isolation time or wide spatial range, which can hardly been applied to endangered species been restricted into a narrow habitat. The Sichuan snub-nosed monkey (Rhinopithecus roxellana) is a species endemic to China, previous studies found significant genetic divergence within habitat. However, the reason of genetic differentiation of R. r. qinlingensis remains unclear. This study plan to extensively collect the genetic samples from habitats in both southern and northern slope of Qinling Mountains, and measure the genetic diversity for each population with microsatellite and mitochondrial D-Loop markers. We also plan to describe the current state and influence factors of the genetic structure of R. r. qinlingensis by analyzing the remote sensing data in Qinling Mountains and a higher-order partial Mantel test based population genetics model, answer the theoretical issue about how habitat fragmentation introduced by human disturbance and natural landscape pattern result in the genetic differentiation between populations and loss of genetic diversity within populations, reveal the specific isolation mechanisms of genetic drift of small populations and forming of isolated populations, and provide scientific basis for the conservation of endangered species.

生境破碎化限制了种群间的个体与基因的交流，降低了物种的遗传多样性，加剧了群体间的遗传分化，对物种生存产生很大影响。由于样本采集的困难和分析方法的限制，以往的研究多致力于解释隔离时间较长，分布较广的物种或种群谱系地理的成因，而对分布较集中的濒危物种很难实现。川金丝猴是我国特有的珍稀濒危物种，最新的研究发现，其分布区内出现了较强的遗传分化，然而导致秦岭种群内部分化的原因尚不明确。本研究拟通过对秦岭南北坡川金丝猴分布区内各个种群的大范围采样，基于微卫星和线粒体DNA两种遗传标记，评估各种群的遗传多样性，并结合秦岭地区卫星遥感数据分析，建立多赋权高阶偏Mantel群体遗传学模型，阐明秦岭川金丝猴遗传结构的现状及其影响因素，回答人为干扰引起的生境破碎化和自然景观格局形成的隔离导致秦岭川金丝猴遗传分化和遗传多样性丧失的理论问题，揭示小种群遗传漂变和孤立种群形成的具体机制，为濒危物种的保护提供科学依据。

物种的遗传结构能够被地理、生态、行为甚至社会因素所影响，由于样本采集困难、数据分析方法有限，以往的研究多致力于解释较大尺度时空下的物种群体遗传结构的成因，对分布集中、隔离时间较短的濒危物种难以进行更加精细的研究。本研究以秦岭川金丝猴为对象，通过对秦岭南北坡川金丝猴分布区内各个种群的大范围采样，基于微卫星和线粒体DNA两种遗传标记，评估各种群的遗传多样性，并结合秦岭地区卫星遥感数据，建立多赋权高阶偏Mantel群体遗传学模型，阐明秦岭川金丝猴遗传结构的现状及其影响因素。发现秦岭川金丝猴遗传多样性水平较高，瓶颈效应检验结果不显著，主要隔离因素均为自然因素。表明目前人为干扰对秦岭川金丝猴遗传水平影响有限，川金丝猴可能通过其独特的“重层社会”和行为特点在某种程度上抵消生境破碎化的影响。本研究提出的模型可以确定物种在精细尺度下的遗传结构的成因，并对每种因素的影响进行量化，为濒危物种的保护提供科学依据。