【作者】 阮向东；

【导师】 方盛国；

【作者基本信息】 浙江大学 ， 动物学， 2007， 博士

【摘要】 藏羚羊(Pantholops hodgsonii)是青藏高原的特有物种。近几十年来,由于人类对栖息地的毁坏和大量猎杀,其生存迄今仍受到严重威胁。藏羚羊栖息地的片段化和种群数量的急剧下降,已使其成为了深受社会各界关注的濒危物种。本文以新疆阿尔金山自然保护区、西藏羌塘自然保护区和青海可可西里自然保护区的藏羚羊为研究对象,选择线粒体DNA控制区和核DNA微卫星作为分子标记,应用MEGA、DnaSP和ARLEQUIN等分析软件进行相关数据处理,开展了藏羚羊遗传多样性、地理种群关系和种群进化历史等方面的研究,获得了如下的主要研究结果:1)藏羚羊新疆种群、西藏种群和青海种群线粒体的平均核苷酸多样性(p)分别为1.87%、2.05%和2.47%,同时,微卫星的期望杂合度(He)分别为0.7139、0.7231和0.7441。2种分子标记的检测结果,均表明了藏羚羊这一物种现今仍具有较高的遗传多样性;2)在藏羚羊的3个地理种群——新疆、青海和西藏种群中:①新疆与青海种群之间的遗传分化指数Fst=0.01347,种群间已达到显著的遗传分化水平(p=0.0367);②新疆与西藏种群之间的遗传分化指数Fst=—0.00416,种群之间存在着丰富的基因流,亦即种群之间未出现遗传分化现象(p=0.7266);③西藏与青海种群之间的遗传分化指数Fst=0.01063,种群间的遗传分化接近于显著水平(p=0.05554)。同时,青海、新疆和西藏种群分别具有5个、4个和3个特有的等位基因。这一结果表明:藏羚羊种内的各个地理种群之间,已出现了不同程度的遗传分化;3)中性测验的结果表明:Fu’s Fs=—28.15(p＜0.01)。同时,错配分布检测曲线图显示出了“种群变化趋向于种群增长模型”的结果。由此揭示了藏羚羊在其进化的历史过程中曾发生过种群膨胀事件,这对于青藏高原其它物种的相关研究,具有一定的参考意义;4)严厉打击对藏羚羊的非法盗猎活动,极力遏制对藏羚羊栖息地的进一步破坏,加强对藏羚羊产仔地的保护和对其种群生物学的研究,是当前有效保护藏羚羊的当务之急。更多还原

【Abstract】 The Tibetan antelope(Pantholops hodgsonii)is endemic to the Tibetan plateau. In the past several decades,the Tibetan antelope has undergone dramatic decline of population size and severe population fragmentation mainly due to poaching and curtailment of the habitats.Therefore,the Tibetan antelope attracted a lot of attentions of the Chinese government,conservation scientists and other conservative organizations in the world.In the present study,57 Tibetan antelope individuals were sampled from Arjin Shan Nature Reserve in Xinjiang,Chang Tang Nature Reserve in Tibet and Kekexili Nature Reserve in Qinghai.The present study based on the analyses of the Tibetan antelope mitochondrial control region and microsatelite analyses with MEGA,DnaSP and ARLEQUIN software to investigate the genetic diversity background, evolutionary history and population relationships.The main results and implications for the conservation of the Tibetan antelope species are as below:1)The average nucleotide variation(p)of the studied Tibetan antelope populations was 2.18%,specifically 1.87%for the Xinjiang population,2.05%for the Xizang population and 2.47%for the Qinghai population.The above data indicated that the genetic diversity of the current Tibetan antelope population is relatively high.2)Among the three Tibetan antelope populations:①there are statistically significant(p=0.0367)genetic differentiation indicated by Fst=0.01347 between the Xinjiang and Qinghai populations;②There was high level of gene flow between the Xinjiang and Xizang populations.The genetic differentiation index(Fst=-0.00416)shows there is no statistically significant genetic differentiation between the Xinjiang and Xizang populations(p=0.7266).③The genetic differentiation index(Fst)is 0.01063 between Xizang and Qinghai populations.There is nearly statistically significant genetic differentiation between the Xizang and Qinghai populations(p=0.05554).Furthermore,the Qinghai,Xinjiang and Xizang population have 5,4 and 3 specific alleles respectively which shows that there is different level of genetic differentiation among three Tibetan antelope populations.3)The neutrality test showed significant Fu’s Fs value of -28.15(p＜0.01),and detection of the mismatch distribution indicated the proximity of the Tibetan antelope population change to the growth-decline model.They both indicated that population expansion has ever occurred to the Tibetan antelope species in the evolutionary history.The results will be of vital significance to the further studies of other wild species on the Tibetan plateau.4)Reinforce the protection of the habitats and prevent poaching activities to keep the high genetic diversity and evolutionary potential of Tibetan antelope. Moreover,some actions should be taken to promote the the gene flow of different Tibetan antelope population,avoid genetic differentiation by habitats protection and ecological obersavation and so on.更多还原