中国假木贼属植物谱系地理学研究

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	中国假木贼属植物谱系地理学研究
	汪勇
Subtype	硕士
Thesis Advisor	张明理 ; 张道远
	2018-06-01
Degree Grantor	中国科学院大学
Place of Conferral	新疆乌鲁木齐
Degree Discipline	理学硕士
Keyword	中国假木贼属谱系地理学西北干旱区青藏高原分布区稳定 Anabasis L. Phylogeography Northwestern China Qinghai-Tibet Plateau Consistently potential distribution
Abstract	假木贼属（Anabasis L.)在我国产 8 种，分布于西北干旱区，主要生于冲积扇、戈壁滩等处，为典型的干旱区荒漠植物。本研究对中国假木贼属及短叶假木贼的谱系地理学、潜在分布区进行分析，旨在了解其遗传多样性及遗传结构并探究其对古气候变迁的响应机制。1. 中国短叶假木贼的谱系地理学研究基于叶绿体基因 psbA-trnH 和 ycf6-psbM 对短叶假木贼 25 个居群 198 份材料进行分析，得到 16 个叶绿体单倍型。 Permut 分析表明其在分布区内具有显著的谱系结构（NST﹥GST， P﹤0.05)。根据 SAMOVA 的结果将短叶假木贼 25 个居群分为四个谱系地理组。基于 BEAST 分析短叶假木贼 16 个叶绿体单倍型的分化时间，大约发生在 2.1795Ma，即更新世早期。短叶假木贼的分化时间可能与更新世早期中国西北地区气候变干变冷有关。分布区预测与错配分析的结果均表明短叶假木贼自第四纪末次冰期以来，地理分布格局基本没有发生变化。2. 中国假木贼属植物的谱系地理学研究我们对中国西北干旱区的假木贼属 7 个种进行谱系地理学研究。通过构建系统发育树，发现假木贼属内种间界限明显，并且 Network 图也证实了该结果。基于分子钟分析，假木贼属的分化时间处于 6.3394Ma，即第三纪末期。种内的分化时间处于 1.838-0.217Ma，即更新世早期到更新世中期。我们推测第三纪末-第四纪初青藏高原的剧烈隆所引起的气候波动，对中国假木贼属及属内种的分化起到了重要的作用。该属具有较宽的生态幅，在气候波动情况下，能适应极端的环境条件，进而表现出自第四纪末次冰期以来地理分布格局基本保持稳定的状态。3. 中国假木贼属地理分布及潜在分布区预测基于最大熵模型（MaxEnt)，预测 7 个种的潜在分布区及该属的多样性中心。结果显示：（1）白垩假木贼、高枝假木贼、毛足假木贼、无叶假木贼、盐生假木贼和展枝假木贼的潜在适生区主要集中在新疆北部、天山南麓及塔里木盆地西侧。短叶假木贼的潜在适生区集中在新疆、甘肃、宁夏和内蒙古的部分地区。（2）中国假木贼属的多样性中心集中在新疆准噶尔盆地、天山南麓、塔里木盆地西侧及甘肃西北部的河西走廊。
Other Abstract	Anabasis L. contains 8 species in China, widely distributes in NorthwesternChina and as a typical eremophytes, growing in alluvial fans, gobi desert. We want toknow the genetic diversity and genetic structure of Anabasis L. and Anabasisbrevifolia. And we also want to know how they response to paleoclimate change.1. The phylogeographic study of Anabasis brevifolia in ChinaSixteen haplotypes were detected in 198 individuals from twenty-fivepopulations based on two chloroplast DNA sequences (i.e. psbA-trnH and ycf6-psbM).Genetic data demonstrated that phylogeographic structure exists across the species’entire distributional range of Anabasis brevifolia by Permut (NST﹥GST, P ﹤ 0.05).Four geographical groups were distinguished by spatial analysis of molecular variance(SAMOVA). Based on BEAST analysis, 16 haplotypes of A. brevifolia resolved as amonophyletic clade, and intraspecific divergence time was estimated approximately at2.1795 Ma, which is consistent with aridification in Northwestern China during theearly Pleistocene. Species distribution modelling (SDM) and pairwise mismatchdistributions both indicted that A. brevifolia maintained a consistently potentialdistribution during the Last Glacial Maximum (LGM).2. The phylogeographic study of Anabasis L. in ChinaTo understand the evolutionary history of Anabasis L., we studied thephylogeography of seven species of this genus. In this study, phylogenetic tree wasconstructed and found that all chloroplast haplotypes are species-specific, and theresult of Network support it. The molecular clock suggested that the main divergencetime for interspecific of Anabasis L. occurred during the late Tertiary (6.3394 Ma).While the main divergence time for intraspecific of Anabasis L. occurred during theearly Pleistocene to the middle Pleistocene (1.838-0.217 Ma). So, we can infer thatwith the change of climatic caused by violent uplift of the Qinghai-Tibet Plateau fromthe end of the Tertiary to the early of Quaternary may caused differentiation ofAnabasis L.. Anabasis L. as a typically super dry-tolerant semi-shrub with widelyecological amplitude can maintained a consistently potential distribution area facedwith the extreme environment compared with others species during the Quaternarylast glacial period.3. Geographical distribution and prediction on potential distribution areas of Anabasis L. in ChinaBased upon the maximum entropy model, potential distribution areas anddiversity center of Chinese Anabasis L. were predicted. The results show that:(1)Anabasis cretacea, Anabasis elatior, Anabasis eriopoda, Anabasis aphylla, Anabasissalsa and Anabasis truncata have extensively potential distribution in the north ofXinjiang, the southern slope of Tianshan Mountain and west margin of Tarim Basin.While Anabasis brevifolia has extensively potential distribution in Xinjiang, Gansu,Ningxia and Inner Mongolia etc. (2) Through the calculation of species richness, wefound that the diversity center of Chinese Anabasis L. mainly concentrated in theXinjiang Junggar basin, southern slope of Tianshan Mountain, west margin of TarimBasin and Hexi Corridor in the northwest of Gansu.
Subject Area	植物学
Language	中文
Document Type	学位论文
Identifier	http://ir.xjlas.org/handle/365004/14989
Collection	研究系统_荒漠环境研究室
Affiliation	中国科学院新疆生态与地理研究所
First Author Affilication	中国科学院新疆生态与地理研究所
Recommended Citation GB/T 7714	汪勇. 中国假木贼属植物谱系地理学研究[D]. 新疆乌鲁木齐. 中国科学院大学,2018.

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