Phylogeography of Quercus aquifolioides provides novel insights into the Neogene history of a major global hotspot of plant diversity in south-west China
Phylogeography of Quercus aquifolioides provides novel insights into the Neogene history of a major global hotspot of plant diversity in south-west China
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Quercus aquifolioides 的系统发育地理学为中国西南地区全球植物多样性主要热点地区的新近纪历史提供了新的见解
DOI：
10.1111/jbi.12836
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发表时间：
2017-02-01
影响因子：
3.9
通讯作者：
Hampe, Arndt
中科院分区：
文献类型：
--
作者：
Du, Fang K.;Hou, Meng;Hampe, Arndt
目的生物多样性热点地区通常与近代地质历史上发生过造山活动的地区有关。众所周知，山地隆起会催化物种辐射，但它们对进化稳定的分类群（如许多树木）的影响仍知之甚少。松栎是东喜马拉雅地区横断山生物多样性热点地区的特有树种，分布广泛。在这里，我们研究了该地区的新近纪和第四纪历史如何驱动物种过去的种群动态以及由此产生的种内多样性的现存模式。中国西南横断山生物多样性热点地区。方法利用4个叶绿体DNA片段和11个核微卫星位点，对整个种域内58个居群的959个个体进行基因分型。采用系统发育重建、分子定年技术和祖先区重建等方法，结合种群遗传统计，推测了水松的生物地理历史。对化石记录的调查和生态位建模练习补充了系统地理学的研究。结果分子和化石证据表明：Q.我们发现种子基因流极有限，花粉基因流广泛（全球F-ST: cpDNA=0.98, nSSR=0）。本研究结果对横断山生物多样性热点地区的古代生物地理历史提供了前所未有的详细认识，表明该地区过去的环境变化可能以与物种之间相同的方式催化了物种内部的辐射多样化。
AimHotspots of biodiversity are often associated with areas that have undergone orogenic activity during recent geological history. Mountain uplifts are known to catalyse species radiation but their impact on evolutionarily stable taxa such as many trees remains little understood. The oak Quercus aquifolioides is endemic to yet widely distributed across the Hengduanshan Biodiversity Hotspot in the Eastern Himalayas. Here, we investigate how the region's Neogene and Quaternary history has driven the species' past population dynamics and the resulting extant patterns of intraspecific diversity.LocationHengduanshan Biodiversity Hotspot in SW China.MethodsWe sampled 58 populations throughout the species range and genotyped a total of 959 individuals at four chloroplast DNA fragments and 11 nuclear microsatellite loci. Phylogenetic reconstructions, molecular dating techniques and ancestral area reconstructions were used in combination with population genetic statistics to infer the biogeographical history of Q. aquifolioides. The phylogeographical study was complemented by a survey of fossil records and a niche modelling exercise.ResultsCombined molecular and fossil evidence indicates that Q. aquifolioides descended during the late Miocene from the central Qinghai-Tibet Plateau into Tibet and the western Sichuan Plateau, and from there, into the area of highest endemism in the Hengduan Mountains sensu lato. Great apparent population stability and a haplotype radiation' in this area contrasted with marked extinction-recolonization dynamics and reduced population diversity in Tibet. We found evidence for extremely limited seed gene flow but extensive pollen gene flow (global F-ST: cpDNA=0.98, nSSR=0.07) with signals of asymmetric pollen dispersal from the Hengduan Mountains into Tibet.Main conclusionOur results provide insights of unprecedented detail into the ancient biogeographical history of the Hengduanshan Biodiversity Hotspot, suggesting that past environmental changes in the region may have catalysed radiative diversifications within species much in the same way as among species.