Multilocus analysis of nucleotide variation and speciation in three closely related Populus (Salicaceae) species
Multilocus analysis of nucleotide variation and speciation in three closely related Populus (Salicaceae) species
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三种密切相关的杨树（杨柳科）物种的核苷酸变异和物种形成的多位点分析。
DOI：
10.1111/mec.13368
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发表时间：
2015-10-01
影响因子：
4.9
通讯作者：
Zhang, Jianguo
中科院分区：
文献类型：
--
作者：
Du, Shuhui;Wang, Zhaoshan;Zhang, Jianguo
历史构造运动和气候波动可以隔离和缩小许多植物物种的地理分布，它们甚至被认为是引发物种分化和最终物种形成的原因。在这里，我们估计了分布于北美和欧亚大陆的三个密切相关的树种--黑杨、黑杨和山杨的核苷酸变异和物种形成。我们分析了这三个物种33个种群的497个个体的6个单拷贝核基因座和3个叶绿体(CpDNA)片段的序列变异。这三种杨树的核苷酸多样性水平较高，表现出较高的核苷酸分化水平。系统发育分析表明，松毛虫的分化早于其他两种。CpDNA单倍型网络结果清楚地显示了从北美到东亚再到欧洲的扩散路线。分子测年结果证实，这三个物种的分化与晚中新世白令大陆桥的裂解和青藏高原在中新世/上新世界线附近的快速隆升相吻合。历史构造作用和气候波动导致的成功异地物种形成，很可能在这三种杨树种的分离分布和分化的形成中发挥了作用。
Historical tectonism and climate oscillations can isolate and contract the geographical distributions of many plant species, and they are even known to trigger species divergence and ultimately speciation. Here, we estimated the nucleotide variation and speciation in three closely related Populus species, Populus tremuloides, P.tremula and P.davidiana, distributed in North America and Eurasia. We analysed the sequence variation in six single-copy nuclear loci and three chloroplast (cpDNA) fragments in 497 individuals sampled from 33 populations of these three species across their geographic distributions. These three Populus species harboured relatively high levels of nucleotide diversity and showed high levels of nucleotide differentiation. Phylogenetic analysis revealed that P.tremuloides diverged earlier than the other two species. The cpDNA haplotype network result clearly illustrated the dispersal route from North America to eastern Asia and then into Europe. Molecular dating results confirmed that the divergence of these three species coincided with the sundering of the Bering land bridge in the late Miocene and a rapid uplift of the Qinghai-Tibetan Plateau around the Miocene/Pliocene boundary. Vicariance-driven successful allopatric speciation resulting from historical tectonism and climate oscillations most likely played roles inthe formation of the disjunct distributions and divergence of these three Populus species.