Mitochondrial introgression and complex biogeographic history of the genus Picea
Mitochondrial introgression and complex biogeographic history of the genus Picea
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云杉属的线粒体渗入和复杂的生物地理学历史
DOI：
10.1016/j.ympev.2015.07.020
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发表时间：
2015-12-01
影响因子：
4.1
通讯作者：
Wang, Xiao-Quan
中科院分区：
文献类型：
--
作者：
Ran, Jin-Hua;Shen, Ting-Ting;Wang, Xiao-Quan
北半球植物的生物地理历史要比南半球复杂得多，这是因为白令海峡和北大西洋陆桥都促进了新生代植物区系的交换，从而导致了不同大陆同源物种之间的杂交。了解洲际基因流动和基因渗入如何影响植物系统发育重建和生物地理推断将是一个有趣的问题。本研究利用2个叶绿体（cp）、1个线粒体（mt）和3个单拷贝核基因标记对云杉（Picea）的系统发育和生物地理历史进行了重新研究。所生成的基因树在拓扑结构上高度不一致，地理上密切相关的物种通常表现出mtDNA的密切亲和力，而不是cp-或核DNA，这表明大陆间和大陆内的基因流动和mtDNA渗入可能普遍发生。然而，所有的基因树都将云杉（Picea breweriatta）确定为最基础的谱系，这与化石证据一起支持了该属的北美起源假说。在云杉的演化过程中，散布和迁移都发挥了重要作用，在中新世和上新世期间，白令海陆桥至少介导了两次“北美向欧亚大陆”的散布。我们的研究再次证明了应用来自三个基因组的数据对于清楚地了解松树家族的进化史的重要性。任何来自单个基因组的标记都不能清楚地揭示近亲同属物种之间的系统发育关系。特别是，mtDNA标记的使用应谨慎，因为在松科植物中，母系遗传的基因流率较低的mtDNA（通过种子）的渗入可能比父系遗传的基因流率较高的cpDNA（通过花粉）的渗入频率要高得多。(C) 2015爱思唯尔公司版权所有。
Biogeographic history of plants is much more complex in the Northern Hemisphere than in the Southern Hemisphere due to that both the Bering and the North Atlantic land bridges contributed to floristic exchanges in the Cenozoic, which led to hybridization between congeneric species from different continents. It would be interesting to know how intercontinental gene flow and introgression have affected plant phylogenetic reconstruction and biogeographic inference. In this study, we reinvestigated the phylogenetic and biogeographic history of Picea, a main component of the Northern Hemisphere forest with many species that originated from recent radiation, using two chloroplast (cp), one mitochondrial (mt) and three single-copy nuclear gene markers. The generated gene trees are topologically highly discordant and the geographically closely related species generally show a close affinity of mtDNA rather than cp- or nuclear DNA, suggesting that inter- and intra-continental gene flow and mtDNA introgression might have occurred commonly. However, all gene trees resolved Picea breweriatta as the basal-most lineage, which, together with fossil evidence, supports the North American origin hypothesis for the genus. Both dispersal and vicariance have played important roles in the evolution of Picea, and the Bering Land Bridge could have mediated the "North America to Eurasia" dispersal at least two times during the Miocene and Pliocene. Our study again demonstrates the importance of applying data from three genomes for a clear understanding of evolutionary histories in the pine family. Any markers from a single genome alone will not reveal a clear picture of the phylogenetic relationships among closely related congeneric species. In particular, mtDNA markers should be cautiously used, considering that introgression of the maternally inherited mtDNA with a lower rate of gene flow (by seeds) could have occurred much more frequently than that of the paternally inherited cpDNA with a higher rate of gene flow (by pollen) in Pinaceae. (C) 2015 Elsevier Inc. All rights reserved.