The genus Artemisia (Asteraceae: Anthemideae) at a continental crossroads: Molecular insights into migrations, disjunctions, and reticulations among Old and New World species from a Beringian perspective
The genus Artemisia (Asteraceae: Anthemideae) at a continental crossroads: Molecular insights into migrations, disjunctions, and reticulations among Old and New World species from a Beringian perspective
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DOI：
10.1016/j.ympev.2012.05.003
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发表时间：
2012-09-01
影响因子：
4.1
通讯作者：
Seigler, David S.
中科院分区：
文献类型：
--
作者：
Riggins, Chance W.;Seigler, David S.
蒿属是菊科中最大的属（约 350-500+ 种），由生态、形态和化学上多样化的物种组成，主要分布在整个北半球。该属的两个主要多样性中心位于欧亚大陆和北美西部，但在整个北太平洋沿岸和北极邻近地区（包括许多岛屿和群岛）都观察到连接这两个地区的植物地理联系。先前的系统发育研究有助于阐明主要谱系并确定可能的姐妹关系，但有关新旧世界物种的关系和迁徙历史的许多问题仍未得到解答。在这里，我们在以白令海峡地区为中心的生物地理背景下研究了蒿属的系统发育，并提供了有关物种关系、迁徙历史以及网状进化在该属中的可能作用的新假设。我们的抽样包括许多新的分类单元，并强调广泛分布的物种、来自拟定保护区的物种以及具有不连续/替代分布的物种的多种种质。 ITS 系统发育包含 173 个种质（94 个新种质和 79 个来自 GenBank），并表明蒿属是并系系，排除了几个亚洲小属和北美 Sphaeromeria 属。在对十三个叶绿体基因座进行调查后，基于两个质体标记（psbA-trnH和tpl32-trnL.间隔区）的系统发育是用简化的数据集构建的，虽然与ITS拓扑结构基本一致，但揭示了新世界和白令海峡物种之间可能的基因渗入的几个案例。我们的分析表明，北美蒿属物种有多个起源，北美西部是东亚和南美洲一些殖民元素的来源。 (C) 2012 Elsevier Inc. 保留所有权利。
Artemisia is the largest genus (ca. 350-500+ spp.) in the tribe Anthemideae and is composed of ecologically, morphologically, and chemically diverse species that are found primarily throughout the Northern Hemisphere. Two major centers of diversity for the genus are located in Eurasia and western North America, but phytogeographic links connecting these two regions are observed all across the North Pacific Rim and adjacent areas in the Arctic, including many islands and archipelagos. Previous phylogenetic studies have helped to clarify major lineages and identify likely sister relationships, but many questions remain unanswered regarding the relationships and migration history of New and Old World species. Here we investigate the phylogenetics of Artemisia within a biogeographic context centered in the Beringian Region and offer new hypotheses concerning species relationships, migration history, and the likely role of reticulate evolution in the genus. Our sampling included many new taxa and emphasized multiple accessions of widespread species, species from proposed refugia, and species with disjunct/vicariant distributions. The ITS phylogeny contained 173 accessions (94 new and 79 from GenBank) and indicated that Artemisia is paraphyletic by the exclusion of several small Asian genera and the North American genus Sphaeromeria. Following a survey of thirteen chloroplast loci, phylogenies based on two plastid markers (psbA-trnH and tpl32-trnL. spacers) were constructed with a reduced data set, and though largely consistent with the ITS topology, revealed several cases of possible introgression among New World and Beringian species. Our analysis reveals that North American Artemisia species have multiple origins, and that western North America has served as a source for some colonizing elements in eastern Asia and South America. (C) 2012 Elsevier Inc. All rights reserved.