Peterson Angela, Harpke Dörte, Peterson Jens, Harpke Alexander, Peruzzi Lorenzo
Institute of Biology Martin-Luther-University of Halle-Wittenberg Halle/Saale Germany.
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben Germany.
Ecol Evol. 2019 Apr 26;9(10):5870-5890. doi: 10.1002/ece3.5170. eCollection 2019 May.
The Irano-Turanian (IT) floristic region is considered an important center of origin for many taxa. However, there is a lack of studies dealing with typical IT genera that also occur in neighboring areas. The species-rich monocot genus Salisb. shows a center of diversity in IT region and a distribution in adjacent regions, therefore representing a good study object to investigate spatial and temporal relationships among IT region and its neighboring areas (East Asia, Euro-Siberia, Himalaya, and Mediterranean). We aimed at (a) testing the origin of the genus and of its major lineages in the IT region, (b) reconstructing divergence times, and (c) reconstructing colonization events. To address these problems, sequences of the ribosomal DNA internal transcribed spacer (ITS) region of 418 individuals and chloroplast intergenic spacers sequences (A-H, L-F) of 497 individuals, representing 116 species from all sections of the genus and nearly its entire distribution area were analyzed. Divergence times were estimated under a random molecular clock based on nrITS phylogeny, which was the most complete data set regarding the representation of species and distribution areas. Ancestral distribution ranges were estimated for the nrITS data set as well as for a combined data set, revealing that most likely originated in southwestern Asia. This genus first diversified there starting in the Early Miocene. In the Middle Miocene, migrated to the Mediterranean and to East Asia, while migration into Euro-Siberia took place in the Late Miocene. During the Pleistocene, the Arctic was colonized and the most widespread species, reached North America. The Mediterranean basin was colonized multiple times from southwestern Asia or Euro-Siberia. Most of the currently existing species originated during the last 3 Ma.
伊朗 - 图兰（IT）植物区系被认为是许多分类群的重要起源中心。然而，缺乏对也出现在邻近地区的典型IT属的研究。物种丰富的单子叶植物属Salisb.在IT地区呈现出多样性中心，并分布于相邻地区，因此是研究IT地区与其邻近地区（东亚、欧洲 - 西伯利亚、喜马拉雅和地中海）之间时空关系的良好研究对象。我们旨在（a）测试该属及其主要谱系在IT地区的起源，（b）重建分歧时间，以及（c）重建定殖事件。为了解决这些问题，分析了代表该属所有组且几乎其整个分布区的116个物种的418个个体的核糖体DNA内转录间隔区（ITS）序列和497个个体的叶绿体基因间隔区序列（A - H、L - F）。基于nrITS系统发育，在随机分子钟下估计分歧时间，nrITS系统发育是关于物种代表性和分布区的最完整数据集。还估计了nrITS数据集以及合并数据集的祖先分布范围，结果表明该属最有可能起源于亚洲西南部。该属在早中新世开始在那里首次多样化。在中中新世，迁移到地中海和东亚，而迁移到欧洲 - 西伯利亚发生在晚中新世。在更新世，北极被定殖，并且最广泛分布的物种到达了北美。地中海盆地多次从亚洲西南部或欧洲 - 西伯利亚定殖。大多数现存物种起源于过去300万年期间。
