Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute of Plant Sciences, University of Goettingen, Untere Karspuele 2, 37073 Goettingen, Germany; Department of Botany, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 166, Washington, DC 20013-7012, USA.
Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute of Plant Sciences, University of Goettingen, Untere Karspuele 2, 37073 Goettingen, Germany.
Mol Phylogenet Evol. 2018 Sep;126:31-44. doi: 10.1016/j.ympev.2018.04.013. Epub 2018 Apr 10.
Zanthoxylum L. (prickly ash) is the only genus in the Citrus L. family (Rutaceae) with a pantropical distribution. We present the first detailed phylogenetic and biogeographic study of the genus and its close relatives in the proto-Rutaceae group. Our phylogenetic analyses based on two plastid and two nuclear markers show that the genus Toddalia Juss. is nested within Zanthoxylum, that earlier generic and intrageneric classifications need revision, and that the homochlamydeous flowers of the temperate species of Zanthoxylum are the result of a reduction from heterochlamydeous flowers. The biogeographic analyses reveal a Eurasian origin of Zanthoxylum in the Paleocene or Eocene with successive intercontinental or long-range migrations. Zanthoxylum likely crossed the North Atlantic Land Bridges to colonize the Americas in the Eocene, and migrated back to the Old World probably via the Bering Land Bridge in the Oligocene or Miocene. Zanthoxylum also colonized several Pacific Islands and the Hawaiian clade shows phylogenetic incongruence between the plastid and nuclear datasets, suggesting hybridization. The Hawaiian species are one of the rare examples of endemic Hawaiian lineages that are older than the current main islands.
花椒属（Zanthoxylum L.）是芸香科（Rutaceae）柑橘属（Citrus L.）中唯一具有泛热带分布的属。我们首次对该属及其在原芸香科组中的近缘属进行了详细的系统发育和生物地理学研究。我们基于两个质体和两个核标记的系统发育分析表明，Toddalia Juss. 属内嵌套在花椒属中，早期的属和属内分类需要修订，并且花椒属温带物种的同型花是异型花的结果。生物地理学分析表明，花椒属起源于古近纪的欧亚大陆，随后经历了洲际或长距离的迁移。花椒属可能在古近纪通过北大西洋陆桥到达美洲，并在渐新世或中新世可能通过白令陆桥返回旧世界。花椒属还殖民了几个太平洋岛屿，而夏威夷分支在质体和核数据集之间表现出系统发育不一致，表明存在杂交。夏威夷物种是比当前主要岛屿更古老的特有夏威夷谱系的罕见例子之一。
