Kim Seon-Hee, Yang JiYoung, Cho Myong-Suk, Stuessy Tod F, Crawford Daniel J, Kim Seung-Chul
Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu 41566, Republic of Korea.
Plants (Basel). 2024 Feb 23;13(5):612. doi: 10.3390/plants13050612.
represents the third largest genus on the Juan Fernández Islands, with six endemic species, five of which occur exclusively on the younger Alejandro Selkirk Island with one species on both islands. While its continental sister species is unknown, on the Juan Fernández Islands appears to be monophyletic and most likely evolved from South American progenitor species. We characterized the complete chloroplast genomes of five species, including accessions of and one each from Alejandro Selkirk and Robinson Crusoe Islands, with the purposes of elucidating molecular evolution and phylogenetic relationships. We found highly conserved chloroplast genomes in size, gene order and contents, and further identified several mutation hotspot regions. In addition, we found two positively selected chloroplast genes ( and ) among species in the islands. The complete plastome sequences confirmed the monophyly of in the islands and corroborated previous phylogenetic relationships among species. New findings in the current study include (1) two major lineages, - and --, (2) the non-monophyly of occurring on the two islands, and (3) the non-monophyly of the alpine species complex.
它是胡安·费尔南德斯群岛上的第三大属，有六个特有物种，其中五个仅出现在较年轻的亚历杭德罗·塞尔扣克岛上，另一个物种在两个岛屿上都有。虽然其大陆姊妹物种尚不清楚，但在胡安·费尔南德斯群岛上它似乎是单系的，很可能是从南美洲祖先物种进化而来。我们对五个物种的完整叶绿体基因组进行了特征分析，包括[物种名]的样本以及来自亚历杭德罗·塞尔扣克岛和鲁滨逊·克鲁索岛各一个样本，目的是阐明分子进化和系统发育关系。我们发现叶绿体基因组在大小、基因顺序和内容上高度保守，并进一步确定了几个突变热点区域。此外，我们在该群岛的物种中发现了两个正选择的叶绿体基因（[基因名]和[基因名]）。完整的质体基因组序列证实了该群岛上[属名]的单系性，并证实了物种间先前的系统发育关系。本研究的新发现包括：（1）两个主要谱系，[谱系名1]和[谱系名2]；（2）出现在两个岛屿上的[物种名]的非单系性；（3）高山物种[物种名]复合体的非单系性。
