Phylogeography of the component plant species and phytophagous insects of warm temperate region in Taiwan and Japan

我们利用等位酶和核苷酸序列分析，对台湾和日本暖温带地区的组成植物物种进行了地理学研究。本研究主要是从台湾及日本各地采集其植物材料后，对野牡丹及前胡进行研究。我们以前阐明，这些植物种的种群在琉球南部（是石垣和是。西表岛）在遗传上与中琉球和北方琉球（冲绳群岛，奄美群岛，（Tokara Isls）这一现象被认为是由于琉球南部和台湾的种群之间的遗传交换造成的。然而，这项研究的结果清楚地表明，南琉球的人口是遗传分化良好，甚至从台湾的这两种植物。因此，强烈建议南琉球种群的F.japonicum和P.japonicum可能已经在地理上与台湾或琉球其他地区分离了很长一段时间，从而获得了遗传独特性。根据等位酶分析，兰屿的日本镰孢和日本对虾种群与冲绳和奄美群岛的遗传相似性大于台湾。它们还共享叶绿体DNA的单倍型。考虑到兰屿是新近形成的火山岛，其植物种群是由中琉球罕见的远距离扩散建立的。这是非常有趣的是，长距离的扩散，从北到南的建议，因为大多数从南到北的扩散事件往往是记录在过去的植物地理学研究。

We performed phylogeographic studies of the component plant species of warm temperate regions of Taiwan and Japan using allozyme and nucleotide sequencing analyses. We mainly examined Farfugium japonicum and Peucedanum japonicum after collecting their plant materials from various locaities of Taiwan and Japan. We formerly elucidated that populations of these plant species in Southern Ryukyu (Is.Ishigaki and Is. Iriomote) are genetically well differentiated from those of Middle and Northern Ryukyu (the Okinawa Isls., the Amami Isls., the Tokara Isls.). It was considered that this phenomenon was caused by genetic exchange between the populations of Southern Ryukyu and Taiwan. However, the results of this study clearly revealed that populations of Southern Ryukyu are genetically well differentiated even from those of Taiwan in these two plant species. Therefore, it was strongly suggested that Southern Ryukyu populations of F.japonicum and P.japonicum have been separated maybe geographically either from Taiwan or the other regions of Ryukyu for long times so that they obtained genetical uniqueness.Another interesting findings of this study is genetic similarities between populations of these two plant species from LanYu Island of Taiwan and Middle Ryukyu. The populations of of F.japonicum and P.japonicum of LanYu are genetically more similar to those of Okinawa and Amami Islands than those of Taiwan based on allozyme analysis. They also share haplotypes of chloroplast DNAs. Taking that Lanyu Island was recently formed volcanic island into account, the plant populations of the islands were established by rare long distance dispersal from Middle Ryukyu. It is very interesting that long distance dispersal from north to south was suggested in this species because mostly dispersal events from south to north are often documented in the past phytogeographical studies.