Systematic study on the process of diversity and distribution of higher plants in the Northern Hemisphere with special reference to the Sino-Japanese region in eastern Asia

本文对绣球花属、黄连属、球球花属、大花蕙兰属、毛菖蒲属和大紫薇属进行了系统地理学研究，并讨论了被子植物在北半球的历史生物地理学意义。研究结果表明，该植物的生物地理格局是相同的，即东亚的起源和物种形成随后扩展到北美。因此，在中新世（约10 Ma）至上新世早期（约5 Ma）期间，本研究所研究的所有分类群均表现出由旧大陆经白令陆桥向新大陆的不对称分布。值得注意的是，中日地区植物类群的总体生物地理格局是，所有谱系的祖先都局限于中国云南和四川，并通过扩散扩大了它们的分布范围。从琉球和日本群岛分布的世系是单系的，DNA序列差异很少。

We investigated phylogeography on the genus of Hydrangea, Coptis, Pieris, Cymbidium, Tricyrtis and Lagerstroemia and discussed on the historical biogeographical implications for angiosperms in the Northern hemisphere. Results indicate the same biogeographic pattern, i.e., origin and speciation in eastern Asia with subsequent expansion into North America. Therefore the all taxa examined in the present study showed asymmetrical disparsal from the Old World to the New World via Bering Land bridge during the Miocene (ca. 10 Ma) to the early Pliocene (ca. 5 Ma). The noteworthy finding was the general biogeograhic pattern in plant taxa restricted to the Sino-Japanese region that all lineages have been restricted ancestrally to the Yunnan & Sichuan Province in China and secondarily expanded their ranges via dispersal. The lineages distributed from the Ryukyu and Japanese Archipelagos are monophyletic with few DNA sequence divergences.