Mechanisms for speciation and breeding system in plant species accompanied with phylogeographic structure.

植物分类单元内的系统地理结构意味着种内在遗传、形态、生殖、生理和/或生态性状上的分化，这些性状为物种形成和进化提供了良好的竞技场。在这个项目中，我们阐明了高山和大陆岛屿系统，琉球群岛，植物类群的地理结构，通过确定cpDMA单倍型或核形态。3种高山植物（Phyllodoce nipponica、Potentilla matsumurae和Diapensia nipponica）的cpDNA单倍型分布具有高度的地理结构性，在厚州中部和东北地区的山区之间存在突变。在本州中部的单倍型被认为是有分歧的，这表明在本州中部的山脉作为避难所在第四纪气候振荡。此外，还对琉球过路黄的种内染色体数目变异和细胞地理学进行了研究。该植物在琉球群岛上的变异范围很广，从2n=16（6 m），2n=17（6 m），2n = 17（7 m），2n=18（4 m），2n =18（5 m），2n =18（6 n），2n=19（5 m），2n=20（2 m）到2n=20（4 m）。高海拔的大型岛屿（例如，Amamioshima岛和Tokunoshima岛）的变化范围较大，表明这些岛屿可能在第四纪气候振荡中充当冰间和/或冰后海侵的避难所。另一方面，低海拔岛屿的细胞型结构简单，这可能是由于在温暖时期的瓶颈效应。

Phylogeographic structures within a plant taxon would imply intraspecific differentiation in genetics, morphologies, reproduction, physiological and/or ecological traits, of which provide good arena for speciation and evolution. In this project, we elucidated phylogeographic structures in plant taxa on high mountains and continental island systems, the Ryukyu Islands, by determining cpDMA haplotypes or Karyomorphology. The distribution of cpDNA haplotypes in three alpine plants (Phyllodoce nipponica, Potentilla matsumurae and Diapensia nipponica) was geographically highly structured, and an abrupt genetic changes were detected between mountains in central Houshu and the Tohoku region. Haplotypes in central Honshu were thought to have diverged, suggesting that mountains in central Honshu served as refugia during the Quaternary climatic oscillations. Moreover, intraspecific variation of chromosome number and cytogeography were examined for samples of Lysimachia mauritiana from the Ryukyu Islands. This plants on the Ryukyu Islands harbor wide range of variation, ranging from 2n=16(6m), 2n=17(6m), 2n=17(7m), 2n=18(4m), 2n=18(5m), 2n=18(6n), 2n=19(5m), 2n=20(2m) to 2n=20(4m). Large islands with high altitude (e.g., Amamioshima Island and Tokunoshima Island) harbor the wider variation, suggesting these islands could act as refugia during the inter- and/or post- glacial transgression in the Quaternary climatic oscillations. On the other hand, islands with lower altitude harbor simple structure in cytotype, which would be attributable to bottleneck effects during the warm periods.