Taxonomic and Phylogeographic Studies of Chrysosplenium macrostemon s.l.(Saxifragaceae)

Chrysosplenium macrostemon s.l.（虎耳草科）的分类学和系统地理学研究

• 批准号: 14540650
• 负责人: WAKABAYASHI Michiko
• 金额: $ 1.98万
• 依托单位: Tokyo Metropolitan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540650/
• 关键词: Chrysosplenium; Chrysosplenium macrostemon s.l.; Classification; Nolecular phylogeneteic analysis; ITS; ETS; 分類の再検計; 分類の再検討

This study aims to reexamine taxonomically Chrysosplenium macrostemon s.l. distributed widely in Pacific Ocean side of Honshu, Shikoku and Kyushu, through the morphological and cytological observations and the molecular phylogenetic analyses. The results obtained are as follows :1.The monopyly of C.macrostemon s.l. was suggested from the analysis of ITS sequenses of rDNA in 43 populations covering 5 species of Ser.Macrostemon (23 populations of C.macrostemon, 6 of C.echinus, 5 of C.fauriae, 4 of C.nagasei, 5 of C.kiotense), and sister group of C.macrostemon s.l. was also suggested to be C.echinus.2.Phylogenetic analysis based on ETS sequences of rDNA was performed in 51 populations of C.macrostemon using C.echinus as its outgroup. The 27 ETS sequence types were recognized. The phylogenetic tree among these types showed that the populations around Itsuki-mura in Kumamoto Prefecture diverged first and the other populations formed a clade. This clade formed polytomy as a whole, and phylogenetic relationships among populations within this clade were obscure.3.One kind of ETS sequence type (Type 4) within the clade was common to 22 populations distributed widely in Kyushu, western part of Shikoku, Kii Peninsular, and Tanzawa Mountais in Kanagawa Prefecture. However, the floral and seed morphology in these populations was very diversified, which suggests that genetic and morphological diversification are not necessarily concordant.4.Chromosome number of C.macrostemon was 2n=22(diploid) in all of 43 populations so far analyzed, and no polyploidy seems to occur in this species.5.Hereafter, the molecular phylogenetic analyses including ITS sequences and the observation of floral and seed morphology in more populations are needed for making a clear conclusion along the purpose of this study.

本研究旨在重新研究大蕊金腰的分类学。通过形态学、细胞学观察和分子系统学分析，发现其广泛分布于日本本州、四国和九州的太平洋沿岸。结果表明：1.小百部的单体性;通过对5个种的43个居群（小颖23个居群、刺小颖6个居群、毛小颖5个居群、长穗小颖4个居群、狭叶小颖5个居群）和小颖姐妹群的rDNA ITS序列分析，提出了小颖的亲缘关系。2.对51个居群的小根香进行了系统发育分析，以小根香为外类群。共识别出27种ETS序列类型。系统发育树分析表明，以熊本县严木村附近的居群最先分化，其余居群形成一支。该分支内有一种ETS序列类型（Type 4）为广泛分布于九州、四国西部、纪伊半岛和神奈川县的丹泽山的22个居群所共有。4.在所分析的43个居群中，小偃麦的染色体数目均为2n=22（二倍体），没有发现多倍体。沿着本研究的目的，还需要对更多居群进行包括ITS序列在内的分子系统发育分析，以及花和种子形态的观察，才能得出明确的结论。