Phylogeographic analysis on the disjunct distribution of rare vascular plants of the Ryukyus

我们证实了琉球苏铁属苏铁的种子形态变异，但是，种子形态变异没有地理趋势，我们不能识别任何种间分类群。报道了台湾四个地区和琉球南部与那国岛一个地区的铃兰科（铃兰科）麦冬（Opalgonreversus）的核型。本文报道了O. reversus与O.在四倍体蛇根草的花形态研究中，我们观察了四倍体蛇根草的花形态。amamiana和二倍体O.日本变种japonica（Rubiaceae）的染色体组，以阐明二倍性和倍性水平之间的关系。通过构建叶绿体DNA系统发育树，研究了四倍化事件和花形态转变的发生次数。日本。在cpDNA测序分析中， 关于我们 两个品种之间。cpDNA单型网络显示O.日本变种amamiana，表明这一品种的单一起源。因为O.日本变种amamiana具有形态学和细胞学实体，被认为是一个单一的谱系，并与O.日本变种Hayataella（Rubiaceae）是台湾特有的单型属，包括H.拟含笑属为了阐明系统的治疗Hayataella，分子系统学分析的基础上nrDNA和cpDNA进行了4种蛇根草。在贝叶斯和最简约的树中，H。michelloides被包括在蛇根草分支中。本文对冲绳特有的新扎头尖唇草（Oxygyne shinzatoi）的染色体特征和分子系统学位置进行了研究。该属的基本染色体数目被认为是x=9。根据18S rDNA序列分析，O. shinzatoi一直被发现属于单系群的族Thismieae。与最近共同祖先的距离分析表明，O.在画眉草族中，以shinzatoi的替代率最低。结合基本染色体数目和代换率特征，确定了O. shinzatoi可以被认为是Thismieae族的基础分类群之一。少

We confirmed the variation of seed morphology in Cycas revoluta (Cycadaceae) of the Ryukyus, however, variation in seed morphology had no geographical tendency and we could not recognize any interspecific taxa in C. revoluta based on seed morphology.Karyotypes of Ophiopogon reversus (Convallariaceae) collected from four localities in Taiwan and one locality on Yonaguni-jima Island in the southern Ryukyus were reported for the first time. The karyotype of O. reversus was different from O. jaburan in having one pair of short submedian chromosomes with secondary constrictions at the proximal region of the long arms.We examined the floral morph of tetraploid Ophiorrhiza japonica var. amamiana and diploid O. japonica var. japonica (Rubiaceae) to elucidate the association of distyly and ploidy levels. Chloroplast DNA phylogeny was reconstructed to determine the number of tetraploidization events and floral morph shifts in O. japonica. In cpDNA sequencing analysis, no haplotype was shared bet … More ween the two varieties. The cpDNA hap lotype network displayed the monophyly of O. japonica var. amamiana, suggesting a single origin of this variety. Because O. japonica var. amamiana having the morphological and cytological entity is recognized as a single lineage and clearly separated from O. japonica var. japonica, this variety can be considered to be a distinct species.Hayataella (Rubiaceae) is a monotypic genus endemic to Taiwan that comprises H. michelloides. To elucidate the systematic treatment of Hayataella, molecular phylogenetic analyses based on nrDNA and cpDNA were conducted with four Ophiorrhiza species. In the Bayesian and the most parsimonious trees, H. michelloides was included in the Ophiorrhiza clade. The monotypic status of Hayataella is, therefore, not considered appropriate, and the combination Ophiorrhiza michelloides is supported.The chromosome characteristics and molecular phylogenetic position of Oxygyne shinzatoi (Burmanniaceae) endemic to Okinawa Island were studied. The basic chromosome number of the genus was thought to be x=9. Based on the 18S rDNA sequence, O. shinzatoi was consistently found to belong to the monophyletic group of tribe Thismieae. Distance analysis from the most recent common ancestor indicated that O. shinzatoi had the lowest substitution rate among the species of tribe Thismieae. Combined with the basic chromosome numbers and the substitution rate characteristics, O. shinzatoi can be considered to be one of the basal taxon of tribe Thismieae. Less