Fritsch P W
Department of Botany and Osher Foundation Laboratory for Molecular Systematics, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118, USA.
Mol Phylogenet Evol. 2001 Jun;19(3):387-408. doi: 10.1006/mpev.2001.0933.
Phylogenetic relationships within the flowering plant genus Styrax were investigated with DNA sequence data from the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) and with chloroplast DNA restriction site data from the genes trnK, rpoC1, and rpoC2. The data sets from each genome were analyzed separately and in combination with parsimony methods. The results strongly support the monophyly of each of the four series of the genus but provide little phylogenetic resolution among them. Reticulate evolution may at least partly explain discordance between the molecular phylogenetic estimates and a prior morphological estimate within series Cyrta. The historical biogeography of the genus was inferred with unweighted parsimony character optimization of trees recovered from a combined ITS and morphological data set, after a series of combinability tests for data set congruence was conducted. The results are consistent with the fossil record in supporting a Eurasian origin of Styrax. The nested phylogenetic position of the South American members of the genus within those from southern North America and Eurasia suggests that the boreotropics hypothesis best explains the amphi-Pacific tropical disjunct distribution occurring within section Valvatae. The pattern of relationship recovered among the species of section Styrax ((western North America + western Eurasia) (eastern North America + eastern Eurasia)) is rare among north-temperate Tertiary forest relicts. The monophyly of the group of species from western North America and western Eurasia provides qualified support for the Madrean-Tethyan hypothesis, which posits a Tertiary floristic connection among the semiarid regions in which these taxa occur. A single vicariance event between eastern Asia and eastern North America accounts for the pattern of relationship among intercontinental disjuncts in series Cyrta.
利用来自核糖体DNA（nrDNA）内部转录间隔区（ITS）的DNA序列数据以及来自trnK、rpoC1和rpoC2基因的叶绿体DNA限制性位点数据，对安息香科开花植物属内的系统发育关系进行了研究。对每个基因组的数据集分别进行分析，并结合简约法进行分析。结果有力地支持了该属四个系列各自的单系性，但在它们之间几乎没有提供系统发育分辨率。网状进化可能至少部分解释了在Cyrta系列中分子系统发育估计与先前形态估计之间的不一致。在对数据集一致性进行了一系列可组合性测试之后，通过对从ITS和形态数据集组合中恢复的树进行非加权简约性状优化，推断出该属的历史生物地理学。结果与化石记录一致，支持安息香属起源于欧亚大陆。该属南美成员在北美南部和欧亚大陆成员中的嵌套系统发育位置表明，泛北极植物区系假说最能解释在Valvatae组内出现的环太平洋热带间断分布。在安息香组物种之间恢复的关系模式（（北美西部+欧亚大陆西部）（北美东部+欧亚大陆东部））在北温带第三纪森林残遗植物中很少见。北美西部和欧亚大陆西部物种组的单系性为马德雷-特提斯假说提供了一定支持，该假说假定在这些分类群出现的半干旱地区之间存在第三纪植物区系联系。东亚和北美东部之间的一次单一的隔离事件解释了Cyrta系列中洲际间断分布之间的关系模式。
