基于5个基因片段的野胡麻属系统位置研究

摘要

To verify monotypic genus Dodartia (formely Scrophulariaceae sensu lato) familial placement and evaluate phylogenetic relation between Dodartia and its relatives, we sampled Dodartia orientalis and its comprehensive and putative relatives, and conducted phylogenetic analyses including Maximum Parsimony and Bayesian inference of one nuclear DNA (ITS) region and four chloroplast DNA gene regions (trnL-F, rps16 ,rbcL, rps2) individually and combined. The main result of the phylogenetic analyses indicate that Dodartia is sister to Lancea with the Bootstrap (BS) values = 97% , Posterior Probability (PP) values = 100% of combined four chloroplast DNA genes data;BS=99% ,PP= 100% of ITS data and BS=100%,PP = 100% of combined four chloroplast DNA genes and ITS data. Dodartia, Lancea and Mazus form a maximum supported monophyletic clade with BS=100% and PP=100% of all the data. This relation was also corroborated by morphological data. Based on these data, we suggest that Dodartia should be included in Mazoideae (Phrymaceae) ,and the most closest relative of Dodartia is Lancea. Dodartia and Lancea maybe included in Mazus and relative to Mazus omeiensis or sister to Mazus.%对单种属野胡麻属(原隶属于广义玄参科)及其可能近缘类群广泛取样,选择合适外类群,通过对4个叶绿体基因联合数据( trnL-F、rps16、rbcL、rps2)、核基因ITS片段、叶绿体基因与核基因ITS片段联合数据,进行最大简约法和贝叶斯法分析,探讨野胡麻属在科级系统位置及其与近缘类群系统发育关系.结果表明,所有系统树都支持野胡麻属先和肉果草属构成姐妹群关系,叶绿体基因联合系统树支持率分别为97％[Bootstrap (BS)]和100％[Posterior probability(PP)]；ITS系统树支持率分别为99％(BS)和100％ (PP);叶绿体基因和ITS联合系统树支持率均为100％(BS和PP).野胡麻属、肉果草属与通泉草属一起构成一单系群,叶绿体基因联合系统树、ITS系统树、叶绿体基因和ITS联合系统树的支持率均为100％(BS和PP).形态学证据也支持野胡麻属、肉果草属和通泉草属这3个属的近缘关系.本研究结果支持单种属野胡麻属隶属于透骨草科的通泉草亚科,与肉果草属亲缘关系最近,这两个属进而与通泉草属近缘,可能隶属于通泉草属内,与岩白翠亲缘关系较近,也可能与通泉草属互为姐妹群关系.