Phylogeny and staminal evolution of Salvia (Lamiaceae, Nepetoideae) in East Asia
Phylogeny and staminal evolution of Salvia (Lamiaceae, Nepetoideae) in East Asia
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东亚丹参（唇形科、荆芥亚科）的系统发育和雄蕊进化
DOI：
10.1093/aob/mcy104
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发表时间：
2018-09-14
期刊：
影响因子：
4.2
通讯作者：
Xiang, Chun-Lei
中科院分区：
文献类型：
--
作者：
Hu, Guo-Xiong;Takano, Atsuko;Xiang, Chun-Lei
背景与目的
鼠尾草属是唇形科中最大的属，目前约有980种。东亚，与。100种，是鼠尾草属三大生物多样性中心之一。然而，这一谱系内的关系仍不清楚，雄蕊杠杆机制，这可能是一个关键的创新属内，一直未得到充分研究。本研究利用6个遗传标记和近全面的分类单元取样，试图阐明东亚鼠尾草（EA）内的雄蕊发育的关系和研究的进化趋势。
方法
对鼠尾草属的91个分类群进行了取样，并包括代表鼠尾草属所有其他主要谱系的34个分类群进行分析。两个核[内转录间隔区（ITS）和外转录间隔区（ETS）]和四个叶绿体DNA标记（psbA-trnH，ycf 1-rps 15，trnL-trnF和rbcL）用于系统发育分析，采用最大简约法（MP），最大似然法（ML）和BEAST，后者也用于估计分歧时间。
关键成果
所有原产于东亚的鼠尾草属物种形成一个分支，并识别出8个主要的亚分支（A-G）。亚支A，包括两个石灰岩特有种（S。sonchifolia和S.石（petrophila），是姐妹的其余EA鼠尾草。在EA分支中观察到6种不同的雄蕊类型。雄蕊A型，具有两个完全可育的后囊，仅见于S。sonchifolia和可能代表祖先雄蕊类型EA鼠尾草。分歧时间估计表明，冠EA鼠尾草开始多样化约。17.4百万年前
结论
本研究支持通过一个广泛定义的鼠尾草和治疗EA鼠尾草作为一个亚属，Glutinaria，认识到该亚属内的八个部分。雄蕊A型在鼠尾草属内表面上是近形的，其它五种类型可能是从它衍生而来的。雄蕊形态在鼠尾草属内是平行进化的，单靠雄蕊结构不足以划分属下的种类。
Background and Aims
Salvia is the largest genus within Lamiaceae, with about 980 species currently recognized. East Asia, with approx. 100 species, is one of the three major biodiversity centres of Salvia. However, relationships within this lineage remain unclear, and the staminal lever mechanism, which may represent a key innovation within the genus, has been understudied. By using six genetic markers and nearly comprehensive taxon sampling, this study attempts to elucidate relationships and examine evolutionary trends of staminal development within the East Asia (EA) Salvia clade.
Methods
Ninety-one taxa of EA Salvia were sampled and 34 taxa representing all other major lineages of Salvia were included for analysis. Two nuclear [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and four chloroplast (psbA-trnH, ycf1-rps15, trnL-trnF and rbcL) DNA markers were used for phylogenetic analysis employing maximum parsimony (MP), maximum likelihood (ML) and BEAST, with the latter also used to estimate divergence times.
Key Results
All Salvia species native to East Asia form a clade, and eight major subclades (A-G) were recognized. Subclade A, comprising two limestone endemics (S. sonchifolia and S. petrophila), is sister to the remainder of EA Salvia. Six distinct stamen types were observed within the EA clade. Stamen type A, with two fully fertile posterior thecae, only occurs in S. sonchifolia and may represent the ancestral stamen type within EA Salvia. Divergence time estimates showed that the crown of EA Salvia began to diversify approx. 17.4 million years ago.
Conclusions
This study supports the adoption of a broadly defined Salvia and treats EA Salvia as a subgenus, Glutinaria, recognizing eight sections within this subgenus. Stamen type A is ostensibly plesiomorphic within EA Salvia, and the other five types may have been derived from it. Staminal morphology has evolved in parallel within the EA Salvia, and staminal structure alone is inadequate to delimit infrageneric categories.