Starr Julian R, Janzen Francesco H, Ford Bruce A
Department of Biology, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada; Canadian Museum of Nature, Ottawa, Ontario K1P 6P4, Canada.
Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
Mol Phylogenet Evol. 2015 Jul;88:105-20. doi: 10.1016/j.ympev.2015.04.001. Epub 2015 Apr 7.
Traditional Cariceae and Carex (1966 spp.) classifications recognised five genera (Carex, Cymophyllus, Kobresia, Schoenoxiphium, Uncinia) and four subgenera (Carex, Vignea, Vigneastra, Psyllophora). However, molecular studies have shown that only Carex, divided into five major lineages (the Core Carex, Schoenoxiphium, Core Unispicate, Vignea and Siderostictae Clades), is natural. These studies have also suggested that many early diverging tribal lineages are East Asian in origin, but the sampling of East Asian groups has been poor, and support for relationships within and among major Cariceae clades has been weak. To test deep patterns of relationship in Carex we assembled the longest sequence dataset yet (ITS, ETS 1f, matK, ndhF, rps16; ca. 4400bp) with taxonomic sampling focused on critical East and Southeast Asian Carex sections that have blurred subgeneric limits (Decorae, Graciles, Mundae) or have been at the heart of theories on tribal origins (Hemiscaposae, Indicae, Surculosae, Euprepes, Mapaniifoliae, Hypolytroides). Results indicate that subg. Vigneastra is highly polyphyletic (in five of seven major lineages recognised), and they provide the strongest support yet seen for all previously recognised major Cariceae clades in a single analysis (⩾93% BS). Moreover, results provide strong evidence for three previously unrecognised early diverging East and Southeast Asian lineages: a "Hypolytroides Clade" (sect. Hypolytroides) sister to the Siderostictae Clade, and for a "Dissitiflora Lineage" (sect. Mundae) and a morphologically diverse "Small Core Carex Clade" (sects. Graciles, Decorae, Mapaniifoliae, Euprepes, Indicae) as successive sisters to approximately 1400 species in the Core Carex Clade. Our findings also suggest that morphological diversification may have occurred in clades dominated by Asian species followed by canalization to a narrower range of morphologies in species-rich, cosmopolitan lineages.
传统的苔草科和苔草属（1966种）分类法认可五个属（苔草属、扇叶苔属、嵩草属、针蔺属、刺子莞属）和四个亚属（苔草亚属、维尼亚苔草亚属、维尼亚苔草亚属、蚤草苔草亚属）。然而，分子研究表明，只有苔草属是自然的，它被分为五个主要分支（核心苔草分支、针蔺分支、单穗苔草分支、维尼亚苔草分支和锈色苔草分支）。这些研究还表明，许多早期分化的族系起源于东亚，但东亚类群的样本较少，对苔草科主要分支内部和之间关系的支持也很薄弱。为了检验苔草属的深层关系模式，我们组装了迄今为止最长的序列数据集（ITS、ETS 1f、matK、ndhF、rps16；约4400bp），分类采样集中在关键的东亚和东南亚苔草组，这些组的亚属界限模糊（美丽苔草组、纤细苔草组、普通苔草组）或一直是族系起源理论的核心（半囊苔草组、印度苔草组、具根苔草组、美苔草组、枫叶苔草组、矮苔草组）。结果表明，维尼亚苔草亚属高度多系（在认可的七个主要分支中的五个分支中），并且它们在单一分析中为所有先前认可的苔草科主要分支提供了迄今为止最强的支持（⩾93% 自展支持率）。此外，结果为三个先前未被认可的东亚和东南亚早期分化分支提供了有力证据：一个“矮苔草分支”（矮苔草组）是锈色苔草分支的姐妹分支，以及一个“异花苔草分支”（普通苔草组）和一个形态多样的“小型核心苔草分支”（纤细苔草组、美丽苔草组、枫叶苔草组、美苔草组、印度苔草组），它们依次是核心苔草分支中约1400个物种的姐妹分支。我们的研究结果还表明，形态多样化可能发生在以亚洲物种为主的分支中，随后在物种丰富的世界性分支中逐渐形成更窄范围的形态。
