Molecular Ecology Group, State Key Laboratory of Grassland Agro-Ecosystem, Lanzhou University, Lanzhou 730000, Gansu, PR China.
Mol Phylogenet Evol. 2012 Apr;63(1):150-8. doi: 10.1016/j.ympev.2012.01.002. Epub 2012 Jan 12.
In this study, we examined diversification history of Rheum and tested the hypothesis that morphological traits related to plant 'body-plans' evolved in parallel in this genus. We sequenced eight chloroplast DNA fragments (representing more than 8000 bps of the sequence for each species) of 34 species from the genus and 13 species from closely related genera. Phylogenetic analyses indicate that all species of Rheum form a monophyletic lineage sister to the two-species genus Oxyria, indicating that radiative diversifications have occurred in its evolutionary history. Our dating analyses further suggest that these radiations largely coincided with the extensive uplifts of the Qinghai-Tibetan Plateau (QTP). Ancestral state reconstruction and likelihood sensitivity tests strongly indicate that both decumbent and 'glasshouse-like' body-plan traits evolved in parallel in different clades. Our findings highlight the importance of the uplift of the QTP in promoting species diversification and the parallel evolution of morphological traits that are putatively adaptive during such an evolutionary history.
在这项研究中，我们研究了大黄属的多样化历史，并检验了形态特征与植物“体式”相关的假说，即在该属中平行进化。我们对来自该属的 34 种和来自近缘属的 13 种植物的 8 个叶绿体 DNA 片段（代表每个物种超过 8000 个碱基对的序列）进行了测序。系统发育分析表明，大黄属的所有物种都与两种物种的 Oxyria 属形成单系，表明其进化历史中发生了辐射多样化。我们的定年分析进一步表明，这些辐射与青藏高原（QTP）的广泛隆起大致吻合。祖先状态重建和似然敏感性测试强烈表明，不同分支中，匍匐和“温室状”体式特征都在平行进化。我们的研究结果强调了青藏高原隆起在促进物种多样化以及在这种进化历史中推测是适应性的形态特征的平行进化方面的重要性。
