The Pleurotus ostreatus species complex is saprotrophic and of significant economic and ecological importance. However, species delimitation has long been problematic because of phenotypic plasticity and morphological stasis. In addition, the evolutionary history is poorly understood due to limited sampling and insufficient gene fragments employed for phylogenetic analyses. Comprehensive sampling from Asia, Europe, North and South America and Africa was used to run phylogenetic analyses of the P. ostreatus species complex based on 40 nuclear single-copy orthologous genes using maximum likelihood and Bayesian inference analyses. Here, we present a robust phylogeny of the P. ostreatus species complex, fully resolved from the deepest nodes to species level. The P. ostreatus species complex was strongly supported as monophyletic, and 20 phylogenetic species were recognized, with seven putatively new species. Data from our molecular clock analyses suggested that divergence of the genus Pleurotus probably occurred in the late Jurassic, while the most recent common ancestor of the P. ostreatus species complex diversified about 39 Ma in East Asia. Species of the P. ostreatus complex might migrate from the East Asia into North America across the North Atlantic Land Bridge or the Bering Land Bridge at different times during the late Oligocene, late Miocene and late Pliocene, and then diversified in the Old and New Worlds simultaneously through multiple dispersal and vicariance events. The dispersal from East Asia to South America in the middle Oligocene was probably achieved by a long-distance dispersal event. Intensification of aridity and climate cooling events in the late Miocene and Quaternary glacial cycling probably had a significant influence on diversification patterns of the complex. The disjunctions among East Asia, Europe, North America and Africa within Clade IIc are hypothesized to be a result of allopatric speciation. Substrate transitions to Apiaceae probably occurred no earlier than 6 Ma. Biogeographic analyses suggested that the global cooling of the late Eocene, intensification of aridity caused by rapid uplift of the QTP and retreat of the Tethys Sea in the late Miocene, climate cooling events in Quaternary glacial cycling, and substrate transitions have contributed jointly to diversification of the species complex.

中文翻译：

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腐生的侧耳平菇种复合体：始于东亚的始新世晚期，多重扩散和复杂的物种形成。

平菇属种是腐生的，具有重要的经济和生态意义。但是，由于表型可塑性和形态停滞，物种划分长期以来一直是个问题。此外，由于有限的采样和用于系统发育分析的基因片段不足，人们对进化史的了解很少。使用来自亚洲，欧洲，北美洲，南美和非洲的综合采样，使用最大似然和贝叶斯推断分析，基于40个核单拷贝直系同源基因，对平菇假单胞菌物种群进行了系统发育分析。在这里，我们介绍了P. ostreatus物种复合体的强大系统发育，从最深的节点到物种水平完全解析。P. ostreatus物种复合体被强烈支持为单系统的，确认了20种系统发育物种，其中7种可能是新物种。来自我们的分子钟分析的数据表明，白灵菇属的发散可能发生在侏罗纪晚期，而东亚扁豆属物种复合体的最新共同祖先在东亚约39 Ma。在渐新世晚期，中新世晚期和上新世晚期，P。ostreatus复合体的物种可能在不同时期从东亚穿过北大西洋陆地桥或白令陆地桥迁移到北美，然后在新旧世界中多样化。同时通过多次传播和冲突事件。渐新世中期从东亚到南美的扩散可能是通过长距离的扩散事件实现的。中新世晚期和第四纪冰川循环中干旱的加剧和气候降温事件可能对该复合体的多样化模式有重大影响。Clade IIc中东亚，欧洲，北美和非洲之间的脱节被认为是异源物种形成的结果。底物向A科的过渡可能不早于6 Ma。生物地理学分析表明，始新世末期的全球降温，中新世晚期QTP的快速上升和特提斯海退缩引起的干旱加剧，第四纪冰川循环中的气候降温事件以及基质转变共同促进了新世纪的多样化。物种复合体。Clade IIc中东亚，欧洲，北美和非洲之间的脱节被认为是异源物种形成的结果。底物向A科的过渡可能不早于6 Ma。生物地理学分析表明，始新世末期的全球降温，中新世晚期QTP的快速升高和特提斯海退缩引起的干旱加剧，第四纪冰川循环中的气候降温事件以及基质转变共同促进了新世纪的多样化。物种复合体。Clade IIc中东亚，欧洲，北美和非洲之间的脱节被认为是异源物种形成的结果。底物向A科的过渡可能不早于6 Ma。生物地理学分析表明，始新世末期的全球降温，中新世晚期QTP的快速升高和特提斯海退缩引起的干旱加剧，第四纪冰川循环中的气候降温事件以及基质转变共同促进了新世纪的多样化。物种复合体。