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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腐生平菇物种复合体：始新世晚期起源于东亚，多重分散，物种形成复杂。


平菇物种复合体是腐生性的，具有重要的经济和生态重要性。然而，由于表型可塑性和形态停滞，物种界定长期以来一直存在问题。此外，由于样本有限和用于系统发育分析的基因片段不足，人们对进化历史知之甚少。使用来自亚洲、欧洲、南北美洲和非洲的综合采样，使用最大似然和贝叶斯推理分析，基于 40 个核单拷贝直系同源基因，对 P. ostreatus 物种复合体进行系统发育分析。在这里，我们提出了 P. ostreatus 物种复合体的稳健系统发育，从最深的节点到物种水平都完全解析。 P. ostreatus 物种复合体被强烈支持为单系，并识别了 20 个系统发育物种，其中有 7 个推定新物种。我们的分子钟分析数据表明，侧耳属的分化可能发生在侏罗纪晚期，而平菇属的最近共同祖先在东亚大约 39 Ma 发生了多样化。 P. ostreatus复合体的物种可能在渐新世晚期、中新世晚期和上新世晚期的不同时期从东亚穿过北大西洋陆桥或白令陆桥迁徙到北美，然后在新旧世界多样化同时通过多个分散和替代事件。渐新世中期从东亚到南美的传播可能是通过长距离传播事件实现的。 中新世晚期和第四纪冰川循环中干旱的加剧和气候变冷事件可能对复合体的多样化模式产生了重大影响。进化枝 IIc 内东亚、欧洲、北美和非洲之间的分离被假设是异域物种形成的结果。基质向伞形科的转变可能不早于 6 Ma 发生。生物地理学分析表明，始新世晚期的全球变冷、青藏高原快速抬升和中新世晚期特提斯海退缩导致的干旱加剧、第四纪冰川循环中的气候变冷事件以及基质转换共同促成了生物多样性的发生。物种复合体。