Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan, 650201, China.
Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan, 650201, China.
Cladistics. 2021 Oct;37(5):518-539. doi: 10.1111/cla.12457. Epub 2021 Apr 15.
Comprising about 82% of the extant fern species diversity, Polypodiales are generally believed to have diversified in the Late Cretaceous. We estimated the divergence times of Polypodiales using both penalized likelihood and Bayesian methods, based on a dataset consisting of 208 plastomes representing all 28 families and 14 fossil constraints reflecting current interpretations of fossil record. Our plastome phylogeny recovered the same six major lineages as a recent nuclear phylogeny, but the position of Dennstaedtiineae was different. The present phylogeny showed high resolution of relationships among the families of Polypodiales, especially among those forming the Aspleniineae. The divergence time estimates supported the most recent common ancestor of Polypodiales and its closest relative dating back to the Triassic, establishment of the major lineages in the Jurassic, and a likely accelerated radiation during the late Jurassic and the Early Cretaceous. The estimated divergence patterns of Polypodiales and angiosperms converge to a scenario in which their main lineages were established simultaneously shortly before the onset of the Cretaceous Terrestrial Revolution, and further suggest a pre-Cretaceous hidden history for both lineages. The pattern of simultaneous diversifications shown here elucidate an important gap in our understanding of the Terrestrial Revolution that shaped today's ecosystems.
水龙骨目（Polypodiales）约占现存蕨类植物物种多样性的 82%，一般认为它在白垩纪晚期就已经多样化了。我们基于包含 208 个质体基因组代表所有 28 个科和 14 个化石约束的数据集，使用惩罚似然和贝叶斯方法来估计水龙骨目的分歧时间，这些化石约束反映了对化石记录的当前解释。我们的质体系统发育树与最近的核系统发育树一样，恢复了六个主要的谱系，但紫萁科的位置不同。本系统发育树在水龙骨目各科之间，尤其是在形成凤尾蕨科的那些科之间，具有很高的分辨率。分歧时间的估计支持水龙骨目及其最近亲缘关系的最古老共同祖先可追溯到三叠纪，主要谱系在侏罗纪建立，并且可能在侏罗纪晚期和白垩纪早期加速辐射。水龙骨目和被子植物的估计分歧模式趋同于一个情景，即在白垩纪陆地革命开始前不久，它们的主要谱系同时建立，这进一步表明这两个谱系在白垩纪之前都有隐藏的历史。这里显示的同时多样化模式阐明了我们对塑造今天生态系统的陆地革命理解中的一个重要空白。
