Chloroplast phylogenomic data support Paleocene - Eocene amphi-Pacific early radiation for the Asian Palmate core Araliaceae

Traditional phylogenies based on analysis of multiple genes have failed to obtain a well-resolved evolutionary history for the backbone of the Asian Palmate group of Araliaceae, the largest clade of the family. In this study we applied the genome skimming approach of next-generation sequencing to address whether the lack of resolution at the base of the Asian Palmate tree is due to molecular sampling error or the footprint of an ancient radiation. Twenty-nine complete plastid genomes of Araliaceae (17 newly sequenced) were analyzed (RAxML, Beast, Lagrange, BioGeoBears) to provide the first phylogenomic reconstruction of the group (95% of genera included). As a result, the early divergences of the Asian Palmate group have been clarified but the backbone of its core is not totally resolved, with short internal branches pointing to an ancient radiation scenario. East Asia is inferred as the most likely ancestral area for the Asian Palmate group (early Upper Cretaceous and the Paleocene) fr...

基于多基因分析的传统系统发育研究始终无法解析五加科（Araliaceae）掌状分支亚洲类群（Asian Palmate group，该科最大演化支）的主干高分辨率演化历史。本研究采用下一代测序技术的基因组浅层测序（genome skimming）方法，旨在探究该类群系统发育基部分辨率不足的成因，究竟源于分子采样误差，还是古老辐射演化留下的演化印记。本研究共分析29个五加科完整质体基因组（其中17个为本次新测序获得），借助RAxML、Beast、Lagrange及BioGeoBears等软件开展分析，完成了该类群的首次系统发育组学重建，涵盖了该类群95%的已知属级类群。研究结果澄清了亚洲掌状分支类群的早期分化关系，但其核心类群的系统发育主干仍未完全解析，内部分支较短的特征印证了古老辐射演化的情景。研究推断东亚为该类群最可能的祖先分布区，其分化时间可追溯至早白垩世晚期与古新世时期……