Mitochondrial genes from eighteen angiosperms fill sampling gaps for phylogenomic inferences of the early diversification of flowering plants

The early diversification of angiosperms is a rapid yet complicated process and thus it renders the phylogenetic analyses of early-diverging angiosperms much difficulty. Plastid and nuclear phylogenomic studies have raised several controversial hypotheses regarding the angiosperm phylogeny, whereas mitochondrial genomes have been largely ignored. In this study, we newly sequenced mitochondrial genomes from 18 angiosperms to fill the sampling gaps in magnoliids, Austrobaileyales, Chloranthales, Ceratophyllales, and early-diverging lineages of eudicots and monocots. A data matrix of 38 mitochondrial genes from 107 taxa was assembled to address this question. Although conflicting phylogenies were recovered in this study from different datasets and analytical methods, congruence was achieved regarding the deep relationships of several major angiosperm lineages: Chloranthales always groups with Ceratophyllales, Austrobaileyales is sister to mesangiosperms, and a previously unplaced clade—Dil...被子植物（angiosperms）的早期分化是一个快速且复杂的演化过程，这使得早期分化类群被子植物的系统发育分析工作难度陡增。质体（plastid）与核基因组系统发育组学研究已围绕被子植物系统发育提出多项存在争议的假说，而线粒体基因组（mitochondrial genome）则长期被学界忽视。本研究新测序了18种被子植物的线粒体基因组，以填补木兰类（magnoliids）、Austrobaileyales、Chloranthales、Ceratophyllales以及真双子叶植物（eudicots）和单子叶植物（monocots）早期分化支系的采样空白。本研究组装了涵盖107个类群、包含38个线粒体基因的数据集矩阵，以解答该科学问题。尽管本研究基于不同数据集与分析方法得到了相互矛盾的系统发育树，但针对多个核心被子植物支系的深层演化关系达成了一致结论：Chloranthales始终与Ceratophyllales聚类为一支，Austrobaileyales作为中生被子植物（mesangiosperms）的姊妹群，以及一个此前未被定位的演化支（clade）——Dil...