Ran Hang, Liu Yanyan, Wu Cui, Cao Yanan
College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China.
Plants (Basel). 2020 Sep 3;9(9):1143. doi: 10.3390/plants9091143.
Phylogenetic analyses of complete chloroplast genome sequences have yielded significant improvements in our understanding of relationships in the woody flowering genus (Adoxaceae, Dipsacales); however, these relationships were evaluated focusing only on species within Central and South America and Southeast Asia. By contrast, despite being a hotspot of diversity, phylogenetic relationships of species in China are less well known. Here, we characterized the complete chloroplast (cp) genomes of 21 species endemic to China, as well as three species. These 24 plastomes were highly conserved in genomic structure, gene order and content, also when compared with other Adoxaceae. The identified repeat sequences, simple sequence repeats (SSRs) and highly variable plastid regions will provide potentially valuable genetic resources for further population genetics and phylogeographic studies on and . Consistent with previous combined phylogenetic analyses of 113 species, our phylogenomic analyses based on the complete cp genome sequence dataset confirmed the sister relationship between and the --- group, the monophyly of four recognized sections in (i.e., sect. , sect. , sect. and sect. ) and the nonmonophyly of sect. and sect. . Additionally, our study confirmed the sister relationships between the clade Valvatotinus and sect. , as well as between sect. and the - group. Overall, our results clearly document the power of the complete cp genomes in improving phylogenetic resolution, and will contribute to a better understanding of plastome evolution in Chinese Adoxaceae.
对完整叶绿体基因组序列的系统发育分析，极大地增进了我们对木本开花植物属（五福花科，川续断目）内物种间关系的理解；然而，这些关系仅针对中美洲、南美洲以及东南亚的物种进行了评估。相比之下，尽管中国是该属植物多样性的一个热点地区，但其物种间的系统发育关系却鲜为人知。在此，我们对21种中国特有种以及3种其他种的完整叶绿体（cp）基因组进行了特征分析。这24个质体基因组在基因组结构、基因顺序和内容上高度保守，即便与其他五福花科植物相比亦是如此。所鉴定出的重复序列、简单序列重复（SSR）以及高变质体区域，将为后续针对该属植物的群体遗传学和系统地理学研究提供潜在的宝贵遗传资源。与先前对113种该属植物进行的联合系统发育分析结果一致，我们基于完整cp基因组序列数据集的系统基因组分析，证实了[某属]与[另一属] - 组之间的姐妹关系、该属四个公认组（即[组名1]组、[组名2]组、[组名3]组和[组名4]组）的单系性，以及[组名5]组和[组名6]组的非单系性。此外，我们的研究还证实了具瓣托叶类分支与[组名7]组之间、[组名8]组与[另一属] - 组之间的姐妹关系。总体而言，我们的结果清楚地证明了完整cp基因组在提高系统发育分辨率方面的作用，并将有助于更好地理解中国五福花科植物的质体基因组进化。
