Complete chloroplast genome sequence determination of Rheum species and comparative chloroplast genomics for the members of Rumiceae
Complete chloroplast genome sequence determination of Rheum species and comparative chloroplast genomics for the members of Rumiceae
复制标题
大黄属完整叶绿体基因组序列测定和酸模科成员叶绿体基因组比较
DOI：
10.1007/s00299-020-02532-0
复制
发表时间：
2020-03-27
影响因子：
6.2
通讯作者：
Wang, Xumei
中科院分区：
文献类型：
--
作者：
Zhou, Tao;Zhu, Honghong;Wang, Xumei
大黄属植物的完整质体有助于阐明蓼科植物的系统发育，比较叶绿体基因组学有助于开发大黄属植物鉴定的遗传标记。大黄（蓼科）广泛分布于亚洲内陆的温带和亚热带地区。大黄属植物通常是多年生草本植物，其中一半是中国特有的，具有重要的药用价值。由于形态特征相似，大黄属植物的种界尚不清楚。对8种大黄、大黄和大黄的叶绿体基因组进行了分析。通过与已发表的两种大黄属（Rheum）的基因组结构比较，发现它们的质体组序列相对保守，具有相同的基因顺序，其中3种Palmata属（Sect. Palmata）显著表现出较高的序列相似性。大黄属植物可利用部分热点区进行鉴定，其中17个质体基因可进行正选择。系统发育分析表明，蓼科各种属均聚在同一类群中，大黄属（Rheum wittrockii）除大黄属（Rheum wittrockii）外，其余各种属构成一个最大简约/最大似然支持值和贝叶斯后验概率较高的单系类群。基于质体的分子定年表明蓼科各物种的分化发生在上白垩纪[7386 - 7799万年前（Ma）]。棕藓属物种的分化发生在1.60 Ma左右，表明其多样性受到第四纪反复气候波动的影响。
Complete plastomes of Rheum species facilitated to clarify the phylogeny of Polygonaceae, and comparative chloroplast genomics contributed to develop genetic markers for the authentication of Rheum species. Rheum (Polygonaceae) is widely distributed throughout the temperate and subtropical areas of Asian interior. Rheum species are usually perennial herbs, and half of them are endemic to China with important medicinal properties. On account of similar morphological characteristics, species delimitation of Rheum still remains unclear. Chloroplast genomes of eight Rheum species, Rumex crispus and Oxyria digyna were characterized. Based on the comparison of genome structure of these species and the two published Rheum species, it is shown that plastome sequences of these species are relatively conserved with the same gene order, and three Sect. Palmata species remarkably showed high sequence similarities. Some hotspots could be used to discriminate the Rheum species, and 17 plastid genes were subject to positive selection. The phylogenetic analyses indicated that all the Polygonaceae species were clustered in the same group and showed that Rheum species, except for Rheum wittrockii, formed a monophyletic group with high maximum parsimony/maximum likelihood bootstrap support values and Bayesian posterior probabilities. The molecular dating based on plastomes indicated that the divergences within Polygonaceae species were dated to the Upper Cretaceous period [73.86-77.99 million years ago (Ma)]. The divergence of Sect. Palmata species was estimated to have occurred around 1.60 Ma, indicating that its diversification was affected by the repeated climatic fluctuation in the Quaternary.