The complete plastome genome sequence of Cynanchum otophyllum (Asclepiadaceae), a unique medicinal species in China

Cynanchum otophyllum Schneid is an important medicinal plant in China. In this paper, the chloroplast genome of C. otophyllum was sequenced based on high-throughput technology, and the chloroplast genome structure characteristics and phylogenetic relationship of C. otophyllum were analyzed. The results showed the complete plastome genome size of C. otophyllumis 160,874bp, including one small single copy (SSC, 19,851bp) and one large single copy (LSC, 92,009bp) regions isolated by a pair of inverted repeat regions (IRs, 24,507bp). The whole plastome genome including 84 protein encoding genes, 8 rRNA and 37 tRNA. Based on the phylogenetic topologies, C. otophyllum shows close association with additional Gomphocarpus and Asclepias genus. This study contributes to an enhanced understanding of the genetic information of C. otophyllum and provides a theoretical basis for the development of molecular markers and phylogeographic of the species, as well as for constructing the phylogenetic tree of Asclepiadaceae.

青阳参（Cynanchum otophyllum Schneid）是中国重要的药用植物。本研究基于高通量测序技术对青阳参的叶绿体基因组进行测序，并分析了其叶绿体基因组的结构特征与系统发育关系。结果表明，该物种的完整质体基因组（plastome genome）大小为160874 bp，包含由一对反向重复区（inverted repeat regions, IRs, 24507 bp）分隔的1个小单拷贝区（small single copy, SSC, 19851 bp）与1个大单拷贝区（large single copy, LSC, 92009 bp）。该完整质体基因组共包含84个蛋白编码基因、8个核糖体RNA（rRNA）基因以及37个转运RNA（tRNA）基因。基于系统发育拓扑结构分析，青阳参与钉头果属（Gomphocarpus）和马利筋属（Asclepias）物种亲缘关系较近。本研究有助于加深对青阳参遗传信息的认知，为该物种的分子标记开发、系统地理学研究以及构建萝藦科（Asclepiadaceae）系统发育树提供了理论依据。