Department of Agriculture, Forestry and Bioresources, Plant Genomics & Breeding Institute, College of Agriculture & Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
Department of Life Sciences, Chromosome Research Institute, Sahmyook University, Seoul, 01795, Republic of Korea.
BMC Plant Biol. 2022 Jan 3;22(1):4. doi: 10.1186/s12870-021-03390-y.
Cynanchum wilfordii (Cw) and Cynanchum auriculatum (Ca) have long been used in traditional medicine and as functional food in Korea and China, respectively. They have diverse medicinal functions, and many studies have been conducted, including pharmaceutical efficiency and metabolites. Especially, Cw is regarded as the most famous medicinal herb in Korea due to its menopausal symptoms relieving effect. Despite the high demand for Cw in the market, both species are cultivated using wild resources with rare genomic information.
We collected 160 Cw germplasm from local areas of Korea and analyzed their morphological diversity. Five Cw and one Ca of them, which were morphologically diverse, were sequenced, and nuclear ribosomal DNA (nrDNA) and complete plastid genome (plastome) sequences were assembled and annotated. We investigated the genomic characteristics of Cw as well as the genetic diversity of plastomes and nrDNA of Cw and Ca. The Cw haploid nuclear genome was approximately 178 Mbp. Karyotyping revealed the juxtaposition of 45S and 5S nrDNA on one of 11 chromosomes. Plastome sequences revealed 1226 interspecies polymorphisms and 11 Cw intraspecies polymorphisms. The 160 Cw accessions were grouped into 21 haplotypes based on seven plastome markers and into 108 haplotypes based on seven nuclear markers. Nuclear genotypes did not coincide with plastome haplotypes that reflect the frequent natural outcrossing events.
Cw germplasm had a huge morphological diversity, and their wide range of genetic diversity was revealed through the investigation with 14 molecular markers. The morphological and genomic diversity, chromosome structure, and genome size provide fundamental genomic information for breeding of undomesticated Cw plants.
杠柳（Cw）和白首乌（Ca）在传统医学中一直被使用，分别在韩国和中国被用作功能性食品。它们具有多种药用功能，许多研究已经开展，包括药物功效和代谢物。特别是，Cw 由于其缓解更年期症状的作用，被认为是韩国最著名的药用植物。尽管市场对 Cw 的需求很高，但这两个物种都是使用野生资源进行栽培的，其基因组信息很少。
我们从韩国当地采集了 160 份 Cw 种质资源，并对其形态多样性进行了分析。其中 5 份 Cw 和 1 份 Ca 形态多样，我们对其进行了测序，并组装和注释了核核糖体 DNA（nrDNA）和完整质体基因组（plastome）序列。我们研究了 Cw 的基因组特征以及 Cw 和 Ca 的质体和 nrDNA 的遗传多样性。Cw 的单倍体核基因组约为 178 Mbp。核型分析显示 45S 和 5S nrDNA 位于 11 条染色体中的一条上。质体序列显示了 1226 个种间多态性和 11 个 Cw 种内多态性。根据 7 个质体标记，将 160 个 Cw 品系分为 21 个单倍型，根据 7 个核标记分为 108 个单倍型。核基因型与反映频繁自然杂交事件的质体单倍型不吻合。
Cw 种质资源具有巨大的形态多样性，通过 14 个分子标记的调查揭示了其广泛的遗传多样性。形态和基因组多样性、染色体结构和基因组大小为未驯化 Cw 植物的培育提供了基础的基因组信息。
