Xu Yufen, Liao Borong, Ostevik Kate L, Zhou Hougao, Wang Fenglan, Wang Baosheng, Xia Hanhan
College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, China.
Coconut Research Institute of Chinese Academy of Tropical Agricultural Sciences, Wenchang, China.
Front Plant Sci. 2022 Jun 2;13:923442. doi: 10.3389/fpls.2022.923442. eCollection 2022.
Chrysanthemum ( Ramat) is an important floricultural crop and medicinal herb. Modern chrysanthemum cultivars have complex genetic backgrounds because of multiple cycles of hybridization, polyploidization, and prolonged cultivation. Understanding the genetic background and hybrid origin of modern chrysanthemum cultivars can provide pivotal information for chrysanthemum genetic improvement and breeding. By now, the origin of cultivated chrysanthemums remains unclear. In this study, 36 common chrysanthemum cultivars from across the world and multiple wild relatives were studied to identify the maternal donor of modern chrysanthemum. Chloroplast (cp) genomes of chrysanthemum cultivars were assembled and compared with those of the wild relatives. The structure of cp genomes was highly conserved among cultivars and wild relatives. Phylogenetic analyses based on the assembled cp genomes showed that all chrysanthemum cultivars grouped together and shared 64 substitutions that were distinct from those of their wild relatives. These results indicated that a diverged lineage of the genus , which was most likely an extinct or un-sampled species/population, provided a maternal source for modern cultivars. These findings provide important insights into the origin of chrysanthemum cultivars, and a source of valuable genetic markers for chrysanthemum breeding programs.
菊花（Ramat）是一种重要的花卉作物和药用植物。由于多次杂交、多倍体化和长期栽培，现代菊花品种具有复杂的遗传背景。了解现代菊花品种的遗传背景和杂交起源可为菊花的遗传改良和育种提供关键信息。到目前为止，栽培菊花的起源仍不清楚。在本研究中，对来自世界各地的36个常见菊花品种和多个野生近缘种进行了研究，以确定现代菊花的母本供体。组装了菊花品种的叶绿体（cp）基因组，并与野生近缘种的叶绿体基因组进行了比较。cp基因组的结构在品种和野生近缘种中高度保守。基于组装的cp基因组的系统发育分析表明，所有菊花品种聚在一起，共有64个与野生近缘种不同的替换位点。这些结果表明，该属的一个分化谱系，很可能是一个已灭绝或未采样的物种/种群，为现代品种提供了母本来源。这些发现为菊花品种的起源提供了重要见解，并为菊花育种计划提供了有价值的遗传标记来源。
