Xia Maoqin, Lee Joongku, Yu Limin, Mu Xianyun, Jiang Wei-Mei, Soltis Douglas E, Liu Luxian, Li Pan
Chongqing Key Laboratory for Germplasm Innovation of Special Aromatic Spice Plants, College of Smart Agriculture, Chongqing University of Arts and Sciences, Chongqing, China.
Department of Environment and Forest Resources, Chungnam National University, Daejeon, South Korea.
Am J Bot. 2025 Sep 4:e70088. doi: 10.1002/ajb2.70088.
The demographic histories of temperate plants in Northeast Asia in response to Quaternary climate oscillations have long been the focus of evolutionary biologists, but have rarely been studied in herbaceous plants. Here, we investigated the phylogeographic patterns of Mukdenia and Oresitrophe.
We sequenced two plastid regions for O. rupifraga (22 populations, 222 individuals), M. acanthifolia (five populations, 50 individuals), and M. rossii (14 populations, 139 individuals). To better understand the phylogeographic patterns of these species, we analyzed genetic diversity/structure, divergence times, demographic history, and distributional changes (with ecological niche modeling). We compared the inferred niche space of these species and addressed isolation by distance (IBD) and isolation by environment (IBE).
We confirmed the monophyly of each species and detected a phylogeographic division corresponding to an arid belt in North China. Oresitrophe rupifraga is inferred to have contracted into four refugia during Pleistocene interglacial periods. Mukdenia acanthifolia and M. rossii appear to have retreated to the Changbai Mountains and Korean Peninsula during that time. In contrast, a larger potential geographic distribution was inferred for each species during glacial periods. Significant ecological niche differentiation was detected among the three species, which may have been associated with their genetic divergence.
Refugial isolation, climatic barriers, and niche differentiation likely influenced the genetic divergence of Oresitrophe and Mukdenia. Our study has implications for the structure of plant diversity in temperate deciduous forests of Northeast Asia and provides insights into conservation units worthy of protection and management for species of both genera.
东北亚温带植物对第四纪气候振荡的种群历史长期以来一直是进化生物学家关注的焦点，但在草本植物中却很少被研究。在此，我们调查了落新妇属和独根草属的系统发育地理格局。
我们对独根草（22个种群，222个个体）、刺叶落新妇（5个种群，50个个体）和虎耳草叶落新妇（14个种群，139个个体）的两个叶绿体区域进行了测序。为了更好地理解这些物种的系统发育地理格局，我们分析了遗传多样性/结构、分歧时间、种群历史以及分布变化（通过生态位建模）。我们比较了这些物种推断的生态位空间，并探讨了距离隔离（IBD）和环境隔离（IBE）。
我们确认了每个物种的单系性，并检测到一个与中国北方干旱带相对应的系统发育地理划分。推断独根草在更新世间冰期收缩到四个避难所。刺叶落新妇和虎耳草叶落新妇在那个时期似乎退缩到了长白山和朝鲜半岛。相比之下，在冰川期推断每个物种有更大的潜在地理分布。在这三个物种之间检测到显著的生态位分化，这可能与它们的遗传分歧有关。
避难所隔离、气候障碍和生态位分化可能影响了独根草属和落新妇属的遗传分歧。我们的研究对东北亚温带落叶林植物多样性的结构具有启示意义，并为这两个属的物种提供了值得保护和管理的保护单元的见解。
