Meng Hong-Hu, Zhang Can-Yu, Song Yi-Gang, Yu Xiang-Qin, Cao Guan-Long, Li Lang, Cai Chao-Nan, Xiao Jian-Hua, Zhou Shi-Shun, Tan Yun-Hong, Li Jie
Plant Phylogenetics and Conservation Group, Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650023, Yunnan, China; Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Nay Pyi Taw 05282, Myanmar.
Plant Phylogenetics and Conservation Group, Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650023, Yunnan, China; Yunnan Normal University, Kunming 650500, Yunnan, China.
Mol Phylogenet Evol. 2022 Jun;171:107458. doi: 10.1016/j.ympev.2022.107458. Epub 2022 Mar 26.
The complexity of global biodiversity in the tropical Indochina Peninsula and subtropical China bioregions has fascinated biologists for decades, but little is known about the spatiotemporal patterns in these regions. Accordingly, the aims of present study were to investigate the evolutionary and distribution patterns of Engelhardia in these regions and establish a model for examining biogeographic patterns and geological events throughout the tropical Indochina Peninsula and subtropical China. The effects of geological events occurring in the area between the Indochina Peninsula and subtropical China bioregions on the two trees species (i.e., E. roxburghiana and E. fenzelii) were evaluated. A robust phylogenetic framework of 884 individuals from 79 populations was used to generate time-calibrated cytoplasmic and nuclear phylogenetic frameworks based on cpDNA, nrDNA, and nSSR data, respectively. When considered along with ancestral area reconstructions, the genetic data were also used to assess and reconstruct the species' population genetic structure and diversity. These analyses yielded important information about the (1) historical distribution relationships between the tropical and subtropical flora of China; (2) effects of the East Asian summer monsoon (EASM) on the evolutionary history of Asia's plants; and (3) importance of biogeography in conservation planning. Although cytoplasmic-nuclear discordance indicated cpDNA and nrDNA were subject to distinct evolutionary mechanisms that reflected respective evolutionary histories of the plastid and nuclear genomes of prior demographic and biogeographic events. The tropical elements of Engelhardia occupied the Indochina Peninsula during the early Eocene, whereas the subtropical elements were transformed from the tropical elements during Miocene cooling and the onset of the EASM at the Oligocene-Miocene boundary, intensified during the late Miocene and Pliocene, facilitating the transformation of Engelhardia from the tropical Indochina Peninsula to subtropical China. Demographic history provided insights into prominent planning frameworks in conservation biology, namely that subtropical China functioned as a refugium during past climate oscillations and will continue to serve in this capacity in the future.
热带中南半岛和亚热带中国生物区域的全球生物多样性的复杂性已经吸引了生物学家数十年，但对于这些区域的时空模式却知之甚少。因此，本研究的目的是调查这些区域黄杞属植物的进化和分布模式，并建立一个模型来研究整个热带中南半岛和亚热带中国的生物地理模式和地质事件。评估了中南半岛和亚热带中国生物区域之间发生的地质事件对这两个树种（即滇黄杞和海南黄杞）的影响。基于叶绿体DNA（cpDNA）、核核糖体DNA（nrDNA）和核简单序列重复（nSSR）数据，使用来自79个种群的884个个体构建了一个强大的系统发育框架，分别生成时间校准的细胞质和核系统发育框架。结合祖先区域重建分析，这些遗传数据还用于评估和重建物种的种群遗传结构和多样性。这些分析得出了关于以下方面的重要信息：（1）中国热带和亚热带植物区系之间的历史分布关系；（2）东亚夏季风（EASM）对亚洲植物进化历史的影响；（3）生物地理学在保护规划中的重要性。尽管细胞质-核不一致表明cpDNA和nrDNA受到不同的进化机制影响，这些机制反映了先前人口统计学和生物地理事件中质体和核基因组各自的进化历史。黄杞属的热带类群在始新世早期占据了中南半岛，而亚热带类群是在渐新世-中新世边界的渐新世冷却和东亚夏季风开始期间，从热带类群转变而来，并在中新世晚期和上新世加剧，促进了黄杞属从热带中南半岛向亚热带中国的转变。种群历史为保护生物学中的重要规划框架提供了见解，即亚热带中国在过去的气候振荡期间起到了避难所的作用，并且在未来将继续发挥这一作用。
