Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia.
V. N. Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russia.
J Plant Res. 2021 Jan;134(1):91-104. doi: 10.1007/s10265-020-01241-9. Epub 2021 Jan 4.
The vast territory of East Asia, including southwestern Beringia, is considered to have been almost ice free during the Pleistocene. Cold-resistant flora may have persisted in this region expanding or contracting its range during the climate cooling. Only a few plant genera have been studied with a sampling area across their entire geographic range in East Asia; therefore, the understanding of the biogeographic history of alpine flora in this region remains limited. In the present study, genetic variation and population structure in 21 populations of the alpine shrub Rhododendron aureum across its range in East Asia were assessed using 18 microsatellite loci. Phylogenetic analyses revealed three main genetic groups: Siberia, Northeast, and North Pacific. According to the geographical pattern of genetic diversity, the North Pacific group includes populations from Kamchatka, south of Russian Far East, and territories close to central Japan. This group is the most diverse and likely diverged earlier than the Siberia and Northeast groups. Ecological niche modeling predicts range expansion of this species during the period of cooling and, together with demographic history, suggests that the divergence between the three main genetic groups predated the Last Glacial Maximum. Similar to other cold-resistant species such as Larix sibirica and Juniperus communis, the pattern of genetic diversity of R. aureum supports the survival of the species at high latitudes during the Pleistocene with limited contribution of the southern populations to expansion of the species range to the Northeast region and Siberia.
东亚广阔的地域，包括西南伯利兹地区，被认为在更新世期间几乎没有冰。耐寒植物可能在该地区持续存在，其范围在气候变冷时扩大或收缩。只有少数几个植物属在整个东亚地理范围内进行了采样研究；因此，对该地区高山植物生物地理历史的了解仍然有限。在本研究中，使用 18 个微卫星位点评估了东亚范围内 21 个高山灌木杜鹃属 Rhododendron aureum 种群的遗传变异和种群结构。系统发育分析揭示了三个主要的遗传群体：西伯利亚、东北和北太平洋。根据遗传多样性的地理模式，北太平洋群体包括来自堪察加半岛、俄罗斯远东南部和接近日本中部的种群。该群体是最多样化的，可能比西伯利亚和东北群体更早分化。生态位模型预测该物种在冷却期间的范围扩大，加上种群历史，表明三个主要遗传群体之间的分化早于末次冰期最大值。与其他耐寒物种如西伯利亚落叶松和刺柏属植物类似，R. aureum 的遗传多样性模式支持该物种在更新世期间在高纬度地区的生存，南部种群对该物种向东北和西伯利亚地区的扩张的贡献有限。
