Shihezi University, Xinjiang Production and Construction Corps Key Laboratory of Oasis Town and Mountain-basin System Ecology, College of Science, Shihezi, Xinjiang, China.
Shihezi University, Xinjiang Production and Construction Corps Key Laboratory of Oasis Town and Mountain-basin System Ecology, College of Life Sciences, Shihezi, Xinjiang, China.
PeerJ. 2022 Apr 29;10:e13345. doi: 10.7717/peerj.13345. eCollection 2022.
Quaternary period geological events and climatic oscillations significantly affect the geographic structure and genetic diversity of species distribution in arid northwestern China. is a relict and endangered shrub that occurs primarily in arid areas of northwestern China. Based on variation patterns present at three cpDNA regions (K-I, L-F and V) and in one nDNA sequence (ITS1-ITS4) in 174 individuals representing 15 populations, the spatial genetic structure and demographic history of was examined across its entire geographic range. The 17 different haplotypes and 10 ribotypes showed two lineages, distributed across the Western (Mazong Mountains, Hexi Corridor, and Alxa Left Banner) and Eastern regions (Urad Houqi, Yinshan Mountains, Urad Zhongqi, and Daqing Mountains) according to the median-joining network and the BI (Bayesian inference) and ML (Maximum likelihood) trees. AMOVA analysis demonstrated that over 65% of the observed genetic variation was related to this lineage split. The expansions of the Ulanbuhe and Tengger deserts and the eastward extension of the Yinshan Mountains since the Quaternary period likely interrupted gene flow and triggered the observed divergence in the two allopatric regions; arid landscape fragmentation accompanied by local environmental heterogeneity further increased local adaptive differentiation between the Western and Eastern groups. Based on the evidence from phylogeographical patterns and the distribution of genetic variation, distributed in the eastern and western regions are speculated to have experienced eastward migration along the southern slopes of the Lang Mountains and westward migration along the margins of the Ulanbuhe and Tengger deserts to the Hexi Corridor, respectively. For setting a conservation management plan, it is recommended that the south slopes of the Lang Mountains and northern Helan Mountains be identified as the two primary conservation areas, as they have high genetic variation and habitats that are more suitable.
第四纪地质事件和气候振荡显著影响了中国西北干旱地区物种分布的地理结构和遗传多样性。四合木是一种残遗的濒危灌木，主要分布在中国西北干旱地区。本研究基于对 174 个个体的三个 cpDNA 区域（K-I、L-F 和 V）和一个 nDNA 序列（ITS1-ITS4）的变异模式，研究了四合木在其整个地理分布范围内的空间遗传结构和种群历史。17 个不同的单倍型和 10 个核型显示了两个谱系，根据中位连接网络和 BI（贝叶斯推断）和 ML（最大似然）树，分布在西部地区（马鬃山、河西走廊和阿拉善左旗）和东部地区（乌兰布和、阴山山脉、乌拉特中旗和大青山）。AMOVA 分析表明，观察到的遗传变异中有超过 65%与这种谱系分裂有关。第四纪以来乌兰布和和腾格里沙漠的扩张以及阴山山脉的向东延伸可能中断了基因流，并引发了两个隔离区的观察到的分化；干旱景观的破碎化伴随着局部环境的异质性，进一步增加了西部地区和东部地区之间的局部适应性分化。基于系统地理格局和遗传变异的分布，推测分布在东部和西部地区的四合木可能分别沿着狼山的南坡向东和沿着乌兰布和和腾格里沙漠的边缘向西迁徙到河西走廊。为了制定保护管理计划，建议将狼山的南坡和贺兰山北部确定为两个主要的保护区域，因为它们具有较高的遗传变异和更适宜的栖息地。
