Demographic history and genetic differentiation of an endemic and endangered Ulmus lamellosa ( Ulmus )
- PDF / 3,834,543 Bytes
- 14 Pages / 595.276 x 790.866 pts Page_size
- 9 Downloads / 215 Views
RESEARCH ARTICLE
Open Access
Demographic history and genetic differentiation of an endemic and endangered Ulmus lamellosa (Ulmus) Huimin Hou1†, Hang Ye1†, Zhi Wang1, Jiahui Wu1, Yue Gao1, Wei Han1, Dongchen Na1, Genlou Sun2* and Yiling Wang1*
Abstract Background: Ulmus lamellosa (one of the ancient species of Ulmus) is an endemic and endangered plant that has undergone climatic oscillations and geographical changes. The elucidation of its demographic history and genetic differentiation is critical for understanding the evolutionary process and ecological adaption to forests in Northern China. Results: Polymorphic haplotypes were detected in most populations of U. lamellosa via DNA sequencing. All haplotypes were divided into three phylogeographic clades fundamentally corresponding to their geographical distribution, namely THM (Taihang Mountains), YM (Yinshan Mountains), and YSM (Yanshan Mountains) groups. The YSM group, which is regarded as ancestral, possessed higher genetic diversity and significant genetic variability in contrast to the YSM and YM groups. Meanwhile, the divergence time of intraspecies haplotypes occurred during the Miocene-Pliocene, which was associated with major Tertiary geological and/or climatic events. Different degrees of gene exchanges were identified between the three groups. During glaciation, the YSM and THM regions might have served as refugia for U. lamellosa. Based on ITS data, range expansion was not expected through evolutionary processes, except for the THM group. A series of mountain uplifts (e.g., Yanshan Mountains and Taihang Mountains) following the Miocene-Pliocene, and subsequently quaternary climatic oscillations in Northern China, further promoted divergence between U. lamellosa populations. Conclusions: Geographical topology and climate change in Northern China played a critical role in establishing the current phylogeographic structural patterns of U. lamellosa. These results provide important data and clues that facilitate the demographic study of tree species in Northern China. Keywords: Ulmus lamellosa, Aat, ITS, Genetic differentiation, Demographic history
Background Examining how historical and contemporary ecological factors contribute to the demographic history and genetic differentiation of plants is a central question in ecology and evolution. Climatic oscillations have dramatically influenced the demographic history and patterns of genetic diversification in many plant species, particularly during * Correspondence: [email protected]; [email protected] † Huimin Hou and Hang Ye contributed equally to this work. 2 Saint Mary’s University, Halifax, Canada 1 School of Life Science, Shanxi Normal University, Linfen 041000, P. R. China
the Pleistocene periods with more frequent glacial–interglacial cycles [1–8]. In Asia, at least four major glaciations are thought to have occurred, which likely affected its flora and fauna, although the glacial advances were not as extensive as that of Europe and North America. Northern China, in particular, experienced seve
Data Loading...
