1. Evolutionary history of a desert perennial Arnebia szechenyi (Boraginaceae): Intraspecific divergence, regional expansion and asymmetric gene flow
- Author
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Hai-Yang Wu, Bin Tian, Meng-Jiao Fu, and Dong-Rui Jia
- Subjects
0106 biological sciences ,Range (biology) ,QH301-705.5 ,Asymmetric gene flow ,Biodiversity ,Plant Science ,Biology ,010603 evolutionary biology ,01 natural sciences ,Gene flow ,Cytonuclear discordance ,Genetic variation ,Biology (General) ,Ecology, Evolution, Behavior and Systematics ,Plant evolution ,Genetic diversity ,Ecology ,fungi ,Botany ,Intraspecific divergence ,Phylogeography ,QK1-989 ,Genetic structure ,Desert growth ,Research Paper ,010606 plant biology & botany - Abstract
The complex interactions of historical, geological and climatic events on plant evolution have been an important research focus for many years. However, the role of desert formation and expansion in shaping the genetic structures and demographic histories of plants occurring in arid areas has not been well explored. In the present study, we investigated the phylogeography of Arnebia szechenyi, a desert herb showing a near-circular distribution surrounding the Tengger Desert in Northwest China. We measured genetic diversity of populations using three maternally inherited chloroplast DNA (cpDNA) fragments and seven bi-paternally inherited nuclear DNA (nDNA) loci that were sequenced from individuals collected from 16 natural populations across its range and modelled current and historical potential habitats of the species. Our data indicated a considerably high level of genetic variation within A. szechenyi and noteworthy asymmetry in historical migration from the east to the west. Moreover, two nuclear genetic groups of populations were revealed, corresponding to the two geographic regions separated by the Tengger Desert. However, analysis of cpDNA data did not show significant geographic structure. The most plausible explanation for the discrepancy between our findings based on cpDNA and nDNA data is that A. szechenyi populations experienced long periods of geographic isolation followed by range expansion, which would have promoted generalized recombination of the nuclear genome. Our findings further highlight the important role that the Tengger Desert, together with the Helan Mountains, has played in the evolution of desert plants and the preservation of biodiversity in arid Northwest China., Highlights • nDNA and cpDNA revealed the phylogeography of Arnebia szechenyi. • nDNA revealed two asymmetric gene flow genetic groups separated by the Tengger Desert. There was an however, the cpDNA results did not show that. • The discrepancy between cpDNA and nDNA is that long periods of geographic isolation followed by range expansion may have promoted generalized recombination of the nuclear genome. • The Tengger Desert and the Helan Mountains have played important roles in the evolution of Arnebia szechenyi.
- Published
- 2021