title: Evolutionary Migration of the Disjunct Salt Cress Eutrema salsugineum (= Thellungiella salsuginea, Brassicaceae) between Asia and North America.
abstract: Eutrema salsugineum (= Thellungiella salsuginea Brassicaceae), a species growing in highly saline habitats, is a good model for use in salt-stress research. However, its evolutionary migrations and genetic variations within and between disjunct regions from central Asia to northern China and North America remain largely unknown. We examined genetic variations and phylogeographic patterns of this species by sequencing ITS, 9 chloroplast (cp) DNA fragments (4379 bp) and 10 unlinked nuclear loci (6510 bp) of 24 populations across its distributional range. All markers suggested the high genetic poverty of this species and the limited number of genetic variations recovered was congruently partitioned between central Asia, northern China and North America. Further modelling of nuclear population-genetic data based on approximate bayesian computation (ABC) analyses indicated that the long-distance dispersals after the recent origin of E. salsugineum may have occurred from central Asia to the other two regions respectively within 20000 years. The fast demographic expansions should have occurred in northern China in a more recent past. Our study highlights the importance of using ABC analyses and nuclear population genetic data to trace evolutionary migrations of the disjunct distributions of the plants in the recent past.
authors.affiliation: MOE Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, China.
authors.forename: Xiao-Juan
authors.initials: XJ
authors.lastname: Wang
authors.affiliation: Molecular Ecology Group, Key Laboratory of Arid and Grassland Ecology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Da-Chuan
authors.initials: DC
authors.lastname: Shi
authors.affiliation: MOE Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, China.
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Molecular Ecology Group, Key Laboratory of Arid and Grassland Ecology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, China.
authors.forename: Yong-Shuai
authors.initials: YS
authors.lastname: Sun
authors.affiliation: MOE Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, China; Molecular Ecology Group, Key Laboratory of Arid and Grassland Ecology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Jian-Quan
authors.initials: JQ
authors.lastname: Liu
mesh_terms: D001208:Asia; D001499:Bayes Theorem; D019607:Brassicaceae / Q000145:classification / Q000235:genetics*; D002736:Chloroplasts / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics*; D021901:DNA, Intergenic; D056426:Genetic Loci; D049810:Genetic Speciation; D014644:Genetic Variation; D008957:Models, Genetic; D009656:North America; D010802:Phylogeny; D058974:Phylogeography; D063148:Plant Dispersal / Q000235:genetics*; D055051:Salt-Tolerant Plants; D017422:Sequence Analysis, DNA
chemical_list: D018742:DNA, Chloroplast; D021901:DNA, Intergenic