Evolutionary Migration of the Disjunct Salt Cress Eutrema salsugineum (= Thellungiella salsuginea, Brassicaceae) between Asia and North America

PLoS One. 2015 May 13;10(5):e0124010. doi: 10.1371/journal.pone.0124010. eCollection 2015.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asia
  • Bayes Theorem
  • Brassicaceae / classification
  • Brassicaceae / genetics*
  • Chloroplasts / genetics
  • DNA, Chloroplast / genetics*
  • DNA, Intergenic
  • Genetic Loci
  • Genetic Speciation*
  • Genetic Variation
  • Models, Genetic
  • North America
  • Phylogeny*
  • Phylogeography
  • Plant Dispersal / genetics*
  • Salt-Tolerant Plants
  • Sequence Analysis, DNA

Substances

  • DNA, Chloroplast
  • DNA, Intergenic

Grants and funding

This research was supported by grants from the National Natural Science Foundation of China (91331102) and Sichuan Province Youth Science and technology innovation team (2014TD003). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.