Nuclear and chloroplast DNA phylogeography reveals vicariance among European populations of the model species for the study of metal tolerance, Arabidopsis halleri (Brassicaceae).
Arabidopsis halleri is a pseudometallophyte involved in numerous molecular studies of the adaptation to anthropogenic metal stress. In order to test the representativeness of genetic accessions commonly used in these studies, we investigated the A. halleri population genetic structure in Europe. Microsatellite and nucleotide polymorphisms from the nuclear and chloroplast genomes, respectively, were used to genotype 65 populations scattered over Europe. The large-scale population structure was characterized by a significant phylogeographic signal between two major genetic units. The localization of the phylogeographic break was assumed to result from vicariance between large populations isolated in southern and central Europe, on either side of ice sheets covering the Alps during the Quaternary ice ages. Genetic isolation was shown to be maintained in western Europe by the high summits of the Alps, whereas admixture was detected in the Carpathians. Considering the phylogeographic literature, our results suggest a distinct phylogeographic pattern for European species occurring in both mountain and lowland habitats. Considering the evolution of metal adaptation in A. halleri, it appears that recent adaptations to anthropogenic metal stress that have occurred within either phylogeographic unit should be regarded as independent events that potentially have involved the evolution of a variety of genetic mechanisms.
Laboratoire de Génétique et Evolution des Populations Végétales, FRE CNRS 3268, Université de Lille-Lille1, F-59655 Villeneuve d'Ascq, France.
Maxime
M
Pauwels
Laboratoire de Génétique et Evolution des Populations Végétales, FRE CNRS 3268, Université de Lille-Lille1, F-59655 Villeneuve d'Ascq, France.
Xavier
X
Vekemans
Laboratoire de Génétique et Evolution des Populations Végétales, FRE CNRS 3268, Université de Lille-Lille1, F-59655 Villeneuve d'Ascq, France.
Cécile
C
Godé
Laboratoire de Génétique et Evolution des Populations Végétales, FRE CNRS 3268, Université de Lille-Lille1, F-59655 Villeneuve d'Ascq, France.
Hélène
H
Frérot
Laboratoire de Génétique et Evolution des Populations Végétales, FRE CNRS 3268, Université de Lille-Lille1, F-59655 Villeneuve d'Ascq, France.
Vincent
V
Castric
Laboratoire de Génétique et Evolution des Populations Végétales, FRE CNRS 3268, Université de Lille-Lille1, F-59655 Villeneuve d'Ascq, France.
Pierre
P
Saumitou-Laprade
D001499:Bayes Theorem; D019607:Brassicaceae / Q000187:drug effects / Q000235:genetics*; D018742:DNA, Chloroplast; D018744:DNA, Plant; D004361:Drug Tolerance / Q000235:genetics*; D004463:Ecology; D005060:Europe; D014644:Genetic Variation; D046448:Ice Cover; D008670:Metals / Q000494:pharmacology*; D018895:Microsatellite Repeats; D008962:Models, Theoretical; D058974:Phylogeography; D011110:Polymorphism, Genetic
D018742:DNA, Chloroplast; D018744:DNA, Plant; D008670:Metals