Northern glacial refugia and altitudinal niche divergence shape genome-wide differentiation in the emerging plant model Arabidopsis arenosa.
Quaternary climatic oscillations profoundly impacted temperate biodiversity. For many diverse yet undersampled areas, however, the consequences of this impact are still poorly known. In Europe, particular uncertainty surrounds the role of Balkans, a major hotspot of European diversity, in postglacial recolonization of more northerly areas, and the Carpathians, a debatable candidate for a northern 'cryptic' glacial refugium. Using genome-wide SNPs and microsatellites, we examined how the interplay of historical processes and niche shifts structured genetic diversity of diploid Arabidopsis arenosa, a little-known member of the plant model genus that occupies a wide niche range from sea level to alpine peaks across eastern temperate Europe. While the northern Balkans hosted one isolated endemic lineage, most of the genetic diversity was concentrated further north in the Pannonian Basin and the Carpathians, where it likely survived the last glaciation in northern refugia. Finally, a distinct postglacial environment in northern Europe was colonized by populations of admixed origin from the two Carpathian lineages. Niche differentiation along altitude-related bioclimatic gradients was the main trend in the phylogeny of A. arenosa. The most prominent niche shifts, however, characterized genetically only slightly divergent populations that expanded into narrowly defined alpine and northern coastal postglacial environments. Our study highlights the role of eastern central European mountains not only as refugia for unique temperate diversity but also sources for postglacial expansion into novel high-altitude and high-latitude niches. Knowledge of distinct genetic substructure of diploid A. arenosa also opens new opportunities for follow-up studies of this emerging model of evolutionary biology.
Natural History Museum, University of Oslo, PO Box 1172 Blindern, Oslo, NO-0318, Norway.|Department of Botany, Faculty of Science, Charles University in Prague, Prague, CZ-128 01, Czech Republic.|Institute of Botany, The Czech Academy of Sciences, Průhonice, CZ-252 43, Czech Republic.
Filip
F
Kolář
Department of Botany, Faculty of Science, Charles University in Prague, Prague, CZ-128 01, Czech Republic.
Gabriela
G
Fuxová
Institute of Botany, University of Innsbruck, Innsbruck, AT-6020, Austria.
Eliška
E
Záveská
Center for Ecological Research, Kyoto University, Kyoto, JP-520-2113, Japan.|Faculty of Agriculture, Ryukoku University, Shiga, JP-612-8577, Japan.|JST PRESTO, Saitama, JP-332-0012, Japan.
Atsushi J
AJ
Nagano
Department of Botany, Faculty of Science, Charles University in Prague, Prague, CZ-128 01, Czech Republic.
Lucie
L
Hyklová
Department of Botany, Faculty of Science, Charles University in Prague, Prague, CZ-128 01, Czech Republic.|Institute of Botany, The Czech Academy of Sciences, Průhonice, CZ-252 43, Czech Republic.
Magdalena
M
Lučanová
Center for Ecological Research, Kyoto University, Kyoto, JP-520-2113, Japan.
Hiroshi
H
Kudoh
Department of Botany, Faculty of Science, Charles University in Prague, Prague, CZ-128 01, Czech Republic.|Institute of Botany, Slovak Academy of Sciences, Bratislava, SK-845 23, Slovak Republic.
Karol
K
Marhold
D017360:Arabidopsis / Q000235:genetics*; D063368:Balkan Peninsula; D017753:Ecosystem; D005061:Europe, Eastern; D005828:Genetics, Population; D018895:Microsatellite Repeats; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D000068236:Refugium
Arabidopsis; RADseq; approximate Bayesian computation; niche differentiation; phylogeography