Origin and expansion of the allotetraploid Aegilops geniculata, a wild relative of wheat.
*This study reconstructs the phylogeography of Aegilops geniculata, an allotetraploid relative of wheat, to discuss the impact of past climate changes and recent human activities (e.g. the early expansion of agriculture) on the genetic diversity of ruderal plant species. *We combined chloroplast DNA (cpDNA) sequencing, analysed using statistical parsimony network, with nonhierarchical K-means clustering of amplified fragment length polymorphism (AFLP) genotyping, to unravel patterns of genetic structure across the native range of Ae. geniculata. The AFLP dataset was further explored by measurement of the regional genetic diversity and the detection of isolation by distance patterns. *Both cpDNA and AFLP suggest an eastern Mediterranean origin of Ae. geniculata. Two lineages have spread independently over northern and southern Mediterranean areas. Northern populations show low genetic diversity but strong phylogeographical structure among the main peninsulas, indicating a major influence of glacial cycles. By contrast, low genetic structuring and a high genetic diversity are detected in southern Mediterranean populations. Finally, we highlight human-mediated dispersal resulting in substantial introgression between resident and migrant populations. *We have shown that the evolutionary trajectories of ruderal plants can be similar to those of wild species, but are interfered by human activities, promoting range expansions through increased long-distance dispersal and the creation of suitable habitats.
Arrigo
Nils
N
Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, 11 rue Emile-Argand, 2009 Neuchâtel, Switzerland.
Felber
François
F
Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, 11 rue Emile-Argand, 2009 Neuchâtel, Switzerland.
Parisod
Christian
C
Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, 11 rue Emile-Argand, 2009 Neuchâtel, Switzerland.
Buerki
Sven
S
Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, 11 rue Emile-Argand, 2009 Neuchâtel, Switzerland.
Alvarez
Nadir
N
Department of Ecology and Evolution, University of Lausanne - UNIL Sorge, Biophore Building, 1015 Lausanne, Switzerland.
David
Jacques
J
UMR Diversité et Adaptation des Plantes Cultivées, SupAgro, 2 Place P. Viala, Domaine de Melgueil, 34130 Mauguio, France.
Guadagnuolo
Roberto
R
Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, 11 rue Emile-Argand, 2009 Neuchâtel, Switzerland.
D005075:Biological Evolution; D057231:Climate Change; D018742:DNA, Chloroplast; D004463:Ecology; D017753:Ecosystem; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008522:Mediterranean Sea; D010802:Phylogeny; D058974:Phylogeography; D006109:Poaceae / Q000235:genetics*; D058614:Seed Dispersal; D057891:Tetraploidy; D014908:Triticum / Q000235:genetics
D018742:DNA, Chloroplast