Pleistocene climate changes, and not agricultural spread, accounts for range expansion and admixture in the dominant grassland species Lolium perenne L.

Authors Organisations
  • José Luis Blanco‐Pastor(Author)
    National Institute of Agricultural Research
  • Stéphanie Manel(Author)
    PSL Research University
  • Philippe Barre(Author)
    Centre Nouvelle-Acquitaine-Poitiers, INRA
  • Anna M. Roschanski(Author)
    Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)
  • Evelin Willner(Author)
    Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)
  • Klaus J. Dehmer(Author)
    Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)
  • Matthew Hegarty(Author)
  • Hilde Muylle(Author)
    Institute for Agriculture and Fisheries Research (ILVO)
  • Tom Ruttink(Author)
    Institute for Agriculture and Fisheries Research (ILVO)
  • Isabel Roldán-Ruiz(Author)
    Institute for Agriculture and Fisheries Research (ILVO)
    Ghent University
  • Thomas Ledauphin(Author)
    Centre Nouvelle-Acquitaine-Poitiers, INRA
  • Abraham Escobar-Gutiérrez(Author)
    Centre Nouvelle-Acquitaine-Poitiers, INRA
  • Jean-Paul Sampoux(Author)
    National Institute of Agricultural Research
Type Article
Original languageEnglish
JournalJournal of Biogeography
Early online date17 May 2019
DOI
Publication statusE-pub ahead of print - 17 May 2019
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Abstract

Aim
Grasslands have been pivotal in the development of herbivore breeding since the Neolithic and still represent the most widespread agricultural land use across Europe. However, it remains unclear whether the current large‐scale genetic variation of plant species found in natural grasslands of Europe is the result of human activities or natural processes.

Location
Europe.

Taxon
Lolium perenne L. (perennial ryegrass).

Methods
We reconstructed the phylogeographic history of L. perenne, a dominant grassland species, using 481 natural populations, including 11 populations of closely related taxa. We combined Genotyping‐by‐Sequencing (GBS) and pool‐Sequencing (pool‐Seq) to obtain high‐quality allele frequency calls of ~500 k SNP loci. We performed genetic structure analyses and demographic reconstructions based on the site frequency spectrum (SFS). We additionally used the same genotyping protocol to assess the genomic diversity of a set of 32 cultivars representative of the L. perenne cultivars widely used for forage purposes.

Results
Expansion across Europe took place during the Würm glaciation (12–110 kya), a cooling period that decreased the dominance of trees in favour of grasses. Splits and admixtures in L. perenne fit historical climate changes in the Mediterranean basin. The development of agriculture in Europe (7–3.5 kya), that caused an increase in the abundance of grasslands, did not have an effect on the demographic patterns of L. perenne. We found that most modern cultivars are closely related to natural diversity from north‐western Europe. Thus, modern cultivars do not represent the wide genetic variation found in natural populations.

Main conclusions
Demographic events in L. perenne can be explained by the changing climatic conditions during the Pleistocene. Natural populations maintain a wide genomic variability at continental scale that has been minimally exploited by recent breeding activities. This variability constitutes valuable standing genetic variation for future adaptation of grasslands to climate change, safeguarding the agricultural services they provide

Keywords

  • cultivar, Europe, genetic diversity, genotyping-by-sequencing, grasslands, perennial ryegrass, phylogeography, pool-Seq, quaternary, site frequency spectrum

Documents

  • Pleistocene climate changes, and not agricultural spread, account for range expansion and admixture in the dominant grassland species Lolium perenne

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