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H 1 Plant ecology influences population genetics: the role of seed banks in structuring genetic diversity

Auteurs : Tellier, Aurélien (Auteur de la Conférence)
CIRM (Editeur )

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    Résumé : Recent population genomics studies focus prevalently on the aspects of demography and adaptation, whereas age structure (for example, in plants via the maintenance of seed banks) has attracted less attention. Germ banking, that is, seed or egg dormancy, is a prevalent and important life-history trait in plants and invertebrates, which buffers against environmental variability and modulates species extinction in fragmented habitats. I will here summarize our recent findings investigating the intertwined effect of germ banking, time-varying population size and selection on genetic polymorphism in the wild tomato species. First, we examine the effect of seed banking on within species variability and local adaptation in the wild tomato Solanum chilense. Population genetic analyses and statistical inference of past demography was conducted on pooled-sequencing from 30 genes from an exhaustive sampling of 23 populations over Chile and Peru. We reveal a north-south colonization associated with relaxed purifying selection in the south as shown by a decrease of genetic variation and an increasing proportion of nonsynonymous polymorphism from north to south and population substructure with at least four genetic groups. We also uncover 1) a decreasing proportion of adaptive amino acid substitutions from north to south suggesting that adaptation is favoured in large populations, while 2) signatures of local adaptation predominantly occur in the smaller populations from the marginal ranges in the south. These results combined with additional germination data suggest that colonization of new habitats was accompanied by local adaptation for shorter seed banks in the marginal populations, shaping in return the available nucleotide diversity and effectiveness of purifying and positive selection. Second, we use ABC and polymorphism data to estimate population divergence times between two wild tomato species in presence of seed banks. We show that unknown seed banking also impedes our knowledge of the speciation process. Joint work with Katharina B. Böndel, Wolfgang Stephan.

    Codes MSC :
    92D15 - Problems related to evolution
    92D40 - Ecology
    92C80 - Plant biology

      Informations sur la Vidéo

      Langue : Anglais
      Date de publication : 02/07/15
      Date de captation : 18/06/15
      Collection : Research talks ; Mathematics in Science and Technology ; Probability and Statistics
      Format : quicktime ; audio/x-aac
      Durée : 00:46:53
      Domaine : Probability & Statistics ; Mathematics in Science & Technology
      Audience : Chercheurs ; Doctorants , Post - Doctorants
      Download : https://videos.cirm-math.fr/2015-06-18_Tellier.mp4

    Informations sur la rencontre

    Nom de la rencontre : Probability and biological evolution / Probabilités et évolution biologique
    Organisateurs de la rencontre : Pardoux, Etienne ; Wakolbinger, Anton
    Dates : 15/06/15 - 19/06/15
    Année de la rencontre : 2015
    URL Congrès : http://conferences.cirm-math.fr/1112.html

    Citation Data

    DOI : 10.24350/CIRM.V.18773103
    Cite this video as: Tellier, Aurélien (2015). Plant ecology influences population genetics: the role of seed banks in structuring genetic diversity. CIRM. Audiovisual resource. doi:10.24350/CIRM.V.18773103
    URI : http://dx.doi.org/10.24350/CIRM.V.18773103


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