High levels of effective long-distance dispersal may blur ecotypic divergence in a rare terrestrial orchid

An Vanden Broeck, Wouter Van Landuyt, Karen Cox, Luc De Bruyn, Ralf Gyselings, Gerard Oostermeijer, Bertille Valentin, Gregor Bozic, Branko Dolinar, Zoltán Illyés, Joachim Mergeay

    Research output: Contribution to journalA1: Web of Science-article

    187 Downloads (Pure)

    Abstract

    BACKGROUND: Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid (Liparis loeselii (L.) Rich.). We used amplified fragment length polymorphism (AFLP)-based assignment tests to quantify effective long-distance dispersal at two different regions in Northwest Europe. In addition, genomic divergence between fen orchid populations occupying two distinguishable habitats, wet dune slacks and alkaline fens, was investigated by a genome scan approach at different spatial scales (continental, landscape and regional) and based on 451 AFLP loci.

    RESULTS: We expected that different habitats would contribute to strong divergence and restricted gene flow resulting in isolation-by-adaptation. Instead, we found remarkably high levels of effective long-distance seed dispersal and low levels of adaptive divergence. At least 15% of the assigned individuals likely originated from among-population dispersal events with dispersal distances up to 220 km. Six (1.3%) 'outlier' loci, potentially reflecting local adaptation to habitat-type, were identified with high statistical support. Of these, only one (0.22%) was a replicated outlier in multiple independent dune-fen population comparisons and thus possibly reflecting truly parallel divergence. Signals of adaptation in response to habitat type were most evident at the scale of individual populations.

    CONCLUSIONS: The findings of this study suggest that the homogenizing effect of effective long-distance seed dispersal may overwhelm divergent selection associated to habitat type in fen orchids in Northwest Europe.

    Original languageEnglish
    JournalBMC Ecology
    Volume14
    Issue number1
    Pages (from-to)20
    DOIs
    Publication statusPublished - 7-Jul-2014

    Thematic list

    • Species and biotopes

    EWI Biomedical sciences

    • B003-ecology
    • B004-botany
    • B270-plant-ecology

    Taxonomic list

    • orchid family (Orchidaceae)

    Policy

    • biodiversity policy
    • Habitats Directive
    • conservation goals

    Geographic list

    • Europe

    Technological

    • genetic technologies

    Free keywords

    • Liparis loeselii
    • groenknolorchis

    Fingerprint Dive into the research topics of 'High levels of effective long-distance dispersal may blur ecotypic divergence in a rare terrestrial orchid'. Together they form a unique fingerprint.

    Cite this