DOI: 10.5061/dryad.3m6917t
title: Data from: Effects of contemporary shifts of range margins on patterns of genetic structure and mating system in two coastal plant species

description: Species’ geographical ranges are often restricted due to niche limitation
 resulting in geographical isolation and reduced population size at range
 margins. Under the ‘abundant center’ paradigm, static marginal populations
 are thus expected to show higher genetic differentiation and lower genetic
 diversity than core populations. Low mate availability may also drive
 shifts towards higher propensity for selfing in geographically marginal
 populations. However, these predictions remain to be validated for
 contemporary range shifts occurring under current environmental change.
 This study is devoted to bridging this gap and assesses the spatial
 patterns of genetic structure and mating system across the geographical
 range of two coastal plant species characterized by contrasting
 contemporary range dynamics: the receding myrmecochorous Dune pansy (Viola
 tricolor subsp. curtisii) and the widespread expanding hydrochorous Rock
 samphire (Crithmum maritimum) Both species exhibited high propensity for
 selfing, with indications of inbreeding depression acting at early life
 stages. In Dune pansy, a biogeographical break was observed between core
 and marginal populations, with trailing-edge populations showing higher
 levels of genetic differentiation, reduced genetic diversity and higher
 levels of selfing estimated through progeny arrays. In contrast, genetic
 structuring was weak in Rock samphire and no clear spatial trends were
 observed in genetic diversity nor in mating system, likely the result of
 efficient long-distance seed dispersal by sea-surface currents. Our study
 highlights that key species differences in life-history traits related to
 dispersal and/or mate limitation modify the expectations of genetic
 diversity loss and mating system shift in contemporary range-expanding
 populations, as compared to historical core populations.
description: genotypes natural
 populations Crithmum maritimumGenotypes of Crithmum
 maritimum for 21 microsatellite loci (22 populations, 515 individuals).
 This file has 24 tabs: descritpion of the data, all genotypes, and then
 one tab per population. Coordinates of the populations are provided.
 Genotypes are provided on two columns per locus. Allele sizes were
 determined on a ABI Prism 3130 sequencer, under
 GeneMapper.genotypes natural
 populations Viola tricolor subsp curtisiiGenotype data for Viola
 tricolor subsp. curtisii (10 microsatellite loci, 563 individuals in 19
 populations). This file has 21 tabs : description of the data, all
 genotypes, and one tab per population. Genotypes are coded on two columns
 per locus. Allele sizes were determined on a ABI Prism 3130 sequencer,
 under GeneMapper.genotypes progeny arrays
 Crithmum maritimumGenotypes of the progeny
 arrays for Crithmum maritimum. The file has two tabs: a description tab,
 and a tab with genotypes.genotypes progeny arrays
 Viola tricolor subsp curtisiiGenotypes of the progeny
 arrays for Viola tricolor subsp curtisii. The file has two tabs: a
 description tab, and a tab with genotypes.