title: Genetic variability and founder effect in the pitcher plant Sarracenia purpurea (Sarraceniaceae) in populations introduced into Switzerland: from inbreeding to invasion.
abstract: OBJECTIVE
  The long-lived and mainly outcrossing species Sarracenia purpurea has been introduced into Switzerland and become invasive. This creates the opportunity to study reactions to founder effect and how a species can circumvent deleterious effects of bottlenecks such as reduced genetic diversity, inbreeding and extinction through mutational meltdown, to emerge as a highly invasive plant.
  
  
  METHODS
  A population genetic survey by random amplified polymorphism DNA markers (RAPD) together with historical insights and a field pollination experiment were carried out.
  
  
  RESULTS
  At the regional scale, S. purpurea shows low structure (thetast=0.072) due to a recent founder event and important subsequent growth. Nevertheless, multivariate statistical analyses reveal that, because of a bottleneck that shifted allele frequencies, most of the variability is independent among populations. In one population (Tenasses) the species has become invasive and genetic analysis reveals restricted gene flow and family structure (thetast=0.287). Although inbreeding appears to be high (Fis >0.410 from a Bayesian estimation), a field pollination experiment failed to detect significant inbreeding depression upon F1 seed number and seed weight fitness-traits. Furthermore, crosses between unrelated individuals produced F1 seeds with significantly reduced fitness, thus showing local outbreeding depression.
  
  
  CONCLUSIONS
  The results suggest that, under restricted gene flow among families, the species may not only have rapidly purged deleterious alleles, but also have undergone some form of selection for inbreeding due to co-adaptation between loci.
authors.affiliation: Department of Ecology and Evolution, Biology Building, University of Lausanne, 1015 Lausanne, Switzerland. Christian.Parisod@unil.ch
authors.forename: Christian
authors.initials: C
authors.lastname: Parisod
authors.forename: Charlotte
authors.initials: C
authors.lastname: Trippi
authors.forename: Nicole
authors.initials: N
authors.lastname: Galland
mesh_terms: D005075:Biological Evolution; D004777:Environment; D018703:Founder Effect; D014644:Genetic Variation / Q000235:genetics; D005843:Geography; D007178:Inbreeding; D019684:Magnoliopsida / Q000235:genetics*; D008957:Models, Genetic; D009154:Mutation; D011157:Population Dynamics; D013557:Switzerland