Get access

Patterns of introduction and adaptation during the invasion of Aegilops triuncialis (Poaceae) into Californian serpentine soils

Authors

  • HARALD MEIMBERG,

    1. CIBIO, Research Center in Biodiversity and Genetic Resources, University of Porto, Campus Agrário de Vairão, 4485-601 Vairão, Portugal
    2. Bioagricultural Sciences and Pest Management, C 129 Plant Sciences, Colorado State University, Fort Collins, CO 80523, USA
    Search for more papers by this author
  • NEIL F. MILAN,

    1. Department of Plant Sciences, University of California, One Shields Ave., Davis, CA 95616, USA
    Search for more papers by this author
  • MARIA KARATASSIOU,

    1. School of Forestry and Natural Environment, Department of Range and Wildlife Science, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
    Search for more papers by this author
  • ERIN K. ESPELAND,

    1. USDA ARS NPARL Pest Management Research Unit, 1500 N. Central Ave, Sidney, MT 59270, USA
    Search for more papers by this author
  • JOHN K. McKAY,

    1. Bioagricultural Sciences and Pest Management, C 129 Plant Sciences, Colorado State University, Fort Collins, CO 80523, USA
    2. Graduate Degree Program in Ecology and Program in Molecular Plant Biology, Colorado State University, Fort Collins, CO 80523, USA
    Search for more papers by this author
  • KEVIN J. RICE

    1. Department of Plant Sciences, University of California, One Shields Ave., Davis, CA 95616, USA
    2. Center for Population Biology, University of California, Davis, CA 95616, USA
    Search for more papers by this author

Harald Meimberg, Fax: +351/252 661780; E-mail: meimberg@mail.icav.up.pt

Abstract

Multiple introductions can play a prominent role in explaining the success of biological invasions. One often cited mechanism is that multiple introductions of invasive species prevent genetic bottlenecks by parallel introductions of several distinct genotypes that, in turn, provide heritable variation necessary for local adaptation. Here, we show that the invasion of Aegilops triuncialis into California, USA, involved multiple introductions that may have facilitated invasion into serpentine habitats. Using microsatellite markers, we compared the polymorphism and genetic structure of populations of Ae. triuncialis invading serpentine soils in California to that of accessions from its native range. In a glasshouse study, we also compared phenotypic variation in phenological and fitness traits between invasive and native populations grown on loam soil and under serpentine edaphic conditions. Molecular analysis of invasive populations revealed that Californian populations cluster into three independent introductions (i.e. invasive lineages). Our glasshouse common garden experiment found that all Californian populations exhibited higher fitness under serpentine conditions. However, the three invasive lineages appear to represent independent pathways of adaptation to serpentine soil. Our results suggest that the rapid invasion of serpentine habitats in California may have been facilitated by the existence of colonizing Eurasian genotypes pre-adapted to serpentine soils.

Get access to the full text of this article

Ancillary