Microbial Ecology

, Volume 56, Issue 3, pp 513–524

Population Evidence of Cryptic Species and Geographical Structure in the Cosmopolitan Ectomycorrhizal Fungus, Tricholoma scalpturatum

  • Fabian Carriconde
  • Monique Gardes
  • Patricia Jargeat
  • Jacob Heilmann-Clausen
  • Bello Mouhamadou
  • Hervé Gryta
Original Article

DOI: 10.1007/s00248-008-9370-2

Cite this article as:
Carriconde, F., Gardes, M., Jargeat, P. et al. Microb Ecol (2008) 56: 513. doi:10.1007/s00248-008-9370-2

Abstract

Tricholoma scalpturatum is an ectomycorrhizal fungus that forms symbioses with roots of diverse trees and shrubs. It is commonly encountered in a wide range of habitats, across temperate ecosystems. A previous study has revealed a high genetic diversity at a local scale, and ruderal abilities. To examine genetic structure at a large geographical scale, a total of 164 basidiocarps were collected from 30 populations located in Western Europe, from Spain to Scandinavia. These samples were analyzed by three molecular methods with different levels of resolution: inter-simple sequence repeats (ISSRs), restriction fragment length polymorphisms (RFLPs) in the rDNA internal transcribed spacer (ITS), and ITS sequence analysis. Considerable genetic variation was found, and the morphospecies was separated into two genetic groups that were distinct from each other. The ISSR data and the relatively low percentage value (96%) of shared sequence polymorphisms in the ITS between isolates from the two groups, strongly suggest cryptic species and long-lasting separation. No geographical exclusion was detected for these two widely distributed taxa. However, high estimates of population differentiation were observed in each group, including between populations less than a few kilometers apart. This result provides evidence for limited gene flow and/or founding effects. It also indicates that T. scalpturatum does not constitute a random mating population, and the hypothesis of endemism cannot be excluded for this cosmopolitan wind-dispersed fungus.

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Fabian Carriconde
    • 1
  • Monique Gardes
    • 1
  • Patricia Jargeat
    • 1
  • Jacob Heilmann-Clausen
    • 2
  • Bello Mouhamadou
    • 1
    • 3
  • Hervé Gryta
    • 1
  1. 1.Laboratoire Evolution et Diversité Biologique, UMR 5174 CNRS-UPS-ENFA, Bât. 4R3Université Paul Sabatier-Toulouse IIIToulouse Cedex 9France
  2. 2.HabitatVisionRøndeDenmark
  3. 3.Laboratoire d’Ecologie Alpine, UMR 5553Université Joseph Fourier, LECA Bât D BiologieGrenoble Cedex 9France