Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): L.C. Grubisha; N. Levsen; M.S. Olson; D.L. Taylor
    Date: 2012
    Source: New Phytologist. 194(2): 548-560. doi: 10.1111/j.1469 8137.2012.04066.x
    Publication Series: Scientific Journal (JRNL)
    Station: Pacific Northwest Research Station
    PDF: Download Publication  (1.34 MB)


    The ectomycorrhizal fungus Tricholoma populinum is host-specific with Populus species. T. populinum has wind-dispersed progagules and may be capable of long-distance dispersal. In this study, we tested the hypothesis of a panmictic population between Scandinavia and North America. DNA sequences from five nuclear loci were used to assess phylogeographic structure and nucleotide divergence between continents. Tricholoma populinum was composed of Scandinavian and North American lineages with complete absence of shared haplotypes and only one shared nucleotide mutation. Divergence of these lineages was estimated at approx. 1.7-1.0 million yr ago (Ma), which occurred after the estimated divergence of host species Populus tremula and Populus balsamifera/Populus trichocarpa at 5 Ma. Phylogeographic structure was not observed within Scandinavian or North American lineages of T. populinum. Intercontinental divergence appears to have resulted from either allopatric isolation; a recent, rare long-distance dispersal founding event followed by genetic drift; or the response in an obligate mycorrhizal fungus with a narrow host range to contractions and expansion of host distribution during glacial and interglacial episodes within continents. Understanding present genetic variation in populations is important for predicting how obligate symbiotic fungi will adapt to present and future changing climatic conditions.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Grubisha, Lisa C.; Levsen, Nicholas.; Olson, Matthew S.; Taylor, D. Lee. 2012. Intercontinental divergence in the Populus-associated ectomycorrhizal fungus, Tricholoma populinum. New Phytologist. 194(2): 548-560. doi: 10.1111/j.1469 8137.2012.04066.x


    host specificity, mycorrhizal fungi, obligate symbiont, phylogeography, Tricholoma populinum

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page