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


    American beech (Fagus grandifolia) is the target of a newly emerging disease in North America called beech leaf disease (BLD) that affects and disfigures leaves and which can lead to tree mortality. Beech leaf disease may be caused by a newly recognized subspecies of the anguinid nematode Litylenchus crenatae subsp. mccannii, but the associations of this nematode with bacterial and fungal taxa are unknown. We examined microbial communities associated with beech leaves affected by BLD in a 16-year-old American beech plantation using molecular methods. We detected L. crenatae subsp. mccannii in anywhere from 45% to 90% of leaves depending on the degree of visual BLD symptoms. Approximately 37% of asymptomatic leaves contained L. crenatae subsp. mccannii, whereas 90% of buds associated with symptomatic leaves contained L. crenatae subsp. mccannii. We found that fungal communities on leaves and buds were unaffected by BLD, but bud and leaves had significantly different fungal communities. Bacterial communities on buds also were unaffected by BLD, but bacterial communities were significantly different between symptomatic and asymptomatic leaves suggesting that the nematode could be altering the community of bacteria on the leaves. Clone libraries indicate that Wolbachia, an intracellular endosymbiont of arthropods, was found only on symptomatic leaves and buds associated with either symptomatic or asymptomatic leaves. In addition, only symptomatic leaves contained taxa in the genus Mucilaginibacter, which previous studies suggest could produce exopolysaccharides. These bacterial taxa could represent a marker for the vector of L. crenatae subsp. mccannii that enables spread between trees and a possible endosymbiont that could facilitate nematode feeding and establishment on nematode infested leaves. Our results are the first to examine changes to the leaf microbiome of this newly emerging pest and may aid identification of mechanisms associated with the spread and success of L. crenatae subsp. mccanni.

    Publication Notes

    • Check the Northern Research Station web site to request a printed copy of this publication.
    • Our on-line publications are scanned and captured using Adobe Acrobat.
    • During the capture process some typographical errors may occur.
    • Please contact Sharon Hobrla, if you notice any errors which make this publication unusable.
    • 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.


    Burke, David J.; Hoke, Adam J.; Koch, Jennifer. 2020. The emergence of beech leaf disease in Ohio: Probing the plant microbiome in search of the cause. Forest Pathology. 50(2): e12579. 12 p.


    Google Scholar


    bacteria, beech leaf disease, Fagus grandifolia, fungi, leaf nematodes, Litylenchus crenatae subsp. mccannii, plant microbiome

    Related Search

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