- Witzell J., Sunnerstam C. & Hansson T.
- Journal of Fungi
- 9(3): 297 [12 p.]
Dutch elm disease (DED) is causing extensive mortality of ecologically and culturally valuable
elm trees (Ulmus spp.). Treatment of elms with the biological vaccine Dutch Trig® has been
found to provide effective protection against DED by stimulating the defensive mechanisms of the
trees. We hypothesized that the same mechanisms could also affect non‐target organisms associated
with elms. We explored the possible effects of vaccination on epiphytes (mainly lichens) and fungal
endophytes living in the bark and young xylem of treated elms. Epiphyte cover percentage was
assessed visually using a grid placed on the trunks, and a culture‐based approach was used to study
endophytes. Epiphyte cover was lower on the trunks of vaccinated trees as compared with unvaccinated
trees, but the difference was not statistically significant. The presence of slow‐growing and
uncommon endophytes seemed to be reduced in continuously vaccinated elms; however, the highest
endophyte diversity was found in elms four years after cessation of the vaccination treatments.
Our findings suggest that although vaccination may shape epiphyte and endophyte communities
in elms, its impacts are not straightforward. More detailed studies are, therefore, needed to inform
the sustainable application of the vaccine as a part of the integrated management of DED.
Keywords: Ulmus spp.; Dutch Trig®; vaccination; biocontrol; epiphytes; endophytes.
- Saturday, 25 February 2023 12:40