|Nielsen, Kristian Fog|
|Ismaiel, Ed - Ed|
|Von Dohren, Hans|
Submitted to: Mycological Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2008
Publication Date: 7/5/2008
Citation: Degenkolb, T., Dieckmann, R., Nielsen, K., Theis, C., Bruckner, H., Grafenhan, T., Zafari, D., Chaverri, P., Ismaiel, A.A., Von Dohren, H., Thrane, U., Samuels, G.J. 2008. The Trichoderma brevicompactum clade: a new lineage with new species, new peptaibiotics and mycotoxins. Mycological Progress. 7(3):177-219. Interpretive Summary: Plant diseases can be controlled using biological agents such as fungi in the genus Trichoderma. The use of these fungi to control diseases is hindered by lack of accurate characterization of potentially useful species. In this research four new species of Trichoderma are discovered, named, described and illustrated. Because these fungi are so small, they must be defined using characters such as the shape of their spores and how they grow as well as DNA sequences. In addition, the chemical products produced by these species of Trichoderma were characterized and some are known to be potentially harmful to animals. As a result species in this group of Trichoderma should not be used as biological control agents. This research will be used by plant pathologists working to develop biological agents to control plant diseases.
Technical Abstract: A new lineage is recognized in Trichoderma/Hypocrea, the Brevicompactum clade. This clade includes T. brevicompactum and the new species T. arundinaceum, T. turrialbense, T. protrudens and Hypocrea rodmanii. With the exception of H. rodmanii, all members of this clade produce trichothecenes harzianum A or trichodermin. All members of the clade produce peptaibiotics, including alamethicins. Strains previously reported as T. harzianum (ATCC 90237) or T. viride (NRRL 3199) to produce trichothecenes are reidentified as T. arundinaceum. No case of trichothecene production by species of Trichoderma or Hypocrea that do not belong to the Brevicompactum clade can be confirmed by chemical analysis. The closest relative of the Brevicompactum clade is the Lutea clade. The Brevicompactum clade is not closely related to species that have biological application. The toxic effects of peptaibiotics are discussed and are considered to be insignificant relative to the potential of these metabolites in biological control of plant disease.