Canadian Forest Service Publications

Evaluation of a fungal antagonist, Phaeotheca dimorphospora, for biological control of tree diseases. 1993. Yang, D.; Plante, F.; Bernier, L.; Piché, Y.; Dessureault, M.; Laflamme, G.; Ouellette, G.B. Canadian Journal of Botany 71: 426-433.

Year: 1993

Issued by: Laurentian Forestry Centre

Catalog ID: 16506

Language: English

Availability: PDF (request by e-mail)

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Phaeotheca dimorphospora, which was first isolated from elm wood and found to be antagonistic in vitro against the Dutch elm disease pathogen Ophiostoma ulmi, was tested for antifungal activity in vitro against ofther tree pathogens by a variation of the agar layer technique. Phaeotheca dimorphospora produced antifungal compounds that were strongly inhibitory against a wide range of tree pathogens in addition to O. ulmi, such as Gremmeniella spp., Armillaria spp., Septoria musiva, Verticillium albo-atrum, Cylindrocladium floridanum, Phytophthora sp., Nectria galligena, and Heterobasidion annosum. Under light and interference microscopy, four types of morphological changes were observed in the pathogens tested: swelling of hyphae, production of resting spores such as chlamydospores and of sclerotia, extrusion of cytoplasm from hyphal tips, and bursting and destruction of mycelium. Chloroform-soluble antagonistic compounds were extracted that showed both fungicidal and fungistatic effects on the test organisms.