Canadian Forest Service Publications

Vegetative incompatibility in diploid isolates of Armillaria North American biological species I and V. 1989. Mallett, K.I.; Hopkin, A.A.; Blenis, P.V. Canadian Journal of Botany 67(10): 3083-3089.

Year: 1989

Issued by: Northern Forestry Centre

Catalog ID: 11277

Language: English

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Vegetative incompatibility among diploid isolates of Armillaria root rot pathogens (Armillaria spp.) was studied using isolates of North American biological species I (Armillaria ostoyae (Romagn.) Herink) and V (Armillaria sinapina Bérubé & Dessureault). Interspecific, intraspecific, and self crosses were made on dialysis membrane over malt agar media and on wood strips and wood blocks. Hyphal interactions were studied using light microscopy and scanning and transmission electron microscopy. On dialysis membrane, hyphae in the contact zone between the two species, the so-called "black line," were melanized and failed to fluoresce with fluorescein diacetate but stained with 3,3'-diaminobenzidine and L-ß-3,4-dihydroxy-phenylalanine, indicating peroxidase and polyphenoloxidase activity in the contact zone. Hyphae adjacent to the contact zone fluoresced and did not show any significant reaction to the other stains. The hyphae of the contact zone in intraspecific crosses and self crosses were not melanized, fluoresced, and did not react with the other stains. No black lines were formed in the interspecific crosses made on or in wood. In both interspecific and intraspecific crosses, pseudosclerotial plates formed between the opposing mycelia. No pseudosclerotial plates were formed in the wood between opposing mycelia of self crosses. Results indicated that the interspecific and intraspecific reactions differ significantly and should be considered as separate and distinct phenomena.