Armillaria sinapina in herbaceous plant material from a peatland in Alberta, Canada

Armillaria sinapina Berube & Dessureault mycelium was isolated once from li ving Carex aquatilis Wahlenb. rhizomes, twice from decomposing C. aquatilis leaves, and three times from decomposing Salix planifolia Pursh leaves in a southern boreal sedge-dominated fen in Alberta, Canada. Restriction fragm ent length polymorphism (RFLP) analyses of the IGS-1 region with the AluI r estriction enzyme were used to identify the isolates, because conspicuous, epigeous basidiomes could not be found in or near the fen. During these ana lyses, two previously unpublished fragment patterns for A. sinapina were fo und, consisting of 399-240-135 base pairs (bp) and 399-240-183-135 bp. Inte rspecific somatic incompatibility and interfertility tests confirmed the id entifications obtained from the RFLP analyses. This is the first report of an annulate species of Armillaria being actively involved in the colonizati on and decomposition of herbaceous plant material in an ecosystem having on ly an organic soil horizon. Surveys for species of Armillaria should be exp anded to include peatlands and herbaceous plant materials, because they may serve as vast potential biomass and genetic diversity reservoirs for this genus.