Competition of Scleroconidioma sphagnicola with fungi decomposing spruce litter needles

Abstract

This study addressed competition of Scleroconidioma sphagnicola Tsuneda, Currah & Thormann with saprotrophic ascomycetes and basidiomycetes. We isolated this fungus, previously considered as a preferentially necrotrophic parasite of moss, from spruce needle litter. Competition of Scleroconidioma sphagnicola was simulated with strains of the autochthonous litter colonizers Ceuthospora pinastri (Fr.) Höhn., Chalara longipes (Preus) Cooke, Setulipes androsaceus (L.) Antonín ( Marasmius androsaceus (L.) Fr.), and Mollisia minutella (Sacc.) Rehm and the wood-decaying fungus Hypholoma fasciculare (Huds.) Quél. Pairings were performed on agar plates with two types of low-nutrient medium made from spruce litter needles. Reisolation on nutritionally rich agar medium following the competition revealed that Sleroconidioma sphagnicola was mostly successfully reisolated even though apparently being replaced by the mycelium of other fungi. It formed strongly melanised mycelium and microsclerotia that seem to be responsible for its resistance to fungal competition. All tested strains of needle litter colonizers were outcompeted by Hypholoma fasciculare. Enzymatic screening aimed at semiquantitative assay of polyphenol oxidase, peroxidase, and tyrosinace revealed that Scleroconidioma sphagnicola, together with other strains, was able to produce polyphenol oxidase and peroxidase on various nutritional media. Activity of tyrosinase was detected only for Hypholoma fasciculare. Previous records of Scleroconidioma sphagnicola from moss, wood, and our isolations from spruce litter suggest that this species possesses an ability to occupy a wide spectrum of niches.