Stimulation of germination of spores of some ectomycorrhizal fungi by other micro-organisms

Abstract

Seven bacterial isolates out of 42 obtained from sporophores of ectomycorrhizal fungi, two out of 36 obtained from mycorrhizas and two out of 40 obtained from soil stimulated germination of certain mycorrhizal fungi. None of the fungal isolates obtained from the same sources stimulated germination of any of the test fungi. One fungus ( Tritirachium roseum ) and one bacterium ( Micrococcus roseus ), which appeared among the spores of Hebeloma crustuliniforme on the surface of agar plates as natural contaminants, also stimulated germination of spores of that fungus. The most active isolate was that of Pseudomonas stutzeri which was obtained from a sporophore of H. crustuliniforme and induced ca 21% of spores of the fungus to germinate within 1 cm of its colonies. Isolates of Corynebacterium spp. obtained from sporophores of H. crustuliniforme and roots of willow ( Salix spp.), mycorrhizal with H. crustuliniforme , stimulated spores of that fungus and of Paxillus involutus . Spores of Laccaria laccata were stimulated by only one isolate (S19 an unidentified soil bacterium). This isolate also stimulated spores of P. involutus and H. crustuliniforme . Spores of the remaining test fungi did not respond to any of the bacterial and fungal isolates tested.