Isolation of Fungi from Hyphæ present in Soil

Abstract

WHILE it is known that fungi may exist in soil both as active mycelium and as dormant spores¹, a major problem in the study of soil fungi has been to discover which fungi in a soil are present as mycelium. Plating methods by which fungal colonies are isolated from soil² or from soil suspensions³ on agar media suffer from the disadvantage that the unit of origin, spore or hypha, of the resulting colonies is not known. Direct microscopic examination, either of Rossi–Cholodny slides or soil films⁴, has the complementary deficiency that although fungal hyphæ are seen, most are sterile and their identity cannot be investigated. I have devised a simple technique for the isolation of fungi directly from hyphæ present in soil. Essentially the method depends on the observation that when a soil suspension is prepared, many of the fungal hyphæ remain with the heavier soil particles of the residue. Removal of the fine suspended material from the residue also permits visual examination of the latter for the presence of individual hyphæ or hyphal masses, which may then be removed and grown on agar media.