Fungi of Soil and Rhizosphere

Abstract

Devising quantitative and qualitative methods for studying soil fungi is fraught with difficulties. Traditional isolation and enumeration techniques, like the soil dilution plate, and its modifications, which in essence involve adding soil, or a diluted suspension, to Petri dishes and covering with a suitable agar medium, are of very limited value in many respects. Usually one cannot distinguish between colonies that arise on the plates from spores and those that come from hyphae, and many inactive propagules will germinate once they are placed in suitable conditions. This makes it difficult to say much about the activity in the soil samples of the species recorded on the plates. Such records can only give very general information about the species present and their distribution in the soil. Warcup (1955) tried to resolve this problem by the microscopic examination of the young colonies arising from the soil particles on the plate. This is very time-consuming and not too successful.