A METHOD UTILIZING MYCELIAL FRAGMENTS TO ESTIMATE THE RELATIVE BIOMASS DENSITIES OF FUNGAL SPECIES IN MIXED CULTURE

A method for determining the relative biomass densities of two fungal species, Trichoderma harzianum and Fusarium culmorum, in mixed cultures, based on fragmentation of their mycelia is described. The mycelia were fragmented using a laboratory blender under standardised conditions. The mycelial fragments were plated onto a medium containing the paramorphogen, sodium deoxycholate, to inhibit colony extension, and small colonies were produced which could be distinguished and enumerated on the basis of their mature characteristics, principally the production of different pigments. A linear relationship between the number of fungal colonies produced and the biomass dry weight was observed. The method has potential applications for studying a wide range of fungal interactions, notably those which occur in plant-associated and soil ecosystems where the vegetative mycelium contributes the majority of the significant biomass present.