Orchid mycorrhizal fungi have been assumed to supply carbohydrates to the orchid seedlings
with which they are associated. To do this they must be able to utilize a regular source of
carbohydrate in the soil, and also to translocate soluble compounds to the orchids. Mycorrhizal
Rhizoctonia spp. were shown to decompose filter paper cellulose in pure culture. Secondly,
R. repens and R. solani, isolated from Dactylorchis purpureUa, were able to compete with other
soil micro-organisms in the exploitation of cellulose buried in unsterilized soil.