Attempts to isolate the ascomycete Hydnotrya tulasnei from fresh hypogeous sporocarps into a pure culture yielded beside H. tulasnei also a strain of Meliniomyces variabilis (MVA-2). Both phenotype and genotype analyses showed that MVA-2 was highly similar to another M. variabilis strain, isolated previously from a root tip of Picea abies. The mycorrhizal potential of both H. tulasnei and M.variabilis is still dubious. Therefore, we tried an in vitro synthesis of root-fungus association between H. tulasnei, both M. variabilis strains and typically ectomycorrhizal (P. abies and Pinus sylvestris) and typically ericoid mycorrhizal (Vaccinium corymbosum) host plants. For comparison, a strain of Rhizoscyphus ericae was included. Both M. variabilis strains formed intracellular structures characteristic of ericoid mycorrhiza in V. corymbosum roots, and also colonised the roots of P. abies and P.sylvestris seedlings, modifying their morphology. Superficially, Picea and Pinus root tips resembled early stages of EcM development, but transversal sections revealed absence of the Hartig net and frequent intracellular colonisation of the cortex. The reference strain of R. ericae showed similar behaviour in Picea, Pinus and Vaccinium roots, only the intracellular colonisation was more intensive and morphology of roots of both conifers was less changed when compared to M. variabilis. H. tulasnei failed to colonise the roots of P. abies and V. corymbosum, possibly due to sub-optimal conditions for its growth.
Vohník M., Fendrych M., Kolařík M., Gryndler M., Hršelová H., Albrechtová J., Vosátka M. (2007): The ascomycete Meliniomyces variabilis isolated from a sporocarp of Hydnotrya tulasnei (Pezizales) intracellularly colonises roots of ecto- and ericoid mycorrhizal host plants. – Czech Mycology 59(2): 215–226.
