Ericoid mycorrhizal fungi from heavy metal polluted soils: their identification and growth in the presence of zinc ions

Ericoid mycorrhizal fungi can alleviate heavy metal toxicity to their host plant, but the mechanisms that lie behind this increased tolerance are unkn own. As a first step in the characterisation of two isolates of Oidiodendro n maius from mycorrhizal roots of Vaccinium myrtillus growing in heavily co ntaminated soils, we investigated their taxonomic position, their mycorrhiz al capabilities and their ability to grow in the presence of heavy metals. When growth was compared with isolates from non-polluted soils, a better pe rformance was observed in the presence of increasing concentrations of zinc salts, especially at higher ion concentrations. The mechanisms of toleranc e may include the production of mucilage and extracellular pigments.