INFLUENCE OF HEAVY-METALS ON GERMINATION OF ARBUSCULAR-MYCORRHIZAL FUNGAL SPORES IN SOILS

A simple device (sandwich of spores in Path dishes) was used to study the effect of soils with different heavy metal concentrations, and different origins of metals, on spore germination of Glomus mosseae and of two arbuscular-mycorrhizal fungal cultures isolated from polluted soils. Germination of G. mosseae spores was reduced to 4 % in the soil with the highest Cd, Zn and Pb concentrations. However, with still high cadmium concentrations varying from 1 to 100 mg/kg(-1), the effect of metals was mitigated or increased depending on pH, phosphorus concentration and soil texture. In two soils containing 17 and 3 ppm Cd, metals did not affect the germination of G. mosseae spores due to their low availability. However, indigenous spores cultures from both soils were more tolerant to high cadmium concentrations than G. mosseae.