The influence of heavy metals on the growth of ectomycorrhizal fungi

Abstract

The reaction of isolates of the ectomycorrhizal species Suillus granulatus, Suillus luteus, Suillus bovinus, Hebeloma spp, Paxillus involutus and Amanita muscaria to the presence of zinc, copper, lead and cadmium, added to a nutritive medium for the determination of their in vitro tolerance, was determined by measuring growth inhibition of the mycelium. The experiments were performed in laboratory conditions by adding suspensions of zinc, copper, lead, and cadmium at three different concentrations to the nutritive medium. The effect of the heavy metals on the growth rate of the mycorrhizal fungi depended on the type of metal and its concentration. Zinc had the lowest degree of influence, whereas cadmium at the highest concentration had the highest degree of influence. S. bovinus, whose mycelium grew very slowly in the presence of all four metals, exhibited the lowest degree of tolerance to the heavy metals; S. granulatus and Amanita muscaria were tolerant to the presence of all four metals, even at high concentrations.