Toxic interactions of metal ions (Cd , Pb , Zn and Sb ) on in vitro biomass production of ectomycorrhizal fungi.

A number of ectomycorrhizal (ECM) fungi, from sites uncontaminated by toxic metals, were investigated to determine their sensitivity to Cd , Pb , Zn and Sb , measured as an inhibition of fungal biomass production, Isolates were grown in liquid media amended with the metals, Individually (over a range of concentrations) and in combination (at single concentrations) to determine any significant interactions between the metals. Significant interspecific variation in sensitivity to Cd and Zn was recorded, while Pb and Sb individually had little effect. The presence of Pb and Sb in the media did however, amcliorate Cd and Zn toxicity in some circumstances. Interactions between Cd and Zn were investigated further over a range of concentrations. Zn was found to significantly ameliorate the toxicity of Cd to three of the four isolates tested. The influence of Zn varied between ECM species and with the concentrations of metals tested.