Effect of Cadmium on the Axenic Growth and Phosphatase Activity of Ectomycorrhizal Fungi, Amanita muscaria and Laccaria ohiensis

The mycorrhizal fungi are of importance in view of interest in the reclamation of toxic metals to polluted sites and influence on plant growth and productivity. Although there appears to be a wide diversity in responses between different plant and fungal symbionts, the amelioration of metal phytotoxicity by mycorrhizal fungi has been widely demonstrated. Ectomycorrhizal fungi inoculated forest trees improve their growth and survival in metal polluted soils than non-mycorrhizal trees. Severe contamination by pollutants such as heavy metals can result in widespread seedling mortality, delay of several decades in revegetation schemes. Metal tolerant strains of fungi have been developed in some laboratories by repeated sub-culturing in metal contaminated medium. The tolerance of ectomycorrhizal fungi growing in vitro towards mine metals, Al, Fe, Cu, Zn, Ni, Cd, Cr, Pb and Hg is more important in order to assess their potential for the establishment of ectomycorrhizae in metal contaminated sites. In the present study, the effect of different concentrations of cadmium on the growth and phosphatase activity of two ectomycorrhizal fungi, Amanita muscaria and Laccaria ohiensis were investigated.