Heavy metals uptake by mycorrhizae of beech in contaminated and uncontaminated soils.

Mycorrhizae may regulate the uptake of heavy metals from the soil by plants also by limiting the translocation into leaves. Differences in the behaviour depend however on the fungus species and on the soil properties. Aim of this work is to evaluate the accumulation of some heavy metals (Cd, Cr, Cu, Pb, Zn) in the mycorrhizae of Fagus sylvatica comparing two sites with very different pollution degree, but similar soil characteristics. Bioaccumulation, expressed as Concentration Factor (CF), was evident only for Cd and Cr, while the contents of Cu, Pb and Zn are lower in the mycorrhizae than in the soils. A different behavior is apparent for Zn with respect to the other two metals. In fact, the CFs for Cu and Pb in the two sites are similar, while those for Zn are considerably higher in the contaminated site. This behaviour is probably related to the translocation of the element from the roots to the tops of the plants.