The effect of different stains of AMF on growth and heavy metal uptake of cucumber (Cucumis sativus)

The aim of this work was study whether the origin of arbuscular mycorrhizal (AM) fungi strains (i.e. adapted and non-adapted to high concentrations of heavy metals) affected the stress resistance and heavy metal uptake of the host. Metal uptake of the host plant was affected by AM symbiosis as well as by the metal type. Cadmium (Cd) and nickel (Ni) were present in the soil in concentrations that are phytotoxic to plants (inhibition of plant growth). Inoculation with AMF reduced the uptake of these metals. Lead (Pb) uptake of the non-inoculated plants, however, did not reach the toxic level. As a consequence of the Zinc (Zn) load, soil Zn concentrations increased, but they did not reach the toxic level. Zinc uptake, as an essential plant micronutrient, was enhanced by the mycorrhizal symbiosis within the experimental period. Cadmium and Ni uptake of the host plans were affected by the origin of AMF strain, too. AMF strains, adapted to high soil Cd levels diminished Cd uptake of the host plant more effectively than the non-adapted strains. Nickel uptake was decreased by the inoculation with two Ni-adapted and by one non-adapted strain, the latter originating from a control plot. Another strain, originating from another control plot, did not affect the Ni uptake of the host plants.