Inoculation of Salix caprea with rhizosphere bacteria enhances the phytoextraction capacity for Zn and Cd

摘要

Due to their metal accumulation potential and their large biomass production, willows are highly attractive plants for phytoextraction of Zn and Cd. The objective of our study was to investigate the effect of various rhizosphere bacteria on the accumulation of Zn and Cd in leaves and on biomass production of metal-accumulating Salix caprea. The rhizosphere bacteria were previously isolated from S. caprea rhizosphere on a contaminated site in southern Austria. The individual strains were inoculated to the roots of one year old plants prior to planting in sterilized contaminated soil. After four month growth, biomass production and heavy metal concentrations in leaves were determined. For most strains, no difference was found between the inoculated and the non-inoculated control regarding leaf biomass and foliar Zn and Cd concentrations. One strain caused a significant increase of Zn (+25%) and Cd (+16%) concentration in leaves, while another strain had a significant effect on leaf biomass (+ 37%). Regarding the total amounts of Zn and Cd in leaves, the increase of leaf biomass had a more pronounced effect than the enhanced foliar Zn and Cd concentrations.