Influence of Cadophora finlandica and other microbial treatments on cadmium and zinc uptake in willows grown on polluted soil

Abstract

We conducted a pot experiment to evaluate the Cd and Zn accumulation in leaves and roots of <i>Salix smithiana</i> (BOKU-03DE-001) and <i>S. caprea</i> (BOKU-01AT-004) clones grown on a metal-contaminated soil as affected by native microbes extracted from the same experimental soil, and the fungus <i>Cadophora finlandica</i>. Plant biomass production of <i>S. smithiana</i> was decreased in all the treatments compared to the sterilized control. In contrast, <i>S. caprea</i> grew best on the non-sterilized soil. Similar effects were observed for plant Zn and Cd contents. Microbial treatments affected metal accumulation differently in the two <i>Salix</i> species. The effects of the microbial treatments on biomass and metal content of leaves were not related to the degree of mycorrhization. A comparison with literature data suggests that the plant response to microbial inoculation in terms of metal accumulation may depend on the plant-internal metal concentration. Our findings also illustrate a difficulty of successful rhizosphere management using metal-tolerant microbial isolates to further enhance the phytoextraction process.