This study investigates the effect of high concentrations of Pb and Zn on biomass production and accumulation of both metals in zinc violets (Viola calaminaria and Viola guestphalica) and two species of violets indigenous to Poland (Viola lutea sudetica and Viola tricolor). The influence of the plants on soil pH also was assessed. The soil used in the experiments, containing 183 mg kg-1 Zn and 53.4 mg kg-1 Pb, was spiked with Zn and Pb at 1,000 mg/kg soil (Treatment 1) or Zn at 10,000 mg/kg and Pb at 1,000 mg/kg (Treatment 2). Zn concentrations were found to be higher in roots than in shoots in all investigated species. In zinc violets, Zn content in the soil correlated with Zn concentrations in plant tissue, both roots and above-ground parts. There was no such dependence among indigenous violets. Since all confirmed hyperaccumulators accumulate metals preferentially in shoots, with lower concentrations in roots, our results suggest that zinc violets should not be classified as Zn hyperaccumulators. V. l. sudetica occurs naturally on soils with low heavy metals content. Its roots accumulated the highest amount of Zn (6,498 mg/kg) observed in the current study with no toxic effects. Roots were able to change the soil pH, but the differences were not significant. V. l. sudetica and V. tricolor increased biomass significantly in Treatment 1 versus the control, but in Treatment 2 neither species differed in biomass from the control. In Viola guestphalica no influence of treatments on dry weight was observed. We suggest that zinc violets can be useful for phytorestoration of contaminated sites.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.