| heal.abstract |
Giant reed (Arundo donax L.) plants were grown outdoors, in pots, for 2 years and were irrigated with metalliferous water containing cadmium (Cd) and nickel (Ni) in low (5 mg/L), medium (50 mg/L) and high (100 mg/L) concentrations, whereas in the control group tap water was used. The determined soil Cd and Ni total contents (extracted by HNO3 + H 2O2) ranged widely (13.5-973.8 mg/kg Cd and 68.5-2543.3 mg/kg Ni). For assessing the metal accumulated in the different soil phases, three extradant solutions were used, giving distinct extractable concentration peaks in the topsoil, following the order EDTA>DTPA» KNO3. At the end of each cultivation period, all plants were harvested and the above-ground parts were divided into three equal pieces, apart from the panicle. Fresh and dry weights as well as heavy metal contents for leaves and stem of each third and the panicles were determined. The results showed that plant growth was not affected by elevated heavy metal content in the irrigation water and, thereafter, in the soil. Cadmium and nickel accumulation in all plant parts was increased in both years by the treatments, and the highest concentrations were determined in the leaves of the lower third. Cadmium showed a clear and stable vertical distribution in all treatments; in leaves, a significant decrease towards the top was determined, while the opposite was observed in stems. Panicle Cd contents were similar to the upper stem thirds, increasing by treatment. Nickel contents were generally higher than that of Cd, and they did not show a significant height effect for all treatments. The determined Cd and Ni total uptake within each third (leaves+stems) showed the highest contents in the middle third for the first year, while, in the second year, metal allocation varied, depending on heavy metal and treatment. |
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