Lead accumulation and tolerance characteristics of Athyrium wardii (Hook.) as a potential phytostabilizer

摘要

Lead (Pb) pollution poses great threats to human health and can trigger serious environmental con sequences. Athyrium wardii (Hook.), a new plant with the potential for phytostabilization of Pb, was identified in a field survey of plant species in a lead-zinc mine tailing located in Sichuan Province, China. The growth, Pb concentration and some physiological and biochemical characteristics of mining ecotypes (ME) and non-mining ecotypes (NME) were analyzed by pot experiment employing different concentrations of Pb(NO_3)_2 in tested soil during four weeks period. The results showed that the A wardii has a higher tolerance to excessive levels of Pb soil contamination. The concentrations of Pb in the shoots and roots of the ME were 3.5 and 3.0 times higher, respectively, than those of the NME when plants were supplied with Pb at 800 mg Pb kg~(-1). A wardii of ME showed higher bio-activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and lower concentrations of malondialdehyde (MDA) and membrane permeability under higher Pb levels, while the opposite tendency was observed in NME. These findings demonstrated that the mining ecotype of A wardii has the potential for phytostabilization of Pb contaminated soils.