Ci accnmulation from Cd contaminated soil by the Cd-tolerant plant Polygonum thunbergii

摘要

Polygonum thunbergii can accumulate a high concentration of Cd in its body. We determined the ability of P.thunbergii to accumulate Cd from the soil into the shoot. We conducted pot experiments in a greenhouse during spring and fall. P. thunbergii was planted in three Cd- contaminated soils (approximately T-Cd 2 mg kg~(-1)), andosol, sandy soil, and alluvial soil. The results showed that all the plants that grew were healthy and did not show any damage due to the Cd treatment. P. thunbergii has a comparatively large biomass. The Cd concentration in the dry matter of the shoot became approximately 20-fold higher than that in the soils. P. thunbergii not only accumulated a high concentration of Cd but also accumulated zinc from the Cd-polluted soil. P. thunbergii being a runner produces roots at the nodes. By increasing the root volume through rooting, the level of Cd accumulation was increased. These results indicated that P. thunbergii is a suitable plant for phytoremediation because of its Cd tolerance, high level of Cd accumulation, and large biomass. We concluded that P. thunbergii is an ideal plant for phytoremediation.