Effects of cadmium and lead on growth, yield, and metal accumulation in cabbage.

摘要

A greenhouse experiment was performed to determine the cadmium (Cd) and lead (Pb) distribution and accumulation in cabbage grown on soil amended with Cd and Pb. The soil was amended with 0, 5, 10, 40, and 80 mg Cd kg-1 in the form of cadmium nitrate [Cd(NO₃)₂] and with 0, 10, 50, 100, and 500 mg Pb kg-1 in the form of lead nitrate [Pb(NO₃)₂]. Main soil properties, concentrations of total and diethylenetriaminepentaacetic acid (DTPA)-extractable Pb and Cd in soil, plant growth, and total contents of metals in leaves and roots were measured. The DTPA-extractable Cd and Pb were significantly and positively related to the addition of Cd and Pb respectively. Cadmium accumulation in cabbage plants was increased with the increase of Cd rates in soil whereas Pb accumulation was significantly increased by the greatest dose of Pb only, in comparison to control treatment. The largest proportions of Pb and Cd accumulated in roots. Cabbage plants did not show growth disturbance and the plants showed no symptoms of phytotoxicity as results of Cd and Pb application. On the contrary, fresh weights of leaves and roots were increased significantly in the lowest applications (5 mg Cd kg-1 and 10 mg Pb kg-1) compared to the control treatment. Further additions of Cd and Pb had positive, but not significant, effects on biomass except for the weight of roots. The tolerance of cabbage plants to high concentrations of these metals in soil is discussed.