CADMIUM AND COPPER INTERACTIONS ON THE ACCUMULATION AND DISTRIBUTION OF CD AND CU IN BIRCH (BETULA-PENDULA ROTH) SEEDLINGS

The effect of different external cadmium (Cd) and copper (Cu) regimes on the concentration of Cd and Cu in roots and shoots of birch (Betula pendula Roth.) seedlings was investigated. The seedlings were grown f or 12 days in a weak nutrient solution (containing all essential nutri ent elements including 0.025 mu M Cu) at pH 4.2 with combinations of a dditional 0-2 mu M CdCl2 and 0-2 mu M CuCl2. Root and shoot concentrat ions of Cu were decreased by Cd in all treatments which included 0.1-2 mu M of additional Cu in the treatment solution. When no extra Cu was added, only the shoot concentration of Cu was decreased by Cd whereas the root concentration was not affected. The shoot concentration of C d was decreased by 0.5 and 2 mu M of additional Cu in the treatment so lution. The root concentration of Cd was decreased by Cu only when the concentration of additional Cu in the treatment solution was equal to or exceeded the concentration of Cd.