Bioccumulation and toxicity of Cu and Cd in Vallisneria spiralis (L.).

Accumulation of Cu and Cd by Vallisneria spiralis was studied under laboratory conditions. Plants showed ability to reduce 5 µg ml(-1) Cu background concentration to below 0.05 µg ml(-1) (m.p.l., WHO 1985) within 48 h. The Cd concentration of 1.0 µg ml(-1) was reduced to below m.p.l. (0.005 µg ml(-1)) in 168 h. Cysteine synthesis was more under Cd stress condition. Both the metals were toxic to the plants at higher concentrations; more in the case of Cd.