SOME EFFECTS OF CADMIUM ON MAIZE PLANTS

The growth of the whole plant and the chlorophyll content, oxygen evol ution, and chloroplast ultrastructure of leaf tissues have been studie d in maize plants grown on a culture medium either without cadmium (Cd ) or supplied with increasing concentrations of the metal. The plants treated with high Cd concentrations showed symptoms of heavy metal tox icity, such as length reduction of both roots and shoots, leaf bleachi ng, ultrastructural alterations of chloroplasts and lowering of photos ynthetic activity. Some symptoms appeared at 100 muM Cd, but the stron g toxic effects of the metal were found only at 250 muM Cd.