1Present Address: Deptt. of Botany, NEHU, Shillong- 793022.
Primary production under the stress of heavy metals such as Zn and Cd on Hydrilla verticillata Royle was studied using light and dark bottle technique. Considerable redution in gross primary productivity (GPP), net primary productivity (NPP) and respiration was recorded with the increase in the concentration of these heavy metals. A similar trend was shown by total chlorophyll pigments. Zn seems to be more toxic than Cd. The interaction of Zn and Cd has reduced the deleterious effect on the metabolism of the plant as compared to their application separately.
