| Experiments were conducted to test the effect of heavy metals (Cu, Zn) on seed germination and root growth in medicinal plant Catharanthus roseus. A randomly selected fifty seeds in three replicates from C. roseus was used. Test solutions were prepared from each metal at three concentrations (50 μM, 100 μM and 500 μM). Distilled water was used as a control treatment. The objective of this work was to evaluate C. roseus for heavy metal tolerance. Effect of heavy metals, Cu and Zn on the plant growth parameters, Fresh weight (FW), dry weight (DW) and water content (WC), alkaloid content and antioxidant enzymes activity, peroxidase (POX), catalase (CAT) was evaluated. The plant growth (FW and DW) and POX activity increased in presence of low concentration (50 μM, 100 μM) in both metals. But in presence of high concentration (500 μM CuCl2), just opposite trend was observed. CAT activity was found to decrease in presence of both metals. Root growth was more readily affected by the heavy metals than seed germination. Further, it was observed that Zn caused higher plant growth as well as antioxidant activity than Cu. Hence, C. roseus showed better tolerance to Zn than Cu. |