MORPHOLOGICAL AND BIOCHEMICAL RESPONSES OF DIFFERENT RICE VARIETIES EXPOSED TO CADMIUM STRESS

A hydroponic experiment was conducted to observe the effects of various cadmium (Cd) levels (0, 50, 100 mu M) on morphology and biochemical responses of nine different rice varieties. Initially, seeds were sown in sand in plastic pots. After 16 days of sowing, uniform seedlings were transferred to hydroponic set-up containing Hoagland solution and continuous aeration was provided with aeration pump. After six days, plants were applied the Cd stress for four weeks, then plants were harvested. Plants growth, biomass, photosynthesis, oxidative stress markers contents, antioxidant enzymes activities and Cd uptake in both root and shoot were measured. Results revealed that Cd negatively affected the plant growth as well as photosynthesis; while, oxidative stress and Cd uptake was increased with increasing Cd stress in all nine rice varieties. From this study, it was found that among all nine rice varieties, the Chenab variety was found most tolerant; while, the Kisan Basmati was found most sensitive variety against Cd stress. However, future studies are needed in order to investigate the detailed mechanism of Cd in different varieties of rice.