Effects of cadmium and simulated acid rain on growth and physiological characteristics of bermudagrass seedling

The effects of cadmium (Cd) and acid rain on the growth of bermudagrass were studied by hydroponic experiment. This study was divided into two separate experimental groups. In the first one, we treated plants only with Cd; in the second, we treated plants with Cd and acid rain. The results showed that the growth of bermudagrass was inhibited by acid rain and higher concentration of Cd. The chlorophyll content (SPAD) of compound treatment plants was significantly lower than that of single treatment with the same Cd concentration, while the malondialdehyde (MDA) content was higher than that of the single treatment. Acid rain aggravated the toxic effect of Cd on bermudagrass. In this experimental treatment, the superoxide dismutase (SOD) activity of the plants treated with Cd and acid rain was always higher than that of the plants treated with Cd alone. The peroxidase (POD) and catalase (CAT) activities of the combined treatment plants increased at low Cd concentration. It showed that SOD plays a major role in anti-oxidation defense. Under higher Cd concentration, the contents of soluble protein, soluble sugar, and free amino acid in plants treated with Cd and acid rain were higher than those treated with Cd alone. The treatment of 1 mg/L Cd and pH4.5 acid rain caused the most serious harm to bermudagrass. Bermudagrass had a certain tolerance to the combined stress of Cd and acid rain. The results provide a theoretical basis for remediation of soil Cd pollution in acid rain area.