Effects of Melatonin on the Growth of Radish Seedlings under Salt Stress

A pot experiment was conducted to study the effects of melatonin (MT) on the growth of radish seedlings under salt stress. MT increased the biomass, chlorophyll content and antioxidant enzyme activity of radish seedlings under salt stress. When the concentrations of MT were 50, 100, 150 and 200 mu mol/L, the activity of SOD improved by 17.26%, 35.20%, 18.97% and 17.27%, respectively, compared with the control, and the activity of CAT improved by 118.44%, 132.55%, 114.82% and 103.69% respectively. When the concentration of MT was 100 mu mol/L, the biomass, chlorophyll content and antioxidant enzyme activity of radish seedlings got the maximums. Therefore, MT could relieve the damage of radish seedlings under salt stress, and the dose of 100 mu mol/L was the best.