| Abstract: In order to explore the effect of low-salt exercise on the growth and antioxidant enzyme activity of tomato seedlings under salt stress, tomato cultivar 'KT636' was used as test material, and five lowsalt exercise levels were set with NaCl concentrations of 0, 25, 50, 75, 100 mmol/L, respectively. After seven days, tomato seedlings labeled NS-100, T25-100, T50-100, T75-100 and T100-100 were simulated with severe salt stress (concentration of NaCl was 100 mmol/L), and the growth indexes and antioxidant enzyme activities of tomato seedlings were analyzed with 1/2 Hoagland nutrient solution as the control. The results showed that there were no significant changes in plant height, stem diameter and leaf dry weight of tomato seedlings under low-salt exercise compared with those without low-salt exercise. Low-salt exercise with 25 mmol/L NaCl could increase plant height and stem diameter under salt stress, and significantly improve leaf area, above-ground dry mass, underground dry mass, plant dry mass and leaf peroxidase dismutase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) activities. The salt tolerance of tomato seedlings was improved to a certain extent by low-salt exercise with 25 mmol/L NaCl. |