Effect of "Lengdongbao" on Some Physiological and Biochemical Characteristics of Tomato Seedlings under Low Temperature Stress

The response of tomato seedling with different concentrations of chill resistance agent to low temperature stress was studied under the temperature 13 C (day)/6 C (night). The results showed that chill resistance agent not only raised the content of the soluble sugar , but also increased the activity of protective enzyme. With the time of low temperature continuing , electrolytic leakage and the contents of MDA would increase,but the electrolytic leakage and the contents of MDA of tomato leaf with the suitable concentrations of chill resistance agent was more lower than CK. The treated tomato exhibited high chill-resistance with better comprehensive appreciation. The suitable concentration is 2. 5~1. 25 g/L.