Effects of Salicylic Acid on Cold Tolerance of Tomato Seedlings

The effects of SA on tolerance of tomato seedlings to cold stress were studied,with the tomato seedlings at three-leaf stage treated with a series of concentration of salicylic acid(SA)(0.5,2.0,and 4.0 mmol/L).The results showed that SA could enhance the tolerance of tomato seedlings to cold stress,with the most effective for the concentration of SA at 2.0 mmol/L.Compared to non-treated tomato seedlings with cold stress,the rate of electrolyte leakage of tomato seedlings could be detected in the leaves of tomato seedlings treated with the concentration of SA at 2.0 mmol/L for 4 days after cold stress,which was significantly lower than other ones.While malondialdehyde(MDA) had a least increase of 73.01%.The content of soluble sugar had a highest increase of 87.35%.Chlorophyll content had a decrease of 16.47%.Therefore,the results suggested that tolerance of tomato seedlings to cold stress could be increased after a pre-treatment with SA at concentration of 2.0 mmol/L.