Abstract: In order to explore the effect of calcium on the SA-induced resistance to Botrytis cinerea in tomato（Solanum lycopersicum）. Tomato Botrytis cinerea susceptible strain‘L402’was pretreated with foliar spraying 8 mmol • L^-1 CaCl₂ and 5 mmol • L^-1 EGTA，respectively. Then followed by application of exogenous 2 mmol • L^-1 SA，3 d before B. cinerea infection. The disease index，ROS accumulation，variations of the activities of main resistance enzymes and their gene expression were analyzed. The results show that the disease index is significantly reduced by 37.27% compared to control in SA treatment 5 d after B. cinerea infection；While in Ca + SA treatment，the disease index reduced by 18% compared to SA treatment. The  production rate and H2O2 content reached the highest level at 1 d and 2 d，respectively，there is difference among treatments：production rate of  and H2O2 content in tomatoes treated by Ca + SA are 33.05% and 29.31% higher than control（H₂O），however，under EGTA + SA treatment significantly reduced by 32.62% and 46.34%，respectively. The peak of disease defense-related enzymes activity and gene expression also exist，difference obtained among treatments：PAL，chintase and β-1,3-glucancse treated by Ca + SA are significantly higher than control，whereas EGTA and EGTA + SA significantly suppress PAL，chitinase，β-1,3-glucanase activity. These results indicate that Ca²⁺ plays a positive regulatory role in the SA-induced resistance to Botrytis cinerea in tomato，which is closely related to the PAL，chitinase，β-1,3-glucanase activity and gene expression.

Key words: tomato, Botrytis cinerea, calcium, salicylic acid, induce resistance, regulation