| In order to discuss the effect of salicylic acid (SA) and brassinolide (BR) on growth and drought resis-
tance of cauliflower seedlings, the cauliflower cultivar, Xuefeng was used as the material, different concentrations of SA and BR were applied to the whole seedlings by foliar spray when the fouth true leaves were expanded fully and treated with drought stress in pot experiment，with sterile deionized water alone as control. The results showed that SA and BR increased the index of high quality seedlings， DW-FW percent of top, root shoot ratio，photosynthetic rate， stomatal conductance, transpiration rate and chlorophyll content and promoted high quality seedling foming of cauliflower seedlings, but had no effect on intercellular CO2 concentration. The SA concentration with the best effect was 50 mg/L and BR was at 0. 01 mg/L. Under drought stress, 50 mg/L SA and 0.01 mg/L BR obviously alleviated the decline of soluble protein content，increased SOD activity，decreased POD activity，and alleviated the accumulation of proline and MDA in cauliflower seedlings' leaves. It was concluded that application of exogenous SA and BR could improve growth
status of cauliflower seedlings and alleviate the cauliflower damage by drought stress to some extent，and the 50 mg/L SA and 0. 01 mg/L BR were the optimal concentration for cauliflower seedlings under this experimental condition. |