摘要：Robinia pseudoacacia seedlings planted in petroleum polluted soil were treated with differentconcentrations of brassinolide (0, 0.1, 0.3 and 0.5 mg L -1 ) by dipping the root before planting andspraying leaf during leaf expansion period. The gas exchange parameters and photosyntheticfluorescence characteristics of seedlings were determined to study the effects of brassinolide onphotosynthesis of R. pseudoacacia seedlings in polluted conditions. The results indicated that theapplication of brassinolide significantly increased the leaf photosynthetic rate, transpiration rate,stomatal conductance and intercellular CO 2 concentration, and it also significantly increased the PSIIoriginal light energy conversion efficiency, PSII noncyclic electron transport efficiency, photochemicalquenching coefficient and the performance of the electron transfer rate of seedlings. In conclusion,brassinolide could effectively counteract the inhibitory effects of petroleum on the gas exchange andthe carboxylation capacity of mesophyll cells of seedlings in 10, 15 and 20 g kg -1 , 0.3 mg L -1 was thefavourable concentration to be used to counteract the adverse effects of petroleum pollution on R.pseudoacacia.
