Fig. 4

Effects of exogenous MT on photosynthetic gas parameters in leaves of M9-T337 seedlings under saline-alkaline stress. CK represents watering with a 1/2 concentration of Hoagland nutrient solution only; SA represents the application of 100 mmol·L⁻¹ composite saline-alkaline solution based on the control; MT represents the spraying of 200 μmol L⁻¹ exogenous MT based on the control; MS represents the spraying of 200 μmol L⁻¹ exogenous MT based on SA; HS represents the spraying of 100 μmol L⁻¹ p-CPA on the basis of MS. A Net photosynthetic rate (Pn); B Intercellular CO₂ concentration (Ci); C Transpiration (Tr); D Stomatal conductance (Gs). Vertical bars represent the standard errors of the means (three replicates. Data show the mean ± SE (n = 3). Different lowercase letters indicate significant differences between treatments with P < 0.05