Abstract: The Iris deal with NaHCO₃ of different concentrations solution, In order to study Iris leaf membrane permeability, soluble protein and lipid peroxide content changes. In this experiment, 1-year-old Iris seedlings is the study object. According to the measurement of cell membrane permeability, MDA, SOD, POD, the soluble protein and other indicators, the response and adapt ability of Iris deal with NaHCO₃. The result shows that: with more NaHCO₃ concentration and increasing stress time stress, the content of Iris leaves soluble protein influenced by NaHCO₃ salt stress tends to totally decline after the first prompt; on the 30^th day, the content of Iris soluble protein with the stress of 0.4% and 0.6% concentration increases by 21.7%, 38.6%, respectively more than those of contrast; membrane permeability of Iris leaves slightly declines in the condition of NaHCO₃ salt stress; during the 10^th day and the 20^th day, membrane permeability has a rapid increase. on the 20^th day under NaHCO₃ press, the POD activity has reached the maximum, by 32.1%,13.8% and 29.5% respectively, compared to control; with the same salt stress and time extension of salt press, SOD activity first increases and then decreases; on the 30^th day, as the product of membrane lipid peroxidation, the content of MDA in Iris leaves at 0.6% concentration accumulates dramatically, along with the increase in salt concentration and salt stress time. Based on the above analysis, there is salt(NaHCO₃)-stress resistance ability in Iris which is the important saline-alkali plant. Therefore, the study provides powerful evidence of salt-stress resistance in Iris, which strengthen the theoretical basis that Iris should be applied to the saline-alkali field control.

Key words: Iris, NaHCO₃ stress, physiological characteristics