Physiological responses of rye seedlings to the combined stress of NaCl, ambrosia and freeze-thaw

Background: Crops are often affected by NaCl, ambrosia and freeze-thaw stress simultaneously during their growth, and many areas in Northeast China are facing such serious ecological stress problems. In this experiment, the physiological responses of rye seedlings to NaCl and ambrosia stress in a freeze-thaw environment were studied by artificial simulation technique. Malondialdehyde (MDA) content, soluble protein (SP) content, superoxide dismutase (SOD) activity, catalase (CAT) activity, net photosynthetic rate (P n ) and transpiration rate (T r ) were determined and analyzed. Results: : The results showed that: After stress treatment, MDA and SP contents of rye seedlings increased by 19.48%-88.96% and 22.54%-107.30%, SOD and CAT activities increased by 4.42%-26.60% and 23.31%-64.68% and P n and T r decreased by 40.00%-71.67% and 20.00%-80.00%. Conclusion: In the face of stress, rye seedlings can reduce the damage caused by stress by increasing osmotic substance and antioxidant enzyme activity, so as to achieve the purpose of adapting to environment. The results revealed that combined NaCl, ambrosia and freeze-thaw stress had a significant superposition effect on plants compared with single NaCl, ambrosia and freeze-thaw stress.