Effects of NaCl stress on physiological indexes of eggplant seedlings

Effects of NaCl at 0, 50, 100, 150, and 200 mmol·L-1 on membrane permeability, MDA content, activities of antioxidant enzymes(SOD, POD and CAT), chlorophyll content, and chlorophyll fluorescence parameters of eggplant seedlings were investigated. The results showed that with the increasing NaCl concentration, the plasma membrane relative permeability and malondialdehyde(MDA) were increasing. The activities of CAT, SOD, and POD first increased and then decreased, while the chlorophyll content decreased gradually. In chlorophyll fluorescence parameters, F0 and NPQ increased, while Fv/Fm, q P, ФPSⅡ and ETR decreased compared to the control group. The results indicated that the physiological characteristics of eggplant seedlings were affected by the NaCl stress. Under the low concentration of NaCl(50 mmol·L-1), no significant differences between the treatment and the control were observed. Under the high concentration of NaCl(150 and 200 mmol·L-1), the symptom of salt injury was gradually appeared on eggplant seedlings. Furthermore, the injury was intensified with the increase of treatment time and concentration of NaCl.