Effects of Seed Priming on Physiology and Quality of Cucumber Under Drought Stress

Taking ‘Lyudao No.7’ cucumber as experimental material, the seeds were induced by 5% PEG for four hours, and the seeds were not induced by 5% PEG as the control.Four drought gradients were set, and two-factor splitting analysis method was used to explore the effects of PEG on cucumber physiology and fruit quality, in order to provide reference basis for the selection of cucumber seed priming or coating agent materials with PEG.The results showed that PEG induced plant superoxide dismutase（SOD）,peroxidase（POD）,and catalase（CAT） activity were increased, chlorophyll content was significantly increased by 22.18%-37.99%,and net photosynthetic rate of 40%-50% maximum field water capacity was increased by 118.60%.The yield of cucumber induced by PEG was higher than that of cucumber not induced by PEG,and the yield at 50%-60% of the maximum field capacity was lower than 60%-70% of the maximum field capacity,but the difference was not significant.At 50%-60% maximum field capacity,soluble solids,soluble sugar,soluble protein of cucumber induced by PEG was higher than that of cucumber without PEG.Vitamin C were significantly increased by 75.38% compared with those without PEG induction,suggesting that effective PEG induction could improve fruit quality by enhancing antioxidant enzyme activity and chlorophyll content and photosynthetic index of plants under drought stress.