Studies On Enhancing Stress-resistance By Exgenous Trehalose In Cucumber Seedlings

The paper tested several main physiological indexes of cumuber under separately abiotic stress including drought injury, salt injury, and chilling injury, to study that trehalose solution of adapive concentration had the ability of improving the stress resistance of cumuber. The results are followed.The firstly, under drought injury with PEG6000, trehalose solution of adapive concentration improved relative water content and chlorophyll content of cucumber leaves, and increased the activitives of peroxidase (POD) and superoxide dismutase (SOD) and catalase (CAT) of cucumber leaves and reduced cell membrane relative permeability and MDA content. These showed that the trehalose solution of adapive concentration had the ability of reducing the drought injury of cumuber. Among several different treatments, the effect of 10mmol.L^-1 treholase solution was better.The secondly, under salt injury of 180 mmol.L^-1 NaCI, these treatments including 5, 10, 20mmol.L^-1 trehalose solutions improved relative water content and chlorophyll content of cucumber leaves, and increased the activitives of peroxidase (POD) and catalase (CAT) of cucumber leaves and reduced cell membrane relative permeability and MDA content. These dataes showed that trehalose solution of adapive concentration reduced salt injury. Distinct tests showed that among the three solutions, 10 mmol.L^-1 was the best.The last, under chilling injury of 4℃, the treatment of 10 mmol.L^-1 improved relative water content and chlorophyll content, and increased the activitives of peroxidase (POD) and catalase (CAT) and reduced cell membrane relative permeability and MDA content. Further more, the result of cumuber seedlings was the same as that of cumuber gemma. These showed that the trehalose solution of 10 mmol.L^-1 improved the chilling resistance of cumuber.These studies showed that the trehalose solution of adapive concentration improved the chilling resistance,drought resistance and salt resistance of cumuber. The next experiments will be done about the most adapive solution that trehalose solution improve stress resistance of cumuber, and the physiological mechanism of stress resistance.