Physiological Responses of Osmanthus fragrans Lour.Young Trees to Different Water Stress

Two-year-old Osmanthus fragrans Lour.was potted to study the physiological responses to different water stress.The results were as followings:The tissue water content,free water content and the ratios of the free water content to bound water content decreased obviously when the condition of the water stress become severe;the bound water content of severe and moderate water stress significantly differed from control while the mild water stress was not.The relative membrane permeability,MAD content,soluble sugar and praline content increased during the process of water stress.The activity of POD and CAT under severe and moderate water stress increased firstly and then decreased during the period of water stress.The activity of POD and CAT under the severe water stress reached the peak on the 6th day while that of the moderate water stress on the 9th day.The activity of POD and CAT under mild water stress increased along the time.