Abstract: The changes of photosynthesis,respiratory intensity,chlorophyll,soluble sugar and soluble protein content of 4 cucumber cultivars with different resistance to Sphaerotheca fuliginea after inoculation were studiedThe results showed that,respiratory intensity of resistant variet ies was apparently higher than control,while the susceptible group was lowerPhotosynthesis and respiratory intensity of resistant varieties increased after inoculat ion,and decreased 5-6 days later,in susceptible variety it was lower than controlThe chlorophyll content were improved both in the resistant and susceptible,the former had larger increase,and this content was correlated with disease resistance of the tested cucumber varieties.Trend of soluble sugar of each cult ivar after inoculation was similar with decrease-increase-decrease-increase,the first apex appeared at the 5th day,and the most decrease was occurred in the 7th day after inoculationThe soluble sugar content of inoculated varieties was markedly lower than the control experimentThis illustrated that sugar in the plant was depleted after inoculat ion,but the correlation of sugar content decrease and disease resistance of cucumber was not provedThe soluble protein content of each variety has increased after inoculation,where the peak value happened earlier in resistant than susceptible onesThis indicated that the susceptible cultivars were more sensitive to the pathogen than the resistanceNegative relationship was found between disease resistance and Sphaerotheca fuliginea infection response.

Key words: Cucumber, Sphaerotheca fuliginea, Physiological changes

CLC Number: 

• S436.421