The Effects Of Dust-fall Upon The Growth-Development Of Cotton

The potted cotton were conducted in this thesis. The changed characters of the anatomical structure, the physiological and bio-chemical characteristics and the yield of cotton under different treatments were studied through physicochemical analysis in laboratory. The main results were as follows:1. The leaves from potted cotton were treated with dust-fall, the results shows .the arrange of fencing tissue in cotton leaves were irregular, the histiocyte from fencing tissue were shrinked and shorted, more seriously, part of them were bent. The space from intercellular was wider, the histiocyte inclusion of sponge tissue were also decreased. However, the vascular bundles of contaminated cotton leaves were regular. In contrast, the anatomized structures in controls were unchanged.2. Contaminated cotton leaves had low chlorophyll contents, the difference of chlorophyll content in cotton leaves from the other two treatments were not distinct. The chlorophyll content of contaminated cotton was 10.7% less than that of the control. The chlorophyll content of cotton with silicon oxide was 4.5% less than that of the control.3. The contaminated cotton leaves had higher temperature and lower stomatal conductance than those of the control. The number of intercellular CO2 concentration, net photosynthesis rates, respiration rates, transpiration rates and photosynthetic rates were all less in the contaminated cotton than that of controls, instrument measurements and statistical analysis using Excel and DPS (version 3.1) revealed some significant difference between leaves from dusted cotton and control at 5% level。4. The activities of SOD in contaminated cotton leaves were high relatively and those in cotton leaves with silicon oxide were relatively low. The activities order (from high to low) of POD were: No-dusted cotton leaves, cotton leaves with dust fall, cotton leaves with silicon oxide. The CAT activities in dusted cotton leaves was less 31.7% than that of control and that of those with silicon oxide was less 24.8% than that of control. However, the content of MDA in dusted cotton was higher 29.9% than that of control and that of those under silicon oxide condition was higher 7% than that of control.