Effect Of Storm Dust On Respiration Rate In Crop Leaves

Along with the rapidly economized development, ecological environment deteriorates day by day. The storm dust threats the people's fitness and the plants'metabolism function, especially in crops. From April to September in 2010, on basis of field experiments, a long-term located experiment was conducted to study the effects of storm dust on respiration rate in crop leaves. In this research, the related physiological parameters after treatment of storm dust covering were examined in 3 sorts of crops which were chosen from native crops; the changed characters of the physiological and bio-chemical characteristics and the dust-retention ability of crop leaves were studied through physiochemical analysis in laboratory. The main results were as follows:1. The contaminated crop (wheat, corn and cotton) leaves had lower stomatal conductance than those of the control. The net photosynthesis rates, respiration rates, transpiration rates and photosynthetic rates were all less in the contaminated crops than that of controls, instrument measurements and statistical analysis using Excel and SPSS revealed some significant difference between leaves from dusted crop leaves and control at 1% level. There was different in these gas exchanged parameters between different leaves, they were basically in line with high Leaf>low Leaf>middle Leaf.2. Overall, contaminated crop leaves had low chlorophyll contents, the difference of chlorophyll content in crop leaves from the other treatment was distinct. The chlorophyll content of contaminated wheat, corn and cotton were 6.64%,4.85%,20.36% less than that of the control.3. After contaminated with sand storm dust, the soluble protein content of wheat, corn, cotton leaves were decreased. There exist in significant difference between leaves from dusted wheat and control wheat, but insignificant difference between leaves from dusted corn, cotton and control corn, cotton.4. After sand storm dust treatment, the MDA of wheat, corn, and cotton leaves increased by 15.89%, 36.67%, 46.2%.And the conductivity of leaves were rapidly growth, the electrical conductivity of wheat and corn leaves reached the highest increase of 18.35%, 19.27% and 37.99%, 41.46% at April and May, while the electrical conductivity of cotton leaves reached 19.69% and 27.61% at May and June.5.In order to research on the dust detaining capability and its rule of different leaves in different crops, three crops in Minqin were chosen to systematically study the accumulation of dust on the leaves of different crops in opening and enclosure surroundings by direct sampling and measurement, and statistical analysis as well, the results show that:①the amount detaining dust per square meter of leaves vary significantly at large contributing to the strong disturbance of external environment;②for the same crops dust detained on the leaves in the enclosed surroundings was obviously less than that in the open ones; illustrating that the amount detaining dust of leaves increase with increment of the particles in the environment.③In the open surroundings, the amount detaining dust of leaves at higher parts of the crops is evidently larger than that of the'Middle'and'Low'parts of the same crop according to the comparison of dust detaining of different leaves vertically in the same crop, because, the dust that had landed down to the road was churned up by cars and people and dropped down to the leaves at the'High'parts of the crop leaves again.