ENZYMATIC ACTIVITY OF ROOT QUALITIES IN PURPLE-FLESHED SWEETPOTATO UNDER FLIED SHADING STRESS Effects of Low Temperature and Low Light Intensity Stress on Photosynthesis in Seedlings of Different Cucumber Varieties A preliminary study on C3 and C4 plants in the Northeast stepps and their ecological distribution Investigation on the Adaptation of Photosynthetic Carbon Metabolism Pathway to Environment of Phragmites communis in Hexi Corridor of Gansu Province Dynamic Characteristics of Photosynthetic Rate and Carbon Assimilation Enzyme Activities of Different Green Organs in Different Genotypes of Wheat The Effects of Sulfur Nutrition on Some Physiological Parameters in Relation to Carbon and Nitrogen Metabolism in Wheat and Maize EFECTS OF CALCIUM SUPPLY ON SUBCELLULAR DISTRIBUTION OF CADMIUM, CHLOROPLAST ULTRASTRUCTURE,RuBPC AND PEPC ACTIVITY IN MAIZE UNDER CADMIUM STRESS The salinity-adaptation physiology in different ecotypes of Phragmites communis in the Yellow River Delta Ⅱ.the characteristics of photosynthetic gas exchange in different ecotypes of Phragmites communis Effects of different accumulated temperature on photosynthetic performances of spring maize varieties during grain-filling period. Effects of Low Temperature and Low Light Intensity Stress on Photosynthesis in Seedlings of Different Cucumber Varieties C4 Pathway Enzymes in Soybean Leaves