Cloning and Characterization of Phosphoenolpyruvate Carboxylase Gene from Echinochloa crusgalli C4 Pathway Enzymes in Soybean Leaves 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 The Effects of Sulfur Nutrition on Some Physiological Parameters in Relation to Carbon and Nitrogen Metabolism in Wheat and Maize Investigation on the Adaptation of Photosynthetic Carbon Metabolism Pathway to Environment of Phragmites communis in Hexi Corridor of Gansu Province Effects of different accumulated temperature on photosynthetic performances of spring maize varieties during grain-filling period.