Comparison of Soil Desiccations in Natural and Acacia Forests in the Ziwuling Mountain of the Loess Plateau Photosynthetic Characteristics after Flowering and Contribution of Non-leaf Green Organs of Cotton to Yield under Mulching-drip Irrigation with Water Deficiency Responses of Photosynthetic Characteristics of Winter Wheat Cultivars Released in Different Decades to Water Deficit in North China Plain Changes in Contents of Polyamines in the Flag Leaf and Their Relationship with Drought-resistance of Rice Cultivars under Water Deficiency Stress 石刁柏花药培养再生植株的生根研究(Ⅱ) Effects of Water Deficiency on the Activities of Key Enzymes Involved in the Starch Synthesis and the Accumulation of Starch for the Transgenic Rice Plants Carrying Antisense Wx gene during Grain Filling Primary studies on the daily dynamic changes of photo-synthesis and transpiration of Salix psammophila Isolation and Expression Analysis of PwWDS1 in Picea wilsonii