Four halophytes(or salt-tolerant species)and their accessory structures of leaf related to adversity tolerance in the desert of northern Xinjiang Leaf Epidermis Ultra-Microstructure Associated with Drought Resistance In Poa Pratensis Cultivars Effects of Bag-removing on the Cell Ultra-microstructure of Apple Fruit Peel during the Sunburn Development in Vitro Effects of Bag-removing on the Cell Ultra-microstructure of Apple Fruit Peel during the Sunburn Development in Vitro