Study of the photosynthesis characteristics and physical signs of four plants at the desert-oasis ecotone 两种生态型芦苇胚性悬浮培养物对渗透胁迫的响应Ⅰ、生长及渗透调节物质的变化 Physiological Responses of Hypnum fertile Sendtn.(Musci:Hypnaceae) to Short-term Extreme Temperature Stress The role of the fertilizing with nitrogen, calcium and sodium chloride in winter wheat leaves adaptation to freezing-thaw stress The relationship between freeze-tolerance and changes in activities of antioxidant enzymes and osmolyte content in the leaves of white clover during early winter freeze-thaw cycles Changes of Physiological Properties in Limonium aureum(Linn.) Hill Seedlings under Salt Stress Related Physiological and Biochemical Characteristics of Diploid and Tetraploid Cymbidium Hybrids under High Temperature Stress