<正>比较分析了6种保水剂在0～0.5mol/!。的NaCI、KCl、CaCl2电解质溶敢。以及pH为2～12的蒸馏水中的吸水倍数和保水剂对土壤水分蒸发的影响。结果素明：随着3种电解质盐溶液浓度升高一保水剂吸水倍数呈下降趋势；CaCl2对『罘水剂吸水倍数的影响明显大干KCL和NaCI。在pH句6～8的蓐馏水中保水剂能保持较好的吸水性能;当pH≤4或pH≥10时吸水倍数明显下降。保水剂对酸性水溶液更为敏感。保水剂能有效地降低土壤水分蒸发速率。几种保水剂呈相似的变化趋蛰。其中"高能抗旱保水训（GN）"表现最佳。以GN进行的土壤质地对保水剂侔水效果影响的试验表明。壤土中睬水剂对抑制土壤水分蒸发速率的效果较明显。

More and more researches about infection structures had been carried out in recent years. Some plant pathogenic fungi could produce infection cushion, appressorium and haustorium to finish infection processes, and their formation and development were very important to plant diseases occurring. Appressorium and associated melanin were critical to penetration, and their formation was controlled by genes, also influenced by such environmental factors as plant surface structures, temperature and pH. Haustorium was not only the organ for nutrient uptakes, but also the area for information exchange between plants and fungi. Extrahaustorial membrane(EHM) was from plant plasma membrane(PM), but their structure and function were different. The interaction between plants and fungi directly led to the ultrastructural changes of haustorium. Research of infection structures and their infection mechanism is significant to prevent and cure the plant diseases in theory and practice.