中文摘要：

水势是植物细胞和组织的重要水分生理参数之一,水势大小影响着植物的代谢、生长发育及抗逆性,也是合理灌溉的生理指标（李德全等,1990）。目前国内在教学、科研中植物水势的测定主要采用小液流法、压力势法、热电偶法和木质部压力探针法。小液流法和压力室法测定水势简便易行,但2种方法都存在难以克服的弊端（王军等,1997）。热电偶法测定水势具有应用范围广、

英文摘要：

The results and characteristics of water potential measurements with four different methods,namely the Chardakov method,Pressure chamber,in situ hygrometry and leaf disc hygrometry were compared on several plants species.Experimental results showed that the former 3 methods produced similar results,but the leaf disc hygrometry yielded significant different results from the other 3 methods.Further investigation showed that the results with the leaf disc hygrometry varied considerably with the equilibrium time and was not able to show the actual water potentials of the plants.The Chardakov method was time-consuming,and its efficiency was very low.Pressure chamber was able to provide accurate and reliable measurements of plant water potentials if the sample water loss could be avoided and the repetitious samples were available.While the in situ hygrometry showed the merits such as more reliable results,non-destructive to plants,no harsh prerequisites for plants and could measure the same spot of a plant continuously.