【作者】 李金光；

【Author】 Li Jinguang (Department of Horti- culture, Beijing Agricultural College, Beijing 102208)

【机构】 北京农学院园艺系；

【摘要】 不同光照条件和不同水分供应条件下,不同部位杏叶片水势的日变化不同。供水和蒸腾失水平衡影响叶水势变化。在供水良好的情况下,上午叶水势不变,下午叶水势下降。但无光照情况下,叶水势全天保持不变。气孔相对开张度通过调节蒸腾影响水势,水势反过来影响气孔开张度;叶水势降低,气孔相对开张度变小。弱光照通过调节气孔开张度而影响叶水势,强光照对气孔已经开张、供水与蒸腾失水平衡的叶片水势影响不大。光诱导气孔开张,低水势诱导气孔关闭。在无供水的情况下,离体叶片水势下降到最低值,并保持一阶段,叶组织出现伤害。外围叶较内膛叶抗脱水能力强。更多还原

【Abstract】 The daily changes of the leaf water potential of apricot are affected by leaf quality, light, state of water supply and water loss by transpiration. In good water supply leaf water potential is stable in a. m. and down in p. m. in day, and doesn’t change in darkness. But it can be down to the lowest point and retain the point for several hours, which results in damage of leaf tissue ucder the condition of no water supply. The degree of relative stoma opening and leaf water potential affect each other in light. Light induces opening of stoma, and low leaf water potential causes the closing of stoma. Strong light hasn’t influence upon leaf water potential if stoma opens and water supply and loss are balanced. The ability of desiccation-tolerance of the leaf outside canpy is higher than that of inside canpy.更多还原