番茄叶片气孔导度及渗透调节物质对快速水分胁迫的响应  

Response of stomatal conductance and osmotic adjustment substances accumulation to rapid drough stress in tomato leaves

作　　者：韩国君[1,2] 陈年来[1,2] 李金霞[2] 张凯[2] 郭艳红[2] 方春媛[2] 

机构地区：[1]甘肃省干旱生境作物学重点实验室,兰州730070 [2]甘肃农业大学资源与环境学院,兰州730070

出　　处：《中国生态农业学报》2013年第9期1100-1106,共7页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金项目(31060072)资助

摘　　要：本研究采用聚乙二醇（PEG-6000）溶液控制番茄的根际水势和利用光合仪控制叶面的空气湿度,监测叶片水势、气孔导度、渗透调节物质含量等指标的变化,揭示快速水分胁迫下番茄的应激性生理响应。结果显示,当Gs小于120 mmol.m 2.s 1时,水分胁迫处理番茄的叶片净光合速率（Pn）小于对照。空气饱和水汽压差（VPD）与番茄叶片Gs呈显著的负相关（R2≥0.892）。在同一空气湿度条件下,水分胁迫处理的番茄叶片Gs仅为对照的43%~51%。快速水分胁迫下番茄叶片的可溶性糖含量呈先增再降的波动,轻度和中度胁迫下可溶性糖含量比对照（0 min）分别增加61.4%~195.8%和56.0%~167.5%。可见,番茄叶片Gs为120 mmol.m 2.s 1是对Pn影响的一个重要阈值。气孔调节是适应快速干旱胁迫的重要应激性生理响应。可溶性糖对维持番茄叶片细胞膨压和适度气孔开度具有一定的渗透调节作用。As the main factors that influence crop yield and quality,drought has been the focus of agro-ecology for decades.To determine the physiological response of plants to fast water stress,root drought was simulated along with photosynthetic control of leaf surface air humidity in tomato.Polyethylene glycol（PEG-6000） solution was used in the drought study.Changes in tomato leaf water potential,stomatal conductance,osmotic adjustment substances and other physiological parameters were monitored.The results showed that the net photosynthetic rate（Pn） of tomato leaves under water stress was lower than that of the control when stomatal conductance（Gs） was less than 120 mmol.m 2.s 1 and vice versa.A significant negative exponentiation correlation was noted between water vapor pressure deficit（VPD） and stomatal conductance（Gs） in tomato.VPD was significantly positively correlated with Gs（R2 ≥ 0.892）.Under specific air humidity condition,maximum Gs under water stress treatment was only 43%~51% that of the control.Soluble sugar content of tomato leaves increased initially and then decreased under the rapid water stress condition.Soluble sugar content increased significantly by 61.4%~195.8% and 56.0%~167.5% over the control.Tomato leaf Gs exhibited a threshold response to Pn,and which threshold value was 120 mmol.m 2.s 1.Soluble sugar was suitable for supporting physiology process such as cell turgor pressure,stomatal opening and photosynthesis.The fluctuation in stomata opening was the mode of adaptation of tomato plant to water stress.Regulation of stomata opening was a critical form of response of tomato plant to drought stress.

关 键 词：番茄 渗透调节 气孔调节 快速水分胁迫 可溶性糖 

分 类 号：Q945[生物学—植物学]