外源水杨酸对NaCl胁迫下番茄幼苗光合特性的影响

采用营养液栽培，研究了外源水杨酸对NaCl胁迫下番茄叶片光合作用和叶绿素荧光参数的影响。结果表明：在NaCl胁迫条件下进行SA处理，番茄叶片净光合速率（Pn）、气孔导度（Gs）均较NaCl胁迫条件下未加SA处理有明显的增加。SA处理减缓了细胞间隙CO₂浓度（Ci）、气孔限制值（Ls）的升、降速度。外源SA减小了NaCl胁迫下番茄叶片叶绿素含量、PSⅡ原初光能转换效率（Fv/Fm）、PSⅡ的潜在活性（Fv/Fo）、光合电子传递量子效率（ΦPSⅡ）、叶绿素光化学猝灭系数（qP）的下降以及初始荧光（Fo）、非光化学猝灭系数（NPQ）的升高。说明外源SA对NaCl胁迫下番茄叶片光合系统的破坏具有保护作用。

Effects of Salicylic Acid on Photosynthesis Characteristics of Tomato Seedlings during NaCl Stress

Effects of exogenous salicylic acid（SA）on photosynthesis and chlorophyll fluorescence in tomato（Lycopersicon esculentum Mill.）leaves under NaCl stress were studied．The results showed that under NaCl stress with SA treatment the levels of net photosynthetic rate（Pn）and stomatal conductance（Gs）increased more obviously than the control without SA，and the increasing or decreasing rate of intercellular CO₂（Ci）concentration and stomatal limitation value（Ls）were faster than that of the control without SA too．The SA treatment inhibits the decreases of chlorophyll contents，intrinsic photochemical efficiency of PSⅡ（Fv/Fm），potential activity of PSⅡ（Fv/Fo），quantum yield of PSⅡ（ΦPSⅡ），chlorophyll photochemical quenching（qP）|and the increases in original fluorescence（Fo）and chlorophyll non-photochemical quenching（NPQ）．These results suggest that SA has protective role against the damage of photosynthetic system under NaCl stress．