中文摘要：

以＂辽园多丽＂番茄品种（Lycopersicon esculentum Mill.）为试材,在第1花序第1花开花当天进行昼间亚高温（35℃）胁迫处理,并喷施10 mmol/L CaCl2和0.2 mmol/L水杨酸（SA）水溶液,以25℃喷施清水为对照,研究叶片净光合速率,叶绿素荧光参数和保护酶活性（SOD和POD）的变化情况,探讨CaCl2和水杨酸对番茄耐亚高温特性的调控作用。结果表明,亚高温胁迫处理使叶片净光合速率下降,气孔导度和胞间CO2浓度略有升高,PSII最大光化学效率（Fv/Fm）和电子传递速率（ETR）降低,说明不是气孔因素导致光合速率的下降。而亚高温条件下喷施10 mmol/L的CaCl2和0.2 mmol/L的SA可以显著提高净光合速率、保护酶活性和PSII最大光化学效率。在处理结束时,使这些指标达到或超过对照水平。CaCl2主要是通过提高气孔的开放程度和防止光合机构的破坏来提高光合速率的,而水杨酸主要是通过改善光合机构的性能提高光合速率的。

英文摘要：

In order to investigate the regulatory effect of CaCl2 and SA on the sub-high temperature resistance of tomato plant, the whole plant under the sub-high temperature stress （day time 35℃） were sprayed 10 mmol/L CaCl2 and 0.2 mmol/L SA during the 1st inflorescence flowering, with the spraying clear water （day time 25℃）as control. The change of net photosynthetic rate （Pn）, chlorophyll fluorescence parameters and the activities of defense enzymes（SOD and POD）in the leaves of tomatoes were studied. The results showed that the sub-high temperature stress （daytime 35℃） reduced the net photosynthetic rate （Pn）, increased the stomatal conductance （Gs） and intercellular CO2 concentration （Ci） and reduced the maximum photochemical efficiency （Fv/Fm） and rate of electronic transmission of photosynthesis （ETR） , these results conducted that the reduced of Pn is not due to the stomatal factor. But under the sub-high temperature condition （daytime 35℃）, spraying CaCl2 （10 mmol/L） and SA （0.2 mmol/L） treatment enhanced the net photosynthetic rate （ Pn）, the activities of defense enzymes and the maximum photochemical efficiency（Fv/Fm ）. At the end of the treatment, these indicators meet or exceed the level of control. The results indicated that CaCl2 enhanced the net photosynthetic rate （Pn） by improving the porosity of the opening and closing and the ability of photosynthetic , while salicylic acid is mainly by improving the ability of the photosynthetic apparatus to promote the net photosynthetic rate （Pn）.