硅对番茄生长及光合作用与蒸腾作用的影响

为探讨番茄对硅的生理响应特性，本文采用营养液培养方法，研究了0（CK）、 0.6（T1）、 1.2（T2）、 1.8（T3）mmol/L 3个硅水平对番茄生长及水和CO2交换参数的影响。结果表明，番茄植株各器官硅含量均随营养液硅水平升高而显著增加，且以叶片差异最为显著，T1、 T2、 T3处理番茄叶片硅（SiO2）含量分别比CK高 250.90%、 403.59%、 552.69%； 番茄生长量、 叶片叶绿素含量均以T2、 T1处理较高，而T3处理则与CK无显著差异。T1、 T2处理的净光合速率（Pn）亦显著高于CK，在11: 00 Pn 达峰值时，分别比CK高15.36%和23.12%，而T3处理则比CK低5.74%；番茄叶片蒸腾速率（Tr）则随硅水平的提高而降低，13: 00时 T1、 T2、 T3处理的Tr分别比CK低7.42%、 11.47%和23.08%，硅处理番茄的瞬时水分利用效率（WUEi）均显著高于CK，11: 00时 WUEi 达峰值时，T1、 T2、 T3 处理分别比CK高 22.22%、 35.47%和17.52%。表明营养液硅（SiO2）水平以1.2 mmol/L为好。

Effects of silicon on growth, photosynthesis and transpiration of tomato

To investigate the physiological response characteristics of tomato (Lycopersicon esculentum) to silicon, the effects of silicon(Si) on the growth, H₂O and CO₂ exchange parameters of tomato were studied under the hydroponics with the 0 (CK), 0.6 (T1), 1.2 (T2) and 1.8 (T3) mmol/L silicon levels. The results indicate that silicon contents of tomato organs are increased dramatically with the increase of Si concentration in culture solution, and the differences in leaves are most significant. The SiO2 contents of leaves of T1, T2 and T3 are increased by 250.90%, 403.59% and 552.69% compared with the CK. Compared with CK, the plant growth and chlorophyll contents of T2 and T1 are higher, while T3 is no significant difference. Simultaneously, net photosynthetic rates (Pn) of T1 and T2 are also significantly higher than that of the CK, which are increased by 15.36% and 23.12%, and at 11: 00 o’clock, Pn of all treatments reach their peaks, while Pn of T3 is 5.74% lower than that of the CK. Transpiration rate (Tr) of tomato leaves is decreased as the silicon concentration increased, and Tr of T1, T2 and T3 are reduced by 7.42%, 11.47% and 23.08% at 13: 00 o’clock in contrast to CK. The instantaneous water use efficiency (WUEi) of tomato dealing with silicon is significantly higher than that of the CK, at 11: 00 o’clock, WUEi of all treatments reach their peaks, and WUEi of T1, T2 and T3 are 22.22%, 35.47% and 17.52% higher than the CK. The experiment demonstrates that the appropriate silicon concentration for optimizing the tomato growth is 1.2 mmol/L.