营养液中的臭氧对番茄根系生理指标的影响

Effects of Ozone on Physiological Index of Tomato Root System in Nutrient Solution

在对循环营养液进行灭菌时,臭氧表现出较好的杀灭效果。为了探明臭氧在对营养液杀菌的同时是否会对植物根系产生伤害,试验以温室中基质栽培的番茄（Solanum lycopersicum L.）为研究对象,比较了3种不同浓度（0、2.0、4.0 mg/L）臭氧营养液浇灌对番茄幼苗期、开花期和结果期根系生理指标丙二醛（MDA）含量及超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性的影响。结果显示,2 mg/L的臭氧营养液使番茄幼苗期根系SOD活性较对照下降,开花期CAT活性和结果期SOD活性较对照均上升,结果期根系MDA含量较对照显著升高;4 mg/L的臭氧营养液较2 mg/L处理的MDA含量显著降低,表明2 mg/L处理有助于番茄根系抵抗臭氧胁迫的伤害;4 mg/L处理会使结果期番茄根系膜脂过氧化系统遭到破坏,打破了番茄自身可以承受的调控范围。因此,4 mg/L的臭氧营养液对结果期番茄的生长产生了不利影响。试验条件下,营养液中的臭氧安全浓度在2-4 mg/L。

During the sterilization of the circulating nutrient solution, ozone showed a good killing effect. To explore if the ozone would harm the plant roots while sterilizing the nutrient solution, tomato（Solanum lycopersicum L.） in soilless culture greenhouse was irrigated by three different concentration（0, 2.0 mg/L, 4.0 mg/L） of ozone nutrient solution. The root physiological indexes including MDA content, SOD, POD and CAT activity was tested during seedling stage, flowering stage and fruiting stage. The results showed that compared with control, in the 2 mg/L ozone nutrient solution treatment, SOD activity decreased during seedling stage; while of CAT activity during flowering stage and SOD activity during fruiting stage increased; and the content of MDA increased significantly. Of 4 mg/L ozone nutrient solution treatment, MDA content decreased significantly compared with 2 mg/L ozone nutrient solution treatment. The results indicated that 2 mg/L ozone nutrient solution could help the root of tomato to resist the damage of ozone stress. 4 mg/L ozone nutrient solution treatment could damage the root membrane lipid peroxidation system, and break the regulation range of tomato itself. Therefore, 4 mg/L ozone nutrient solution had a negative impact to the growth of tomato. It should be considered that the safe ozone concentrations in the nutrient solution be 2 to 4 mg/L.