外源硅对青枯病感病番茄叶片抗氧化酶活性的影响

Effects of exogenous silicon supply on the activity of antioxidant enzymes of tomato leaves infected by Ralstonia solanacearum

【目的】探讨青枯菌侵染下外源硅处理对番茄青枯病的抗性效果及生理作用机理，为青枯病的有效防治提供参考依据．【方法】选择青枯病易感番茄品种为试验材料，通过盆栽土培和水培试验，研究硅处理和青枯菌Ralstonia solanacearum接种对番茄青枯病病情指数、叶片抗氧化酶活性的影响．【结果和结论】硅能显著增强番茄青枯病抗性．硅处理使青枯病的病情指数在土培试验和水培试验下分别降低29.1％～93.0％和6.3％～100.0％．青枯菌侵染条件下硅处理能显著增加番茄叶片抗氧化酶活性．在土培试验中，加硅使番茄叶片的POD、CAT酶活性分别增加了43.17％和23.17％；水培试验在接种第3天，加硅使POD、CAT、PAL酶活性分别增加了122％、337％和31％．本研究表明硅对番茄青枯病的抗性机理可能是硅诱导植物产生一系列生物化学防御反应，增强了番茄对青枯病菌的抗性．

[Objective]The objective of this study was to investigate the physiological mechanism of sili-con-induced resistance of tomato plant to bacterial wilt .[Method]Pot experiments with soil and hydropo-nic cultivation were conducted to study the effects of silicon supply on the disease index of bacterial wilt and antioxidant enzymes of tomato leaves .[Result and conclusion]The results showed that exogenous Si treatment reduced the disease index of bacterial wilt by 29.1%-93.0% respectively in soil cultivation experiment and 6.3% -100% respectively in hydroponic experiment compared with no-Si-treatment.Compared with the no-silicon treatment , Si application increased POD and CAT activity of tomato leaves by 43.17% and 23.17% in soil cultivation experiment .Si amendments significantly increased POD , CAT and PAL activity of tomato leaves by 122%, 337% and 31% respectively in hydroponic experi-ments.In conclusion, Si supply has an important role in suppressing bacterial wilt caused by Ralstonia solanacearum.The pathogen resistance mediated by Si is associated with the activation of defense-related enzyme activities in leaves .