A hydroponic experiment was conducted to determine the effects of different levels of potassium (0, 4.0 mmol · L-1, 8.0 mmol · L-1 and 16.0 mmol·L-1) on the physiological indices of different tomato cultivars [nematode-susceptible (HS), nematode-resistant (HR) and common (CK) cultivars]. Based on the results, the activities of SOD, POD and CAT, and the contents of total phenol and flavonoid increased significantly with increased potassium concentration within 0~8.0 mmol · L-1. On the other hand,MDA content decreased significantly with increased potassium concentration. However, the activities of SOD, POD and CAT, and flavonoid content dropped at potassium level of 16.0 mmol · L-1 for HR cultivar. Contrarily, MDA content increased if potassium level was 16.0 mmol · L-1 for HR cultivar. The activities of SOD, POD and CAT, along with the contents of total phenol and flavonoid for HR cultivar were higher and MDA content lower than for HS and CK cultivars. Test of significance of the degree of interaction between potassium and cultivar showed that the activities of protective enzymes under potassium application were higher for HR than for HS and CK cultivars.%采用水培试验,研究了不同K水平(0、4.0 mmol·L-1、8.0 mmol·L-1、16.0 mmol·L-1)对易感线虫品种"早熟2号"(HS)、抗线虫品种"06h-42"(HR)、普通品种"中杂102"(CK)3个番茄品种抗逆生理指标的影响.结果表明,在0~8.0 mmol·L-1 K浓度范围内,随着K浓度的升高,番茄体内的SOD、POD、CAT活性及总酚和类黄酮含量显著增加,MDA含量显著下降,但过量的K(16.0mmol·L-1)则会降低HR体内的SOD、POD、CAT活性和类黄酮含量,增加其MDA含量.对于不同番茄品种而言,HR的SOD、POD、CAT活性及总酚和类黄酮含量显著高于CK和HS,MDA含量显著低于CK和HS.通过交互作用显著性检验发现,K有利于番茄体内保护性酶活性的提高,在HR中较CK和HS更为显著.
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