天然酚类化合物与两种化学杀菌剂的联合抑菌活性研究

为探索天然酚类化合物百里香酚、和厚朴酚与化学合成杀菌剂百菌清、啶酰菌胺混配的增效作用,筛选出能够防治灰霉病的混剂,本研究将百里香酚、和厚朴酚分别与百菌清、啶酰菌胺以不同比例混配,采用菌丝生长速率法测定其对灰葡萄孢菌Botrytis cinerea的抑菌活性,并将Bliss法、Mansour法和孙云沛法结合,以优化筛选方案,评价混剂的联合毒力。实验结果表明:将Bliss法、Mansour法和孙云沛法结合使用能够有效降低筛选工作量,且准确率较高;百里香酚和百菌清以质量比5:1、2:3、1:5和1:10比例混配,和厚朴酚和百菌清以质量比10:1、5:1、3:2、2:3和1:10比例混配均表现出协同增效作用;和厚朴酚和百菌清以10:1比例混配时协同增效作用最明显,其CTC值为309.15,以1:10比例混配时抑菌活性最高,其对B. cinerea的EC₅₀为0.29 mg/L,高于杀菌剂百菌清。因此,将定性分析方法与定量分析方法结合使用是筛选杀菌剂混剂配方的合理方案,天然酚类化合物百里香酚、和厚朴酚与百菌清以合理比例混配所得混剂具有防治灰霉病的潜力。

Synergistic Antifungal Activity of Natural Phenolic Compounds and Two Chemical Fungicides

In order to explore the synergistic effect of the mixtures of natural phenolic compounds (thymol and honokiol) with synthetic fungicides (chlorothalonil and boscalid) and screen out the novel fungicide mixtures which could control gray mold, in this study, thymol and honokiol were mixed with chlorothalonil and boscalid in different proportions, respectively, and the antifungal activity of the mixtures against Botrytis cinerea was determined by mycelium growth rate method. The Bliss’s method, Mansour’s method and Sun’s method were combined to optimized screening program, and the combined toxicity of the fungicide mixtures was evaluated. The results showed that the combination of Bliss’s method, Mansour’s method and Sun’s method could effectively reduce the screening workload and achieve high accuracy. The mixtures of thymol and chlorothalonil in mass ratios of 5:1, 2:3, 1:5, 1:10, and the mixtures of honokiol and chlorothalonil in mass ratios of 10:1, 5:1, 3:2, 2:3 and 1:10 showed a good synergistic effect. Among the mixtures of honokiol and chlorothalonil, the mass ratio of 10:1 showed the highest synergistic effect, with CTC value of 309.15. The mixture of honokiol and chlorothalonil in the mass ratio of 1:10 showed the highest antifungal activity, with EC₅₀ value of 0.29 mg/L against B. cinerea, which was higher than that of chlorothalonil. Therefore, the combined use of the qualitative analysis methods and quantitative analysis methods is a proper scheme to screen the fungicide mixtures. The mixtures of natural phenolic compounds (thymol and honokiol) and chlorothalonil at reasonable ratios has the potential to control gray mold.