Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2021, Vol. 37 ›› Issue (14): 150-157.doi: 10.11924/j.issn.1000-6850.casb2020-0656

Special Issue: 植物保护

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Synergistic Antifungal Activity of Natural Phenolic Compounds and Two Chemical Fungicides

Li Jiajun1(), Tao Lihong1, Ye Min1(), Wang Kaibo1,2(), Wu Wenwei2, He Chengxing2, Fan Liming1, Su Fawu1   

  1. 1State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201
    2Institute of Agricultural Environment and Resource, Yunnan Academy of Agricultural Sciences, Kunming 650205
  • Received:2020-11-16 Revised:2021-01-11 Online:2021-05-15 Published:2021-05-19
  • Contact: Ye Min,Wang Kaibo E-mail:1347178595@qq.com;yeminpc@126.com;wangkaibo4015@163.com

Abstract:

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.

Key words: natural phenolic compounds, thymol, honokiol, synthetic fungicides, synergistic effect, Botrytis cinerea

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