Effect of mint oil against Botrytis cinerea on table grapes and its possible mechanism of action

• DOI: 10.1007/s10658-017-1375-6
• Publication Date: 2017-11-10T05:02:35Z
• Authors: Ren Xueuan; Song Dandan; Liang Zhuo; Kong Qingjun
• Keywords: 0303 health sciences; 03 medical and health sciences

This paper assessed the antifungal effects of sage oil, lavender oil, mint oil, and tea tree oil on the postharvest fungal pathogen, Botrytis cinerea, which causes gray molds. The change of morphology, physiological, and biochemical characteristics about fungal hyphae and conidia were determined. As results show, all four oils can effectively inhibit the growth of B.cinerea and the antifungal effects are dose dependent. The best antifungal effect has been found from mint oil. According to in vitro studies, volatile vapor worked better than direct contact. With volatile vapor, the growth of B.cinerea was inhibited completely at 2 for all four oils. Mint oil at 500 μL/L and its volatile vapor at 25 could inhibit both conidia germination and disease incidence significantly in vivo. Observations by using scanning electron microscope and transmission electron microscope revealed that, mint oil could destroy the ultrastructure of hyphae and conidia, resulting in markedly shriveling and crinkling of the hyphae and conidia. It could also thicken and disrupt cell wall, causing cellular nucleic acids and proteins divulged with the damage of the cell wall. The chemical composition analysis of mint oil using GC/MS revealed that its main components were cyclohexanol, cyclohexanone, and some alkenes and alkanes. The majority of the components were effective antifungal agents. The content of volatile cyclohexanol and cyclohexanone were found to be 39.79% and 22.24% respectively.