Antifungal activity and mechanism of Mentha spicata essential oil and the major compounds on Botryosphaeria dothidea and their potential application to postharvest quality of Actinidia chinensis fruit

Botryosphaeria dothidea is an important pathogenic fungal, which cause the serious threats to crop and the substantial economic losses. Plant essential oils (EOs) have the strong antifungal activity, and induce fruit resistance to microorganisms. The antifungal activity and mechanism of Mentha spicata EOs and major compounds against B. dothidea, and the extending shelf life of Actinidia chinensis fruit were investigated. The results showed that estragole was a most abundant in M. spicata EOs compounds. M. spicata EOs, D-carvone, estragole and fenchone exhibited strong inhibitory effects on B. dothidea. M. spicata EOs and fenchone had significantly increased the electrical conductivity of B. dothidea solution, and caused to loss of nucleic acid and soluble protein. M. spicata EOs and estragole suppressed the cellulase and peroxidase of B. dothidea, however, fenchone promoted the xylanase activity. B. dothidea proliferation on A. chinensis fruit was inhibited by M. spicata EOs and major compounds during day 3 to 7 in situ. M. spicata EOs and fenchone promoted the A. chinensis fruit cellulase activity, however, the xylanase activity significantly reduced. The peroxidase activity of A. chinensis fruit increased by estragole. This study showed that M. spicata EOs has great potential as antifungal agent used for fruit postharvest.