Evaluation of the antifungal and biochemical activities of mefentrifluconazole against Botrytis cinerea.

Mefentrifluconazole is the first product of a new sub-class of triazoles fungicides, i.e., the isopropanol triazoles, with the broad spectrum and high activity. In this study, the potential and biochemical activities of mefentrifluconazole against Botrytis cinerea were investigated. The frequency distribution of all EC values of mefentrifluconazole against mycelial growth and germ tube elongation of 106 isolates formed unimodal curve, with the mean EC values of 0.124 ± 0.025 and 0.015 ± 0.008 μg/mL, respectively. The effect of mefentrifluconazole against gray mold was determined on detached leaves of cucumber in vivo, the treatment of mefentrifluconazole at 200 μg/mL provided 100% preventative efficacy and 72.7% curative efficacy. No evident correlation was detected between the sensitivity of B. cinerea to mefentrifluconazole and that to tebuconazole, difenoconazole, myclobutanil, hexaconazole, triadimefon, flusilazole and pyrisoxazole (P > 0.05). Mefentrifluconazole treatment resulted in the increase of mycelium branch, the decrease of ergosterol content and the changes of the permeability of cell membrane. These studies evaluated the potential of mefentrifluconazole to control gray mold and helped us to understand the possible biochemical activity of mefentrifluconazole against B.cinerea.