Resistance of Venturia inaequalis to the sterol biosynthesis-inhibiting fungicide, penconazole [1-(2-(2,4-dichlorophenyl)pentyl)-1H-1,2,4-triazole]

摘要

The likelihood of the development of penconazole tolerance in Venturia inaequalis was demonstrated using chemical mutagenesis of a wild isolate of the pathogen not previously exposed to penconazole. Mutant strains displayed a high degree of resistance which was stable. There was significant variation in the rate of total lipid and ergosterol biosynthesis between the resistant and sensitive strains. Low uptake of penconazole due to energy-dependent efflux was found to be the mechanism underlying penconazole resistance in the mutant strains, which also exhibited negatively correlated cross-resistance to mancozeb.