Antifungal volatile organic compounds from Burkholderia sp. BV6 control gray mold disease of cherry tomato

Abstract

Botrytis cinerea is a fungal pathogen that acts as a necrotroph, causing gray mold disease and affecting over 1400 plants. The biocontrol effect of microbial volatile organic compounds (VOCs) in controlling postharvest diseases has gradually gained significant attention as a research hotspot. This study evaluated the biocontrol effects of VOCs produced by Burkholderia sp. BV6 on B. cinerea in vitro and in vivo. The results showed that the strain BV6 volatiles suppressed the mycelial growth of B. cinerea. The antifungal effect of strain BV6 volatiles against B. cinerea was enhanced by optimizing the inoculation method and inoculation quantity of strain BV6. The volatiles of strain BV6 showed wide-spectrum antifungal activity against several plant pathogenic fungi. Solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC/MS) analysis identified 24 volatile compounds, the most abundant of which (2-nonanol, 2-nonanone, 2-tridecanol, and 2-undecanol) showed dose-dependent antifungal activity. Among them, 2-nonanol exhibited the strongest antifungal activity toward B. cinerea, with a minimum inhibitory volume (MIV) of 1.5 μL/plate (equal to 21.43 μL/L). Strain BV6 and 2-nonanol reduced the lesion diameter and disease severity of of gray mold in cherry tomatoes caused by B. cinerea. These results suggest that fumigation with 2-nonanol or strain BV6 is a promising method for protecting cherry tomatoes against gray mold disease. Furthermore, this study demonstrated the antifungal efficacy of both strain BV6 and 2-nonanol against B. cinerea and their biocontrol potential for postharvest cherry tomatoes.