Control effects of Bacillus siamensis G-3 volatile compounds on raspberry postharvest diseases caused by Botrytis cinerea and Rhizopus stolonifer

Abstract

Post-harvest diseases of raspberries affect their storage and subsequently the ability to provide consumers with fresh products. The antifungal activity of microbial volatile organic compounds (MVOCs) against both pre and postharvest diseases has previously been demonstrated, but the control of raspberry postharvest diseases caused by Botrytis cinerea and Rhizopus stolonifer using MVOCs has not been extensively studied. We have thus investigated the effects of Bacillus siamensis G-3 volatile organic compounds (VOCs) on controlling the diseases caused by B. cinerea and R. stolonifer. Bioassays of the VOCs of B. siamensis G-3 exhibited significant control effects (89.4%) on the two pathogens. The VOCs composition was studied with solid phase micro extraction and GC/mass spectrometry (SPME-GC-MS), and 22 VOCs, different from the controls, were identified. Among these compounds, only 2, 6-di-tert-butyl-4-methylphenol (BHT), and 2,4-di-tert-butylphenol (2,4-DTBP) had significant control effects on the pathogens (*P < 0.05), 52.38 and 93.33%, respectively, compared with the controls in vivo. With the 2,4-DTBP treatments, the raspberries could be stored for 20 d at 0 °C, with the disease rate maintained at ∼10%. In addition, we have reported for the first time, that 2,4-DTBP may be a better preservative than BHT and could be used as a bio-fumigant for controlling raspberry postharvest diseases caused by B. cinerea and R. stolonifer in vivo.