Biocontrol activities of grey mould of grapes with the volatile organic compounds generated by yeast HXMG-1 isolated from grapes

Abstract

The pathogenic bacterias of postharvest crops are reduced by volatile organic compounds (VOCs) generated by yeasts. The yeast HXMG-1, which works well against gray mold of grapes pathogens (Botrytis cinerea), was assessed for its potential to create volatile organic compounds (VOCs) as one of its ways of working. Using a double Petri dish assay, the effect of HXGM-1-produced VOCs on mycelial development and spore development of the target pathogens was evaluated. Compared to the control, the VOCs produced by yeast HXMG-1 signi cantly restricted the growth of mycelium and spore germination of Botrytis cinerea. Speci cally, the mycelium growth of Botrytis cinerea was entirely restricted and the rate of spore germination of Botrytis cinerea only 20.11% at a concentration of 1×10 9 CFU/mL. It was also found that the VOCs could signi cantly inhibit mycelium growth with 82.46% inhibition with treatment of concentration of 1×10 8 CFU/mL. The VOCs caused the mycelium to grow curved, resulting in larger mycelial tips, fewer nuclei, and shorter mycelial septum spacing. In in vivo tests, noninjure or injure grapes were arti cially inoculated with pathogen hyphal disk followed by biofumigation with VOCs generated by yeast HXMG-1, and the treatments (Wp2 and Wp3) signi cantly controlled pathogenic infection, con rming the results of in vitro tests. Through the creation of a phylogenetic tree, HXMG-1 was recognized as a member of the Ascomycota, Hemiascomycota, Yeasts, and Hansenula sp. families. In conclusion, the yeast strain HXMG-1 created VOCs that signi cantly inhibited the development of Botrytis cinerea on grapes and is expected to be further developed and utilized. This study lays the foundation for the using of Hansenula sp. for biological control of postharvest diseases.