Antagonistic activity of volatile organic compounds of endophytic bacteria from sword brake fern (Pteris ensiformis) against soil-borne fungal pathogens

Abstract

The use of endophytic bacteria in the control of plant diseases, especially soil pathogenic fungi such as showed good results. Endophytic bacteria have various mechanisms to control plant pathogen, but the mechanism of endophytic bacteria in producing volatile organic compounds (VOCs) has not been widely studied. The objective of this research was to evaluated the antagonistic activity of VOCs produced by endophytic bacteria from the nail sword (Pteris ensiformis) aginst three soil borne pathogen fungus, R. solani, S. rolfsii and Fusarium sp. Endophytic bacterial isolates used were APE15, APE22, APE33, and APE35. The study was conducted by cupping method to determine the inhibition of endophytic bacteria VOCs against three soil borne fungal pathogens. GC-MS analysis was conducted to determine the content of volatile compounds produced by endophytic bacteria. The results showed that four endophytic bacterial isolates can inhibited R. solani growth (92.11%-96.05%), S.rolfsii (87.28%-93.10%), and Fusarium sp. (27.73%-57.55%). The GC-MS analysis showed that there were several antifungal compounds detected i.e. octanal, cytronellyl acetate, silane, 9-octacenamide, n-dimetylpalmitamide, and isobutyryl chloride. Octanal was presumed as the most influential compound that inhibited the three soil borne fungal pathogens because it was a dominant compound was detected.