Antifungal, Insecticidal and Herbicidal Properties of Volatile Components from Paenibacillus polymyxa Strain BMP-11

The volatiles produced by Paenibacillus polymyxa strain BMP-11 which was isolated from the rhizosphere soil of cucumber in a greenhouse were analyzed by SPME-GC-MS. Based on the preliminary test, three kinds of purchased commercial products 1-octen-3-ol, benzothiazole and citronellol were chosen to give further assessment of their bioactivity. Antifungal bioassays in sealed dishes revealed that those three compounds strongly inhibited the mycelia growth of the eight pathogens at a low treatment dosage and induced the mycelial morphological abnormalities. During the experiment, we even found that citronellol completely prevented the pigment production of the tested fungus, Fusarium oxysporum, however, 1-octen-3-ol and benzothiazole had slight effect. The germination was inhibited to different degrees when spores of Botrytis cinerea exposed to these compounds for 24 h in water agar plate. Furthermore, fumigation results showed that 1-octen-3-ol and benzothiazole had strong toxicity against Tribolium castaneum, LC50 was 16.76 and 3.50 mg L-1, respectively. The fumigation activity was also found similar to the positive control, 1,3-dichloropropene (LC50=10.13 mg L-1). Results of herbicidal assays showed that tested compounds had inhibitory effects on the seed germination and seedling growth of Amaranthus retroflexus, Echinochloa crusgalli and Chenopodium album. Findings of the present study suggested that the antifungal, insecticidal and herbicidal properties of the components were contained in volatiles. These agents or even their derivatives may have a potential to be used as fungicide, insecticide as well as herbicide.