Detection of potential volatile inhibitory compounds produced by endobacteria with biocontrol properties towards Fusarium oxysporum f. sp. cubense race 4

A variety of volatile compounds were detected from six endobacteria isolated from different host species. From this, only two isolates (LCB01 and AVA02) produced volatile compounds capable of inhibiting the growth of the pathogenic Fusarium oxysporum f. sp. cubense race 4 (FocR4). Inhibition by volatile compounds produced by isolate LCB01 ( Herbaspirillum spp.) was the most effective with 20.3% inhibition towards FocR4. Volatile compounds profiles indicated that inhibition may be attributed to the presence of single compounds such as 2-pentane 3-methyl, methanethiol and 3-undecene, or their action synergistically. Both methanethiol and 3-undecene were also produced by AVA02 ( Pseudomonas spp.), but the absence of 2-pentane 3-methyl seemed to have affected the inhibitory effect with only 1.4% inhibition. The absence or the low levels of the three compounds in the other four isolates resulted in no inhibition of FocR4. These observations strongly suggest the antifungal nature of the three volatile compounds towards FocR4.