Evaluation of biocontrol potential of Achromobacter xylosoxidans against Fusarium wilt of melon

To investigate the potential of biological control measures against soil-borne plant pathogens, this study evaluated the in vitro and in vivo antifungal activity of endophytic bacteria, Achromobacter xyloxidans, against isolates of Fusarium oxysporum and Fusarium solani responsible of Fusarium wilt of melon (Cucumis melo) in Tunisia. Twenty-one Fusarium isolates were recovered and identified from diseased tissues of different melongrowing regions. The bacterial isolate was recovered and identified from contaminated Petri plates of the Fusarium phytopathogenic isolate. In vitro assay, the results showed positive effects of A. xylosoxidans by reducing significantly 80% of pathogen mycelial growth compared to the control. Furthermore, under greenhouse conditions, A. xylosoxidans significantly reduced 60% of disease severity on melon plants inoculated with Fusarium isolates. According to our results, A. xylosoxidans could be used as a promising and potentially Fusarium disease bio-control agent.