Fusaric acid and phytotoxic metabolites produced by Fusarium oxysporum f.sp. albedinis: effects on date palm and their use for resistance screening trial

Bayoud disease caused by the soil born pathogen Fusarium oxysporum f.sp. albedinis (Foa) is one of the most destructive disease of date palm in North Africa. Foa produce in the culture filtrate phytotoxins that have been proposed to play an important role in the onset of the disease symptoms. In this study the processes response of date palm cultivars to Foa toxin extract and fusaric acid (FA) was investigated. Using susceptible and resistant cultivars, it was found that dichloromethane extract (DCM) from culture filtrate of Foa and FA showed a dose-response effect. In vitro sensitivity of date palm cultivars to DCM extract (50μg/ml) was positively correlated with susceptibility to bayoud disease in the field. This study suggests that Foa host selective toxin acting as selective agent, contribute to the pathogenesis and could be used on breeding for resistance.