Reliable detection of the fungal pathogen Fusarium oxysporum f.sp albedinis, causal agent of Bayoud disease of date palm, using molecular techniques

Bayoud, caused by the soilborne fungus Fusarium oxysporum f.sp. albedinis (FOA), is the most serious disease of date palm. Since the disease is located in the North African countries of Morocco and Algeria, and advancing steadily eastwards, the ultimate goal is to prevent spread of the pathogen to other date-growing areas in the region and farther afield. Molecular diagnostic techniques have been developed for detection of FOA. In view of the fact that the fungus does not exist in Israel, DNA of FOA was obtained to determine the reliability of these methods for diagnostic purposes. Random amplified polymorphic DNA was not reliable enough for differentiation between FOA and various pathogenic and saprophytic Fusarium isolates. However, the polymerase chain reaction utilizing FOA-specific primers was accurate and enabled amplification of a unique band specific to FOA DNA alone, and not that of the other tested pathogenic and saprophytic Fusaria. The availability of a rapid and reliable diagnostic tool for detection of FOA will enable the Plant Protection and Inspection Services of the Israel Ministry of Agriculture to test date palm tissue for the presence of the pathogen.