Identification and Characterisation of pv. as the Causal Agent of Olive Knot Disease in Croatian, Slovenian and Portuguese Olive ( L.) Orchards.

Strains of pv. (), isolated from infected olive trees ( L.) in three European countries (Croatia, Slovenia and Portugal) were identified and characterised according to their colony morphology, physiological and biochemical features. According to the LOPAT scheme, 38.6% of isolates were grouped in the Ib cluster. The Portuguese strains were fully consistent with the typical LOPAT profile for this bacterium. Conversely, most Slovenian strains showed delayed oxidase activity, whilst Croatian strains did not produce any fluorescent pigment when grown in vitro. For molecular identification, both end-point and real-time PCR were used, as well as MALDI-TOF, which was additionally used for proteomic analysis and the subsequent species identification of a number of strains that showed deviations from expected LOPAT results. was confirmed as a causal agent of olive knot disease in 46.6% of olive orchards screened. Overall, these data suggests a possible correlation of certain features with the geographical origin and the ecological niche of isolates.