Pseudomonas savastanoi and Other Bacteria Colonizing the Surface of Olive Leaves in the Field

Abstract

There were characteristic seasonal fluctuations in the populations of most of the bacteria. The abundance of P. savastanoi on healthy leaves in April and October supports earlier suggestions that the phylloplane of the host may be an important source of readily available inoculum in the epidemiology of olive knot disease.

Epidemiology and Control of Plant Diseases Caused by Phytopathogenic Bacteria: The Case of Olive Knot Disease Caused by Pseudomonas savastanoi pv. savastanoi

“…There are few studies on the epidemiology of olive knot disease and most data of epiphytic Psv populations on the aerial surface of the tree come from studies done in southern Italy (Ercolani, 1971(Ercolani, , 1978(Ercolani, , 1979(Ercolani, , 1983(Ercolani, , 1985(Ercolani, , 1991(Ercolani, , 1993 and southeastern Spain (Quesada et al, 2007;Quesada et al, 2010a;2010b). In the aforementioned studies, epiphytic Psv populations in the phyllosphere of olive trees were estimated by washing, followed by plating serial dilution of the washings.…”

“…These bacteria would be incorporated to the knot subsequently to the infection caused by the etiologic agent, according to García de los Ríos (1989). Indeed, a symbiotic relationship may exist between Psv and Pantoea (or may be other bacteria) because they are found together not only in knots but also as epiphytic bacteria in infected plants (Ercolani, 1978(Ercolani, , 1991Quesada et al, 2007). Furthermore, preliminary tests have shown that strains of an uncharacterized Erwinia, isolated from Psv-related olive knots, could have a synergistic effect with Psv in the development of typical symptoms of olive knot disease (Fernandes & Marcelo, 2002).…”

Note: Occurrence and persistence of culturable clostridial spores on the leaves of horticultural plants

“…The following crops were sampled near Trinitapoli, Molfetta, Monopoli, Castellana Grotte and Scanzano Jonico, in the SE of Italy, where they were grown commercially during the spring (sp), summer (su), autumn (au) or winter (wi) in 1991 strokes of 3 cm min-') at room temperature in the dark for 2 h (Ercolani 1978). After transfer of the flask into an anaerobic cabinet (mod.…”

“…Separate counts for each colony type were made under a Controls using the suspending and plating media indicated above and the procedures described elsewhere (Ercolani 1978) failed to detect spores inside the leaves and showed that over 90°/o of the spores on the phylloplane were washed off into the peptone water under the conditions described above.…”

Efeito da radiação ultravioleta B sobre a comunidade bacteriana epifítica de soja (Glycine max L. Merril)

“…Esse habitat pode variar a extremos de temperatura e exposição ultravioleta em prazos muito curtos (DICKINSON et al, 1975;ERCOLANI, 1978ERCOLANI, , 1991JACQUES et al, 1995 Para que se possa combater ou se adaptar a esses impactos, um primeiro passo importante é buscar conhecê-los, definindo-se cenários agrícolas a partir de cenários futuros das mudanças climáticas.…”