| Abstract: | The epiphytic survival of virulent and avirulent (indoleacetic acid-deficient mutants) isolates of Pseudomonas syringae subsp. savastanoi, and their ability to colonize the olive phylloplane, was monitored for up to 30 days after artificial inoculation of several olive cultivars. After an initial decrease in numbers, the virulent bacteria multiplied and established a potential inoculum on olive leaf surfaces. In contrast, the numbers of avirulent bacteria rapidly diminished, so that they were eventually no longer detectable. Under the conditions used in this study, none of the avirulent mutants (producers or non-producers of bacteriocins) were able to compete with or successfully to inhibit the virulent isolate in vivo. This was probably due to the lack of epiphytic multiplication of the avirulent mutants. |
