ISHS Acta Horticulturae 590: IX International Workshop on Fire Blight
CHARACTERISATION OF TWO FLUORESCENT STRAINS OF PSEUDOMONAS AS BIOCONTROL AGENTS AGAINST FIRE BLIGHT |
| Authors: | O. Galasso, G. Sponza, C. Bazzi, J.L. Vanneste |
| Keywords: | Erwinia amylovora, bacterial antagonists, inhibitory compounds, apple, pear |
| DOI: | 10.17660/ActaHortic.2002.590.44 |
| Abstract:
Experiments were carried out in 1999, 2000 and 2001 in Italy and New Zealand to determine the effectiveness in preventing and/or limiting progression of fire blight infections on flowers and shoots of apple and pear of two fluorescent Pseudomonas strains isolated from apple buds (IPV-BO G19 and IPV-BO 3371). The activity of these two strains against Erwinia amylovora was tested in minimal medium. The strain IPV-BO G19 was found to produce a peptide antibiotic when grown in agar medium but not when grown in liquid medium. In contrast, strain IPV-BO 3371 was found to produce a non-peptidic antibiotic when grown in liquid medium and on agar plates. None of these compounds acted as a siderophore. The efficacy of these two strains in reducing the incidence of fire blight on apple and pear flowers, on pear shoots, and on pear fruitlets was compared with that of two known biocontrol agents (P. fluorescens A 506, Pantoea agglomerans Eh252). Water and streptomycin were used as positive and negative controls, respectively. For strain IPV-BO 3371 relative protection on apple flowers in the greenhouse was 77%, but variable on pear shoots (87 to 40%) and on pear flowers (6 to 49%); for strain IPV-BO G19 relative protection on apple flowers in the field was 79%, 52% on apple flowers in the greenhouse, 40 to 58% on pear shoots and 34 to 25% on pear flowers. These two strains seem promising for biocontrol of fire blight, as in some cases they out-performed P. fluorescens A 506, P. agglomerans Eh252 and streptomycin. | |
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