Biological control of tomato bacterial spot by seed microbiolization

Abstract

Six plant growth promoting rhizobacteria isolates -two Streptomyces (DFs1296 and DFs1315), three Bacillus (DFs1414, DFs1420 and DFs1423) and one Pseudomonas (DFs1421) -were used to microbiolize tomato seeds for the control of bacterial spot caused by Xanthomonas gardneri. Three assays were conducted in a completely randomized design with six replications. In each assay, X. gardneri suspensions (10 8 CFUmL -1 ) were spray-inoculated on the leaves. In the first and second assays, three and four leaves, respectively, were assessed for disease severity. In the third assay, three leaves per plant were assessed for the number of lesions per leaf, leaf area and dry weight. Results showed that one of the Bacillus sp. isolate (DFs1420) consistently provided the greatest relative reduction (48%) of tomato bacterial spot severity.

A centenary for bacterial spot of tomato and pepper

“…hortorum pv. gardneri disease severity by 48% in tomato (Naue et al, 2014 ). Rahnella aquatilis application on seed, soil, root, or leaves reduced X .…”

Inhibition of Xanthomonas fragariae, Causative Agent of Angular Leaf Spot of Strawberry, through Iron Deprivation

“…On strawberries, BCAs belonging to the bacterial species B. subtilis and amyloliquefaciens , or fungal/yeast species such as Aureobasidium pullulans, Beauveria bassiana, Ampelomyces quisqualis , and Trichoderma harzianum , have been tested in foliar applications for antagonism of strawberry pathogens, including Botrytis cinerea ( Sylla et al, 2015 ) and Sphaerotheca macularis ( Pertot et al, 2008 ). Several studies have also chronicled the efficacy of BCAs against species of Xanthomonas that are foliar pathogens on crops other than strawberry ( Mishra and Arora, 2012 ; Naue et al, 2014 ; Van Hop et al, 2014 ). However, we are not aware of any study that has assessed BCAs or BCA-derived products in relation to X. fragariae on strawberry.…”

Special issue in honour of Prof. Reto J. Strasser - Can be performance indexes used to select plant growth-promoting rhizobacteria?

“…These bacteria had in vitro and/or in vivo known skills: 24 isolates showed biocontrol in vivo for at least one phytopathogen (bacteria, fungi or nematode) and/or growth promotion (common beans, fig, garlic, kale, onion, peach, rice, and tomato). The others produced in vitro antimicrobial compounds and enzymes related to biocontrol and/or growth promotion: seven isolates had all eight abilities evaluated; 35 isolates did not produce only one of the compounds (usually chitinases); 25 isolates showed six traits (also usually did not produce chitinases); and to contrast, the other two isolates produced only one or two compounds (Zanatta et al 2007, Corrêa et al 2014, Naue et al 2014, Mota et al 2017.…”