Field Use of Protective Bacteriophages against Pectinolytic Bacteria of Potato

Abstract

The pectinolytic Dickeya solani bacterium is an important pathogen found in potatoes. We conducted laboratory and field experiments mimicking severe and mild Dickeya spp. infection and investigated the application of a mixture of two lytic bacteriophages before and after bacterial infection to protect the plants. Application of the phage solution to tuber disks and wounded tubers did not completely eliminate the infection but reduced the development of soft rot symptoms by 59.5–91.4%, depending on the phage concentration. In the field trial, plants treated with bacteriophages after severe Dickeya infection had 5–33% greater leaf cover and 4–16% greater tuber yield compared to untreated plants. When simulating a mild infection, leaf cover was 11–42% greater, and tuber yield was 25–31% greater compared to untreated plants. We conclude that the phage mixture has the potential to protect potatoes ecologically from D. solani.

Potential of Limestonevirus Bacteriophages for Ecological Control of Dickeya solani Causing Bacterial Potato Blackleg

“…However, phages require their hosts to exist and be available, without which they quickly disappear from the environment. In the experiment described in [31], the bacteriophages φDs3CZ and φDs20CZ were detected in 6 out of 15 soil samples where they were applied in the middle of the growing season. At the end of the growing season, however, they were only detected in 1 out of 15 samples.…”

“…The effectiveness of the phages φDs3CZ and φDs20CZ on D. solani was investigated through artificial inoculation of potato tubers (variety 'Red Anna') in a greenhouse pot experiment. The tubers were prepared for the experiments following the method described in [31]. Immediately prior to planting, the tubers underwent severe mechanical wounds through cross-section, while the stem-ends and bud-ends were mildly pricked with a sterile steel needle (diameter: 3 mm, length: 10 mm).…”

“…A small-plot field trial was carried out on the test site described in [31]. The experimental rows were separated by one row of the untreated variety 'Monika' and, at the end of each row, one plant of the untreated variety 'Monika' was grown.…”

“…None of the varieties showed strong susceptibility to the evaluated bacteria. Therefore, the highly susceptible variety 'Red Anna' was selected for the greenhouse and field trial [31].…”

Xanthomonas euvesicatoria-Specific Bacteriophage BsXeu269p/3 Reduces the Spread of Bacterial Spot Disease in Pepper Plants

“…The review represents not a small number of in vitro, ex vivo and in vivo experiments, which indicates a serious increase in interest in them [22]. Bacteriophage mixtures have been reported as effective biocontrol agents against several pathogens, including pectinolytic bacteria Dickeya solani in potatoes [23], Ralstonia solanacearum, the causal agent of bacterial wilt of solanaceous plants [24] and against the bacterial soft-rot-causing agent of onion, Pectobacterium carotovorum subsp. carotovorum [25].…”