Survival and dispersal of a marked strain of Pseudomonas syringae in a maple nursery

Abstract

A pathogenic Pseudomonas syringae strain resistant to rifampicin and nalidixic acid was sprayed upon and colonized maple twigs and perennial ryegrass. The inoculated twigs were sampled at intervals of 2‐3 weeks from July 1985 to September 1986, and epiphytic populations of the marked strain recovered during this time ranged from undetectable to 104 colony‐forming units/g. The results showed that this strain of P. syringae could overwinter on maple twigs and potentially serve as a source of inoculum in the spring. Aerial dispersal was also investigated. The marked strain inoculated onto grass growing in pots was detected on medium in inverted petri plates, on maple leaves and with an Andersen sampler positioned from 12 to 100 cm above the grass. The number of detectable cells that dispersed vertically upwards was low even in the presence of wind, rain, or irrigation water. The marked strain inoculated onto maple branches was isolated from grasses under the inoculated trees, showing that P. syringae was dispersed downward. Lateral dispersal of the marked strain from inoculated to uninoculated trees was not detected. The identity of the antibiotic‐resistant strain isolated from the trees and grasses was confirmed by DNA restriction‐fragment profile analysis.

Induction of pear blossom blast caused by Pseudomonas syringae pv. syringae

“…Pseudomonas syringae pv, syringae strain API, isolated in the Hood River Valley from Asian pear (Pyrus pyrifolia), was used in all the experiments, A spontaneous derivative P.s. pv, syringae strain Pss2-3RNH (Malvick & Moore! 1988) resistant to rifampicin and nalidixic acid also was used.…”

Preliminary investigations of the risk of plant debris as a <i>Pseudomonas syringae</i> pv <i>actinidiae</i> inoculum source

“…In a similar study on the Pseudomonas syringae pathovar causing tip dieback and leaf spotting of maple, Malvick & Moore (1988) used a marked strain to demonstrate upwards dispersal of the bacterium from inoculated grass in a maple nursery. Nearly all the airborne bacteria detected were captured 12 cm above grass during wind-driven rain or sprinkler irrigation.…”

Pilus-mediated adsorption of Pseudomonas syringae to the surface of host and non-host plant leaves

“…An important feature in the ecology of the bacterium is the ability of many strains to function as ice-forming nuclei at relatively high subzero temperatures, a phenomenon widely studied in terms of its molecular basis and ecological implications (Lindow, 1983;Warren & Wolber, 1991). The ecology, such as pattern of epiphytic growth and spread of the bacterium under field conditions, has also been studied (Butterworth & McCartney, 1991;Hirano & Upper, 1983;Lindemann et al, 1982;Malvick & Moore, 1988;O'Brien & Lindow, 1989). Hirano et a!.…”