Induction of disease resistance in common bean susceptible to halo blight bacterial pathogen after seed bacterization with rhizosphere pseudomonads.
Year: 1991
Type: article
Abstract: With the aim of elucidating the immunizing ability of plant-growth-affecting rhizosphere pseudomonads, seeds of a susceptible bean (Phaseolus vulgaris L) cv. Bonita, were subjected to bacterization before challenging with the halo blight bacterial pathogen Pseudomonas syringae pv. phaseolicola. In the greenhouse, induced systemic resistance to halo blight was found in bean plants treated with a plant growth stimulatory strain of P. fluorescens (S 97), whereas deleterious pseudomonads MA 250 and VS 50 were found to induce susceptibility towards the disease. Immunization ability of S 97 was reduced at low inoculum densities (<107 live cells per ml) or eliminated when the suspension was autoclaved. The maximum disease protection, measured in terms of number of halo blight lesions in trifoliate leaves, was obtained at the highest inoculum concentration (108 live cells per ml). Agar diffusion assay in vitro revealed that S 97 exhibits bacteriostatic activity against the bean pathogen. It is suggested that S 97 might evolve substances already during seed germination that are translocated to the foliage; there they might accumulate around the site of bacterial multiplication and contribute to their restricted growth.
DOI: 10.2323/jgam.37.495
Author: SADHNA ALSTRÖM
Institution: Swedish University of Agricultural Sciences
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W1994293657