Abstract: Fluorescent Pseudomonas spp. are described which are effective for the control of diseases caused by the soil-borne fungus, Gaeumannomyces graminis (Gg), such as take-all, in small grain crops or turf grass. The subject biocontrol strains have a unique genotype as shown by a characteristic banding pattern, and exhibit root-colonizing ability which is characterized by both higher population density on roots and extended colonizing activity compared to known Gg-suppressive strains. A further property is the ability of a strain to duplicate the level of biocontrol obtained naturally in a take-all decline soil. Methods for isolation and identification of the strains and their use to control diseases caused by Gg are provided. In particular, strains of P. fluorescens NRRL B-21806 and NRRL B-21807.

Abstract: Transgenic fluorescent Pseudomonas spp. are described which have a biosynthetic locus which encodes for the production of the antibiotic phenazine-1-carboxylic acid stably introduced into the genome, have a locus which encodes for the production of the antibiotic 2,4-diacetylphloroglucinol, and are effective for control of diseases caused by the soil-borne fungus, Rhizoctonia. Strains are also described which control diseases caused by Gaeumannomyces graminis or Pythium, in addition to Rhizoctonia, or have the ability to control all three diseases.