Submitted to: International Plant Growth Promoting Rhizobacteria Workshop
Publication Type: Abstract only
Publication Acceptance Date: 3/20/2006
Publication Date: 5/20/2006
Citation: Landa, B.B., Mavrodi, O., De La Fuente, L., Allende Molar, R., Mavrodi, D., Thomashow, L.S., Weller, D.M. 2006. Biogeography of 2,4-diacetylphloroglucinol-producing pseudomonas fluorescens.. International Plant Growth Promoting Rhizobacteria Workshop. P35, page 57. Interpretive Summary:
Technical Abstract: Strains of Pseudomonas fluorescens producing the antibiotic 2,4-diacetylphloroglucinol (phlD+) are biocontrol agents of soilborne pathogens and play a key role in the disease suppressiveness of some soils. Considerable variation among isolates has been observed by using genomic fingerprinting techniques such as ARDRA, RAPD, DGGE, rep-PCR, and phlD RFLP analyses, and also by phylogenic analysis of phlD. Groups resolved by BOX-PCR, phlD RFLP analysis, and phylogenetic analysis of phlD correlated very well, and to date, 22 genotypes (A to T and PfY & PfZ) have been described, with at least six more genotypes suggested by recent studies. The genotype of and isolate is predictive of how aggressively it will colonize the wheat or pea rhizosphere. Wheat , pea and flax monoculture appears to preferentially enrich for certain genotypes from the “seed bank” of genotypes naturally present in a soil. Most genotypes A, D and perhaps C and F are comospolitan, appearing in different locations worldwide. Genotype M is widely distributed throughout Western Europe. A detailed description of the genetic diversity and geographic distribution of phlD+ P. fluorescens will help to facilitate our understanding of the role that these rhizobacteria play in plant defense in agro- and natural ecosystems.