Project Number: 5348-22000-013-00
Project Type: Appropriated

Start Date: Mar 05, 2007
End Date: Mar 04, 2012

Objective:
The long-term objective of this program is to develop biologically based technology for controlling soilborne pathogens of wheat, barley, and Brassicas, grown as part of cereal-based production systems. Five specific objectives will be addressed over the next five years. Objective 1: Evaluate the genotypic diversity between species and within pathogen populations of root pathogens in direct-seeded cereal-based cropping systems. Objective 2: Identify and characterize microorganisms and mechanisms active in the suppression of soilborne pathogens by rhizobacteria. Objective 3: Identify the determinants responsible for differential rhizosphere competence among genotypes of DAPG-producing Pseudomonas fluorescens strains. Objective 4: Identify and characterize the molecular mechanisms of host-microbe interactions, including the action of host genes governing disease resistance and biological control. Objective 5: Identify and develop biocontrol technology for suppression of root pathogens in cereal-based cropping systems.

Approach:
Biological control of root pathogens Gaeumannomyces, Pythium, Rhizoctonia, and Fusarium by naturally occurring and genetically engineered microorganisms will be developed and quantified in different soils. The genetic determinants and molecular mechanisms responsible for toot colonization and pathogen suppression will be characterized with emphasis on the genetics and regulation of phenazine and phloroglucinol biosynthesis. Structural loci for these anti-fungal metabolites will be used to engineer improved biocontrol agents. The genetic and physiological diversity of populations of the root pathogens, and influence of cropping system on pathogen populations and diversity will be determined. New sources & mechanisms of resistance will be identified. Practical root diseases control will be accomplished by both maximizing the activity of natural biocontrol agents. Formerly 5348-22000-012-00D (2/07). BL level - 2, Pending on date of certification.