Project Number: 5348-22000-016-00
Project Type: Appropriated

Start Date: Mar 05, 2012
End Date: Mar 04, 2017

Objective:
The long-term objective of this program is to develop biologically based technology for controlling soilborne pathogens of wheat, barley and brassica crops, grown as part of cereal-based production systems. Three specific objectives will be addressed over the next five years. Objective 1: Evaluate the pathogenic diversity, host range, and geographical distribution of fungal and nematode root pathogens, and the influence of cropping systems on soilborne diseases. Objective 2: Characterize microorganisms and mechanisms active in suppression of soilborne diseases. Objective 3: Identify and characterize molecular mechanisms of host-microbe interactions, including the action of host genes governing disease resistance and biological control.

Approach:
Biological control of soilborne fungal pathogens such as Gaeumannomyces, Rhizoctonia, Pythium, Fusarium and nematodes by naturally-occurring and genetically-altered microorganisms will be developed and quantified in agricultural soils. Molecular approaches will be used to detect and quantify soilborne pathogens and their microbial antagonists, and to characterize microbial communities in bulk soil and the rhizosphere. Genetic determinants and molecular mechanisms responsible for root colonization and pathogen suppression will be characterized with emphasis on the genetics and regulation of phenazine and phloroglucinol biosynthesis in vitro and in situ. The genetic and physiological diversity of populations of root pathogens and their microbial antagonists, and influence of cropping systems on pathogens and antagonists will be determined. Genomes of pathogens and antagonists will be analyzed. New sources and mechanisms of host resistance will be identified. Practical disease control will be accomplished by maximizing the activity of natural biocontrol agents.