Project Number: 5442-22000-043-00
Project Type: Appropriated

Start Date: Mar 21, 2007
End Date: Mar 20, 2012

Objective:
The overall goal is to characterize host-pathogen interactions and pathogen biology in both fungal and viral pathogen systems in order to facilitate a better understanding of the fundamental processes resulting in resistance, or susceptibility and disease development. More specifically, objectives are: to identify and characterize pathogenicity/virulence determinants and host genes important in net blotch of barley; to identify and characterize host selective toxins and their corresponding host sensitivity genes important in Stagonospora nodorum blotch of wheat; and to identify and characterize pathogenicity/virulence factors important in viral diseases of barley.

Approach:
Identification and characterization of pathogenicity/virulence determinants and host genes important in net blotch of barley will involve monitoring the Pyrenophora teres pathogen population through systematic field collections followed by evaluation of individual isolates on a set of differential hosts, identification of avirulence genes in Pyrenophora teres mapping populations, identification and mapping of resistance genes that are effective against specific avirulence genes, and identification of molecular markers useful for introgression of these resistance genes into germplasm. Identification and characterization of host selective toxins and their corresponding host sensitivity genes important in Stagonospora nodorum blotch of wheat will involve identification, purification, and characterization of host-selective toxins produced by S. nodorum field isolates, identification of toxin sensitivity genes that correlate with host-selective toxins produced by S. nodorum through evaluation of host mapping populations, and evaluation of the role of each toxin in disease. Identification and characterization of pathogenicity/virulence factors important in viral diseases of barley will involve identification of viral genome sequences and intragenomic interactions affecting pathogenicity and virulence of barley stripe mosaic virus and oat blue dwarf virus, and production of infectious clones and their use in a reverse genetics approach to analyze viral phenotypes and further elucidate genome structure / function relationships. BL-1; 3/4/04