Project Number: 5442-22000-037-00
Project Type: Appropriated

Start Date: Mar 26, 2004
End Date: Apr 30, 2008

Objective:
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 in barley and wheat. Specifically: to identify and evaluate the importance of virulence factors in net blotch of barley and Stagonospora nodorum blotch of wheat; to identify and evaluate resistance genes effective against net blotch of barley, and Stagonospora blotch and tan spot of wheat; to determine genetic variability within field populations of the tan spot pathogen, P. tritici-repentis; and to identify and characterize pathogenicity/virulence factors and host genes important in viral diseases of barley.

Approach:
We will identify and characterize pathogenicity/virulence factors of Pyrenophora teres (net blotch of barley), Stagonospora nodorum (S. nodorum blotch of wheat), Barley stripe mosaic hordeivirus and Oat blue dwarf marafivirus, and evaluate their importance in disease production. Phytotoxic compounds produced in S. nodorum culture filtrates will be identified and characterized through toxin purification and correlation of disease susceptibility with toxin sensitivity in segregating host populations. A molecular map of P. teres will be developed that is useful in identification and evaluation of virulence factors using AFLP analysis of segregating fungal populations. Genetic variability of P. tritici-repentis will be determined through characterization of field populations on differential hosts and phylogenetic analysis. Factors influencing viral pathogenicity and virulence will be identified and characterized through production of infectious cDNA clones and use of a reverse genetics approach for analysis of viral phenotypes. Identification and characterization of host resistance will involve identification and evaluation of resistance genes effective against net blotch, S. nodorum blotch, and tan spot (P. tritici-repentis) through analysis of segregating host populations in combination with molecular mapping techniques, and development of a higher resolution map in the vicinity of a known BSMV resistance gene to provide the potential framework for eventual map-based cloning of the gene. BL-1; 3/4/04

Project Team

Edwards, Michael Friesen, Timothy

Related National Programs

Plant Diseases (303)

Related Projects

The Genetics of Pathogen-Barley Interactions