Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/10/1998
Publication Date: N/A
Technical Abstract: Host resistance to dwarf bunt (DB), caused by the fungus Tilletia controversa, is an integral part of disease management in the U.S. and has been actively utilized in cultivar development in the northwestern U.S. for over 50 years. This review explains the role of host resistance in DB control in the U.S., what the resistance consists of, and how it is evaluated. Until the recent advent of effective seed treatment fungicides, successful DB control relied on resistance which is still the primary means of disease control in several areas. Use of the resistance gene Bt-8 and others during the last 25 years has eliminated yield and quality losses in areas that historically had the worst disease incidence in the U.S. Currently, we appear to be at least one step ahead of DB in the U.S. with regard to resistance. Numerous high yielding and commercially acceptable cultivars with Bt-8 resistance are available to control the pathogenic races of T. controversa that currently exist in the U.S. Also, cultivars and germplasm lines are available and in the process of being developed that have near immunity to DB from Bt-11, Bt-12, and other sources. Like Bt-8, there are no U.S. isolates that are virulent to Bt-11 or Bt-12. In addition, efforts are underway to pyramid some of these genes to provide cultivars and germplasm with theoretically even more stable resistance.