Submitted to: Phytopathology
Publication Type: Other
Publication Acceptance Date: May 1, 1999
Publication Date: N/A
Technical Abstract: Winter wheat cultivars that are highly resistant to dwarf bunt, caused by Tilletia controversa, have been developed for areas of the western United States. Most of the cultivars derive their resistance from PI 178383, which is known to have the bunt resistance genes Bt-8, Bt-9, and Bt-10. It has been assumed cultivars originating from crosses with PI 178383 likely have all three of these genes because the cultivars were resistant when tested against races that are virulent to Bt-9 and Bt-10, but are avirulent to Bt-8. Resistance to dwarf bunt and common bunt is controlled by the same resistance and virulence genes which follow the classical gene-for-gene system. Field tests repeated 2-3 years with hybrid test races of common bunt demonstrated that the cultivars Hansel, Manning, Promontory, and Weston are susceptible to races that lack virulence to Bt-8, whereas Luke, Lewjain, and Winridge are resistant to these races. All of these cultivars are highly resistant to pathogenic races of dwarf bunt in the United States. These results demonstrate that resistance to dwarf bunt among United States cultivars that derive dwarf bunt resistance from PI 178383 is more broadly based than previously thought.