Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/9/2006
Publication Date: 7/6/2006
Citation: Steffenson, B.J., Jin, Y. Resistance to race ttks of Puccinia graminis f. sp. tritici in barley. Phytopathology. 96:5110. Interpretive Summary:
Technical Abstract: In 1999, a new race of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici) was detected in eastern Africa. This race, designated TTKS (or Ug99), has raised great concern among plant scientists because it is highly virulent on many wheat cultivars grown across the world and is therefore considered a threat to global food security. Preliminary tests also indicate that race TTKS is virulent on Midwestern barley cultivars carrying the durable resistance gene Rpg1. Given the ease by which rust spores can be disseminated over long distances, race TTKS will likely spread out from eastern Africa into other major cereal production regions of the world. To address the threat posed by this race to barley production in the Midwest, we initiated a project to identify resistance in the primary genepool of barley. Barley accessions previously reported to carry stem rust resistance were evaluated to race TTKS as seedlings in replicated greenhouse tests. Resistant germplasm was identified and included cultivated barley lines carrying the resistance gene complex Rpg5/rpg4, landraces from Switzerland, and several wild barley accessions from Israel and Tajikistan. Research is underway to study the inheritance of resistance to race TTKS in barley and to introgress the resistance into adapted germplasm lines that can be used by breeders.