ARS | Publication request: Stem Rust Resistance in Triticum monococcum Germplasm of the Ug99 Lineage

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: April 20, 2008
Publication Date: July 15, 2008
Citation: Rouse, M., Jin, Y. 2008. Stem rust resistance in Triticum monococcum germplasm of the Ug99 lineage. American Phytopathological Society. 98:S136-137.

Technical Abstract: Wheat stem rust, caused by Puccinia graminis f. sp. tritici, has been effectively controlled through the use of genetic resistance. The recently identified race TTKSK (Ug99) possesses virulence to many resistance genes that have been used in wheat breeding worldwide. One strategy to aid breeders in developing resistant varieties is to provide resistance genes transferred from wild relatives to wheat. Stem rust resistance genes Sr22 and Sr35, derived from Triticum monococcum are effective against race TTKSK. In order to identify additional genes from this wild relative of wheat, we screened 1061 accessions deposited in the National Small Grains Collection against TTKSK and two additional races with broad virulence. We identified 614 accessions (57.9%) with resistance to TTKSK with infection types ranging from 0 to 2+. Among these resistant accessions, 91 accessions (8.58% of the total) were also resistant to TTTT and TRTT. Results from the preliminary screening suggested that novel resistance genes to race TTKSK are likely to be present in T. monococcum. These resistant accessions are being characterized further by testing with additional stem rust races. Crosses among selected resistant T. monococcum accessions have been initiated to determine the number and allelic relationships of stem rust resistance genes.