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United States Department of Agriculture

Agricultural Research Service

Research Project: GENETICS, POPULATION BIOLOGY, AND HOST-PARASITE INTERACTIONS OF CEREAL RUST FUNGI AND THEIR DISEASES

Location: Cereal Disease Laboratory

Title: Stem rust resistance in Aegilops tauschii germplasm

Authors
item ROUSE, MATTHEW
item Olson, Eric -
item Gill, Bikram -
item Pumphrey, Michael -
item JIN, YUE

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 4, 2011
Publication Date: July 6, 2011
Citation: Rouse, M.N., Olson, E.L., Gill, B.S., Pumphrey, M.O., Jin, Y. 2011. Stem rust resistance in Aegilops tauschii germplasm. Crop Science. 51:2074-2078.

Interpretive Summary: Wild wheat relatives have been a valuable source of disease resistance genes for wheat. The wild wheat relative, Aegilops tauschii, has been used for the transfer of three wheat stem rust resistance genes. A new race of Puccinia graminis f. sp. tritici, the causal fungus of wheat stem rust, designated race TTKSK or Ug99 threatens wheat globally because of it’s unique virulence combination. In order to identify potentially new stem rust resistance genes in Ae. tauschii germplasm, we evaluated 456 non-duplicated accessions deposited in the USDA National Small Grains Collection (Aberdeen, ID) and the Wheat Genetic and Genomic Resources Center collection (Kansas State University, Manhattan, KS), with six races of Puccinia graminis including TTKSK (Ug99). Ninety-eight accessions (22%) were identified as resistant to race TTKSK. A broad range of resistant reactions were found to race TTKSK. Accessions resistant to one race were often resistant to other races as well. However, only 12 of the accessions resistant to race TTKSK were also resistant to the other five races. Results from this germplasm screening will facilitate further studies on the genetic characterization of accessions with potentially new sources of resistance to race TTKSK.

Technical Abstract: Aegilops tauschii Cosson, the D genome donor of hexaploid wheat, Triticum aestivum L., has been used extensively for the transfer of agronomically important traits to wheat, including stem rust resistance genes Sr33, Sr45, and Sr46. In order to identify potentially new stem rust resistance genes in Ae. tauschii germplasm, we evaluated 456 non-duplicated accessions deposited in the USDA National Small Grains Collection (Aberdeen, ID) and the Wheat Genetic and Genomic Resources Center collection (Kansas State University, Manhattan, KS), with races TTKSK (Ug99), TRTTF, TTTTF, TPMKC, RKQQC, and QTHJC of Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn. Ninety-eight accessions (22%) were identified as resistant to race TTKSK. A broad range of resistant infection types (; to 2+) were found in reaction to race TTKSK. Resistance was significantly associated among most of the races in pair-wise comparisons. However, resistance was largely race-specific. Only 12 of the accessions resistant to race TTKSK were also resistant to the other five races. Results from this germplasm screening will facilitate further studies on the genetic characterization of accessions with potentially novel sources of resistance to race TTKSK.

Last Modified: 9/29/2014
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