|TURNER, KATHRYN - The Land Institute|
|Rouse, Matthew - Matt|
|ANDERSON, JAMES - University Of Minnesota|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2016
Publication Date: 4/15/2016
Citation: Turner, K., Jin, Y., Rouse, M.N., Anderson, J. 2016. Stem rust resistance in 'Jagger' winter wheat. Crop Science. 56:1-7. doi: 10.2135/cropsci2015.11.0683.
Interpretive Summary: Jagger is a hard red winter wheat and has been utilized widely as a parent to develop winter wheat varieties throughout the U.S. southern Great Plains. Jagger has resistance to TTTTF, the most virulent stem rust race detected in North America. The genetic basis of this resistance remains unknown. Rust infection assays and DNA marker analyses in progenies of several Jagger crosses and genetic stocks concluded that the stem rust resistance in Jagger was conferred by a combination of resistance genes Sr7a and Sr38. The genetic information obtained and DNA markers identified through this study will be useful in understanding the genetic basis of stem rust resistance in current wheat varieties in the United States and in facilitating breeding programs to develop stem rust resistant varieties.
Technical Abstract: "Jagger" has been utilized widely as a parent to develop hard red winter wheat varieties throughout the U.S. southern Great Plains. Jagger has resistance to stem rust pathogen race TTTTF, which is virulent to many winter wheat cultivars, yet the genetic basis of this resistance remains unknown. Marker analysis and resistance to leaf rust and stripe rust demonstrated that Jagger has the 2NS/2AS translocation from Triticum ventricosum. This segment contains resistance genes Sr38, Lr37 and Yr17. Jagger's stem rust infection types, however, indicate that another stem rust resistance gene is present besides Sr38. Jagger is resistant to TTTTF whereas the Sr38 stem rust differential line, "VPM1", is susceptible. A BC1F3 population developed from the cross Jagger/2*LMPG was tested with race TTTTF. Resistant and susceptible DNA bulks were genotyped with a custom 9,000 SNP Illumina iSelect Bead Chip using bulked segregant analysis. We identified a locus linked with the resistance gene on chromosome arm 4AL, where Sr7 is located. Crosses between Jagger BC1F3's resistant to TTTTF and germplasm with Sr7a identified no recombinants, indicating that the resistance to TTTTF in Jagger could be conferred by Sr7a. We confirmed the effectiveness of Sr7a resistance to race TKTTF, which caused the stem rust epidemic in Ethiopia from 2013 to 2014. Identified molecular markers may be used to screen for the resistance gene Sr7a and track its presence in breeding programs.