|Esvelt Klos, Kathy|
|HAYES, PATRICK - Oregon State University|
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2016
Publication Date: 5/23/2016
Citation: Esvelt Klos, K.L., Gordon, T.C., Bregitzer, P.P., Hayes, P., Chen, X., Bonman, J.M. 2016. Barley stripe rust resistance QTL: Development and validation of SNP markers for resistance to Puccinia striiformis f. sp. hordei. Phytopathology. doi: 10.1094/PHYTO-09-15-0225-R.
Interpretive Summary: Barley stripe rust is a disease with the potential to reduce both yield and quality in cool wet growing conditions. Breeding plants with genetic resistance is the best approach to protecting barley against stripe rust. We identified the chromosomal regions carrying resistance in the Ethiopian cultivar Grannelose Zweizeilige by crossing it with the susceptible, but regionally adapted cultivar Lenetah. In order for resistance to be inherited, at least two of the four genes had to be passed on to progeny plants. Molecular markers that identified the resistance genes were validated in a second cross, proving that they could be used in marker assisted selection to transfer resistance genes into varieties destined for release to growers. Using markers to select for disease resistance frees resources for use on other traits, such as end use quality and grain yield.
Technical Abstract: Quantitative trait loci (QTL) linked with seedling and field resistance to barley stripe rust were mapped in 156 recombinant inbred lines (RILs) derived from a Lenetah by Grannelose Zweizeilige (GZ) cross. A major QTL for seedling resistance on chromosome 4H (LOD = 15.94 at 97.19 cM) was identified, validating previous results. Additional QTL were identified on chromosome 4H and 6H (LOD = 5.39 at 72.7 cM and 4.24 at 34.46 cM, respectively), and suggested on chromosome 7H (LOD=2.04 at 81.07 cM). All resistance alleles were derived from GZ. Evaluations of adult plant response in Corvallis, OR in 2013 and 2015 provided evidence of linkage at the same positions. However, the minor QTL on 4H was not statistically significant in either location/year, while the 7H QTL was significant in both. Markers flanking these QTL were evaluated in RILs derived from a 95SR316A by GZ cross for their ability to predict seedling resistance. 95SR316A by GZ RILs with GZ alleles at the major 4H QTL and at least one other were 91-92% R to MR. Markers for at least 2 QTL must be tracked to transfer the barley stripe rust resistance from GZ to an elite germplasm background through MAS.