|Xiao, Xiangye - Purdue University|
|Ohm, Herbert - Purdue University|
|Hunt, Greg - Purdue University|
|Poland, Jesse - Purdue University|
|Kong, Lingrang - Purdue University|
Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2016
Publication Date: 4/13/2016
Citation: Xiao, X., Ohm, H., Hunt, G.J., Poland, J.A., Kong, L., Nemacheck, J.A., Williams, C.E. 2016. Genotyping-by-sequencing to re-map QTL for type II Fusarium head blight and leaf rust resistance in a wheat-tall wheatgrass introgression recombinant inbred population. Molecular Breeding. 36:51. doi: 10.1007/s11032-016-0472-0.
Interpretive Summary: Wheat genes for resistance to Fusarium Head Blight and Leaf Rust were previously identified, but they were mapped incorrectly by another research group. We used a high-throughput method to generate molecular markers for the resistance genes, constructed an accurate map, and converted some markers into a format that is easily used by breeders. We also identified wheat lines that contained both resistance genes for use in cultivar development. This work makes these important genes available for breeders to use with marker-assisted breeding when constructing new wheat cultivars.
Technical Abstract: Fusarium graminaerum (Fusarium head blight; FHB) and Puccinia recondita Roberge ex Desmaz. f. sp. tritici Eriks. & E. Henn (leaf rust; LR) are two major fungal pathogens threatening the wheat crop; consequently identifying resistance genes from various sources is always of importance to wheat breeders. We identified tightly linked single nucleotide polymorphism (SNP) markers for the FHB-resistance QTL Qfhs.pur-7EL and the LR-resistance gene Lr19 using genotyping-by-sequencing (GBS) in a wheat-tall wheatgrass introgression-derived recombinant inbred line (RIL) population. 1700 high-confidence SNPs were used to conduct the linkage and QTL analysis. Qfhs.pur-7EL was mapped to a 2.9 cM region containing four markers within a 43.6 cM segment of wheatgrass chromosome 7el2 that was translocated onto wheat chromosome 7DL. Lr19 from 7el1 was mapped to a 1.21 cM region containing two markers in the same area, in repulsion. Five lines were identified with the resistance-associated SNP alleles for Qfhs.pur-7EL and Lr19 in coupling. Two SNP markers in the Qfhs.pur-7EL region were converted into PCR-based KASP markers. Investigation of the genetic characteristics of the parental lines of this RIL population indicated that they are translocation lines in two different wheat cultivar genetic backgrounds instead of 7E-7D substitution lines in Thatcher wheat background, as previously reported in the literature.