Expression of a Thatcher Wheat Adult Plant Stem Rust Resistance QTL on Chromosome Arm 2BL is Enhanced by Lr34

Stem rust caused by Puccinia graminis f. sp. tritici (Pgt) remains a constraint to wheat production in East Africa. In this study, we characterized the genetics of stem rust resistance, identified QTLs, and described markers associated with stem rust resistance in the spring wheat line CI 14275. The 113 recombinant inbred lines, together with their parents, were evaluated at the seedling stage against Pgt races TTKSK, TRTTF, TPMKC, TTTTF, and RTQQC. Screening for resistance to Pgt races in the field was undertaken in Kenya, Ethiopia, and the United States in 2016, 2017, and 2018. One gene conferred seedling resistance to race TTTTF, likely Sr7a. Three QTL were identified that conferred field resistance. QTL QSr.cdl-2BS.2, that conferred resistance in Kenya and Ethiopia, was validated, and the marker Excalibur_c7963_1722 was shown to have potential to select for this QTL in marker-assisted selection. The QTL QSr.cdl-3B.2 is likely Sr12, and QSr.cdl-6A appears to be a new QTL. This is the first study to both detect and validate an adult plant stem rust resistance QTL on chromosome arm 2BS. The combination of field QTL QSr.cdl-2BS.2, QSr.cdl-3B.2, and QSr.cdl-6A has the potential to be used in wheat breeding to improve stem rust resistance of wheat varieties.

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Molecular mapping of an adult plant stem rust resistance gene Sr56 in winter wheat cultivar Arina

Theoretical and Applied Genetics ◽

10.1007/s00122-014-2311-1 ◽

2014 ◽

Vol 127 (6) ◽

pp. 1441-1448 ◽

Cited By ~ 41

Author(s):

Urmil Bansal ◽

Harbans Bariana ◽

Debbie Wong ◽

Mandeep Randhawa ◽

Thomas Wicker ◽

...

Keyword(s):

Winter Wheat ◽

Stem Rust ◽

Rust Resistance ◽

Molecular Mapping ◽

Wheat Cultivar ◽

Stem Rust Resistance ◽

Adult Plant ◽

Stem Rust Resistance Gene ◽

Winter Wheat Cultivar ◽

Plant Stem

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Adult Plant Stem Rust Resistance in Durum Wheat Glossy Huguenot – Mapping, Marker Development and Validation

10.21203/rs.3.rs-1133072/v1 ◽

2021 ◽

Author(s):

Rohit Mago ◽

Chunhong Chen ◽

Xiaodi Xia ◽

Alex Whan ◽

Kerrie Forrest ◽

...

Keyword(s):

Stem Rust ◽

Rust Resistance ◽

Molecular Mapping ◽

Descent Method ◽

Snp Markers ◽

Stem Rust Resistance ◽

Adult Plant ◽

Specific Pcr ◽

Plant Stem ◽

Stem Rust Resistance Genes

Abstract An F3 population from a Glossy Huguenot (GH)/Bansi cross used in a previous Australian study was advanced to F6 for molecular mapping of adult plant stem rust resistance. Maturity differences among F6 lines confounded assessments of stem rust response. GH was crossed with a stem rust susceptible F6 recombinant inbred line (RIL), GHB14 (M14), with similar maturity and an F6:7 population was developed through single seed descent method. F7 and F8 RILs were tested along with the parents at different locations. The F6 individual plants and both parents were genotyped using the 90K single nucleotide polymorphism (SNP) wheat array. Stem rust resistance QTL on the long arms of chromosomes 1B (QSrGH.cs-1BL) and 2A (QSrGH.cs-2AL) were detected. QSrGH.cs-1BL and QSrGH.cs-2AL were both contributed by GH and explained 22% and 18% adult plant stem rust response variation, respectively, among GH/M14 RIL population. RILs carrying combinations of these QTL reduced more than 14% stem rust severity compared to those that possessed QSrGH.cs-1BL and QSrGH.cs-2AL individually. QSrGH.cs1BL was demonstrated to be the same as Sr58/Lr46/Yr29/Pm39 through marker genotyping. Lines lacking QSrGH.cs-1BL were used to Mendelise QSrGH.cs-2AL. Based on genomic locations of previously catalogued stem rust resistance genes and the QSrGH.cs-2AL map, it appeared to represent a new APR locus and was permanently named Sr63. SNP markers associated with Sr63 were converted to kompetetive allele specific PCR (KASP) assays and were validated on a set of durum cultivars.

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