Mapping of genes for leaf and stem rust resistance in bread wheat genotype Selection 212

Resistance genes for leaf and stem rusts in bread wheat line Selection212 are recessive in nature. Both leaf and stem rust resistance genes, named tentatively as LrSel212 and SrSel212, have been mapped to the short arm of chromosome 2B separated by genetic distance of 16.4 cM. Xwmc474 was the closest marker located between two genes, 5.6 cM proximal to LrSel212 and 10.8 cM distal to SrSel212. Leaf rust pathotype 77-5 is virulent to leaf rust resistance genes located on chromosome 2B viz., Lr13, Lr16, Lr23, Lr35 and Lr73, but avirulent to Selection212, suggesting that LrSel212 is distinct from these genes. Six stem rust resistance genes have been assigned to chromosome 2B viz., Sr19, Sr20, Sr23, Sr36, Sr39 and Sr40. Stem rust pathotype 40A used in genetic analysis was virulent to Sr19 and Sr20, but avirulent to Selection212; and the latter showed a significantly lower infection type in comparison to Sr39. Sr23 and Sr36 showed susceptibility to few other stem rust pathotypes to which Selection212 was resistant. While the response of Sr40 to Indian pathotypes of Pgt is not known, differences in the genetic distance and nature of inheritance between Selection212 and Sr40 indicate their distinct identity. However, test of allelism with Sr40 is required to confirm whether SrSel212 represents a different locus. Selection212 may be useful in broadening the genetic base of rust resistance in wheat.

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Identification of Winter Habit Bread Wheat Landraces in the National Small Grains Collection with Resistance to Emerging Stem Rust Pathogen Variants

Plant Disease ◽

10.1094/pdis-04-21-0743-re ◽

2021 ◽

Author(s):

Tyler Gordon ◽

Yue Jin ◽

Samuel Gale ◽

Matthew Rouse ◽

Samuel Stoxen ◽

...

Keyword(s):

Bread Wheat ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Stem Rust Resistance ◽

Field Nursery ◽

Small Grains ◽

Stem Rust Resistance Genes ◽

Landrace Accessions ◽

Rust Resistance Genes

Wheat stem rust caused by Puccinia graminis f. sp. tritici (Pgt) is a widespread and recurring threat to wheat production. Emerging Pgt variants are rapidly overcoming major gene resistance deployed in wheat cultivars and new sources of race-nonspecific resistance are urgently needed. The National Small Grains Collection (NSGC) contains thousands of wheat landrace accessions that may harbor unique and broadly effective sources of resistance to emerging Pgt variants. All NSGC available facultative and winter-habit bread wheat landraces were tested in a field nursery in St. Paul, MN against a bulk collection of six common U.S. Pgt races. Infection response and severity data were collected on 9,192 landrace accessions at the soft-dough stage and resistant accessions were derived from single spikes. Derived accessions were tested in St. Paul a second time to confirm resistance and in a field nursery in Njoro, Kenya against emerging races of Pgt with virulence to many known resistance genes including Sr24, Sr31, Sr38, and SrTmp. Accessions resistant in the St. Paul field were also tested at the seedling stage with up to 13 Pgt races, including TTKSK and TKTTF, and with 19 molecular markers linked with known stem rust resistance genes or genes associated with modern breeding practices. Forty-five accessions were resistant in both U.S. and Kenya field nurseries and lacked alleles linked with known stem rust resistance genes. Accessions with either moderate or strong resistance in the U.S. and Kenya field nurseries and with novel seedling resistance will be prioritized for further study.

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Use of Molecular Markers to Identify Certain Stem Rust Resistance Genes in Thirteen Bread Wheat Cultivars Registered in Egypt

Egyptian Journal of Phytopathology ◽

10.21608/ejp.2014.96766 ◽

2014 ◽

Vol 42 (1) ◽

pp. 193-203

Author(s):

Mostafa El-Shamy ◽

Ayman Omar

Keyword(s):

Molecular Markers ◽

Bread Wheat ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Stem Rust Resistance ◽

Wheat Cultivars ◽

Stem Rust Resistance Genes ◽

Rust Resistance Genes

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Genetics of Stem Rust Resistance in Wheat Cvs. Pasqua and AC Taber

Phytopathology ◽

10.1094/phyto.1998.88.2.171 ◽

1998 ◽

Vol 88 (2) ◽

pp. 171-176 ◽

Cited By ~ 20

Author(s):

J. Q. Liu ◽

J. A. Kolmer

Keyword(s):

Leaf Rust ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Field Resistance ◽

Stem Rust Resistance ◽

Adult Plant ◽

Leaf Rust Resistance Gene ◽

Stem Rust Resistance Genes ◽

Rust Resistance Genes

Canadian wheat cvs. Pasqua and AC Taber were examined genetically to determine the number and identity of stem rust resistance genes in both. The two cultivars were crossed with stem rust susceptible line RL6071, and sets of random F6 lines were developed from each cross. The F6 lines, parents, and tester lines with single stem rust resistance genes were grown in a field rust nursery, inoculated with a mixture of stem and leaf rust races, and evaluated for rust resistance. The same wheat lines were tested by inoculation with specific stem rust races in seedling tests to postulate which Sr genes were segregating in the F6 lines. Segregation of F6 lines indicated that Pasqua had three genes that conditioned field resistance to stem rust and had seedling genes Sr5, Sr6, Sr7a, Sr9b, and Sr12. Leaf rust resistance gene Lr34, which is in Pasqua, was associated with adult-plant stem rust resistance in the segregating F6 lines. Adult-plant gene Sr2 was postulated to condition field resistance in AC Taber, and seedling genes Sr9b, Sr11, and Sr12 also were postulated to be in AC Taber.

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Mapping of Novel Leaf Rust and Stem Rust Resistance Genes in the Portuguese Durum Wheat Landrace PI 192051

G3 Genes|Genome|Genetics ◽

10.1534/g3.119.400292 ◽

2019 ◽

Vol 9 (8) ◽

pp. 2535-2547 ◽

Cited By ~ 3

Author(s):

Meriem Aoun ◽

James A. Kolmer ◽

Matthew N. Rouse ◽

Elias M. Elias ◽

Matthew Breiland ◽

...

Keyword(s):

Durum Wheat ◽

Leaf Rust ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Stem Rust Resistance ◽

Wheat Landrace ◽

Stem Rust Resistance Genes ◽

Rust Resistance Genes

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Identification of the stem rust resistance genes in the introgression lines of spring bread wheat using molecular markers

10.18699/plantgen2019-019 ◽

2019 ◽

Keyword(s):

Molecular Markers ◽

Bread Wheat ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Stem Rust Resistance ◽

Introgression Lines ◽

Spring Bread Wheat ◽

Stem Rust Resistance Genes ◽

Rust Resistance Genes

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Seedling Stage Resistance of Iranian Bread Wheat Germplasm to Race Ug99 of Puccinia graminis f. sp. tritici

Plant Disease ◽

10.1094/pdis-02-12-0138-re ◽

2013 ◽

Vol 97 (3) ◽

pp. 387-392 ◽

Cited By ~ 2

Author(s):

Mohsen Mohammadi ◽

Davoud Torkamaneh ◽

Mehran Patpour

Keyword(s):

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Stem Rust Resistance ◽

Puccinia Graminis ◽

Wheat Cultivars ◽

Breeding Lines ◽

Wheat Germplasm ◽

Stem Rust Resistance Genes ◽

Rust Resistance Genes

Following emergence of Ug99, the new virulent race of Puccinia graminis f. sp. tritici in Africa, a global effort for identification and utilization of new sources of Ug99-resistant germplasm has been undertaken. In this study, we conducted replicated experiments to evaluate the resistance of Iranian wheat germplasm to the TTKSK lineage of the Ug99 race of P. graminis f. sp. tritici. We also evaluated for presence of stem rust resistance genes (i.e., Sr2, Sr24, Sr26, Sr38, Sr39, Sr31, and Sr1RSAmigo) in wheat cultivars and breeding lines widely cultivated in Iran. Our phenotyping data revealed high levels of susceptibility to Ug99 in Iranian bread wheat germplasm. Our genotyping data revealed that Iranian cultivars do not carry Sr24, Sr26, or Sr1RSAmigo. Only a few salt-tolerant cultivars and breeding lines tested positively for Sr2, Sr31, Sr38, or Sr39 markers. In conclusion, the genetic basis for resistance to Ug99 in Iranian wheat cultivars was found to be vulnerable. Acquiring knowledge about existing resistance genes and haplotypes in wheat cultivars and breeding lines will help breeders, cereal pathologists, and policy makers to select and pyramid effective stem rust resistance genes.

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Stem Rust Resistance in A-Genome Diploid Relatives of Wheat

Plant Disease ◽

10.1094/pdis-04-10-0260 ◽

2011 ◽

Vol 95 (8) ◽

pp. 941-944 ◽

Cited By ~ 39

Author(s):

M. N. Rouse ◽

Y. Jin

Keyword(s):

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Infection Type ◽

Genetic Resistance ◽

Wheat Breeding ◽

Stem Rust Resistance ◽

Wheat Stem Rust ◽

A Genome ◽

Stem Rust Resistance Genes

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, has been effectively controlled through the use of genetic resistance. P. graminis f. sp. tritici race TTKSK (Ug99) possesses virulence to many resistance genes that have been used in wheat breeding worldwide. One strategy to aid breeders in developing resistant cultivars is to utilize resistance genes transferred from wild relatives to wheat. Stem rust resistance genes have previously been introgressed from Triticum monococcum to wheat. In order to identify additional resistance genes, we screened 1,061 accessions of T. monococcum and 205 accessions of T. urartu against race TTKSK and four additional P. graminis f. sp. tritici races: TTTTF, TRTTF, QFCSC, and MCCFC. A high frequency of the accessions (78.7% of T. monococcum and 93.0% of T. urartu) were resistant to P. graminis f. sp. tritici race TTKSK, with infection types ranging from 0 to 2+. Among these resistant accessions, 55 T. monococcum accessions (6.4% of the total) were also resistant to the other four races. Associations of resistance in T. monococcum germplasm to different races indicated the presence of genes conferring resistance to multiple races. Comparing the observed infection type patterns to the expected patterns of known genes indicated that previously uncharacterized genes for resistance to race TTKSK exist in both T. monococcum and T. urartu.

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