Peer Review #1 of "Evaluation and identification of stem rust resistance genes Sr2, Sr24, Sr25, Sr26, Sr31 and Sr38 in wheat lines from Gansu Province in China (v0.1)"

Wheat stem rust, caused byPuccinia granimisf. sp.tritici, severely affects wheat production, but it has been effectively controlled in China since the 1970s. However, the appearance and spread of wheat stem rust races Ug99 (TTKSK, virulence toSr31), TKTTF (virulence toSrTmp) and TTTTF (virulence to the cultivars carryingSr9eandSr13) have received attention. It is important to clarify the effectiveness of resistance genes in a timely manner, especially for the purpose of using new resistance genes in wheat cultivars for durable-resistance. However, little is known about the stem rust resistance genes present in widely used wheat cultivars from Gansu. This study aimed to determine the resistance level at the seedling stage of the main wheat cultivars in Gansu Province. A secondary objective was to assess the prevalence ofSr2,Sr24,Sr25,Sr26,Sr31, andSr38using molecular markers. The results of the present study indicated that 38 (50.7%) wheat varieties displayed resistance to all the tested races ofPuccinia graminisf. sp.tritici.The molecular marker analysis showed that 13 out of 75 major wheat cultivars likely carriedSr2; 25 wheat cultivars likely carriedSr31; and nine wheat cultivars likely carriedSr38. No cultivar was found to haveSr25andSr26, as expected. Surprisingly, no wheat cultivars carriedSr24. The wheat lines with known stem rust resistance genes could be used as donor parent for further breeding programs.

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Peer Review #1 of "Identification of stem rust resistance genes in wheat cultivars in China using molecular markers (v0.1)"

10.7287/peerj.4882v0.1/reviews/1 ◽

2018 ◽

Keyword(s):

Molecular Markers ◽

Peer Review ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Stem Rust Resistance ◽

Wheat Cultivars ◽

Stem Rust Resistance Genes ◽

Rust Resistance Genes

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Peer Review #2 of "Identification of stem rust resistance genes in wheat cultivars in China using molecular markers (v0.1)"

10.7287/peerj.4882v0.1/reviews/2 ◽

2018 ◽

Author(s):

M Rouse

Keyword(s):

Molecular Markers ◽

Peer Review ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Stem Rust Resistance ◽

Wheat Cultivars ◽

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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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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