scholarly journals A prebreeding study of introgression spring bread wheat lines carrying combinations of stem rust resistance genes, Sr22+Sr25 and Sr35+Sr25

2021 ◽  
Vol 25 (7) ◽  
pp. 713-722
Author(s):  
S. N. Sibikeev ◽  
O. A. Baranova ◽  
A. E. Druzhin
Keyword(s):  
Bread Wheat ◽  
Agronomic Traits ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Spring Bread Wheat ◽  
Laboratory Conditions ◽  
One Year ◽  
Stem Rust Resistance Genes ◽  
Wheat Lines ◽  
Rust Resistance Genes

The Sr22, Sr35, and Sr25 genes attract the attention of bread wheat breeders with their effectiveness against Puccinia graminis f. sp. tritici race Ug99 and its biotypes. The effectiveness and impact of Sr22+Sr25 and Sr35+Sr25 gene combinations on agronomic traits have not yet been studied. In the present article, these traits were studied using the spring bread wheat lines L503/W3534//L503, L503/Sr35//L503/3/L503 carrying the Sr22+Sr25 and Sr35+Sr25 genes during 2016–2020. These lines were assessed for resistance to P. graminis f. sp. tritici under natural epiphytotics and to the Saratov, Lysogorsk and Omsk populations of the pathogen and to the PgtZ1 (TKSTF) and PgtF18.6 fungus isolates in laboratory conditions (TKSTF + Sr33). The presence of the studied Sr-genes was confirmed by using molecular markers. Prebreeding studies were conducted during 2018–2020 vegetation periods. Under the natural epiphytotics of the pathogen and in the laboratory conditions, the Sr22+Sr25 combination was highly effective, while Sr35+Sr25 was ineffective. For grain yield, the lines with the Sr22+Sr25 and Sr35+Sr25 genes were superior to the recipient cultivar L503 in one year (Sr22+Sr25 in 2019; Sr35+Sr25 in 2018), with a decrease in 2020, but in general there were no differences. For the period 2018–2020, both combinations showed a decrease in 1000 grains weight and an increase in the germination-earing period. The line with Sr22+Sr25 genes showed insignificant effects on gluten and dough tenacity, but the ratio of dough tenacity to extensibility was higher, and flour strength, porosity and bread volume were lower; in the line with Sr35+Sr25 genes, the gluten content was lower, but the strength, tenacity of the dough and the ratio of dough tenacity to extensibility were higher, flour strength and the porosity of the bread were at the recipient level, but the volume of bread was lower.

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

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 387-392 ◽  
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.

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

Plant Disease ◽  
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.

scholarly journals Evaluation and identification of stem rust resistance genesSr2,Sr24,Sr25,Sr26,Sr31andSr38in wheat lines from Gansu Province in China

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4146 ◽  
Author(s):  
Xiao Feng Xu ◽  
Dan Dan Li ◽  
Yang Liu ◽  
Yue Gao ◽  
Zi Yuan Wang ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Stem Rust Resistance ◽  
Gansu Province ◽  
Wheat Cultivars ◽  
Wheat Stem Rust ◽  
Stem Rust Resistance Genes ◽  
Wheat Lines ◽  
Rust Resistance Genes

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.

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

2019 ◽  
Vol 79 (01) ◽  
Author(s):  
Omkar M. Limbalkar ◽  
J. B. Sharma ◽  
S. K. Jha ◽  
N. Mallick ◽  
M. Niranjana ◽  
...  
Keyword(s):  
Genetic Distance ◽  
Leaf Rust ◽  
Bread Wheat ◽  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Infection Type ◽  
Stem Rust Resistance ◽  
Stem Rust Resistance Genes ◽  
Rust Resistance Genes

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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