scholarly journals Evaluation of Bread Wheat Varieties to Dominant Races of Stem Rust (<i>Puccinia graminis f. sp. Tritici</i>) Pathogen

2015 ◽  
Vol 3 (6) ◽  
pp. 121
Author(s):  
Alemayehu Hailu Welderufael
1976 ◽  
Vol 54 (19) ◽  
pp. 2204-2214 ◽  
Author(s):  
Mishael Oichoe Osoro ◽  
G. J. Green

Experiments were designed to show whether or not virulence genes reduce fitness and bring about stabilizing selection. The competitive abilities of seven related races of Puccinia graminis f. sp. tritici were studied on seedlings of three to five susceptible wheat varieties by growing mixtures of the races in greenhouses, growth cabinets, and field plots. In experiments in which simple races with few virulence genes were mixed with complex races with one, two, or three extra virulence genes, the complex races predominated after 4 to 10 generations in five of the six mixtures, and the simple race predominated in one mixture. A complex race predominated over simple races in the field experiment. It was concluded that virulence genes did not impair the fitness of the wheat stem rust races studied.In one race mixture studied in growth cabinets the complex race predominated at 25 °C, and the simple race, at 15 °C. Temperature did not differentially influence the competitive abilities of the races in three other mixtures.Incubation periods for all races were shorter at higher temperatures, but races C18(15B-1L) and C33(15B-1L) developed faster than races C9(15B-1L), C37(15), C38(15B-1L), C42(15), and C49(15) at all temperatures. In addition, races C18(15B-1L) and C33(15B-1L) produced more urediospores per pustule than races C9(15B-1L), C37(15), and C49(15). The differences in incubation period and spore production are considered to be the most important factors studied and they could cause the differences in aggressiveness of the seven races.


Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2359-2366 ◽  
Author(s):  
Bekele Hundie ◽  
Bedada Girma ◽  
Zerihun Tadesse ◽  
Erena Edae ◽  
Pablo Olivera ◽  
...  

In Ethiopia, breeding rust resistant wheat cultivars is a priority for wheat production. A stem rust epidemic during 2013 to 2014 on previously resistant cultivar Digalu highlighted the need to determine the effectiveness of wheat lines to multiple races of Puccinia graminis f. sp. tritici in Ethiopia. During 2014 and 2015, we evaluated a total of 97 bread wheat and 14 durum wheat genotypes against four P. graminis f. sp. tritici races at the seedling stage and in single-race field nurseries. Resistance genes were postulated using molecular marker assays. Bread wheat lines were resistant to race JRCQC, the race most virulent to durum wheat. Lines with stem rust resistance gene Sr24 possessed the most effective resistance to the four races. Only three lines with adult plant resistance possessed resistance effective to the four races comparable with cultivars with Sr24. Although responses of the wheat lines across races were positively correlated, wheat lines were identified that possessed adult plant resistance to race TTKSK but were relatively susceptible to race TKTTF. This study demonstrated the importance of testing wheat lines for response to multiple races of the stem rust pathogen to determine if lines possessed non-race-specific resistance. [Formula: see text] Copyright © 2019 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .


1967 ◽  
Vol 45 (7) ◽  
pp. 1077-1091 ◽  
Author(s):  
K. Katsuya ◽  
G. J. Green

Variations in the prevalence of races 56 and 15B-1 (Can.) of wheat stem rust (Puccinia graminis Pers. f. sp. tritici Erikss. and Henn.) have occurred that cannot be explained by changes in the wheat varieties grown in Western Canada. The reasons for the changes in prevalence were investigated by comparing in growth cabinets the reproductive potentials or aggressiveness of the two races and the factors that might influence them. When a mixture of urediospores of the two races was used to inoculate three susceptible varieties for successive uredial generations, race 56 predominated at 25 and 20 °C, and race 15B-1 (Can.) predominated at 15 °C. Experimentation showed that the urediospores of race 56 were more infective than those of 15B-1 (Can.) and that the incubation period of race 56 was shorter than that of race 15B-1 (Can.). Pustules of race 56 grew faster than those of race 15B-1 (Can.) during early stages of development but those of 15B-1 (Can.) ultimately became larger than those of race 56. Race 56 produced more urediospores per pustule than race 15B-1 (Can.) on the susceptible varieties Little Club, Red Bobs, and Marquis at 15 and 20 °C. Infection density markedly affected competitive abilities. Race 56 tended to predominate in light infections but race 15B-1 (Can.) tended to predominate in heavy infections. Pustule size decreased as infection density increased. The possible significance of these findings under field conditions is discussed. It seems likely that the rise of race 15B-1 (Can.) to predominance in 1950 resulted not only from the selection pressure of the widely grown varieties that were resistant to race 56 and susceptible to 15B-1 (Can.) but from the lower temperatures that prevailed and favored 15B-1 (Can.) over 56. The rise to predominance of race 56 from 1956 to 1961 may have resulted from the greater aggressiveness of that race under the moderate or warm conditions that prevailed.


1941 ◽  
Vol 19c (11) ◽  
pp. 438-445 ◽  
Author(s):  
T. Johnson ◽  
Margaret Newton

Eighteen stem rust resistant wheat varieties were tested, in the greenhouse, for their reaction to three physiologic races of Puccinia graminis Tritici Erikss. and Henn. at three different temperatures: a constant low temperature of about 60° F., a constant high temperature of about 80° F., and an intermediate temperature which fluctuated daily from 50° to 55° F. at night to 70° to 85° F. at midday.At the low and at the intermediate temperature some of the varieties proved immune while others proved highly or moderately resistant. At the high temperature five varieties (Bokveld, Iumillo, Gaza, Red Egyptian, and N.A. 95 Egypt) were immune or highly resistant; six varieties (Marquillo × Waratah, Hope, Hochzucht, Minor, Bobin Gaza Robin, and Federation × Acme) were moderately resistant; and seven varieties (Kenya, Syria, McMurachy, Sweden, Rhodesian, Talberg, and Eureka) were moderately or completely susceptible.


Science ◽  
2013 ◽  
Vol 341 (6147) ◽  
pp. 786-788 ◽  
Author(s):  
Sambasivam Periyannan ◽  
John Moore ◽  
Michael Ayliffe ◽  
Urmil Bansal ◽  
Xiaojing Wang ◽  
...  

Wheat stem rust, caused by the fungus Puccinia graminis f. sp. tritici, afflicts bread wheat (Triticum aestivum). New virulent races collectively referred to as “Ug99” have emerged, which threaten global wheat production. The wheat gene Sr33, introgressed from the wild relative Aegilops tauschii into bread wheat, confers resistance to diverse stem rust races, including the Ug99 race group. We cloned Sr33, which encodes a coiled-coil, nucleotide-binding, leucine-rich repeat protein. Sr33 is orthologous to the barley (Hordeum vulgare) Mla mildew resistance genes that confer resistance to Blumeria graminis f. sp. hordei. The wheat Sr33 gene functions independently of RAR1, SGT1, and HSP90 chaperones. Haplotype analysis from diverse collections of Ae. tauschii placed the origin of Sr33 resistance near the southern coast of the Caspian Sea.


2016 ◽  
Vol 106 (11) ◽  
pp. 1352-1358 ◽  
Author(s):  
Jayaveeramuthu Nirmala ◽  
Shiaoman Chao ◽  
Pablo Olivera ◽  
Ebrahiem M. Babiker ◽  
Bekele Abeyo ◽  
...  

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, can cause severe yield losses on susceptible wheat varieties and cultivars. Although stem rust can be controlled by the use of genetic resistance, population dynamics of P. graminis f. sp. tritici can frequently lead to defeat of wheat stem rust resistance genes. P. graminis f. sp. tritici race TKTTF caused a severe epidemic in Ethiopia on Ug99-resistant ‘Digalu’ in 2013 and 2014. The gene Sr11 confers resistance to race TKTTF and is present in ‘Gabo 56’. We identified seven single-nucleotide polymorphism (SNP) markers linked to Sr11 from a cross between Gabo 56 and ‘Chinese Spring’ exploiting a 90K Infinium iSelect Custom beadchip. Five SNP markers were validated on a ‘Berkut’/‘Scalavatis’ population that segregated for Sr11, using KBioscience competitive allele-specific polymerase chain reaction (KASP) assays. Two of the SNP markers, KASP_6BL_IWB10724 and KASP_6BL_IWB72471, were predictive of Sr11 among wheat genetic stocks, cultivars, and breeding lines from North America, Ethiopia, and Pakistan. These markers can be utilized to select for Sr11 in wheat breeding and to detect the presence of Sr11 in uncharacterized germplasm.


2021 ◽  
pp. 23-27
Author(s):  
Elmira Aleksandrovna Konkova

Stem rust (pathogen - biotrophic fungus Puccinia graminis f. sp. tritici Erikss. & Henning) – a particularly deleterious disease of bread wheat. In this article the results of the analysis of the structure of samples of Saratov populations of wheat stem rust pathogen by signs of virulence during 2016-2020 were presented. A total of 60 pathogen isolates were characterized for virulence. In general, Saratov P. graminis populations were characterized as highly virulent during the study period. The significant variation in the virulence frequencies of P. graminis was observed in lines with the genes Sr9b, Sr9g, Sr12, Sr21, Sr25, Sr27, Sr30, Sr32, Sr33, Sr7a+12, Sr17+13. The other Sr lines used in the analysis, the virulence rates remained consistently high in all the years of research. Genes and combinations of genes: SrSatu, Sr24, Sr25+9g, Sr25+31, Sr25+38 were shown to be effective to P. graminis populations in 2016-2020.


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