Mutations in wheat showing altered field resistance to yellow and brown rust

Genome ◽  
2002 ◽  
Vol 45 (6) ◽  
pp. 1035-1040 ◽  
Author(s):  
L A Boyd ◽  
P H Smith ◽  
A H Wilson ◽  
P N Minchin

Intensive screening of a small population of mutagenised wheat lines revealed a large number of lines with altered resistance to both yellow and brown rust. The parental cultivar Guardian has an intermediate level of adult plant resistance to this disease; mutants were therefore isolated that showed either enhanced resistance or enhanced susceptibility to yellow rust. Seven lines were identified that gave an altered yellow rust disease phenotype as adult plants under both field and greenhouse conditions. Simultaneous field testing for brown rust infection identified two of these lines as having increased resistance to brown rust.Key words: Disease resistance, mutants, wheat, yellow rust.

2002 ◽  
Vol 38 (SI 1 - 6th Conf EFPP 2002) ◽  
pp. S73-S75
Author(s):  
L.A. Boyd ◽  
J.A. Howie ◽  
T. Worland ◽  
R. Stratford ◽  
P.H. Smith

The isolation and study of plant resistance genes is revealing a story more complicated than the gene-for-gene hypothesis originally implied. The story of resistance is complicated even further by the discovery of genes that appear to have a negative effect on resistance. Early studies in the wheat line Hobbit ‘sib’ identified a number of chromosomes that reduced the level of field resistance to the fungal pathogen Puccinia striiformis f.sp. tritici, the causal agent of yellow rust on wheat. From a series of deletion mutants generated in Hobbit ‘sib’ a number of mutant lines were selected that gave enhanced resistance to yellow rust. The phenotypic, genetic and molecular characterisation of some of these mutants is presented.


Author(s):  
Nedim Altın ◽  
Hüseyin Güngör ◽  
İsmet Yıldırım

This study was conducted to determine the response of 19 bread wheat varieties to natural infection of leaf diseases under ecological conditions of Düzce in the Western Black Sea Region. The trial was established in accordance with randomized block with four replications and the seeds were planted on 17.11.2015. The wheat varities were observed for the associated diseases including septoria leaf spot disease (caused by Septoria tritici during milking stage), yellow rust disease (caused by Puccinia striiformis at the end of the flowering period), brown rust disease (caused by Puccinia recondita at the beginning of milking stage). The disease severity were assessed in the field conditions according to natural contamination. According to determined diseases severity, the most sensitive variety against septoria leaf spot disease was “Bereket” with 60%, while the most tolerant variety was “Aslı” with 14%. The most sensitive variety against yellow rust disease was “Tekirdağ” with 45.4%, while the most tolerant variety was “Midas” with 0.6%. The most sensitive variety against brown rust disease was “Tahirova” with 22%, while the most tolerant variety was “Midas” with 0.2%. The results indicated that promising wheat varieties for future breeding studies were: Aldane, Aslı, Konya 2002, Köprü, Masaccio and Tosunbey (against septoria leaf spot disease), Aslı, Esperia, Kate A1, Karasunya Odeska, Masaccio and Midas (against yellow rust disease), Aldane, Aslı, Bereket, Köprü, Masaccio, Midas and Tekirdağ (against brown rust disease).


Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 413-419 ◽  
Author(s):  
Peter N. Njau ◽  
Yue Jin ◽  
Julio Huerta-Espino ◽  
Beat Keller ◽  
Ravi P. Singh

The race Ug99 of Puccinia graminis f. sp. tritici causing stem rust disease of wheat was initially identified in Uganda in 1998. It was designated as TTKSK based on the North American nomenclature and has caused periodic losses to wheat crops in East Africa. Ug99 has recently moved out of Africa to Yemen and West Asia. The most effective approach to prevent losses from stem rust is through the deployment of resistant cultivars. More effective sources of resistance need to be identified and incorporated in the existing commercial cultivars. The first Stem Rust Resistance Screening Nursery (1stSRRSN) assembled by the International Maize and Wheat Improvement Center (CIMMYT) consisted of elite and advanced CIMMYT bread wheat lines and was evaluated for resistance to Ug99 in Njoro, Kenya for four consecutive seasons (2005 to 2007). Seedling reactions were determined in the greenhouse at the Cereal Disease Laboratory, St. Paul, MN. Two race-specific genes, Sr24 and Sr25, were found to confer resistance to Ug99, although Sr24 became ineffective to a mutant race of Ug99, TTKST, in 2007. Three previously uncharacterized genes, one each from synthetic wheat, Chinese germplasm, and other genetic backgrounds, were detected. Although 30% of the screened lines were susceptible in the seedling stage, these lines displayed various levels of adult plant resistance (APR) in the field tests. Presence of the APR gene Sr2, identified based on the pseudo-black chaff phenotype on glumes and darkened internode, was common in wheat lines with APR. The information on the resistance identified in the 1stSRRSN constitutes an important source for breeding wheat for durable resistance.


Author(s):  
I.V. GRUZDEV ◽  
◽  
P.YU. KROUPIN ◽  
L.S. BOLSHAKOVA ◽  
M.G. DIVASHUK ◽  
...  

The paper presents the results of studying the field resistance of a large number of spring triticale samples to brown rust pathogen under the natural infectious background of the Moscow pathogen population in 2012–2015, as well as the identification of some effective Lr-genes in these samples.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Desmond E. P. Klenam ◽  
Michael O. Bodunrin ◽  
Stefania Akromah ◽  
Emmanuel Gikunoo ◽  
Anthony Andrews ◽  
...  

Abstract An overview of the characterisation of rust by colour is presented. Each distinct rust colour is caused by atmospheric impurities, high or low moisture content and high or low oxygen environment over time. Yellow rust is mainly due to the high moisture environment over a period of time, which drips. Brown rust is dry, crusty and due to water and oxygen contact with localised patches on component surfaces. Black rust, the most stable form, occurs in low moisture and low oxygen environment. The rust residue shows where the reaction started, especially in contact with chlorides. The causative factors of red rust are atmospheric and similar to black rust in a chloride-containing environment. The effect of packaging, manufacturing and environmental factors on rust colour is briefly discussed. Visual characterization of rust could pre-empt root causes and analytical tools for validation. The limitations of these concepts are mentioned and directions for future research highlighted.


2004 ◽  
Vol 17 (11) ◽  
pp. 1242-1249 ◽  
Author(s):  
Phil H. Smith ◽  
John A. Howie ◽  
Anthony J. Worland ◽  
Rebecca Stratford ◽  
Lesley A. Boyd

Two mutants were isolated in wheat that showed enhanced resistance towards Puccinia striiformis f. sp. tritici, the fungal causal agent of yellow rust. The altered phenotype of I3-48 is due to a minimum of two mutation events, each showing a partial, additive effect, with one mutation segregating with a deletion on the long arm of chromosome 4D. In the case of I3-54, the enhanced resistance is due to a single, dominant mutation. In both mutants, the expression of the enhanced resistance is growth-stage specific. With I3-54, the full resistance phenotype is apparent from the third seedling leaf onwards, while with I3-48, a full resistance phenotype is only seen on the tenth and subsequent leaves. In addition to the enhanced resistance towards yellow rust, I3-48 also shows enhanced resistance towards brown rust, and I3-54 shows enhanced resistance to powdery mildew.


2020 ◽  
Vol 5 (1) ◽  
pp. 29-38
Author(s):  
M. A. Gad ◽  
Kh. Y. Abdel- Halim ◽  
Fayza A. Seddik ◽  
Hanim M. A. Soliman

Author(s):  
Valeria Moreno Heredia

Yellow rust is caused by the fungus Puccinia striiformis f.sp.tritici (Pst), which due to its great migratory capacity, adaptation to different environments, and high levels of mutation; is one of the most devastating wheat diseases worldwide. Due to this, several strategies have been implemented to control the disease, the best being genetic improvement. The key to develop resistant cultivars is understanding the interactions between wheat and Pst. Therefore, this work synthesizes the most important investigations carried out in the last 30 years regarding: cellular, histological, and molecular interactions between wheat and Pst. This will allow a deeper and more complete understanding of the interaction between resistance and virulence genes in the yellow rust disease. The results of this work revealed that the early stage of infection, in susceptible and resistant cultivars, is the same qualitatively, but not quantitatively. However, a clear difference at the histological and molecular level, in terms of the amount and type of genes expressed, begins 48 hours after infection. It was also found that the haustorium, in addition to absorbing nutrients from the host; can also manipulate its metabolism to benefit itself, and can make some nutrients on its own. Keywords: haustorio, Puccinia striiformis f.sp.tritici, histological, resistance genes, virulence genes. Resumen La roya amarilla es causada por el hongo Puccinia striiformis f.sp.tritici (Pst), el cual debido a su gran capacidad migratoria, adaptación a diferentes ambientes, y niveles altos de mutación; es la enfermedad más devastadoras del trigo a nivel mundial. Debido a esto, varias estrategias han sido implementadas para controlar la enfermedad, siendo la mejor, el mejoramiento genético. La clave para desarrollar cultivares resistentes, es el entendimiento de las interacciones entre el trigo y Pst. Por lo tanto, este trabajo sintetiza las investigaciones más importantes realizadas en los últimos 30 años, en cuanto a interacciones celulares, histológicas y moleculares entre el trigo y Pst. Esto permitirá un entendimiento más profundo y completo de la interacción entre los genes de resistencia y virulencia, en la enfermedad de la roya. Los resultados revelaron que la fase temprana de infección en cultivares susceptibles y resistentes, es igual cualitativamente, pero no cuantitativamente. Sin embargo, una diferencia clara a nivel histológico y molecular, en cuanto a la cantidad y al tipo de genes expresados, empieza 48 hr post infección. También, se halló que el haustorio además de absorber nutrientes del huésped, también manipula el metabolismo de éste para su beneficio y puede elaborar algunos nutrientes por sí mismo. Palabras Clave: haustorio, Puccinia striiformis f.sp.tritici, histológico, genes de resistencia, genes de virulencia.


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