scholarly journals Mutations in wheat leading  to enhanced resistance to the fungal pathogen of 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
Keyword(s):  
Fungal Pathogen ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Field Resistance ◽  
Deletion Mutants ◽  
Molecular Characterisation ◽  
Wheat Line ◽  
Enhanced Resistance ◽  
Negative Effect ◽  
Mutant Lines

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.

scholarly journals Mutations in Wheat Exhibiting Growth-Stage-Specific Resistance to Biotrophic Fungal Pathogens

2004 ◽  
Vol 17 (11) ◽  
pp. 1242-1249 ◽  
Author(s):  
Phil H. Smith ◽  
John A. Howie ◽  
Anthony J. Worland ◽  
Rebecca Stratford ◽  
Lesley A. Boyd
Keyword(s):  
Fungal Pathogens ◽  
Growth Stage ◽  
Puccinia Striiformis ◽  
Specific Resistance ◽  
Yellow Rust ◽  
Dominant Mutation ◽  
Resistance Phenotype ◽  
The Third ◽  
Enhanced Resistance ◽  
Seedling Leaf

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.

Distribution of Puccinia striiformis f. sp. tritici races and virulence in wheat growing regions of Kenya from 1970 TO 2014

Plant Disease ◽  
2021 ◽  
Author(s):  
Mercy Wamalwa ◽  
Ruth Wanyera ◽  
Julian Rodriguez-Algaba ◽  
Lesley Boyd ◽  
James Owuoche ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Fungal Pathogen ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Stripe Rust Resistance ◽  
Scar Markers ◽  
Seedling Resistance ◽  
Sequence Characterized Amplified Region ◽  
Triticum Spp ◽  
Virulence Diversity

Stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), is a major threat to wheat (Triticum spp.) production worldwide. The objective of this study was to determine the virulence of Pst races prevalent in the main wheat growing regions of Kenya, which includes Mt. Kenya, Eastern Kenya, and the Rift Valley (Central, Southern, and Northern Rift). Fifty Pst isolates collected from 1970 to 1992 and from 2009 to 2014 were virulence phenotyped using stripe rust differential sets, and 45 isolates were genotyped with sequence characterized amplified region (SCAR) markers to differentiate among the isolates and identify aggressive strains PstS1 and PstS2. Virulence corresponding to stripe rust resistance genes Yr1, Yr2, Yr3, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, Yr27 and the seedling resistance in genotype Avocet S were detected. Ten races were detected in the Pst samples obtained from 1970 to 1992, and three additional races were detected from 2009 to 2014, with a single race being detected in both periods. The SCAR markers detected both Pst1 and Pst2 strains in the collection. Increasing Pst virulence was found in the Kenyan Pst population, and that diverse Pst race groups dominated different wheat growing regions. Moreover, recent Pst races in east Africa indicated possible migration of some race groups into Kenya from other regions. This study is important in understanding Pst evolution and virulence diversity and useful in breeding wheat cultivars with effective resistance to stripe rust. Keywords: pathogenicity, Puccinia f. sp. tritici stripe (yellow) rust, Triticum aestivum

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
Keyword(s):  
Yellow Rust ◽  
Field Testing ◽  
Small Population ◽  
Field Resistance ◽  
Brown Rust ◽  
Adult Plant ◽  
Rust Disease ◽  
Enhanced Resistance ◽  
Wheat Lines ◽  
Resistance Mutants

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.

scholarly journals Evolution of Physiologic Races and Virulence of Puccinia striiformis on Wheat in Syria and Lebanon

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 499-504 ◽  
Author(s):  
A. H. Yahyaoui ◽  
M. S. Hakim ◽  
M. El Naimi ◽  
N. Rbeiz
Keyword(s):  
Resistance Genes ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Wheat Breeding ◽  
Natural Conditions ◽  
Breeding Programs ◽  
Land Race ◽  
Physiologic Races ◽  
Resistant Genotypes

Virulence-avirulence phenotypes of Puccinia striiformis isolates collected in Lebanon and Syria were determined on seedlings of the wheat-yellow rust differential genotypes. We found 25 and 11 physiologic races over 6 years (1994 to 1999) in Syria and Lebanon, respectively. The composition of physiologic races found in Syria and Lebanon differed greatly between 1994 and 1999. Races identified in 1999, such as 230E150 and 230E134, have wider spectra of virulence on resistant genotypes than races collected in 1994. In Lebanon, three races were found in 1994 compared with six races in 1999. Yellow rust differential genotypes were used in a trap nursery to monitor yellow rust populations under natural conditions. Races identified from cultivars in the trap nursery in Syria and Lebanon, and from land race cultivars in Iraq, were recovered among the races identified from farm fields. Yellow rust samples were collected from Yemen, and none of the races identified from Yemen samples were identical to those in Syria and Lebanon. Virulence frequencies in the yellow rust population on the differential genotypes tested in the trap nurseries were above 70% for some resistance genes. Yellow rust populations in Syria and Lebanon have diverse virulence phenotypes. P. striiformis populations appear to be changing over, and this would be an important consideration for wheat breeding programs in the region.

Microsatellite Genotyping of the Wheat Yellow Rust Pathogen Puccinia striiformis

2017 ◽  
pp. 59-70 ◽  
Author(s):  
Sajid Ali ◽  
Muhammad R. Khan ◽  
Angelique Gautier ◽  
Zahoor A. Swati ◽  
Stephanie Walter
Keyword(s):  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Microsatellite Genotyping ◽  
Rust Pathogen

scholarly journals Characterization of yellow rust (Puccinia striiformis Westend.): review

2018 ◽  
Author(s):  
Liga Feodorova-Fedotova ◽  
◽  
Biruta Bankina ◽  
Keyword(s):  
Puccinia Striiformis ◽  
Yellow Rust

scholarly journals Understanding Interactions Histological, Cytological, and Molecular Among the fungus P. Striiformis Tritici and Wheat

2021 ◽  
Author(s):  
Valeria Moreno Heredia
Keyword(s):  
Virulence Genes ◽  
Puccinia Striiformis ◽  
Early Stage ◽  
Yellow Rust ◽  
Complete Understanding ◽  
Rust Disease ◽  
Resistant Cultivars ◽  
Wheat Diseases ◽  
Migratory Capacity ◽  
Palabras Clave

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.

scholarly journals Brown and Yellow Rust of Wheat in India –Significance of Climate on It’s Races and Resistance

2021 ◽  
pp. 72-91
Author(s):  
Katravath Srinivas ◽  
Shaik Moizur Rahman ◽  
Manu Yadav ◽  
Mamta Sharma
Keyword(s):  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Yield Potential ◽  
Dominant Factor ◽  
Yield Reduction ◽  
Rust Disease ◽  
Comprehensive Overview ◽  
Economic Significance ◽  
Grain Damage ◽  
Significant Yield

Wheat is one of the most important staple food crops having global economic significance. Grown globally around 215 million hectares area with production of more than 600 million tons. Wheat is constrained in its production due to several biotic factors, among them yellow rust of wheat, Puccinia striiformis Westend. f.sp. tritici Eriks and Henn. (Pst) and brown rust of wheat, Puccinia recondita f.sp. tritici (Eriks. and E. Henn.) D.M. Henderson (Ptr) continues to be a serious threat and dominant factor limiting its yield potential globally. The estimated yield losses range from 10-70%, while in a severe epidemic the grain damage can be as great as 100%. Pathogens are considered to be favoured by the cooler areas but current races are more adaptable to high temperatures causing significant yield reduction in wheat. In India, prevalent pathotypes for yellow rust include 46S119, 110S119, and 238S119. Yr5, Yr10, Yr15, YrSp, and YrSk genes are resistant to Pst pathotypes in Indian conditions, while in the case of leaf rust of wheat, prevalent pathotypes are 77-5, 77-9, and 104-2. Lr9, Lr19, Lr24, Lr25, Lr29, Lr32, Lr39, Lr45, and Lr47 are the genes having resistance to Ptr pathotypes in Indian conditions. This publication provides a comprehensive overview of the stripe and leaf rusts of wheat in India and their virulent races, types of host resistance and provides a tool for effective management of wheat rust disease.

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