scholarly journals Virulence surveillance of wheat black stem rust fungus

2014 ◽  
Vol 11 (2) ◽  
pp. 803-812
Author(s):  
Baghdad Science Journal
Keyword(s):  
Leaf Rust ◽  
Disease Severity ◽  
Stem Rust ◽  
Yellow Rust ◽  
Rust Fungus ◽  
The North ◽  
Rust Diseases ◽  
Northern Regions ◽  
Infection Disease ◽  
Wheat Rust

General survey for wheat rust diseases in Iraqi fields was done during the seasons of 2010, 2011 and 2012. The survey covered different fields in southern, middle and northern regions. Results of the first season indicated that most of Iraqi cultivars such as Tmmoze2, IPA 99 and Mexipak showed different types of susceptibility to both yellow and leaf rust infection. Disease severity increased when the conditions were favorable for infections with using susceptible cultivars. The severity of leaf rust was less in the north region comparing with the middle and south regions. Most of the introduced cultivars such as Sham6 and Cimmyto showed susceptible reaction to yellow and leaf rust. Yellow rust was in epiphytotic form at the Iraqi-Syrian-Turkish triangle where the disease severity was 100%. Low disease severity of stem rust was observed on some cultivars (1-5%), except for the cultivar Mexipak which showed 40%S in Najaf. Rusts at season of 2011 were restricted mostly in Baghdad and the yellow rust was dominant. The AUDPC of 15 wheat cultivars showed that Sawa and Sali were highly susceptible to the three types of rusts while Babil113 and Tamoze2 were resistant. No rusts were detected at season 2012.

scholarly journals Comparison of Genomic Prediction Methods for Yellow, Stem, and Leaf Rust Resistance in Wheat Landraces from Afghanistan

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 558
Author(s):  
Muhammad Massub Tehseen ◽  
Zakaria Kehel ◽  
Carolina P. Sansaloni ◽  
Marta da Silva Lopes ◽  
Ahmed Amri ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Ridge Regression ◽  
Genomic Prediction ◽  
Bayesian Models ◽  
Predictive Ability ◽  
Rust Diseases ◽  
Wheat Landraces ◽  
Gp Model ◽  
Wheat Rust

Wheat rust diseases, including yellow rust (Yr; also known as stripe rust) caused by Puccinia striiformis Westend. f. sp. tritici, leaf rust (Lr) caused by Puccinia triticina Eriks. and stem rust (Sr) caused by Puccinia graminis Pres f. sp. tritici are major threats to wheat production all around the globe. Durable resistance to wheat rust diseases can be achieved through genomic-assisted prediction of resistant accessions to increase genetic gain per unit time. Genomic prediction (GP) is a promising technology that uses genomic markers to estimate genomic-assisted breeding values (GBEVs) for selecting resistant plant genotypes and accumulating favorable alleles for adult plant resistance (APR) to wheat rust diseases. To evaluate GP we compared the predictive ability of nine different parametric, semi-parametric and Bayesian models including Genomic Unbiased Linear Prediction (GBLUP), Ridge Regression (RR), Least Absolute Shrinkage and Selection Operator (LASSO), Elastic Net (EN), Bayesian Ridge Regression (BRR), Bayesian A (BA), Bayesian B (BB), Bayesian C (BC) and Reproducing Kernel Hilbert Spacing model (RKHS) to estimate GEBV’s for APR to yellow, leaf and stem rust of wheat in a panel of 363 bread wheat landraces of Afghanistan origin. Based on five-fold cross validation the mean predictive abilities were 0.33, 0.30, 0.38, and 0.33 for Yr (2016), Yr (2017), Lr, and Sr, respectively. No single model outperformed the rest of the models for all traits. LASSO and EN showed the lowest predictive ability in four of the five traits. GBLUP and RR gave similar predictive abilities, whereas Bayesian models were not significantly different from each other as well. We also investigated the effect of the number of genotypes and the markers used in the analysis on the predictive ability of the GP model. The predictive ability was highest with 1000 markers and there was a linear trend in the predictive ability and the size of the training population. The results of the study are encouraging, confirming the feasibility of GP to be effectively applied in breeding programs for resistance to all three wheat rust diseases.

SCREENING OF WHEAT LR-GENES FOR RESISTANCE TO PUCCINIA TRITICINA IN THE NORTH CAUCASUS REGION CONDITIONS

1970 ◽  
pp. 54-56
Author(s):  
G. V. Volkova ◽  
O. A. Kudinova ◽  
O. F. Vaganova
Keyword(s):  
Winter Wheat ◽  
Leaf Rust ◽  
Puccinia Triticina ◽  
North Caucasus ◽  
Breeding Programs ◽  
Lr Genes ◽  
Caucasus Region ◽  
Highly Efficient ◽  
The North ◽  
Wheat Rust

Currently, more than 70 wheat rust resistance genes are known, but few of them are effective. The purpose of this work is to screen lines of Lr gene carriers for resistance to leaf rust under conditions of the North Caucasus region. Investigations were carried out in 2016-2018 at the infectious site of VNIIBZR. Research material was 49 near isogenic lines of winter wheat cultivar Thatcher. Infectious material was the combined populations of P. triticina, obtained as a result of route surveys of industrial and breeding crops of winter wheat in the areas of the Krasnodar, Stavropol Territories and the Rostov Region, conducted in 2016-2018. According to the assessment, the genes are ranked as follows: - highly efficient genes (plants with no signs of damage): Lr9, Lr42, Lr43 + 24 and Lr50; effective (1R-5R) Lr genes: 19, 24, 29, 36, 37, 38, 45, 47; moderately effective (10MR-20MR) Lr genes: 17, 18, 21, 22a, 28, 32, 41, 52. The remaining Lr-lines were susceptible to P. triticina (25 MR - 90S) to varying degrees. Highly efficient and effective genes Lr9, Lr19, Lr24, Lr29, Lr38, Lr42, Lr43 + 24, Lr47 and Lr50 showed resistance in the seedling phase and can be recommended for inclusion in breeding programs to protect wheat from leaf rust in different phases of plant ontogenesis in the North Caucasus region.

Resistance of Tangmai 4 wheat to powdery mildew, stem rust, leaf rust, and stripe rust and its chromosome composition

2004 ◽  
Vol 84 (4) ◽  
pp. 1015-1023 ◽  
Author(s):  
H. J. Li ◽  
R. L. Conner ◽  
B. D. McCallum ◽  
X. M. Chen ◽  
H. Su ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Leaf Rust ◽  
Stripe Rust ◽  
Stem Rust ◽  
Northern China ◽  
Western Canada ◽  
C Banding ◽  
Rust Diseases ◽  
Hard Red Winter Wheat ◽  
Secale Cereale L

The hard red winter wheat Tangmai 4 did not develop symptoms of infection following inoculation with powdery mildew (Erysiphe graminis DC. f. sp. tritici E. Marchal) isolates from regions of western Canada and northern China. Tangmai 4 exhibited resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) and leaf rust (P. triticina Eriks.) races from western Canada. This wheat line was resistant to individual stripe rust (P. striiformis Westend. f. sp. tritici Eriks.) races from the U.S. and Canada. Sequential C-banding and genomic in situ hybridization (GISH), and electrophoretic analyses of high molecular weight glutenins and gliadins demonstrated that Tangmai 4 carried a pair of T1BL·1RS wheat-rye (Secale cereale L.) translocated chromosomes. Since the genes located on T1BL·1RS are no longer effective in controlling powdery mildew and the rust diseases, Tangmai 4 must carry additional genes for resistance to these diseases, which makes it a valuable resource for the improvement of resistance in wheat against these diseases. Key words: T1BL·1RS translocation, disease resistance, sequential C-banding and GISH, glutenin, gliadin

Seedling resistances to rust diseases in international triticale germplasm

2010 ◽  
Vol 61 (12) ◽  
pp. 1036 ◽  
Author(s):  
J. Zhang ◽  
C. R. Wellings ◽  
R. A. McIntosh ◽  
R. F. Park
Keyword(s):  
Leaf Rust ◽  
Stripe Rust ◽  
Plant Resistance ◽  
Stem Rust ◽  
Rust Resistance ◽  
Adult Plant Resistance ◽  
Stem Rust Resistance ◽  
Adult Plant ◽  
Seedling Resistance ◽  
Rust Diseases

Seedling resistances to stem rust, leaf rust and stripe rust were evaluated in the 37th International Triticale Screening Nursery, distributed by the International Wheat and Maize Improvement Centre (CIMMYT) in 2005. In stem rust tests, 12 and 69 of a total of 81 entries were postulated to carry Sr27 and SrSatu, respectively. When compared with previous studies of CIMMYT triticale nurseries distributed from 1980 to 1986 and 1991 to 1993, the results suggest a lack of expansion in the diversity of stem rust resistance. A total of 62 of 64 entries were resistant to five leaf rust pathotypes. In stripe rust tests, ~93% of the lines were postulated to carry Yr9 alone or in combination with other genes. The absence of Lr26 in these entries indicated that Yr9 and Lr26 are not genetically associated in triticale. A high proportion of nursery entries (63%) were postulated to carry an uncharacterised gene, YrJackie. The 13 lines resistant to stripe rust and the 62 entries resistant to leaf rust represent potentially useful sources of seedling resistance in developing new triticale cultivars. Field rust tests are needed to verify if seedling susceptible entries also carry adult plant resistance.

scholarly journals Wheat Breeding for Disease Resistance: Review

2019 ◽  
Vol 4 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Gadisa Alemu
Keyword(s):  
Disease Resistance ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Yellow Rust ◽  
Wheat Breeding ◽  
High Yield ◽  
Breeding Programs ◽  
Rust Resistance Genes

Breeding for disease resistance is a central focus of plant breeding programs, as any successful variety must have the complete package of high yield, disease resistance, agronomic performance, and end - use quality. Wheat breeding is focused on high yield, pathogen resistance and abiotic stress tolerance. Among diseases of wheat yellow rust, stem rust, and leaf rust are the most damaging diseases of wheat and other small grain cereals . Disease resistance in wheat breeding with one exception, the diseases of wheat that is important because of their effect on yield. Resistance to all diseases together can is important to avoid an unexpected loss in effectiveness of the resistance of a cu ltivar to a major disease. The genetic resistance to stem rust, leaf rust and yellow rust can be characterized as qualitative and quantitative resistances. Vertical resistance is specific to pathogen isolates based on single or very few genes. Race - specifi c is used to describe resistance that interacts differentially with pathogen races. Quantitative resistance is defined as resistance that varies in continuous way between the various phenotypes of the host population, from almost imperceptible to quite str ong. With the need to accelerate the development of improved varieties, genomics - assisted breeding is becoming an important tool in breeding programs. With marker - assisted selection, there has been success in breeding for disease resistance. Generally, bre eding programs have successfully implemented molecular markers to assist in the development of cultivars with stem, leaf and stripe rust resistance genes. When new rust resistance genes are to be deployed in wheat breeding programs, it unfortunately takes several years before the new sources of resistance will become available in commercial wheat cultivars. This is due to the long process involved in the establishment of pure breeding wheat lines. Biotechnology based techniques are available to accelerate t he breeding process via doubled haploid production.

Wheat Rusts

1995 ◽  
Author(s):  
RA McIntosh ◽  
CR Wellings ◽  
RF Park
Keyword(s):  
Stripe Rust ◽  
Resistance Genes ◽  
Stem Rust ◽  
Chromosome Location ◽  
Resistant Cultivars ◽  
Rust Diseases ◽  
Pathogen Variation ◽  
The World ◽  
Wheat Rust ◽  
Wheat Rusts

Although stem rust has been controlled by means of resistant cultivars, leaf and stripe rust continue as problems for many growing areas of the world. Wheat Rusts: An Atlas of Resistance Genes has been prepared by specialists from one of the leading international laboratories, and illustrates with colour photographs typical resistance phenotypes associated with most known genes for resistance to the three rust diseases of wheat. Relevant details for each gene include chromosome location, aspects of genetics and pathogen variation, the effects of environment on expression, origin, availability in genetic and breeding stocks, and use in agriculture. This atlas includes an introduction to host:pathogen genetics, methodologies for wheat rust research and breeding for resistance.

scholarly journals Description of Wheat Rusts and Their Virulence Variations Determined through Annual Pathotype Surveys and Controlled Multi-Pathotype Tests

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Mesfin Kebede Gessese
Keyword(s):  
Leaf Rust ◽  
Stripe Rust ◽  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Yellow Rust ◽  
Stripe Rust Resistance ◽  
Wheat Production ◽  
The World ◽  
Rust Resistance Genes

Wheat production started in Australia around 1788 using early maturing varieties adapted to Australian conditions that were able to escape diseases as well as moisture stress conditions. Wheat production is concentrated on mainland Australia in a narrow crescent land considered as the wheat belt occupying an area of about 13.9 million hectares. Rusts are the most important production constraints to wheat production in the world and Australia causing significant yield losses and decreased the qualities of grains. Wheat is affected by three different types of rust diseases: leaf rust, stripe rust or yellow rust, and stem rust. Each species of the rust pathogen has many races or pathotypes that parasitize only on certain varieties of host species, which can only be traced and identified by differential cultivars. Pathotype surveillance is the basis for information on the virulence or pathogenic variations existing in a particular country or wheat growing region of the world. Studies in pathotype variation are conducted in controlled environments using multi-pathotype tests. The currently cultivated commercial wheat varieties of Australia possess leaf rust resistant genes: Lr1, Lr3a, Lr13, Lr13+, Lr14a, Lr17a, Lr17b, Lr20, Lr23, Lr24, Lr26, Lr27, Lr31, Lr34, Lr37, and Lr46; stem rust resistance genes: Sr2, Sr5, Sr8a, Sr8b, Sr9b, Sr9g, Sr11, Sr12, Sr13, Sr15, Sr17, Sr22, Sr24, Sr26, Sr30, Sr36, Sr38, and Sr57; and stripe rust resistance genes: Yr4, Yr9, Yr17, Yr18, Yr27, and Yr33. This paper discusses the historical and current significance of rusts to wheat production in the world with particular reference to Australia viz-a-viz detail description of each of the three rusts and their respective virulence variations through the resistance genes deployed in the commercial cultivars.

scholarly journals Resistance to Leaf and Yellow Rust in a Collection of Spanish Bread Wheat Landraces and Association with Ecogeographical Variables

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 187
Author(s):  
Fernando Martínez-Moreno ◽  
Patricia Giraldo ◽  
Cristina Nieto ◽  
Magdalena Ruiz
Keyword(s):  
Leaf Rust ◽  
Bread Wheat ◽  
Yellow Rust ◽  
Latency Period ◽  
Field Trials ◽  
Seedling Stage ◽  
North West ◽  
The North ◽  
Rust Severity ◽  
High Precipitation

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature.

scholarly journals Wheat rust epidemics damage Ethiopian wheat production: A decade of field disease surveillance reveals national-scale trends in past outbreaks

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245697
Author(s):  
M. Meyer ◽  
N. Bacha ◽  
T. Tesfaye ◽  
Y. Alemayehu ◽  
E. Abera ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Disease Prevalence ◽  
Spatial Data Analysis ◽  
Disease Spread ◽  
Economic Losses ◽  
Wheat Stem Rust ◽  
Wheat Production ◽  
Wheat Rust ◽  
Wheat Rusts

Wheat rusts are the key biological constraint to wheat production in Ethiopia—one of Africa’s largest wheat producing countries. The fungal diseases cause economic losses and threaten livelihoods of smallholder farmers. While it is known that wheat rust epidemics have occurred in Ethiopia, to date no systematic long-term analysis of past outbreaks has been available. We present results from one of the most comprehensive surveillance campaigns of wheat rusts in Africa. More than 13,000 fields have been surveyed during the last 13 years. Using a combination of spatial data-analysis and visualization, statistical tools, and empirical modelling, we identify trends in the distribution of wheat stem rust (Sr), stripe rust (Yr) and leaf rust (Lr). Results show very high infection levels (mean incidence for Yr: 44%; Sr: 34%; Lr: 18%). These recurrent rust outbreaks lead to substantial economic losses, which we estimate to be of the order of 10s of millions of US-D annually. On the widely adopted wheat variety, Digalu, there is a marked increase in disease prevalence following the incursion of new rust races into Ethiopia, which indicates a pronounced boom-and-bust cycle of major gene resistance. Using spatial analyses, we identify hotspots of disease risk for all three rusts, show a linear correlation between altitude and disease prevalence, and find a pronounced north-south trend in stem rust prevalence. Temporal analyses show a sigmoidal increase in disease levels during the wheat season and strong inter-annual variations. While a simple logistic curve performs satisfactorily in predicting stem rust in some years, it cannot account for the complex outbreak patterns in other years and fails to predict the occurrence of stripe and leaf rust. The empirical insights into wheat rust epidemiology in Ethiopia presented here provide a basis for improving future surveillance and to inform the development of mechanistic models to predict disease spread.

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