The role of minimum disease resistance standards for the control of cereal diseases

2007 ◽  
Vol 58 (6) ◽  
pp. 588 ◽  
Author(s):  
Hugh Wallwork
Keyword(s):  
Disease Resistance ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Historical Background ◽  
Wheat Varieties ◽  
Cereal Diseases ◽  
The Way

A set of Minimum Disease resistance Standards (MDS) has been developed for rust resistance in new wheat varieties in Australia. These standards aim to provide protection to growers from varieties that produce large amounts of inoculum and, more specifically, protect the usefulness of resistance genes by reducing the probability of new pathotypes evolving with virulences that can overcome them. This paper provides a historical background to the establishment of MDS in Australia, the rationale for its introduction and the appropriateness of different resistance scales, problems that have been encountered, and the way forward to fully implement MDS. A brief consideration is also given as to which other wheat and barley diseases MDS may usefully be applied to.

Effectiveness of major resistance genes and identification of new sources for disease resistance in wheat

2011 ◽  
Vol 59 (3) ◽  
pp. 241-248 ◽  
Author(s):  
G. Vida ◽  
M. Cséplő ◽  
G. Gulyás ◽  
I. Karsai ◽  
T. Kiss ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Genetic Material ◽  
Leaf Rust Resistance ◽  
Wheat Varieties ◽  
Major Resistance Genes ◽  
Greenhouse Tests

Among the factors which determine yield reliability an important role is played by disease resistance. One of the breeding aims in the Martonvásár institute is to develop wheat varieties with resistance to major diseases. The winter wheat varieties bred in Martonvásár are examined in artificially inoculated nurseries and greenhouses for resistance to economically important pathogens. The effectiveness of designated genes for resistance to powdery mildew and leaf rust has been monitored over a period of several decades. None of the designated major resistance genes examined in greenhouse tests is able to provide complete resistance to powdery mildew; however, a number of leaf rust resistance genes provide full protection against pathogen attack (Lr9, Lr19, Lr24, Lr25, Lr28 and Lr35). In the course of marker-assisted selection, efficient resistance genes (Lr9, Lr24, Lr25 and Lr29) have been incorporated into Martonvásár wheat varieties. The presence of Lr1, Lr10, Lr26, Lr34 and Lr37 in the Martonvásár gene pool was identified using molecular markers. New sources carrying alien genetic material have been tested for powdery mildew and leaf rust resistance. Valuable Fusarium head blight resistance sources have been identified in populations of old Hungarian wheat varieties. Species causing leaf spots (Pyrenophora tritici-repentis, Septoria tritici and Stagonospora nodorum) have gradually become more frequent over the last two decades. Tests on the resistance of the host plant were begun in Martonvásár four years ago and regular greenhouse tests on seedlings have also been initiated.

scholarly journals The determination of the resistance inheritance against common bunt in wheat and half-diallel hybrids

2019 ◽  
Vol 55 (No. 4) ◽  
pp. 254-260
Author(s):  
Gülçin Akgören Palabiyik ◽  
İsmail Poyraz ◽  
Ahmet Umay
Keyword(s):  
Disease Resistance ◽  
Bread Wheat ◽  
Resistance Genes ◽  
Common Bunt ◽  
Wheat Varieties ◽  
Complete Dominance ◽  
Selection For ◽  
Half Diallel ◽  
Dominant Genes

This study was conducted to determine the inheritance of common bunt resistance in twelve bread wheat varieties and their half-diallel hybrids in Turkey. The disease ratings were performed on the F2 generations of the hybrids in field conditions. The obtained data were analysed by the χ2 test to determine the effective gene numbers and inheritance type in the disease resistance. In addition, the data were evaluated according to the Jinks-Hayman diallel analyses. In conclusion, it was found that of the twelve wheat parents, four contained three resistance genes and four of them contain two resistance genes. The dominant genes were prominent in the population and complete dominance was present. Therefore, the selection for disease resistance should be delayed until the following generations.

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.

scholarly journals Development of multiplex PCR to detect slow rust resistance genes Lr34 and Lr46 in wheat

2019 ◽  
Vol 60 (3-4) ◽  
pp. 301-304 ◽  
Author(s):  
Roksana Skowrońska ◽  
Michał Kwiatek ◽  
Agnieszka Tomkowiak ◽  
Jerzy Nawracała
Keyword(s):  
Multiplex Pcr ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Wheat Variety ◽  
Puccinia Triticina ◽  
Wheat Varieties ◽  
Large Yield ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Rust Resistance Genes

Abstract Leaf rust caused by Puccinia triticina belongs to one of the most dangerous fungal diseases of wheat (Triticum aestivum L.) and is the cause of large yield losses every year. Here we report a multiplex polymerase chain reaction (PCR) assay, which was developed for detection of two important wheat slow rust resistance genes Lr34 and Lr46, using two molecular markers: csLV34 and Xwmc44, respectively. The presence of genes was analyzed in one winter wheat variety TX89D6435 and five spring wheat varieties: Pavon F76, Parula ‘S’, Rayon 89, Kern, Mochis 88. Both Lr34 and Lr46 genes were identified in variety TX89D6435, gene Lr34 was also identified in Parula ‘S’ and Kern varieties, and gene L46 occurs in Pavon F76 and Mochis 88 variety. None of the resistance genes tested was detected in the Rayon 89 variety. The use of the multiplex PCR method allowed to shorten the analysis time, reduce costs of analyses, and reduce the workload.

scholarly journals When Does Spatial Diversification Usefully Maximize the Durability of Crop Disease Resistance?

2020 ◽  
Vol 110 (11) ◽  
pp. 1808-1820
Author(s):  
Benjamin Watkinson-Powell ◽  
Christopher A. Gilligan ◽  
Nik J. Cunniffe
Keyword(s):  
Disease Resistance ◽  
Resistance Genes ◽  
Cost Effective ◽  
Landscape Scale ◽  
Economic Modeling ◽  
Breaking Strain ◽  
Resistance Breaking ◽  
Crop Disease ◽  
Spatial Diversification ◽  
The Way

Maximizing the durability of crop disease resistance genes in the face of pathogen evolution is a major challenge in modern agricultural epidemiology. Spatial diversification in the deployment of resistance genes, where susceptible and resistant fields are more closely intermixed, is predicted to drive lower epidemic intensities over evolutionary timescales. This is due to an increase in the strength of dilution effects, caused by pathogen inoculum challenging host tissue to which it is not well-specialized. The factors that interact with and determine the magnitude of this spatial suppressive effect are not currently well understood, however, leading to uncertainty over the pathosystems where such a strategy is most likely to be cost-effective. We model the effect on landscape scale disease dynamics of spatial heterogeneity in the arrangement of fields planted with either susceptible or resistant cultivars, and the way in which this effect depends on the parameters governing the pathosystem of interest. Our multiseason semidiscrete epidemiological model tracks spatial spread of wild-type and resistance-breaking pathogen strains, and incorporates a localized reservoir of inoculum, as well as the effects of within and between field transmission. The pathogen dispersal characteristics, any fitness cost(s) of the resistance-breaking trait, the efficacy of host resistance, and the length of the timeframe of interest all influence the strength of the spatial diversification effect. A key result is that spatial diversification has the strongest beneficial effect at intermediate fitness costs of the resistance-breaking trait, an effect driven by a complex set of nonlinear interactions. On the other hand, however, if the resistance-breaking strain is not fit enough to invade the landscape, then a partially effective resistance gene can result in spatial diversification actually worsening the epidemic. These results allow us to make general predictions of the types of system for which spatial diversification is most likely to be cost-effective, paving the way for potential economic modeling and pathosystem specific evaluation. These results highlight the importance of studying the effect of genetics on landscape scale spatial dynamics within host−pathogen disease systems. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

Incorporation of leaf rust resistance genes into winter wheat genotypes using marker-assisted selection

2007 ◽  
Vol 55 (2) ◽  
pp. 149-156 ◽  
Author(s):  
M. Gál ◽  
G. Vida ◽  
A. Uhrin ◽  
Z. Bedő ◽  
O. Veisz
Keyword(s):  
Winter Wheat ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Marker Assisted Selection ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Wheat Breeding ◽  
Wheat Varieties ◽  
Rust Resistance Genes ◽  
Leaf Rust Resistance Genes

The breeding and cultivation of resistant wheat varieties is an effective way of controlling leaf rust ( Puccinia triticina Eriks.). The use of molecular markers facilitates the incorporation of the major leaf rust resistance genes ( Lr genes) responsible for resistance into new varieties and the pyramiding of these genes. Marker-assisted selection was used to incorporate the Lr genes currently effective in Hungary ( Lr9 , Lr24 , Lr25 , Lr29 ) into winter wheat varieties. The Lr genes were identified using STS, SCAR and RAPD markers closely linked to them. Investigations were made on how these markers could be utilised in plant breeding, and near-isogenic lines resembling the recurrent variety but each containing a different Lr gene were developed to form the initial stock for the pyramiding of resistance genes. The results indicate that the marker-assisted selection technique elaborated for resistance genes Lr24 , Lr25 and Lr29 can be applied simply and effectively in wheat breeding, while the detection of the Lr9 marker is uncertain.

scholarly journals Mining of Leaf Rust Resistance Genes Content in Egyptian Bread Wheat Collection

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1378
Author(s):  
Mohamed A. M. Atia ◽  
Eman A. El-Khateeb ◽  
Reem M. Abd El-Maksoud ◽  
Mohamed A. Abou-Zeid ◽  
Arwa Salah ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Field Evaluation ◽  
Leaf Rust Resistance ◽  
Adult Plant ◽  
Rust Disease ◽  
Wheat Varieties ◽  
Lr Genes ◽  
Slow Rusting

Wheat is a major nutritional cereal crop that has economic and strategic value worldwide. The sustainability of this extraordinary crop is facing critical challenges globally, particularly leaf rust disease, which causes endless problems for wheat farmers and countries and negatively affects humanity’s food security. Developing effective marker-assisted selection programs for leaf rust resistance in wheat mainly depends on the availability of deep mining of resistance genes within the germplasm collections. This is the first study that evaluated the leaf rust resistance of 50 Egyptian wheat varieties at the adult plant stage for two successive seasons and identified the absence/presence of 28 leaf rust resistance (Lr) genes within the studied wheat collection. The field evaluation results indicated that most of these varieties demonstrated high to moderate leaf rust resistance levels except Gemmeiza 1, Gemmeiza 9, Giza162, Giza 163, Giza 164, Giza 165, Sids 1, Sids 2, Sids 3, Sakha 62, Sakha 69, Sohag 3 and Bany Swif 4, which showed fast rusting behavior. On the other hand, out of these 28 Lr genes tested against the wheat collection, 21 Lr genes were successfully identified. Out of 15 Lr genes reported conferring the adult plant resistant or slow rusting behavior in wheat, only five genes (Lr13, Lr22a, Lr34, Lr37, and Lr67) were detected within the Egyptian collection. Remarkedly, the genes Lr13, Lr19, Lr20, Lr22a, Lr28, Lr29, Lr32, Lr34, Lr36, Lr47, and Lr60, were found to be the most predominant Lr genes across the 50 Egyptian wheat varieties. The molecular phylogeny results also inferred the same classification of field evaluation, through grouping genotypes characterized by high to moderate leaf rust resistance in one cluster while being highly susceptible in a separate cluster, with few exceptions.

A synteny map and disease resistance gene comparison between barley and the model monocot Brachypodium distachyon

Genome ◽  
2010 ◽  
Vol 53 (5) ◽  
pp. 406-417 ◽  
Author(s):  
Tom Drader ◽  
Andris Kleinhofs
Keyword(s):  
Disease Resistance ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Brachypodium Distachyon ◽  
Stem Rust Resistance ◽  
Rust Resistance Gene ◽  
Stem Rust Resistance Gene ◽  
High Level

Grass species have coevolved with current economically important crop pathogens over millions of years. During this time, speciation of current domestic crops has occurred, resulting in related yet divergent genomes. Here, we present a synteny map between the crop species Hordeum vulgare and the recently sequenced Brachypodium distachyon genome, focusing on regions known to harbor important barley disease resistance genes. The resistance genes have orthologous genes in Brachypodium that show conservation of the form and likely the function of the genes. The level of colinearity between the genomes is highly dependent on the region of interest and, at the DNA level or protein level, the gene of interest. The stem rust resistance gene Rpg1 has an ortholog with a high level of identity at the amino acid level, while the stem rust resistance gene Rpg5 has two orthologs with a high level of identity, one corresponding to the NBS-LRR domain and the other to the serine/threonine protein kinase domain, on different contigs. Interestingly, the predicted product of the Brachypodium Rpg1 ortholog contained a WD40 domain at the C-terminal end. The stem rust resistance gene rpg4 (actin depolymerizing factor 2) also has an ortholog with a high level of identity, in which one of the three residues indicated by allele sequencing in barley cultivars to be important in disease resistance is conserved. The syntenous region of the seedling spot blotch resistance locus, Rcs5, has a high level of colinearity that may prove useful in efforts to identify and clone this gene. A synteny map and orthologous resistance gene comparisons are presented.

Sign in / Sign up

Export Citation Format

Share Document