scholarly journals Evaluation of a Novel Molecular Marker Associated with the Tan Spot Disease Response in Wheat

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 513
Author(s):  
Pao Theen See ◽  
Caroline S. Moffat
Keyword(s):  
Molecular Marker ◽  
Hexaploid Wheat ◽  
Wheat Breeding ◽  
Tan Spot ◽  
Growth Stages ◽  
Disease Score ◽  
Wheat Varieties ◽  
Disease Response ◽  
Spot Disease ◽  
Tan Spot Disease

After nearly 40 years of DNA molecular marker development in plant breeding, the wheat research community has amassed an extensive collection of molecular markers which have been widely and successfully used for selection of agronomic, physiological and disease resistance traits in wheat breeding programs. Tan spot is a major fungal disease of wheat and a significant global economic challenge and is caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr). Here, the potential for using a PCR-based marker (Ta1AS3422) present on the short arm of wheat chromosome 1A, was evaluated for effectiveness in distinguishing tan spot disease susceptibility. The marker was initially screened against 40 commercial Australian hexaploid wheat varieties, and those that amplified the marker had an overall lower disease score (2.8 ± 0.7 for seedlings and 2.4 ± 0.4 for plants at the tillering stage), compared to those lacking the marker which exhibited a higher disease score (3.6 ± 0.8 for both growth stages). The potential of Ta1AS3422 as a marker for the tan spot disease response was further assessed against a panel of 100 commercial Australian hexaploid wheat varieties. A significant association was observed between marker absence/presence and tan spot disease rating (Pearson’s chi-squared test, χ2 (6) = 20.53, p = 0.002), with absence of Ta1AS3422 associated with susceptibility. This simple and cost-effective PCR-based marker may be useful for varietal improvement against tan spot, although further work is required to validate its effectiveness.

scholarly journals Evaluation of Pyrenophora tritici-repentis Infection of Wheat Heads

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 417
Author(s):  
Pao Theen See ◽  
Nikki Schultz ◽  
Caroline S. Moffat
Keyword(s):  
Recovery Rate ◽  
Pcr Detection ◽  
Tan Spot ◽  
Spore Suspension ◽  
Etiological Agent ◽  
Seed Infection ◽  
Grain Development ◽  
Spot Disease ◽  
Pyrenophora Tritici Repentis ◽  
Tan Spot Disease

The incidence of wheat head infection by Pyrenophora tritici-repentis (Ptr), the etiological agent of tan spot disease, was evaluated during grain development in a glasshouse experiment. Heads artificially inoculated with a Ptr spore suspension developed widespread brown spots across the spikelets, and mycelia and conidophores were observed on glumes and awns. Seeds of heavily infected heads were darkened and shrivelled, but no red smudge symptoms were apparent. The recovery rate of Ptr isolates from the inoculated wheat heads was low, and colonies that were re-isolated displayed an irregular morphology with reddish mycelia when grown on agar plates. The presence of Ptr on inoculated wheat heads was assessed directly via PCR detection, and a limitation of Ptr hyphae to proliferate beyond the point of contact of spore inoculum on floret tissues was observed. The systemic transmission of Ptr from infected seeds was minimal; however, saprophytic growth of the pathogen occurred on the senescing leaves of wheat plants grown from inoculated seeds. Thus, even though Ptr seed infection is not as common as foliar infection, infected seeds are still a source of disease inoculum and screening for pathogen contamination is advisable.

Hybrid necrosis as a problem in handling hexaploid × tetraploid wheat crosses

1980 ◽  
Vol 94 (2) ◽  
pp. 377-382 ◽  
Author(s):  
R. S. Gregory
Keyword(s):  
Hexaploid Wheat ◽  
Tetraploid Wheat ◽  
Wheat Breeding ◽  
Small Scale ◽  
Hybrid Necrosis ◽  
Agronomic Characters ◽  
Wheat Varieties ◽  
Hybrid Plants ◽  
Plant Breeding Institute ◽  
Selection For

SummaryA tetraploid wheat breeding programme was initiated at the Plant Breeding Institute in 1970. Hexaploid × tetraploid wheat crosses were expected to contribute to the improvement of the tetraploid wheats but severe hybrid necrosis caused the death of the pentaploid Fxhybrid plants in most crosses. The genotypes of tetraploid wheat selections derived from crosses involving Rampton Rivet, a non-carrier of Neu were determined by test crossing to hexaploid wheat varieties which were known to carry the Neim allele. Similarly, hexaploid wheat selections which did not carry Ne2 were identified from crosses involving Maris Ranger by test crossing to durum selections which carried the Nef allele. By the careful choice of one parent, hexaploid x tetraploid wheat crosses were then made which avoided the hybrid necrosis problem. Segregation of the Ne% gene was as expected but selection for agronomic characters appeared to favour the retention of the dominant allele of the Ne1gene. Nevertheless, test crossing on a relatively small scale still identified many non-carriers.

scholarly journals Phytopathological screening and molecular marker analysis of wheat germplasm from Kazakhstan and CIMMYT for resistance to tan spot

2019 ◽  
Vol 23 (7) ◽  
pp. 879-886 ◽  
Author(s):  
A. M. Kokhmetova ◽  
M. N. Atishova ◽  
M. T. Kumarbayeva ◽  
I. N. Leonova
Keyword(s):  
Molecular Marker ◽  
Wheat Breeding ◽  
Tan Spot ◽  
Leaf Spot Disease ◽  
Wheat Cultivars ◽  
Wheat Germplasm ◽  
Ptr Toxa ◽  
Marker Analysis ◽  
Race 1 ◽  
Molecular Marker Analysis

Tan spot caused by the fungus Pyrenophora tritici-repentis is an important leaf spot disease in wheat growing areas throughout the world. The study aims to identify wheat germplasm resistant to tan spot based on phytopathological screening and molecular marker analysis. A collection of 64 common wheat germplasms, including cultivars and breeding lines from Kazakhstan and CIMMYT, was assessed for tan spot resistance in greenhouse conditions and characterized using the Xfcp623 molecular marker, diagnostic for the Tsn1 gene. All wheat cultivars/lines varied in their reaction to tan spot isolate race 1, ranging from susceptible to resistant. Most accessions studied (53 %) were susceptible to Ptr race 1. Spring wheat cultivars were more susceptible to race 1 than winter wheat cultivars. As a result of genotyping, an insensitive reaction to Ptr ToxA was predicted in 41 wheat cultivars (64 %). The tsn1 gene carriers identified included 27 Kazakhstani and 14 CIMMYT cultivars/lines, demonstrating insensitivity to Ptr ToxA. The majority of the Tsn1 genotype were sensitive to race 1 and showed susceptibility to the pathogen in the field. Disease scores from seedling stage positively correlated with field disease ratings. Of particular interest are 27 wheat accessions that demonstrated resistance to spore inoculation by Ptr race 1, were characterized by insensitivity to ToxA and showed field resistance to the pathogen. The results of this study will contribute to wheat breeding programs for tan spot resistance with Marker Assisted Selection using the closely flanking markers.

Microsatellites as markers for Australian wheat improvement

2001 ◽  
Vol 52 (12) ◽  
pp. 1121 ◽  
Author(s):  
N. Harker ◽  
L. R. Rampling ◽  
M. R. Shariflou ◽  
M. J. Hayden ◽  
T. A. Holton ◽  
...  
Keyword(s):  
Molecular Marker ◽  
Genetic Markers ◽  
Wheat Breeding ◽  
Genetic Maps ◽  
Wheat Varieties ◽  
Breeding Programs ◽  
Wheat Improvement ◽  
Australian Wheat ◽  
Mapping Populations

Microsatellite markers have been shown to be highly polymorphic and simple to use in hexaploid wheat. This study aimed to establish microsatellites as informative markers for Australian wheat improvement. By screening microsatellites developed as part of the Wheat Microsatellite Consortium and other available microsatellite sources, 257 informative microsatellites for Australian wheat varieties were identified and reported in the Australian National Wheat Molecular Marker Program microsatellite database (http://www.scu.edu.au/research/cpcg/). Of these, 151 microsatellites identifying 172 loci were scored on at least 1 of 4 double haploid mapping populations and were then integrated, where possible, into existing genetic maps. Polymorphism information content values were calculated for most microsatellites to establish a reference for their value for future investigations. The mapping of available microsatellites enhances the quality of the genetic maps and may provide useful genetic markers for traits of interest to the Australian wheat breeding programs.

Endophytes from wheat as biocontrol agents against tan spot disease

2016 ◽  
Vol 92 ◽  
pp. 17-23 ◽  
Author(s):  
S. Larran ◽  
M.R. Simón ◽  
M.V. Moreno ◽  
M.P. Santamarina Siurana ◽  
A. Perelló
Keyword(s):  
Tan Spot ◽  
Biocontrol Agents ◽  
Spot Disease ◽  
Tan Spot Disease

Tan spot disease under the lenses of plant pathologists

2021 ◽  
pp. 589-622
Author(s):  
Reem Aboukhaddour ◽  
◽  
Mohamed Hafez ◽  
Stephen E. Strelkov ◽  
Myriam R. Fernandez ◽  
...  
Keyword(s):  
Plant Pathology ◽  
Crop Production ◽  
Plant Pathogens ◽  
Tan Spot ◽  
Cereal Crops ◽  
Comprehensive Review ◽  
Spot Disease ◽  
The Past ◽  
Pyrenophora Tritici Repentis ◽  
Tan Spot Disease

Necrotrophic plant pathogens pose an important threat to crop production, and many fungi in the Pleosporales have caused the sudden emergence of major epidemics on cereal crops. Tan spot of wheat, caused by Pyrenophora tritici-repentis, is one example, and since its emergence in the 1970s, scientists have explored its virulence and interactions with the host. In this chapter, our aim is to provide a comprehensive review of the most significant landmarks in tan spot research over the past 50 years from a plant pathology perspective.

scholarly journals Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease

2010 ◽  
Vol 121 (8) ◽  
pp. 1527-1539 ◽  
Author(s):  
Hetty C. van den Broeck ◽  
Hein C. de Jong ◽  
Elma M. J. Salentijn ◽  
Liesbeth Dekking ◽  
Dirk Bosch ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Hexaploid Wheat ◽  
Wheat Breeding ◽  
Wheat Varieties

scholarly journals SSR analysis of the genomic DNA of perspective Uzbek hexaploid winter wheat varieties

2018 ◽  
Vol 22 (6) ◽  
pp. 634-639
Author(s):  
A. T. Adylova ◽  
G. K. Norbekov ◽  
E. E. Khurshut ◽  
E. V.  Nikitina ◽  
F. N. Kushanov
Keyword(s):  
Microsatellite Loci ◽  
Hexaploid Wheat ◽  
Wheat Variety ◽  
Wheat Breeding ◽  
Wheat Varieties ◽  
Local Conditions ◽  
Microsatellite Primer ◽  
Ssr Analysis ◽  
The Mean ◽  
The Individual

The objective of this study was to investigate the genetic diversity of hexaploid wheat varieties of Uzbekistan breeding using simple sequence repeat (SSR) markers. These varieties are adapted to local conditions, and can be considered as the most important supplier of genetic resources for cultivation in Uzbekistan and other countries. Microsatellite markers are now most widely used and effective classes of DNA markers for genotyping, certification and classification of plant varieties. In this paper, genotyping results of 32 hexaploid wheat domestic varieties using 144 microsatellite primer pairs are presented. Microsatellite primer pairs were chosen from literature data and 36 primer pairs (from 144) gave polymorphic well-reproducible PCR-fragments. The individual SSR spectra differing in number of amplicons were obtained for each variety. A total number of 141 alleles for 36 microsatellite loci were detected. The number of alleles per locus ranged from 2 to 6, the mean number of alleles per locus (Na) was 3 alleles. For the studied genotypes group the effective number of alleles (ne) characterizing the loci by the allele frequency, varied from 1.7 to 4.8, the mean number of alleles per locus was 2.8. The expected heterozygosity (He) ranged from 0 to 0.792, averaging 0.626, in studied wheat population. The amplified fragment sizes ranged from 93 to 552 bp. The polymorphic index content (PIC) ranged from 0 to 0.758. A dendrogram was constructed using the alleles set of microsatellite loci, reflecting the phylogenetic differences of the studied hexaploid wheat varieties. It showed that Uzbekistan breeding varieties are divided into two main clusters, which may be evidence of their common origin.  A genetic formula has been developed for each Uzbek wheat variety. It can be used for identification, certification of these varieties, as well as for the selection of parental pairs in the wheat breeding programs.

scholarly journals Evaluation of a Multilocus Indel DNA Region for the Detection of the Wheat Tan Spot Pathogen Pyrenophora tritici-repentis

Plant Disease ◽  
2016 ◽  
Vol 100 (11) ◽  
pp. 2215-2225 ◽  
Author(s):  
Pao Theen See ◽  
Caroline S. Moffat ◽  
Joseph Morina ◽  
Richard P. Oliver
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Tan Spot ◽  
Qpcr Assay ◽  
Rapid Screening ◽  
Leaf Spot Disease ◽  
Growth Stages ◽  
Spot Disease ◽  
Pyrenophora Tritici Repentis ◽  
Specificity And Sensitivity ◽  
Field Samples

Tan spot or yellow (leaf) spot disease of wheat (Triticum spp.) is caused by Pyrenophora tritici-repentis, a necrotrophic fungal pathogen that is widespread throughout the main wheat-growing regions in the world. This disease is currently the single most economically important crop disease in Australia. In this study, a real-time quantitative polymerase chain reaction (qPCR) assay was developed as a diagnostic tool to detect the pathogen on wheat foliar tissue. A multicopy locus (PtrMulti) present in the P. tritici-repentis genome was assessed for its suitability as a qPCR probe. The primer pair PtrMulti_F/R that targets the region was evaluated with respect to species specificity and sensitivity. A PtrMulti SYBR qPCR assay was developed and proved to be suitable for the identification and relative quantification of P. tritici-repentis with a detection limit of DNA levels at <0.1 pg. Variation of the PtrMulti copy number between the geographical representatives of P. tritici-repentis strains examined was minimal, with the range of 63 to 85 copies per genome. For naturally infected wheat field samples, the incidence of P. tritici-repentis DNA on leaves quantified by qPCR varied up to 1,000-fold difference in the concentration, with a higher incidence of DNA occurring on the lower canopy for most of the growth stages examined. At the early growth stages, qPCR assay was able to detect P. tritici-repentis DNA on the younger leaves in the absence of visible tan spot lesions. These results demonstrate the potential of PtrMulti probe to be used for early detection and rapid screening of tan spot disease on wheat plants.

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