scholarly journals Methodical Considerations and Resistance Evaluation against Fusarium graminearum and F. culmorum Head Blight in Wheat. Part 3. Susceptibility Window and Resistance Expression

2020 ◽  
Vol 8 (5) ◽  
pp. 627 ◽  
Author(s):  
Andrea György ◽  
Beata Tóth ◽  
Monika Varga ◽  
Akos Mesterhazy
Keyword(s):  
Winter Wheat ◽  
Fusarium Graminearum ◽  
Disease Index ◽  
Head Blight ◽  
Resistance Level ◽  
Wheat Genotypes ◽  
Fusarium Infection ◽  
Host Stage ◽  
Important Trait ◽  
Resistance Expression

Flowering is the most favorable host stage for Fusarium infection in wheat, which is called the susceptibility window (SW). It is not known how long it takes, how it changes in different resistance classes, nor how stable is the plant reaction in the SW. We have no information, how the traits disease index (DI), Fusarium-damaged kernel rate (FDK), and deoxynivalenol (DON) respond within the 16 days period. Seven winter wheat genotypes differing in resistance were tested (2013–2014). Four Fusarium isolates were used for inoculation at mid-anthesis, and 4, 8, 11, 13, and 16 days thereafter. The DI was not suitable to determine the length of the SW. In the Fusarium-damaged kernels (FDK), a sharp 50% decrease was found after the 8th day. The largest reduction (above 60%) was recorded for DON at each resistance level between the 8th and 11th day. This trait showed the SW most precisely. The SW is reasonably stable in the first 8–9 days. This fits for all resistance classes. The use of four isolates significantly improved the reliability and credit of the testing. The stable eight-day long SW helps to reduce the number of inoculations. The most important trait to determine the SW is the DON reaction and not the visual symptoms.

scholarly journals The Influence of the Dilution Rate on the Aggressiveness of Inocula and the Expression of Resistance against Fusarium Head Blight in Wheat

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 943 ◽  
Author(s):  
Beata Toth ◽  
Andrea Gyorgy ◽  
Monika Varga ◽  
Akos Mesterhazy
Keyword(s):  
Fusarium Head Blight ◽  
Dilution Rate ◽  
Fusarium Graminearum ◽  
Fusarium Culmorum ◽  
Disease Index ◽  
Head Blight ◽  
Important Trait

In previous research, conidium concentrations varying between 10,000 and 1,000,000/mL have not been related to any aggressiveness test. Therefore, two Fusarium graminearum and two Fusarium culmorum isolates were tested in the field on seven genotypes highly differing in resistance at no dilution, and 1:1, 1:2, 1:4, 1:8, and 1:16 dilutions in two years (2013 and 2014). The isolates showed different aggressiveness, which changed significantly at different dilution rates for disease index (DI), Fusarium-damaged kernels (FDK), and deoxynivalenol (DON). The traits also had diverging responses to the infection. The effect of the dilution could not be forecasted. The genotype ranks also varied. Dilution seldomly increased aggressiveness, but often lower aggressiveness occurred at high variation. The maximum and minimum values varied between 15% and 40% for traits and dilutions. The reductions between the non-diluted and diluted values (total means) for DI ranged from 6% and 33%, for FDK 8.3–37.7%, and for DON 5.8–44.8%. The most sensitive and most important trait was DON. The introduction of the aggressiveness test provides improved regulation compared to the uncontrolled manipulation of the conidium concentration. The use of more isolates significantly increases the credibility of phenotyping in genetic and cultivar registration studies.

Near-infrared versus visual sorting of Fusarium-damaged kernels in winter wheat

2008 ◽  
Vol 88 (6) ◽  
pp. 1087-1089 ◽  
Author(s):  
Stephen N Wegulo ◽  
Floyd E Dowell
Keyword(s):  
Quality Assurance ◽  
Winter Wheat ◽  
Fusarium Head Blight ◽  
Key Words ◽  
Fusarium Graminearum ◽  
Near Infrared ◽  
Strongly Correlated ◽  
Head Blight ◽  
Rater Reliability ◽  
Key Words Wheat

Fusarium head blight (scab) of wheat, caused by Fusarium graminearum, often results in shriveled and/or discolored kernels, which are referred to as Fusarium-damaged kernels (FDK). FDK is a major grain grading factor and therefore is routinely determined for purposes of quality assurance. Measurement of FDK is usually done visually. Visual sorting can be laborious and is subject to inconsistencies resulting from variability in intra-rater repeatability and/or inter-rater reliability. The ability of a single-kernel near-infrared (SKNIR) system to detect FDK was evaluated by comparing FDK sorted by the system to FDK sorted visually. Visual sorting was strongly correlated with sorting by the SKNIR system (0.89 ≤ r ≤ 0.91); however, the SKNIR system had a wider range of FDK detection and was more consistent. Compared with the SKNIR system, visual raters overestimated FDK in samples with a low percentage of Fusarium-damaged grain and underestimated FDK in samples with a high percentage of Fusarium-damaged grain. Key words: Wheat, Fusarium head blight, Fusarium-damaged kernels, single-kernel near-infrared

scholarly journals Chemical Activation of the Ethylene Signaling Pathway Promotes Fusarium graminearum Resistance in Detached Wheat Heads

2019 ◽  
Vol 109 (5) ◽  
pp. 796-803 ◽  
Author(s):  
Nora A. Foroud ◽  
Reyhaneh Pordel ◽  
Ravinder K. Goyal ◽  
Daria Ryabova ◽  
Anas Eranthodi ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Fusarium Graminearum ◽  
Host Response ◽  
Chemical Activation ◽  
Disease Spread ◽  
Plant Signaling ◽  
Head Blight ◽  
Wheat Genotypes ◽  
Ethylene Signaling Pathway

Plant signaling hormones such as ethylene have been shown to affect the host response to various pathogens. Often, the resistance responses to necrotrophic fungi are mediated through synergistic interactions of ethylene (ET) with the jasmonate signaling pathway. On the other hand, ET is also an inducer of senescence and cell death, which could be beneficial for some invading necrotrophic pathogens. Fusarium graminearum, a causative agent in Fusarium head blight of wheat, is a hemibiotrophic pathogen, meaning it has both biotrophic and necrotrophic phases during the course of infection. However, the role of ET signaling in the host response to Fusarium spp. is unclear; some studies indicate that ET mediates resistance, while others have shown that it is associated with susceptibility. These discrepancies could be related to various aspects of different experimental designs, and suggest that the role of ET signaling in the host response to FHB is potentially dependent on interactions with some undetermined factors. To investigate whether wheat genotype can influence the ET-mediated response to FHB, the effect of chemical treatments affecting the ET pathway was studied in six wheat genotypes in detached-head assays. ET-inhibitor treatments broke down resistance to both initial infection and disease spread in three resistant wheat genotypes, whereas ET-enhancer treatments resulted in reduced susceptibility in three susceptible genotypes. The results presented here show that the ET signaling can mediate FHB resistance to F. graminearum in different wheat backgrounds.

scholarly journals The Effect of Fusarium Graminearum Inoculation on Winter Wheat at ARDS Turda,

2012 ◽  
Vol 69 (1) ◽  
Author(s):  
Rozalia KADAR ◽  
Amin Said SARDAR Amin Said SARDAR
Keyword(s):  
Winter Wheat ◽  
Fusarium Graminearum ◽  
Head Blight ◽  
Fusarium Spp ◽  
Flowering Stage ◽  
Stage Number ◽  
Precise Data

Fusarium  Head Blight (FHB), caused by Fusarium spp., has become one of the most destructive diseases in the world’s wheat growing areas, especially in humid and semihumid regions. More precise data relating the effects of FHB on yield have been obtained using inoculated trials. The situation is totally changed by inoculation with Fusarium. Because this disease affected wheat in flowering stage, number of grain/spike is strongly diminished. It can be observed the behavior of Turda 95 and Dumbrava varieties created at ARDS Turda which lose less number of grain than other cultivars.

scholarly journals Methodical Considerations and Resistance Evaluation against F. graminearum and F. culmorum Head Blight in Wheat. The Influence of Mixture of Isolates on Aggressiveness and Resistance Expression

2020 ◽  
Vol 8 (7) ◽  
pp. 1036 ◽  
Author(s):  
Akos Mesterhazy ◽  
Andrea Gyorgy ◽  
Monika Varga ◽  
Beata Toth
Keyword(s):  
Fusarium Head Blight ◽  
Genetic Research ◽  
Disease Index ◽  
Head Blight ◽  
Resistance Evaluation ◽  
Fhb Resistance ◽  
Correct Data ◽  
Resistance Tests ◽  
Better Than ◽  
Resistance Expression

In resistance tests to Fusarium head blight (FHB), the mixing of inocula before inoculation is normal, but no information about the background of mixing was given. Therefore, four experiments (2013–2015) were made with four independent isolates, their all-possible (11) mixtures and a control. Four cultivars with differing FHB resistance were used. Disease index (DI), Fusarium damaged kernels (FDK) and deoxynivalenol (DON) were evaluated. The isolates used were not stable in aggressiveness. Their mixtures did not also give a stable aggressiveness; it depended on the composition of mix. The three traits diverged in their responses. After the mixing, the aggressiveness was always less than that of the most pathogenic component was. However, in most cases it was significantly higher than the arithmetical mean of the participating isolates. A mixture was not better than a single isolate was. The prediction of the aggressiveness level is problematic even if the aggressiveness of the components was tested. Resistance expression is different in the mixing variants and in the three traits tested. Of them, DON is the most sensitive. More reliable resistance and toxin data can be received when instead of one more independent isolates are used. This is important when highly correct data are needed (genetic research or cultivar registration).

scholarly journals Characterization of QTL and eQTL controlling early Fusarium graminearum infection and deoxynivalenol levels in a Wuhan 1 x Nyubai doubled haploid wheat population

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
François Fauteux ◽  
Yunli Wang ◽  
Hélène Rocheleau ◽  
Ziying Liu ◽  
Youlian Pan ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Doubled Haploid ◽  
Expression Patterns ◽  
Doubled Haploid Population ◽  
Post Inoculation ◽  
Head Blight ◽  
Wheat Genotypes ◽  
Wheat Population ◽  
Fhb Resistance ◽  
Moderately Resistant

Abstract Background Fusarium head blight (FHB) is a major disease of cereal crops, caused by the fungal pathogen Fusarium graminearum and related species. Breeding wheat for FHB resistance contributes to increase yields and grain quality and to reduce the use of fungicides. The identification of genes and markers for FHB resistance in different wheat genotypes has nevertheless proven challenging. Results In this study, early infection by F. graminearum was analyzed in a doubled haploid population derived from the cross of the moderately resistant wheat genotypes Wuhan 1 and Nyubai. Three quantitative trait loci (QTL) were identified: 1AL was associated with lower deoxynivalenol content, and 4BS and 5A were associated with reduced F. graminearum infection at 2 days post inoculation. Early resistance alleles were inherited from Wuhan 1 for QTL 1AL and 4BS and inherited from Nyubai for the 5A QTL. Cis and trans expression QTL (eQTL) were identified using RNA-seq data from infected head samples. Hotspots for trans eQTL were identified in the vicinity of the 1AL and 4BS QTL peaks. Among differentially expressed genes with cis eQTL within the QTL support intervals, nine genes had higher expression associated with FHB early resistance, and four genes had higher expression associated with FHB early susceptibility. Conclusions Our analysis of genotype and gene expression data of wheat infected by F. graminearum identified three QTL associated with FHB early resistance, and linked genes with eQTL and differential expression patterns to those QTL. These findings may have applications in breeding wheat for early resistance to FHB.

scholarly journals Resistance in Winter Wheat Lines to Initial Infection and Spread Within Spikes by Deoxynivalenol and Nivalenol Chemotypes of Fusarium graminearum

Plant Disease ◽  
2011 ◽  
Vol 95 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Peter Horevaj ◽  
Liane R. Gale ◽  
Eugene A. Milus
Keyword(s):  
United States ◽  
Winter Wheat ◽  
Fusarium Graminearum ◽  
The United States ◽  
Blight Resistance ◽  
Head Blight ◽  
Initial Infection ◽  
Additional Information ◽  
Progress Curve ◽  
Wheat Lines

Head blight of wheat in the United States is caused primarily by the deoxynivalenol (DON)-producing chemotype of Fusarium graminearum. However, the discovery of the nivalenol (NIV) chemotype of F. graminearum in Louisiana and Arkansas necessitates having resistance in wheat to both chemotypes. The objectives of this research were to quantify resistance of selected winter wheat lines to initial infection and pathogen spread within spikes, to determine whether wheat lines selected for resistance to the DON chemotype also have resistance to the NIV chemotype, and to improve the methods for quantifying resistance to initial infection. A susceptible check (Coker 9835) and 15 winter wheat lines, which are adapted to the southeastern United States and possess diverse sources of head blight resistance, were evaluated for head blight resistance in a series of greenhouse and growth-chamber experiments. Significant levels of resistance to both initial infection and spread within a spike were found among the lines, and lines with resistance to isolates of the DON chemotype had even higher levels of resistance to isolates of the NIV chemotype. Quantifying resistance to initial infection was improved by standardizing the inoculum and environmental conditions. Additional information related to resistance to spread within a spike was obtained by calculating the area under the disease progress curve from 7 to 21 days after inoculation.

scholarly journals Fitness traits of deoxynivalenol and nivalenol-producing Fusarium graminearum species complex strains from wheat

2017 ◽  
Author(s):  
C.P. Nicolli ◽  
F.J. Machado ◽  
P. Spolti ◽  
E.M. Del Ponte
Keyword(s):  
Fusarium Graminearum ◽  
Mycelial Growth ◽  
Species Complex ◽  
Head Blight ◽  
Fitness Traits ◽  
Fusarium Graminearum Species Complex ◽  
Important Trait ◽  
South Of Brazil ◽  
Species Specific ◽  
Moderately Resistant

AbstractFusarium graminearum of the 15-acetyl(A)deoxynivalenol(D0N) chemotype is the main cause of Fusarium head blight (FHB) of wheat in south of Brazil. However, 3-ADON and nivalenol(NIV) chemotypes have been found in other members of the species complex causing FHB in wheat. To improve our understanding of the pathogen ecology, we assessed a range of fitness-related traits in a sample of 30 strains representatives of 15-ADON (F. graminearum), 3-ADON (F. cortaderiae and F. austroamericanum) and NIV (F. meridionale and F. cortaderiae). These included: perithecia formation on three cereal-based substrates, mycelial growth at two suboptimal temperatures, sporulation and germination, pathogenicity towards a susceptible and a moderately resistant cultivar and sensitivity to tebuconazole. The most important trait favoring F. graminearum was its 2x higher sexual fertility (> 40% PPI = perithecia production index) than the other species (< 30% PPI); PPI varied among substrates (maize > rice > wheat). In addition, sensitivity to tebuconazole appeared lower in F. graminearum which had the only strain with EC50 > 1 ppm. In the pathogenicity assays, the DON-producers were generally more aggressive (1.5 to 2x higher final severity) towards the two cultivars, with 3-ADON or 15-ADON leading to higher area under the severity curve than the NIV strains in the susceptible and moderately resistant cv., respectively. There was significant variation among strains of a same species with regards asexual fertility (mycelial growth, macroconidia production and germination), which suggest a strain-rather than a species-specific differences. These results contribute new knowledge to improve our understanding of the pathogen-related traits that may explain the dominance of certain members of the species complex in specific wheat agroecosystems.

scholarly journals Quantification of Fusarium graminearum in Harvested Grain by Real-Time Polymerase Chain Reaction to Assess Efficacies of Fungicides on Fusarium Head Blight, Deoxynivalenol Contamination, and Yield of Winter Wheat

2009 ◽  
Vol 99 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Y. J. Zhang ◽  
P. S. Fan ◽  
X. Zhang ◽  
C. J. Chen ◽  
M. G. Zhou
Keyword(s):  
Polymerase Chain Reaction ◽  
Winter Wheat ◽  
Fusarium Head Blight ◽  
Real Time ◽  
Fusarium Graminearum ◽  
Disease Assessment ◽  
Strong Positive Correlation ◽  
Head Blight ◽  
Chain Reaction ◽  
Polymerase Chain

We used a real time polymerase chain reaction-based assay and visual disease assessment to evaluate the efficacies of Js399-19, tebuconazole, a mixture of tebuconazole and thiram, azoxystrobin, carbendazim, and thiram on the development of Fusarium head blight (FHB) and deoxynivalenol (DON) contamination and on the yield of winter wheat (cv. Nannong no. 9918) after artificial inoculation under field conditions with Fusarium graminearum. The incidence of infected spikelets (IIS), amount of F. graminearum DNA (Tri5 DNA), total DON (containing DON, 3-acetyl-deoxynivalenol, and 15-acetyl-deoxynivalenol) concentration, and 1,000-grain weight (TGW) were quantified in 2006 and 2007. A strong positive correlation was found between IIS or Log10Tri5 DNA and total DON concentration in the harvested grain. The Js399-19, tebuconazole, and the mixture of tebuconazole and thiram significantly reduced IIS of FHB, amount of Tri5 DNA, and total DON within the grain and increased TGW. Although azoxystrobin, carbendazim, and thiram can increase TGW, they had no effect on the occurrence of F. graminearum compared with those of the untreated controls. Surprisingly, azoxystrobin and carbendazim significantly increased the total DON content in the harvested grain because they might have stimulated the amount of total DON production per Tri5 DNA. The fungicides Js399-19, tebuconazole, and the mixture of tebuconazole and thiram were the most effective in controlling FHB and reducing DON contamination of the wheat.

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