Estimating the Production and Release of Ascospores from a Field-Scale Source of Fusarium graminearum Inoculum

Fusarium head blight (FHB) is a devastating disease of wheat and barley caused by the fungus Fusarium graminearum. The fungus produces spores that may be transported over long distances in the atmosphere. In order to predict the atmospheric transport of F. graminearum, the production and release of ascospores must be known. We conducted a series of laboratory and field experiments to estimate perithecia production and ascospore release from a field-scale source of F. graminearum inoculum. Perithecia were generated on artificial (carrot agar) and natural (corn stalk) substrates. Artificial substrates produced 15 ± 0.4 perithecia/cm2, and natural substrates produced 44 ± 2 perithecia/cm2. Eighty perithecia were excised from both substrate types and allowed to release ascospores every 24 h. Perithecia generated from artificial and natural substrates released a mean of 104 ± 5 and 276 ± 16 ascospores over 10 days, respectively. A volumetric spore trap was placed inside a 1-acre clonal source of inoculum in 2011 and 2012. Results indicated that ascospores were released predominantly during the night (1900 to 0700). Estimates of ascospore production for our field-scale sources of inoculum were approximately 400 million ascospores/day for 10 days. Mathematical models can use estimates of ascospore production to assist in predicting the transport of F. graminearum.

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Impact of the biofungicide tetramycin on the development of Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat

World Mycotoxin Journal ◽

10.3920/wmj2019.2494 ◽

2020 ◽

Vol 13 (2) ◽

pp. 235-246

Author(s):

W.Q. Shi ◽

L.B. Xiang ◽

D.Z. Yu ◽

S.J. Gong ◽

L.J. Yang

Keyword(s):

Fusarium Head Blight ◽

Fusarium Graminearum ◽

Spore Germination ◽

Field Experiments ◽

Synergistic Effects ◽

Field Trials ◽

Head Blight ◽

Mycelium Growth ◽

Key Aspects

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.

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The Spread of a Released Clone of Gibberella zeae from Different Amounts of Infested Corn Residue

Plant Disease ◽

10.1094/pdis-03-11-0218 ◽

2011 ◽

Vol 95 (11) ◽

pp. 1458-1464 ◽

Cited By ~ 9

Author(s):

Melissa D. Keller ◽

Wade E. Thomason ◽

David G. Schmale

Keyword(s):

Fusarium Graminearum ◽

Wheat Cultivar ◽

Gibberella Zeae ◽

Corn Stalk ◽

Head Blight ◽

Inoculum Sources ◽

Length Polymorphisms ◽

Amplified Fragment Length Polymorphisms ◽

Corn Residue ◽

Moderately Resistant

Corn residue is a significant source of inoculum for epidemics of Fusarium head blight (FHB) in wheat and barley, but little is known about the influence of different amounts of corn residue on FHB. We monitored the spread of a released clone of Gibberella zeae (Fusarium graminearum), causal agent of FHB, from small 0.84-m-diameter research plots containing 45, 200, or 410 g of infested corn stalk pieces in winter wheat and barley fields in Virginia over 3 years (2008 to 2010). The fungus was recaptured through the collection of wheat and barley spikes at 0 and 3 m from the source and the released clone was identified in heterogeneous background populations using amplified fragment length polymorphisms. Results showed a slightly greater intensity of recovery of the clone at a greater distance when more infested residue was present. Plots containing larger amounts of inoculum (410 g) generally resulted in a smaller decline of recovery of the clone at 3 m from the source, indicating a greater spread from the larger inoculum source. The clone was also recovered at distances ≥18 m from inoculum sources. Larger amounts of corn residue generally had less influence on clone recovery in plots containing a moderately resistant wheat cultivar than those containing a susceptible wheat cultivar.

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Effects of Temperature and Moisture on Development of Fusarium graminearum Perithecia in Maize Stalk Residues

Applied and Environmental Microbiology ◽

10.1128/aem.02436-15 ◽

2015 ◽

Vol 82 (1) ◽

pp. 184-191 ◽

Cited By ~ 16

Author(s):

Valentina Manstretta ◽

Vittorio Rossi

Keyword(s):

Fusarium Graminearum ◽

Crop Residues ◽

Head Blight ◽

Dispersal Patterns ◽

Content Type ◽

Predominant Component ◽

Effects Of Temperature ◽

Ascospore Production ◽

Maize Stalks ◽

Over Time

ABSTRACTFusarium graminearumis the predominant component of the Fusarium head blight complex of wheat.F. graminearumascospores, which initiate head infection, mature in perithecia on crop residues and become airborne. The effects of temperature (T) and moisture on perithecium production and maturation and on ascospore production on maize stalk residues were determined. In the laboratory, perithecia were produced at temperatures between 5 and 30°C (the optimum was 21.7°C) but matured only at 20 and 25°C. Perithecia were produced when relative humidity (RH) was ≥75% but matured only when RH was ≥85%; perithecium production and maturation increased with RH. Equations describing perithecium production and maturation over time as a function ofTand RH (R2> 0.96) were developed. Maize stalks were also placed outdoors on three substrates: a grass lawn exposed to rain; a constantly wet, spongelike foam exposed to rain; and a grass lawn protected from rain. No perithecia were produced on stalks protected from rain. Perithecium production and maturation were significantly higher on the constantly wet foam than on the intermittently wet lawn (both exposed to rain). Ascospore numbers but not their dispersal patterns were also affected by the substrate.

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Low-Cost Spore Traps: An Efficient Tool to Manage Fusarium Head Blight through Improved Cropping Systems

Agronomy ◽

10.3390/agronomy11050987 ◽

2021 ◽

Vol 11 (5) ◽

pp. 987

Author(s):

Hans-Rudolf Forrer ◽

Annegret Pflugfelder ◽

Tomke Musa ◽

Susanne Vogelgsang

Keyword(s):

Fusarium Head Blight ◽

Field Experiments ◽

Cropping Systems ◽

Low Cost ◽

Infected Plant ◽

Petri Dish ◽

Head Blight ◽

Host Genotype ◽

Spore Trap ◽

Power Sources

Fusarium head blight (FHB) is a devastating disease of wheat. Worldwide, Fusarium graminearum is the most dominant FHB-causing species. Its most common toxin, deoxynivalenol (DON), impairs food and feed safety and has an enormous economic impact. Agronomic factors such as crop rotation, soil management and host genotype strongly influence the occurrence of F. graminearum. Infected plant debris from previous crops, on which perithecia and ascospores develop, represent the main source for FHB, and hence, improved cropping systems aim to reduce this inoculum to decrease the infection risk. The best measure to evaluate the disease pressure is spore traps that detect deposited airborne ascospores. Commercial spore traps are expensive and require power sources, thus, they are not suitable for investigations in field experiments with different treatments. In consequence, we developed spore traps containing a Petri dish with Fusarium-selective agar, protected by aluminum dishes and attached on a wooden board. We compared the data of our low-cost trap with those of a commercial high-throughput jet sampler and obtained equivalent results. In field experiments to compare cropping systems, we observed a high correlation between the DON content in wheat grains and the number of colonies from deposited spores. Our spore trap proved to be a highly valuable tool to not only study FHB epidemiology but also to identify innovative cropping systems with a lower risk for FHB and DON contamination.

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Fitness Attributes of Fusarium graminearum Isolates from Wheat in New York Possessing a 3-ADON or 15-ADON Trichothecene Genotype

Phytopathology ◽

10.1094/phyto-07-13-0206-r ◽

2014 ◽

Vol 104 (5) ◽

pp. 513-519 ◽

Cited By ~ 28

Author(s):

Pierri Spolti ◽

Emerson M. Del Ponte ◽

Jaime A. Cummings ◽

Yanhong Dong ◽

Gary C. Bergstrom

Keyword(s):

New York ◽

Fusarium Graminearum ◽

Wheat Cultivar ◽

Wheat Variety ◽

Head Blight ◽

Wheat Kernels ◽

Ascospore Production

In all, 50 isolates of Fusarium graminearum from wheat spikes in New York, including 25 isolates each of the 15-acetyl-deoxynivalenol (15-ADON) and 3-ADON genotype, were tested to determine whether 3-ADON isolates are more fit for saprophytic survival and pathogenicity on wheat spikes than are 15-ADON isolates. The isolates were characterized and compared for 14 different attributes of saprophytic fitness and pathogenic fitness on a susceptible wheat variety. Isolates of the two genotypes could not be differentiated for most of these traits. Three principle components—ascospore production on corn stalks, total trichothecene amount in wheat kernels, and incidence of diseased spikelets up from the point of inoculation—accounted for 29.4, 18.9, and 10.8% of the variation among the isolates, respectively. A bootstrapping procedure grouped the isolates into two distinct groups, with 27 and 23 isolates each, with isolates from both genotypes represented in similar proportions (15-ADON/3-ADON, n = 14/13 and 11/12). Within the contemporary population of F. graminearum causing wheat head blight in New York, isolates with a 3-ADON genotype did not possess any detectable advantage over isolates with a 15-ADON genotype in saprophytic fitness or in pathogenic fitness on a susceptible wheat cultivar.

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Monitoring the Long-Distance Transport of Fusarium graminearum from Field-Scale Sources of Inoculum

Plant Disease ◽

10.1094/pdis-06-13-0664-re ◽

2014 ◽

Vol 98 (4) ◽

pp. 504-511 ◽

Cited By ~ 34

Author(s):

Aaron J. Prussin ◽

Qing Li ◽

Rimy Malla ◽

Shane D. Ross ◽

David G. Schmale

Keyword(s):

Fusarium Graminearum ◽

Logistic Regression Model ◽

Management Strategies ◽

Field Scale ◽

Head Blight ◽

Long Distance ◽

Long Distance Transport ◽

Polymorphic Microsatellites ◽

Distance Transport ◽

Clonal Isolate

The fungus Fusarium graminearum causes Fusarium head blight (FHB) of wheat. Little is known about dispersal of the fungus from field-scale sources of inoculum. We monitored the movement of a clonal isolate of F. graminearum from a 3,716 m2 (0.372 ha) source of inoculum over two field seasons. Ground-based collection devices were placed at distances of 0 (in the source), 100, 250, 500, 750, and 1,000 m from the center of the clonal sources of inoculum. Three polymorphic microsatellites were used to identify the released clone from 1,027 isolates (790 in 2011 and 237 in 2012) of the fungus. Results demonstrated that the recovery of the released clone decreased at greater distances from the source. The majority (87%, 152/175 in 2011; 77%, 74/96 in 2012) of the released clone was recaptured during the night (1900 to 0700). The released clone was recovered up to 750 m from the source. Recovery of the released clone followed a logistic regression model and was significant (P < 0.041 for all slope term scenarios) as a function of distance from the source of inoculum. This work offers a means to experimentally determine the dispersal kernel of a plant pathogen, and could be integrated into management strategies for FHB.

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Impact of microalgal phenolic extracts on the control of Fusarium graminearum and deoxynivalenol contamination in wheat

World Mycotoxin Journal ◽

10.3920/wmj2018.2427 ◽

2019 ◽

Vol 12 (4) ◽

pp. 367-378 ◽

Cited By ~ 1

Author(s):

P.T. Scaglioni ◽

V. Scarpino ◽

F. Marinaccio ◽

F. Vanara ◽

E. Badiale Furlong ◽

...

Keyword(s):

Grain Yield ◽

Fusarium Graminearum ◽

Untreated Control ◽

Field Experiments ◽

Septoria Tritici Blotch ◽

Septoria Tritici ◽

In Vitro Experiments ◽

Head Blight ◽

Phenolic Extracts

In this study, microalgal phenolic extracts (MPE) of Nannochloropsis sp. and Spirulina sp. were tested in in vitro experiments and, in comparison with synthetic fungicides, in field experiments, for their ability to control Fusarium graminearum development and limit deoxynivalenol (DON) contamination. In in vitro experiments, the Nannochloropsis and Spirulina extracts inhibited fungal biomass by 34 and 25%, respectively, compared with the untreated control. This effect was confirmed by a reduction in ergosterol production (-80% for Nannochloropsis and -75% for Spirulina) and in DON content (-97% for Nannochloropsis and -62% for Spirulina). In field experiments, application of the fungicide prothioconazole and prothioconazole + tebuconazole resulted in control of Fusarium head blight (FHB) and foliar disease, leading to a significant increase in grain yield (+13%) and a reduction in DON content (-46%) compared to the untreated control. The application of MPE at wheat flowering reduced the severity of FHB compared with the control (-35% for Spirulina and -39% for Nannochloropsis). However, the MPE did not significantly control foliar diseases (Septoria tritici blotch) and therefore did not enhance the grain yield. Moreover, no effect in reducing the DON content in comparison to the control was observed in the field. In view of that, the use of MPE in wheat fields as real alternatives to conventional fungicides requires the discovery of solutions to empower their persistence and efficacy.

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Using UAV-Based Hyperspectral Imagery to Detect Winter Wheat Fusarium Head Blight

Remote Sensing ◽

10.3390/rs13153024 ◽

2021 ◽

Vol 13 (15) ◽

pp. 3024

Author(s):

Huiqin Ma ◽

Wenjiang Huang ◽

Yingying Dong ◽

Linyi Liu ◽

Anting Guo

Keyword(s):

Winter Wheat ◽

Fusarium Head Blight ◽

Hyperspectral Imagery ◽

Spectral Feature ◽

Support Vector ◽

Detection Accuracy ◽

Feature Combination ◽

Field Scale ◽

Head Blight ◽

Detection Model

Fusarium head blight (FHB) is a major winter wheat disease in China. The accurate and timely detection of wheat FHB is vital to scientific field management. By combining three types of spectral features, namely, spectral bands (SBs), vegetation indices (VIs), and wavelet features (WFs), in this study, we explore the potential of using hyperspectral imagery obtained from an unmanned aerial vehicle (UAV), to detect wheat FHB. First, during the wheat filling period, two UAV-based hyperspectral images were acquired. SBs, VIs, and WFs that were sensitive to wheat FHB were extracted and optimized from the two images. Subsequently, a field-scale wheat FHB detection model was formulated, based on the optimal spectral feature combination of SBs, VIs, and WFs (SBs + VIs + WFs), using a support vector machine. Two commonly used data normalization algorithms were utilized before the construction of the model. The single WFs, and the spectral feature combination of optimal SBs and VIs (SBs + VIs), were respectively used to formulate models for comparison and testing. The results showed that the detection model based on the normalized SBs + VIs + WFs, using min–max normalization algorithm, achieved the highest R2 of 0.88 and the lowest RMSE of 2.68% among the three models. Our results suggest that UAV-based hyperspectral imaging technology is promising for the field-scale detection of wheat FHB. Combining traditional SBs and VIs with WFs can improve the detection accuracy of wheat FHB effectively.

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Screening of Durum Wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) Italian Cultivars for Susceptibility to Fusarium Head Blight Incited by Fusarium graminearum

Plants ◽

10.3390/plants10010068 ◽

2020 ◽

Vol 10 (1) ◽

pp. 68

Author(s):

Gaetano Bentivenga ◽

Alfio Spina ◽

Karim Ammar ◽

Maria Allegra ◽

Santa Olga Cacciola

Keyword(s):

Durum Wheat ◽

Fusarium Head Blight ◽

Fusarium Graminearum ◽

Triticum Turgidum ◽

Disease Incidence ◽

Morphological Characteristics ◽

Pcr Amplification ◽

Conidial Suspension ◽

Head Blight ◽

Italian Origin

In 2009, a set of 35 cultivars of durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) of Italian origin was screened for fusarium head blight (FHB) susceptibility at CIMMYT (Mexico) and in the 2019–20 cropping season, 16 of these cultivars, which had been included in the Italian National Plant Variety Register, were tested again in southern and northern Italy. Wheat cultivars were artificially inoculated during anthesis with a conidial suspension of Fusarium graminearum sensu lato using a standard spray inoculation method. Inoculum was a mixture of mono-conidial isolates sourced in the same areas where the trials were performed. Isolates had been characterized on the basis of morphological characteristics and by DNA PCR amplification using a specific primer set and then selected for their virulence and ability to produce mycotoxins. The susceptibility to FHB was rated on the basis of the disease severity, disease incidence and FHB index. Almost all of the tested cultivars were susceptible or very susceptible to FHB with the only exception of “Duprì”, “Tiziana” and “Dylan” which proved to be moderately susceptible. The susceptibility to FHB was inversely correlated with the plant height and flowering biology, the tall and the late heading cultivars being less susceptible.

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

Canadian Journal of Plant Science ◽

10.4141/cjps08053 ◽

2008 ◽

Vol 88 (6) ◽

pp. 1087-1089 ◽

Cited By ~ 14

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

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