Mitigation of Fusarium Head Blight in Wheat Caused by Fusarium Graminearum Through the Use of Host Resistance Genes and Biological Controls PDF Download

Author: Gabrielle Nowakowski
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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The fungal pathogen, Fusarium graminearum, is a primary causal agent of the wheat (Triticum aestivum L.) disease Fusarium head blight in North America. Heavy infection from this pathogen leads to economic losses due to a decrease in the quality and quantity of grain. Infection by F. graminearum also leads to accumulation of deoxynivalenol (DON), a mycotoxin that produces harmful side effects to both humans and animals when ingested. Development of resistant wheat cultivars is needed to maintain a sustainable, safe, food supply. In this study, a double haploid population derived from a cross between two winter wheat cultivars, Flourish and Emerson, was used to identify quantitative trait loci (QTL) associated with FHB symptoms and DON accumulation in the grain. So far, there are no fully resistant cultivars of wheat to protect against FHB infection. Therefore, alternative methods need to be considered. A newly developed bio-fungicide containing a fungal antagonist to F. graminearum, Clonostachys rosea, was studied and compared to the commercially available fungicide, Caramba® (active ingredient, metconazole). These QTL were present on chromosomes 1B, 2B, 4D, 6D and 7A. Results from this study showed that there was some potential in using C. rosea in a bio-fungicide treatment plan. However, the fungi's sensitivity to environmental conditions may have contributed to poor and inconsistent control of F. graminearum in this study.

Author: Anita Behari
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Fusarium head blight (FHB) is a fungal disease of wheat and other cereals caused by species of Fusarium, namely Fusarium graminearum. This disease is sporadic and highly weather dependent, and affects wheat production globally resulting in reduced grain quality and contamination with mycotoxins. The mycotoxin most commonly associated with FHB is deoxynivalenol (DON). DON is a virulence factor in disease, as well as toxic to plants, humans, and animals. Ultimately, reducing DON contamination in grain depends on preventing infection and subsequent disease. Current mitigation strategies for FHB include the use of moderately resistant cultivars and fungicides; however, when conditions are conducive to disease development even a combination of mitigation strategies offers limited control. Improving mitigation of FHB depends on an improved understanding of disease development, especially the effects of weather variables on facilitating infection, disease, and DON accumulation in cultivars with varying levels of resistance. Additionally, given that global wheat production is threatened by rust and wheat blast, identifying other mitigation strategies for FHB will support flexibility with disease control. The purpose of this dissertation was to examine the effects of temperature on disease development and DON accumulation in cultivars varying in resistance to FHB, and to explore biological control (biocontrol) as an additional tool for FHB mitigation. The first objective was to examine the effects of cultivar (moderately resistant: Alsen and susceptible: Wheaton) and temperature (15C and 22C) on fungal spread, ergosterol accumulation, and DON accumulation in Fusarium head blight diseased wheat. Using the point inoculation technique, the florets of the central spikelet of wheat heads were inoculated with a macroconidia suspension. Wheat heads were harvested every two days over a period of thirty days, with one floret per spikelet used to collect data on incidence of F. graminearum, while the other floret was used for extraction of DON and ergosterol. The moderately resistant cultivar Alsen was found to have the least fungal spread, DON, and ergosterol, while 15C also reduced fungal spread, DON, and ergosterol. The combination of Alsen 15C had the lowest F. graminearum incidence, and the least DON and ergosterol. The second objective was to isolate, identify, and characterize microbes from environmental sources in Pennsylvania, with the abilities to inhibit F. graminearum and remove DON from liquid culture. Additionally, the third objective was to screen Bacillus isolates isolated from quinoa in Bolivia and Ecuador for the same abilities. Microbes (mostly bacteria) were isolated from soil and plant material using various media and selected based on morphology for co-culturing with F. graminearum, while samples of soil and plant material were incubated in mineral salt media with DON and tested individually using GC-ECD to monitor DON removal from liquid culture. A total of 151 microbes were screened for inhibition, 59 of which were isolated from mineral salt media containing DON. Of the 151 microbes, 12 were found to inhibit F. graminearum, of which 4 were also able to reduce DON levels in culture. Five other microbes from the mineral salt media incubations were found to significantly decrease DON in culture, but did not inhibit F. graminearum. The fourth objective was to field test spray treatments of two microbes, one able to inhibit F. graminearum and the other able to remove DON, separately and combined, for their effects on FHB disease incidence, head severity, Fusarium damaged kernels (FDK), and DON accumulation in a FHB moderately resistant and a FHB susceptible cultivar of wheat. Using non-parametric two-way ANOVA analyses between medians, we found that treatment, cultivar, and treatment*cultivar were significant for all measured variables. Additionally, for some of the measured variables, microbe treatments were found to exacerbate disease and DON accumulation. Future research can further elucidate the effects of weather variables on affecting disease and DON accumulation in cultivars with varying degrees and types of resistance. Biocontrol research can focus on supporting the establishment and antagonistic activities of biocontrol agents in field environments. This dissertation contributes to furthering the understanding of factors influencing disease and DON levels, as well as the use of F. graminearum inhibition and DON removal for FHB biocontrol.

Author: Valentina Spanic
Publisher: Mdpi AG
ISBN: 9783036598932
Category : Science
Languages : en
Pages : 0

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Fusarium head blight (FHB), caused by several Fusarium species-mainly Fusarium graminearum, F. culmorum, and F. avenaceum-is a devastating disease of wheat which reduces both grain yield and quality. FHB affects the grain protein content by destroying starch granules, storage proteins, and cell walls and consequently decreases the quality of dough properties. It is also associated with mycotoxin contamination and is a significant threat to animal and human health. Furthermore, Fusarium spp. affect plant development and trigger different morphological, physiological, biochemical, and molecular changes. Current climate change scenarios predict an increase in the number of epidemics caused by this disease, and many different strategies for disease control are currently being researched. This Special Issue aims to detail the latest achievements regarding Fusarium disease in wheat, including the genetics or physiology of resistance, resistance mechanisms, host-pathogen interactions, and agronomic approaches in the field (fungicidal management, the integration of host resistance and fungicides, and the timing of fungicide application). Original research, reviews, and opinions on recent advances in strategies for the control of Fusarium disease in wheat were also welcome.

Author: Ashley E. Muckle
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Yang Zhuping
Publisher: CIMMYT
ISBN: 9789686923223
Category :
Languages : en
Pages : 24

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Author: Nathan H. Karplus
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Fusarium head blight (FHB) of wheat has become an increasingly important disease over the past 25 years. Significant grain and quality reductions due to FHB can be observed when there is a favorable environment for disease development. Fusarium graminearum, the primary fungal pathogen that causes FHB in the U.S. produces deoxynivalenol, a mycotoxin that can cause serious health problems for both humans and livestock when consumed in FHB infected grain. While cultural practices and fungicide treatments can suppress FHB, the use of resistant cultivars is also an essential tool for control of FHB. Breeding for resistance to FHB has become a very large part of wheat and barley breeding programs in temperate climates. Various sources of resistance have been used to develop new cultivars that have high levels of resistance. The primary objective of this study was to combine multiple sources of resistance using a recombinant inbred line (RIL) population derived from three FHB-resistant University of Illinois breeding lines (IL96-6472, IL97-6755 and IL97-1828) to obtain transgressive segregants that are significantly better than the three parents. The RIL population, consisting of 266 lines, was evaluated for FHB resistance in the greenhouse and in a mist irrigated, inoculated disease nursery. Forty-three simple sequence repeat (SSR) and 250 Diversity Arrays Technology (DArT) polymorphic markers were used to create a linkage map using Joinmap 3.0. PlabQTL was used for composite interval mapping and detection of significant QTL. QTL were found for all measured traits except for mean severity in the 2009 greenhouse evaluation. QTL on the short arm of chromosome 3B were identified for all measured traits and accounted for 4.2% to 18.8% of the phenotypic variation, depending on the trait. We believe that these markers are associated with Fhb1 or QTL tightly linked to Fhb1. Minor QTL were also found on chromosomes 7B, 1A, 5D, 6B and 6A and explained a smaller amount of phenotypic variation (between 2.5% and 8.7%). A total of 13 transgressive segregants were found that were significantly better than the mean of the three FHB-resistant parents for more than one trait. These thirteen lines were found to carry many of the resistance alleles associated with the QTL found in the study. Although the population was derived from three FHB-resistant parents, and there were likely QTL that were not detected due to a lack of polymorphism, we believe that multiple genes for resistance were combined in the transgressive segregants observed in the RIL. The second study examined the performance of FHB-resistant and susceptible cultivars with three fungicide treatments. Until recently, there were few fungicides labeled for suppression of FHB. Numerous studies have shown that fungicides containing the active ingredient tebuconazole are very effective in reducing losses caused by FHB. While fungicides can be a useful tool for FHB suppression, they do not provide complete control, and their efficacy is greatly affected by timing. Planting cultivars that are resistant to FHB infection provides farmers with continual protection against the disease. The experiment was grown as a split plot with fungicide treatment (No Fungicide, Prosaro® (tebuconazole+prothioconazole) and Folicur® (tebuconazole) as the main plot and cultivar (6 susceptible and 6 resistant) as the sub-plots. Based on the results of this experiment, it is apparent that resistant cultivars are a necessity to provide the best control of FHB. Under the extremely heavy disease pressure of our FHB nursery, fungicides did not provide sufficient control of FHB on susceptible cultivars. Not surprisingly, we found the best method for controlling FHB is to plant a resistant cultivar in addition to applying a fungicide; however, we were interested to see how resistant cultivars alone would perform when compared to susceptible cultivars treated with a fungicide. Resistant cultivars performed impressively, and it was apparent that resistant cultivars are an essential first step of an effective program for controlling FHB. Resistant cultivars without fungicides were able to yield well and provide excellent net economic returns that were not significantly different than resistant cultivars that were treated with a fungicide. This would suggest that under low to moderate disease pressure there no need for fungicide application for FHB control. This experiment illustrated that resistant cultivars provide sufficient protection from FHB; however, to achieve high quality grain with low levels of FDK and DON, fungicide application may be needed in years when there is a high risk of severe disease pressure.

Author: Sudheer Kumar
Publisher: CRC Press
ISBN: 0429894074
Category : Science
Languages : en
Pages : 157

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Wheat Blast provides systematic and practical information on wheat blast pathology, summarises research progress and discusses future perspectives based on current understanding of the existing issues. The book explores advance technologies that may help in deciding the path for future research and development for better strategies and techniques to manage the wheat blast disease. It equips readers with basic and applied understanding on the identification of disease, its distribution and chances of further spread in new areas, its potential to cause yield losses to wheat, the conditions that favour disease development, disease prediction modelling, resistance breeding methods and management strategies against wheat blast. Features: Provides comprehensive information on wheat blast pathogen and its management under a single umbrella Covers disease identification and diagnostics which will be helpful to check introduction in new areas Discusses methods and protocol to study the different aspects of the disease such as diagnostics, variability, resistance screening, epiphytotic creation etc. Gives deep insight on the past, present and future outlook of wheat blast research progress This book’s chapters are contributed by experts and pioneers in their respective fields and it provides comprehensive insight with updated findings on wheat blast research. It serves as a valuable reference for researchers, policy makers, students, teachers, farmers, seed growers, traders, and other stakeholders dealing with wheat.

Author: Kurt J. Leonard
Publisher: American Phytopathological Society
ISBN:
Category : Barley
Languages : en
Pages : 544

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The book provides a comprehensive record of current knowledge on the nature of Fusarium head blight, the damage it causes, and current research on how to control it. The book begins with a historical account of Fusarium head blight epidemics that gives context to recent attempts to control epidemics in wheat and barley. A review of pathogen taxonomy and population biology helps scientists to see relationships among head blight pathogens and other Fusarium species. The information on epidemiology included in this review also provides an understanding of the weather conditions and cultural practices that promote explosive epidemics. New information on infection processes will lead the reader to a better understanding of how to breed for resistance in wheat and barley.

Author: Pravin Gautam
Publisher: GRIN Verlag
ISBN: 3640989538
Category : Science
Languages : en
Pages : 241

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Doctoral Thesis / Dissertation from the year 2010 in the subject Biology - Botany, grade: none, University of Minnesota - Twin Cities, language: English, abstract: Fusarium head blight caused by Fusarium graminearum Schwabe is an economically important disease as it results in yield and quality losses of infected grain and the accumulation of mycotoxins produced by the invading fungus. Though it is well established that moisture around the anthesis period promotes FHB development and trichothecene accumulation, the role of moisture from anthesis to harvest has been largely overlooked. The objective of this study was to examine the influence of environmental factors, especially moisture, host resistance, and pathogen variation on infection, FHB disease development and mycotoxin production and accumulation in planta. The split-split-plot Field experiments were conducted in 2006-2008. Main plots were the duration of mist-irrigation after inoculation. Three wheat cultivars used as sub-plots were Alsen, 2375 and Wheaton. Sub-sub-plots were F. graminearum isolates. Plots were inoculated twice, at anthesis. FHB severity was assessed 21 dai. Visually scabby kernels, deoxynivalenol, 15-acetyldeoxynivalenol, 3-acetyldeoxynivalenol and nivalenol were determined on grain harvested at maturity. Additionally, in 2007 and 2008, whole heads were sampled at 0, 7, 11, 14, 21, 28 and 41 dai analyzed for mycotoxins. Severity, VSK and the DON concentration of mature grain, were significantly higher in the susceptible wheat cultivar Wheaton than in the other two cultivars examined. Although FHB severities were not significantly different in plots receiving different durations of mist irrigation, VSK were significantly lower in the treatments receiving the least amount of mist-irrigation than for treatments receiving mist-irrigation for longer periods, suggesting that extended periods of moisture promote disease development. DON was however significantly lower in the longest misting trea

Author: Carlos Bolanos-Carriel
Publisher:
ISBN: 9780438724112
Category : Fungal diseases of plants
Languages : en
Pages : 0

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Book Description
Fusarium head blight (FHB) caused by Fusarium graminearum, the FHB-associated mycotoxin deoxynivalenol (DON), and foliar fungal diseases are significant threats to wheat production. This research 1) evaluated the effects of fungicide chemical class, application timing, and cultivar resistance on FHB and DON under field conditions; 2) evaluated the effects of field-applied fungicide chemical class, grain moisture, and time on DON under grain storage conditions; 3) evaluated the effects of field-applied fungicide chemical class and time on trichothecene-related gene (Tri5) expression under grain storage conditions; 4) determined the optimum F. graminearum spore concentration and spike bagging period following inoculation for accurately discriminating between FHB resistant and susceptible wheat cultivars under greenhouse conditions; and 5) determined the optimum timing of fungicide applications for control of foliar fungal diseases of wheat under field conditions. A triazole fungicide controlled FHB and DON more effectively than a strobilurin fungicide. A triazole applied 6 days after anthesis was as effective as an anthesis (standard timing) application, indicating a wider window of application for growers' needed flexibility. In storage, DON decreased over time in grain of a moderately resistant cultivar treated with a triazole and increased in grain of a susceptible cultivar treated with a strobilurin. During storage, DON biosynthesis Tri5 gene expression increased over time during storage of high grain moisture grain, a significant reduction in the relative expression of the Tri5 gene and a downregulation of the gene occurred in the triazole treatment whereas expression of the gene increased in the strobilurin treatment. In the greenhouse, lower concentrations of F. graminearum inoculum (6.25 x 10 3 and 1.25 x 104 spores/mL) were more efficient in discriminating between a moderately resistant and a susceptible wheat cultivar compared to the standard concentration (1 x 105 spores/mL). The optimum spike bagging period following inoculation for discrimination between a moderately resistant and a susceptible cultivar was 48 hours or 72 hours (the standard). Foliar fungicide applications in field plots at the flag leaf and boot growth stages of wheat were more effective in protecting yield than later applications. Results from this research will enhance knowledge in the epidemiology and management of FHB, DON, and foliar fungal diseases of wheat.