Fusarium Head Blight Severity Research Articles

Genetic Diversity, Mycotoxin Profiles, and Population Structure of Fusarium spp. Associated with Fusarium Head Blight in Georgia, United States.

Fusarium head blight (FHB) has become a limiting factor in soft red winter wheat production in the southeast United States. Recent epidemics have occurred in Georgia, but genetic information on the Fusarium species responsible for FHB is unknown. This study aimed to assess pathogen population structure and genetic diversity, trichothecene profiles, and representative pathogenicity of 196 Fusarium isolates collected from 44 wheat (n = 85) and 53 corn (n = 111) fields in Georgia. Phylogenetic analysis using the translation elongation factor 1-alpha (635 bp) and RNA polymerase second largest subunit (930 bp) sequence data resolved isolates into 185 haplotypes, which represented 12 Fusarium species grouped under five species complexes. F. graminearum with 15-acetyl-deoxynivalenol (15ADON) chemotype (75.6%) and F. incarnatum (57.7%) predominated in wheat and corn, respectively, with a surprisingly higher frequency of nivalenol (NIV) F. graminearum (21.8%). Using nine variable numbers of tandem repeat markers, 82 multilocus genotypes out of 86 F. graminearum isolates were identified and grouped into two genetic clusters, pop1fg (n = 29) and pop2fg (n = 32), as part of the North American populations (NA1 and NA2) but with no chemotype differentiation. F. graminearum populations in Georgia are mostly clonal and might have evolved through at least two introductions from the northeast United States and Canada and local adaptation to maintain high genetic diversity. Pathogenicity of F. graminearum isolates from wheat and corn had high FHB severity (>60%) in wheat, which depicted the risk they can pose towards future FHB outbreaks. Overall, this baseline study provided important information on Fusarium species diversity including F. graminearum associated with FHB in Georgia that will be useful to formulate integrated disease management incorporating improved host resistance and fungicide spray programs.

Evaluation of speed breeding conditions for accelerating Fusarium head blight and deoxynivalenol screening in wheat

AbstractFeeding the world's ever‐increasing population requires continuous development of high‐yielding and disease‐resistant cultivars of food crops such as wheat (Triticum aestivum L.). Speed breeding, which utilizes longer photoperiod times and higher temperatures, is a technique that accelerates plant development and is rapidly being adopted by wheat breeders across the globe to fast‐track cultivar development. Plant diseases are a major threat to crop production, and breeding for disease resistance is a major goal of crop breeders. Fusarium head blight (FHB), caused by Fusarium graminearum, is a major disease of small grain cereals, affecting their yield and quality. The aim of present work was to assess if speed breeding conditions can be used to accelerate reliable assessment of FHB severity and mycotoxin deoxynivalenol (DON) accumulation in wheat varieties. We screened a set of six spring wheat genotypes with different levels of genetic resistance (two moderately susceptible, two highly susceptible, one moderately resistant, and one resistant) for their response to FHB at 14 days after inoculation (dai) and 21 dai and DON accumulation under normal versus speed breeding conditions. FHB severity and DON accumulation were found to be highly correlated at all time points under normal and speed breeding conditions. Robust differentiation between resistant and susceptible genotypes could be achieved at 14 dai rather than the normal period of 21 dai, saving at least a week in phenotyping. Combined with the accelerated growth, flowering, and maturity under these conditions, efficient FHB screening and DON evaluation under speed breeding conditions will fast‐track development of resistant wheat varieties.

Fusarium head blight detection, spikelet estimation, and severity assessment in wheat using 3D convolutional neural networks

Fusarium head blight (FHB) is one of the most significant diseases affecting wheat and other small grain cereals worldwide. Developing FHB-resistant cultivars is critical but requires field and greenhouse disease assessment which are typically laborious and time-consuming. In this work, we developed automated applications based on 3-dimensional (3D) convolutional neural networks (CNN) that detect FHB symptoms expressed in wheat, estimate the total number of spikelets versus the total number of infected spikelets on a wheat head, and subsequently calculate FHB severity index. Such tools are an important step toward the creation of automated and efficient phenotyping methods. The data used to generate the results are 3D point clouds consisting of four color channels – red, green, blue (RGB), and near-infrared (NIR) – collected using a multispectral 3D scanner. Our 3D CNN models for FHB detection achieved 100% accuracy. The influence of the multispectral information on performance was evaluated; the results showed the dominance of the RGB channels over both the NIR (720 nm peak wavelength) and the NIR plus RGB channels combined. Our best 3D CNN models for estimation of total and infected number of spikelets achieved mean absolute errors (MAE) of 1.13 and 1.56, respectively. Our best 3D CNN models for FHB severity estimation achieved 8.6 MAE. A linear regression analysis between the visual FHB severity assessment and the FHB severity predicted by our 3D CNN showed a significant correlation.

Bacillus velezensis RC218 and emerging biocontrol agents against Fusarium graminearum and Fusarium poae in barley: in vitro, greenhouse and field conditions

Fusarium head blight (FHB) is one of the most common diseases in Argentina, affecting the quality and yield of barley grains. Fusarium graminearum sensu stricto (ss) and Fusarium poae are causal agents of FHB and potential sources of mycotoxin contamination in barley. Conventional management strategies do not lead to a complete control of FHB; therefore, biological control emerges as an eco-friendly alternative in the integrated management of the disease. In the present work, Bacillus velezensis, Bacillus inaquosorum, Bacillus nakamurai and Lactobacillus plantarum were evaluated as potential biocontrol agents against F. graminearum ss and F. poae on barley-based media. Bacillus velezensis RC218 was selected to carry out greenhouse and field trials in order to reduce FHB and mycotoxin accumulation. This strain was able to control growth of both Fusarium species and reduced deoxynivalenol (DON) and nivalenol (NIV) production by 66 % and 79 %, respectively. Bacillus inaquosorum and B. nakamurai were more effective in controlling F. poae growth, and the mean levels of reduction in DON accumulation were 50 and 38 %, and 93 and 26 % for NIV, respectively. Lactobacillus plantarum showed variable biocontrol capacity depending on the strain, with no significant mycotoxin reduction. The biocontrol on incidence and severity of FHB in the greenhouse and field trials was effective, being more efficient against F. graminearum ss and DON accumulation than against F. poae and NIV occurrence. This study provides valuable data for the development of an efficient tool based on biocontrol agents to prevent FHB-producing Fusarium species development and mycotoxin occurrence in barley, contributing to food safety.

Controlling Fusarium head blight in wheat through a Mixture of varieties in an organic production system

In the organic production system, the management of diseases and pests is based on agricultural practices rather than the use of certified phytosanitary inputs. The mixture of varieties is an agricultural practice that has shown its interest not only in the management of diseases and pests but also in the increase and stability of crop yields. The objective of our study is to evaluate the performance of this practice in the management of fusarium head blight in wheat. To achieve this objective, we conducted four trials. Two trials (one on durum and the other on soft wheat) in 2019 on a certified organic farm and the two trials were repeated in 2020. During the two years of experimentation, we compared the mixture of four durum wheat varieties and the mixture of four soft wheat varieties with the monoculture varieties. In the field, we evaluated the severity of Fusarium head blight and wheat yield components as well as the grain yield. The results showed a significant difference between the different treatments for Fusarium head blight severity and yield components for both species and in both years of the experiment.

Root Silicon Amendment Enhances Barley’s Resistance to Fusarium Head Blight in the Field

Background: Silicon (Si) amendment plays an important role in enhancing the resistance of several plant species to diverse pathogens. To date, a few studies have focused on how Si application helps barley, a higher Si absorber and accumulator monocot, to resist fungal diseases, including Fusarium head blight (FHB), which reduces the quality and safety of harvested products worldwide. However, no study has ever been conducted to demonstrate Si's ability to suppress FHB development in barley heads under uncontrolled climatic conditions. Materials and Methods: This 2-year field study elucidated the effect of multiple Si applications at 1.7 mM via roots in two barley cultivars, Arabi Aswad (AS moderately resistant) and Arabi Abiad (AB moderately susceptible), to control four Fusarium species with diverse pathogenicity. The incidence of FHB (DI type I resistance), severity of FHB (DS type II), and Fusarium-damaged kernels (FDK type III) were also tested to describe the nature of the Si-enhanced barley resistance. Results: Si treatment at 1.7 mM under soil culture decreased FHB development by enhancing all resistance types measured in the present research. DI, DS, and FDK were reduced by 18.7%, 20.3%, and 20.2%, respectively, in Si-Fusarium-inoculated treatments relative to fungal-inoculated controls. Si absorption in barley strengthened the defense system measured by type I and type II on AB to a level comparable to AS not amended with Si. Irrespective of the barley cultivar, however, Si resulted in a quasi-similar reduction of FDK. Importantly, Si treatment at 1.7 mM decreased the damage of FHB in previous analyses conducted on AS and AB under in vitro and growth chamber environments, showing that Si enhanced the expression of resistance to FHB infection in seedlings and adult barley plants. Conclusion: All of these results are promising outcomes for the application of Si as a safe and effective method against Fusarium species. This study provides new insights into the potential of multiple Si applications at 1.7 mM via roots for boosting barley’s resistance to FHB with a bright prospect for Si use in barley cultivation under field conditions.

Multi-locus genome-wide association studies reveal the genetic architecture of Fusarium head blight resistance in durum wheat.

Durum wheat is more susceptible to Fusarium head blight (FHB) than other types or classes of wheat. The disease is one of the most devastating in wheat; it reduces yield and end-use quality and contaminates the grain with fungal mycotoxins such as deoxynivalenol (DON). A panel of 265 Canadian and European durum wheat cultivars, as well as breeding and experimental lines, were tested in artificially inoculated field environments (2019-2022, inclusive) and two greenhouse trials (2019 and 2020). The trials were assessed for FHB severity and incidence, visual rating index, Fusarium-damaged kernels, DON accumulation, anthesis or heading date, maturity date, and plant height. In addition, yellow pigment and protein content were analyzed for the 2020 field season. To capture loci underlying FHB resistance and related traits, GWAS was performed using single-locus and several multi-locus models, employing 13,504 SNPs. Thirty-one QTL significantly associated with one or more FHB-related traits were identified, of which nine were consistent across environments and associated with multiple FHB-related traits. Although many of the QTL were identified in regions previously reported to affect FHB, the QTL QFhb-3B.2, associated with FHB severity, incidence, and DON accumulation, appears to be novel. We developed KASP markers for six FHB-associated QTL that were consistently detected across multiple environments and validated them on the Global Durum Panel (GDP). Analysis of allelic diversity and the frequencies of these revealed that the lines in the GDP harbor between zero and six resistance alleles. This study provides a comprehensive assessment of the genetic basis of FHB resistance and DON accumulation in durum wheat. Accessions with multiple favorable alleles were identified and will be useful genetic resources to improve FHB resistance in durum breeding programs through marker-assisted recurrent selection and gene stacking.

Elevated CO2 Can Worsen Fusarium Head Blight Disease Severity in Wheat but the Fhb1 QTL Provides Reliable Disease Resistance.

Fusarium head blight (FHB) is a destructive fungal disease of wheat that causes significant economic loss due to lower yields and the contamination of grain with fungal toxins (mycotoxins), particularly deoxynivalenol (DON). FHB disease spread and mycotoxin contamination has been shown to worsen at elevated CO2, therefore, it is important to identify climate-resilient FHB resistance. This work evaluates whether wheat with the Fhb1 quantitative trait locus (QTL), the most widely deployed FHB resistance locus in wheat breeding programs, provides reliable disease resistance at elevated CO2. Near-isogenic wheat lines (NILs) derived from either a highly FHB susceptible or a more FHB resistant genetic background, with or without the Fhb1 QTL, were grown in growth chambers at ambient (400 ppm) and elevated (1000 ppm) CO2 conditions. Wheat was inoculated with Fusarium graminearum and evaluated for FHB severity. At elevated CO2, the NILs derived from more FHB-resistant wheat had increased disease spread, greater pathogen biomass and mycotoxin contamination, and lower rates of DON detoxification; this was not observed in wheat from a FHB susceptible genetic background. The Fhb1 QTL was not associated with increased disease severity in wheat grown at elevated CO2 and provided reliable disease resistance.

Barley shows reduced Fusarium head blight under drought and modular expression of differentially expressed genes under combined stress.

Plants often face simultaneous abiotic and biotic stress conditions; however, physiological and transcriptional responses under such combined stress conditions are still not fully understood. Spring barley (Hordeum vulgare) is susceptible to Fusarium head blight (FHB), which is strongly affected by weather conditions. We therefore studied the potential influence of drought on FHB severity and plant responses in three varieties of different susceptibility. We found strongly reduced FHB severity in susceptible varieties under drought. The number of differentially expressed genes (DEGs) and strength of transcriptomic regulation reflected the concentrations of physiological stress markers such as abscisic acid or fungal DNA contents. Infection-related gene expression was associated with susceptibility rather than resistance. Weighted gene co-expression network analysis revealed 18 modules of co-expressed genes that reflected the pathogen- or drought-response in the three varieties. A generally infection-related module contained co-expressed genes for defence, programmed cell death, and mycotoxin detoxification, indicating that the diverse genotypes used a similar defence strategy towards FHB, albeit with different degrees of success. Further, DEGs showed co-expression in drought- or genotype-associated modules that correlated with measured phytohormones or the osmolyte proline. The combination of drought stress with infection led to the highest numbers of DEGs and resulted in a modular composition of the single-stress responses rather than a specific transcriptional output.

Pyramiding Fusarium head blight resistance QTL from T. aestivum, T. dicoccum and T. dicoccoides in durum wheat

Key messageFHB resistance of durum wheat was improved by introgression of Fhb1 and resistance genes from emmer wheat and by selection against adverse alleles of elite durum wheat.Durum wheat is particularly susceptible to Fusarium head blight (FHB) and breeding for resistance is impeded by the low genetic variation within the elite gene pool. To extend the genetic basis for FHB resistance in durum wheat, we analyzed 603 durum wheat lines from crosses of elite durum wheat with resistance donors carrying resistance alleles derived from Triticum aestivum, T. dicoccum and T. dicoccoides. The lines were phenotyped for FHB resistance, anthesis date, and plant height in artificially inoculated disease nurseries over 5 years. A broad variation was found for all traits, while anthesis date and plant height strongly influenced FHB severities. To correct for spurious associations, we adjusted FHB scorings for temperature fluctuations during the anthesis period and included plant height as a covariate in the analysis. This resulted in the detection of seven quantitative trait loci (QTL) affecting FHB severities. The hexaploid wheat-derived Fhb1 QTL was most significant on reducing FHB severities, highlighting its successful introgression into several durum wheat backgrounds. For two QTL on chromosomes 1B and 2B, the resistance alleles originated from the T. dicoccum line Td161 and T. dicoccoides accessions Mt. Hermon#22 and Mt. Gerizim#36, respectively. The other four QTL featured unfavorable alleles derived from elite durum wheat that increased FHB severities, with a particularly negative effect on chromosome 6A that simultaneously affected plant height and anthesis date. Therefore, in addition to pyramiding resistance genes, selecting against adverse alleles present in elite durum wheat could be a promising avenue in breeding FHB-resistant durum wheat.

Venturicidin A Is a Potential Fungicide for Controlling Fusarium Head Blight by Affecting Deoxynivalenol Biosynthesis, Toxisome Formation, and Mitochondrial Structure.

Fusarium graminearum, which causes Fusarium head blight (FHB) in cereals, is one of the most devastating fungal diseases by causing great yield losses and mycotoxin contamination. A major bioactive ingredient, venturicidin A (VentA), was isolated from Streptomyces pratensis S10 mycelial extract with an activity-guided approach. No report is available on antifungal activity of VentA against F. graminearum and effects on deoxynivalenol (DON) biosynthesis. Here, VentA showed a high antagonistic activity toward F. graminearum with an EC50 value of 3.69 μg/mL. As observed by scanning electron microscopy, after exposure to VentA, F. graminearum conidia and mycelia appeared abnormal. Different dyes staining revealed that VentA increased cell membrane permeability. In growth chamber and field trials, VentA effectively reduced disease severity of FHB. Moreover, VentA inhibited DON biosynthesis by reducing pyruvic acid, acetyl-CoA production, and accumulation of reactive oxygen species (ROS) and then inhibiting trichothecene (TRI) genes expression and toxisome formation. These results suggest that VentA is a potential fungicide for controlling FHB.

Fusarium graminearum Effector FgNls1 Targets Plant Nuclei to Induce Wheat Head Blight.

Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most devastating diseases of wheat and barley worldwide. Effectors suppress host immunity and promote disease development. The genome of F. graminearum contains hundreds of effectors with unknown function. Therefore, investigations of the functions of these effectors will facilitate developing novel strategies to enhance wheat resistance to FHB. We characterized a F. graminearum effector, FgNls1, containing a signal peptide and multiple eukaryotic nuclear localization signals. A fusion protein of green fluorescent protein and FgNls1 accumulated in plant cell nuclei when transiently expressed in Nicotiana benthamiana. FgNls1 suppressed Bax-induced cell death when co-expressed in N. benthamiana. We revealed that the expression of FgNLS1 was induced in wheat spikes infected with F. graminearum. The Fgnls1 mutants significantly reduced initial infection and FHB spread within a spike. The function of FgNLS1 was restored in the Fgnls1-complemented strains. Wheat histone 2B was identified as an interacting protein by FgNls1-affinity chromatography. Furthermore, transgenic wheat plants that silence FgNLS1 expression had significantly lower FHB severity than control plants. This study demonstrates a critical role of FgNls1 in F. graminearum pathogenesis and indicates that host-induced gene silencing targeting F. graminearum effectors is a promising approach to enhance FHB resistance. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

An Integrated Multi-Model Fusion System for Automatically Diagnosing the Severity of Wheat Fusarium Head Blight

Fusarium has become a major impediment to stable wheat production in many regions worldwide. Infected wheat plants not only experience reduced yield and quality but their spikes generate toxins that pose a significant threat to human and animal health. Currently, there are two primary methods for effectively controlling Fusarium head blight (FHB): spraying quantitative chemical agents and breeding disease-resistant wheat varieties. The premise of both methods is to accurately diagnosis the severity of wheat FHB in real time. In this study, a deep learning-based multi-model fusion system was developed for integrated detection of FHB severity. Combination schemes of network frameworks and backbones for wheat spike and spot segmentation were investigated. The training results demonstrated that Mobilev3-Deeplabv3+ exhibits strong multi-scale feature refinement capabilities and achieved a high segmentation accuracy of 97.6% for high-throughput wheat spike images. By implementing parallel feature fusion from high- to low-resolution inputs, w48-Hrnet excelled at recognizing fine and complex FHB spots, resulting in up to 99.8% accuracy. Refinement of wheat FHB grading classification from the perspectives of epidemic control (zero to five levels) and breeding (zero to 14 levels) has been accomplished. In addition, the effectiveness of introducing HSV color feature as a weighting factor into the evaluation model for grading of wheat spikes was verified. The multi-model fusion algorithm, developed specifically for the all-in-one process, successfully accomplished the tasks of segmentation, extraction, and classification, with an overall accuracy of 92.6% for FHB severity grades. The integrated system, combining deep learning and image analysis, provides a reliable and nondestructive diagnosis of wheat FHB, enabling real-time monitoring for farmers and researchers.

Multi-locus genome-wide association study of fusarium head blight in relation to days to anthesis and plant height in a spring wheat association panel.

Fusarium head blight (FHB) is a highly destructive fungal disease of wheat to which host resistance is quantitatively inherited and largely influenced by the environment. Resistance to FHB has been associated with taller height and later maturity; however, a further understanding of these relationships is needed. An association mapping panel (AMP) of 192 predominantly Canadian spring wheat was genotyped with the wheat 90K single-nucleotide polymorphism (SNP) array. The AMP was assessed for FHB incidence (INC), severity (SEV) and index (IND), days to anthesis (DTA), and plant height (PLHT) between 2015 and 2017 at three Canadian FHB-inoculated nurseries. Seven multi-environment trial (MET) datasets were deployed in a genome-wide association study (GWAS) using a single-locus mixed linear model (MLM) and a multi-locus random SNP-effect mixed linear model (mrMLM). MLM detected four quantitative trait nucleotides (QTNs) for INC on chromosomes 2D and 3D and for SEV and IND on chromosome 3B. Further, mrMLM identified 291 QTNs: 50 (INC), 72 (SEV), 90 (IND), 41 (DTA), and 38 (PLHT). At two or more environments, 17 QTNs for FHB, DTA, and PLHT were detected. Of these 17, 12 QTNs were pleiotropic for FHB traits, DTA, and PLHT on chromosomes 1A, 1D, 2D, 3B, 5A, 6B, 7A, and 7B; two QTNs for DTA were detected on chromosomes 1B and 7A; and three PLHT QTNs were located on chromosomes 4B and 6B. The 1B DTA QTN and the three pleiotropic QTNs on chromosomes 1A, 3B, and 6B are potentially identical to corresponding quantitative trait loci (QTLs) in durum wheat. Further, the 3B pleiotropic QTN for FHB INC, SEV, and IND co-locates with TraesCS3B02G024900 within the Fhb1 region on chromosome 3B and is ~3 Mb from a cloned Fhb1 candidate gene TaHRC. While the PLHT QTN on chromosome 6B is putatively novel, the 1B DTA QTN co-locates with a disease resistance protein located ~10 Mb from a Flowering Locus T1-like gene TaFT3-B1, and the 7A DTA QTN is ~5 Mb away from a maturity QTL QMat.dms-7A.3 of another study. GWAS and QTN candidate genes enabled the characterization of FHB resistance in relation to DTA and PLHT. This approach should eventually generate additional and reliable trait-specific markers for breeding selection, in addition to providing useful information for FHB trait discovery.

High-density genetic mapping of Fusarium head blight resistance and agronomic traits in spring wheat.

Fusarium head blight (FHB) has rapidly become a major challenge to successful wheat production and competitive end-use quality in western Canada. Continuous effort is required to develop germplasm with improved FHB resistance and understand how to incorporate the material into crossing schemes for marker-assisted selection and genomic selection. The aim of this study was to map quantitative trait loci (QTL) responsible for the expression of FHB resistance in two adapted cultivars and to evaluate their co-localization with plant height, days to maturity, days to heading, and awnedness. A large doubled haploid population of 775 lines developed from cultivars Carberry and AC Cadillac was assessed for FHB incidence and severity in nurseries near Portage la Prairie, Brandon, and Morden in different years, and for plant height, awnedness, days to heading, and days to maturity near Swift Current. An initial linkage map using a subset of 261 lines was constructed using 634 polymorphic DArT and SSR markers. QTL analysis revealed five resistance QTL on chromosomes 2A, 3B (two loci), 4B, and 5A. A second genetic map with increased marker density was constructed using the Infinium iSelect 90k SNP wheat array in addition to the previous DArT and SSR markers, which revealed two additional QTL on 6A and 6D. The complete population was genotyped, and a total of 6,806 Infinium iSelect 90k SNP polymorphic markers were used to identify 17 putative resistance QTL on 14 different chromosomes. As with the smaller population size and fewer markers, large-effect QTL were detected on 3B, 4B, and 5A that were consistently expressed across environments. FHB resistance QTL were co-localized with plant height QTL on chromosomes 4B, 6D, and 7D; days to heading on 2B, 3A, 4A, 4B, and 5A; and maturity on 3A, 4B, and 7D. A major QTL for awnedness was identified as being associated with FHB resistance on chromosome 5A. Nine small-effect QTL were not associated with any of the agronomic traits, whereas 13 QTL that were associated with agronomic traits did not co-localize with any of the FHB traits. There is an opportunity to select for improved FHB resistance within adapted cultivars by using markers associated with complementary QTL.

Near infrared hyperspectral imaging method to assess Fusarium Head Blight infection on winter wheat ears

The scope of this article is to present a laboratory-based method for the assessment of Fusarium Head Blight (FHB) on ears of winter wheat using Near Infrared Hyperspectral Imaging (NIR-HSI) in the spectral range 900–1700 nm. Inoculated and non-inoculated winter wheat ears were collected from a trial field in Belgium and analysed in the laboratory. Using a dichotomous classification tree framework, Partial Least Squares Discriminant Analysis (PLS-DA) models were developed and applied at pixel level to discriminate the different parts of the ears, namely the awns, the stem and the healthy and infected parts of the ears. This study proposes the use of spectral information at pixel level instead of averaging the spectral signature of the ear. This approach allows using the spatial information of the data in order to provide a quantitative assessment of the severity of the infection on the ear. The results presented in this work confirm that wavelengths related to water and nitrogen are important for the detection of FHB. The validation of the models indicates a good performance for the detection of FHB infection at pixel level with a sensitivity of 96 % and a specificity of 100 %. Furthermore, the validation of the method at ear level shows good performance for the detection of FHB-infected ears with a sensitivity of 99.4 % and a specificity of 91.9 %. The literature reports similar performances, but using equipment with a broader spectral range (400–2500 nm). The present study thus indicates that good discrimination performance can be achieved using a much narrower spectral range. In addition, the obtained results suggest that the method can discriminate three classes of FHB severity, which enables a semi-quantitative assessment of the FHB infection.

Evaluation of fusariosis resistance in commercial onion varieties in Burkina Faso

Fusarium head blight is a serious fungal disease that affects various crops, including onions, in many parts of the world, including Burkina Faso. Onion varieties that have been identified as efficient in other areas may not necessarily perform well in Burkina Faso, given the particular environmental and agronomic conditions of the region. Therefore, the aim of this study was to identify onion varieties that demonstrate resistance or tolerance to Fusarium head blight, as well as yield high harvests, in the specific soil and climate conditions of Burkina Faso. To achieve this, seven onion varieties were evaluated during the dry season in Tabtenga, located in the commune of Loumbila. The incidence rates and the severity of Fusarium head blight were assessed at 35 and 75 days after transplanting. The results indicated that the varieties Noflaye, Prema 178, Rouge de Tana, and Super Yali displayed the lowest incidence of Fusarium head blight. However, the severity of the disease was not statistically different across all the varieties tested. Bulb yields ranged from 11.50 to 20.75 tons per hectare. This study is the first to provide data on the resistance of onion varieties to Fusarium head blight in the central agro-ecological zone of Burkina Faso. These findings suggest that the identified varieties may hold promise for sustainable onion production in the region. However, to confirm the results, multi-local trials should be conducted across both dry and rainy seasons.

Aggressiveness and mycotoxin profile of Fusarium avenaceum isolates causing Fusarium seedling blight and Fusarium head blight in UK malting barley.

Fusarium avenaceum causing Fusarium seedling blight (FSB) and Fusarium head blight (FHB) on barley is associated with economic losses of crop yield and quality, and the accumulation of mycotoxins including the enniatins (ENNs) A, A1, B and B1. Although F. avenaceum is the main producer of ENNs, studies on the ability of isolates to cause severe Fusarium diseases or produce mycotoxins in barley are limited. In this work, we investigated the aggressiveness of nine isolates of F. avenaceum to two cultivars of malting barley, Moonshine and Quench, and defined their ENN mycotoxin profiles in in vitro and in planta experiments. We assessed and compared the severity of FSB and FHB caused by these isolates to disease severity by F. graminearum, F. tricinctum and F. poae. Quantitative real-time polymerase chain reaction and Liquid Chromatography Tandem Mass Spectrometry assays were used to quantify pathogen DNA and mycotoxin accumulation, respectively, in barley heads. Isolates of F. avenaceum were equally aggressive to barley stems and heads and caused the most severe FSB symptoms resulting in up to 55% reductions of stem and root length. Fusarium graminearum caused the most severe FHB disease, followed by the isolates of F. avenaceum with the most aggressive F. avenaceum isolates capable of causing similar bleaching of barley heads as F. avenaceum. Fusarium avenaceum isolates produced ENN B as the predominant mycotoxin, followed by ENN B1 and A1 in vitro. However, only the most aggressive isolates produced ENN A1 in planta and none produced ENN A or beauvericin (BEA) either in planta or in vitro. The capacity of F. avenaceum isolates to produce ENNs was related to the accumulation of pathogen DNA in barley heads, whilst FHB severity was related to the synthesis and accumulation of ENN A1 in planta. Cv. Moonshine was significantly more resistant than Quench to FSB or FHB, caused by any Fusarium isolate, and to the accumulation of pathogen DNA, ENNs or BEA. In conclusion, aggressive F. avenaceum isolates are potent ENN producers causing severe FSB and FHB with ENN A1 requiring further investigation as potential virulence factor for F. avenaceum in cereals.

A status update on fusarium head blight on Western Canadian wheat

Fusarium head blight (FHB) is a devastating disease of wheat in Canada and disease surveillance is a critical component of integrated disease management, disease forecasting, prioritizing research and breeding efforts, grain handling, and cleaning post harvest. We report on the recent trends of FHB in Canadian wheat including incidence and severity from 1995 to 2021 based on data from 208,247 samples. Our results show a steady increase in FHB incidence from 1995, with an epidemic year in 2016, followed by several years of low incidence. Results also indicated that FHB severity has been stable over time, but not always correlated with incidence. Data from the analysis of 26,538 samples from 2018 to 2021 demonstrate a strong positive correlation between the number of Fusarium damaged kernels (severity) and concentrations of the mycotoxin deoxynivalenol. Together, our results provide the most robust survey of FHB in Canada to date, which complement national and international disease monitoring and management efforts.

GSEYOLOX-s: An Improved Lightweight Network for Identifying the Severity of Wheat Fusarium Head Blight

Fusarium head blight (FHB) is one of the most detrimental wheat diseases. The accurate identification of FHB severity is significant to the sustainable management of FHB and the guarantee of food production and security. A total of 2752 images with five infection levels were collected to establish an FHB severity grading dataset (FHBSGD), and a novel lightweight GSEYOLOX-s was proposed to automatically recognize the severity of FHB. The simple, parameter-free attention module (SimAM) was fused into the CSPDarknet feature extraction network to obtain more representative disease features while avoiding additional parameters. Meanwhile, the ghost convolution of the model head (G-head) was designed to achieve lightweight and speed improvements. Furthermore, the efficient intersection over union (EIoU) loss was employed to accelerate the convergence speed and improve positioning precision. The results indicate that the GSEYOLOX-s model with only 8.06 MB parameters achieved a mean average precision (mAP) of 99.23% and a detection speed of 47 frames per second (FPS), which is the best performance compared with other lightweight models, such as EfficientDet, Mobilenet-YOLOV4, YOLOV7, YOLOX series. The proposed GSEYOLOX-s was deployed on mobile terminals to assist farmers in the real-time identification of the severity of FHB and facilitate the precise management of crop diseases.