Search Results (394)

Fusarium head blight in barley (Hordeum vulgare) reduces grain yield and can lead to the accumulation of deoxynivalenol (DON) and nivalenol (NIV) in grains. We surveyed Fusarium species and evaluated DON and NIV concentrations in barley grains in four regions of Rio Grande do Sul, the southernmost state in subtropical Brazil. Seven Fusarium species were identified: F. asiaticum, F. avenaceum, F. cortaderiae, F. graminearum, F. gerlachii, F. meridionale and F. poae. DON (0 to 10,200 µg/kg) and NIV (0 to 1630 µg/kg) were detected in 74% and 70% of the samples, respectively, with higher concentrations found in experimental fields. However, in commercial barley fields, most samples fell below 2000 µg/kg of DON, which is the maximum limit allowed by Brazilian legislation for grains intended for processing. The seasonality of temperature and precipitation influenced mycotoxin concentrations. Therefore, the variability of Fusarium species in Rio Grande do Sul and a high incidence of DON and NIV in barley grains highlight the complexity of this pathosystem. This variability of Fusarium species may also influence the effectiveness of measures to control the disease, particularly in relation to genetic resistance and fungicide application. Full article

Wheat leaf rust (Lr), caused by Puccinia triticina Eriks. (Pt), is one of the most important diseases affecting wheat production worldwide. Using resistant wheat cultivars is the most economic and environmentally friendly way to control leaf rust. The Chinese wheat cultivar Xinong1163-4 has shown good resistance to Lr in field trials. To identify the genetic basis of Lr resistance in Xinong1163-4, 195 recombinant inbred lines (RILs) from the Xinong1163-4/Thatcher cross were phenotyped for Lr severity in three environments: the 2017/2018, 2018/2019, and 2019/2020 growing seasons in Baoding, Hebei Province. Bulked segregant analysis and simple sequence repeat markers were then used to identify the quantitative trait loci (QTLs) for Lr adult plant resistance (APR) in the population. As a result, six QTLs were detected, designated as QLr.hbau-1BL.1, QLr.hbau-1BL.2, and QLr.hbau-1BL.3. These QTLs were predicted to be novel. QLr.hbau-4BL, QLr.hbau-4BL.1, and QLr.hbau-3A were identified at similar physical positions to previously reported QTLs. Based on chromosome positions and molecular marker testing, QLr.hbau-1BL.3 shares similar flanking markers with Lr46. Lr46 is a non-race-specific APR gene for leaf rust, stripe rust, and powdery mildew. Similarly, QLr.hebau-4BL showed resistance to multiple diseases, including leaf rust, stripe rust, Fusarium head blight, and powdery mildew. The QTLs identified in this study, as well as their closely linked markers, can potentially be used for marker-assisted selection in wheat breeding. Full article

Fusarium head blight (FHB) is a major devastating wheat fungal disease. Mycotoxins act as virulent factor for FHB progression, including deoxynivalenol (DON), 15-acetyl deoxynivalenol (15-ADON), 3-acetyl deoxynivalenol (3-ADON), deoxynivalenol-3-glucoside (D3G), and zearalenone (ZEN). To identify resistant germplasm against FHB and mycotoxin accumulation, we evaluated 99 wheat cultivars for FHB severity using point inoculation by three FHB isolates under greenhouse and field conditions. FHB severity of selected varieties evaluated in the fields were correlated with that in greenhouse (p < 0.01). Inoculated spikes from 20 varieties were examined for mycotoxin accumulation, employing an LC-MS/MS method that differentiated five mycotoxins. Five cultivars exhibited resistance to both FHB and mycotoxin accumulation, with FHB severity averaging from 13.36% to 33.37%, and DON accumulation below 2400.0 µg/kg, across various conditions. Seven dominant varieties exhibited moderate resistance to FHB and mycotoxin accumulation. FHB severity was significantly positively correlated with DON accumulation, but negatively correlated to the D3G to DON ratio, across distinct groups of FHB resistance (p < 0.01) after inoculation of three distinct isolates, although no correlation was observed within-group. In the present study, Shannong20, Huaimai20, and Sunlin were identified with resistance to both FHB and mycotoxins with superior agronomic performance, providing promising materials for improving disease resistance in breeding programs. Full article

Wheat (Triticum aestivum L.) is the world’s most indispensable staple crop and a vital source of food for human diet. Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), constitutes a severe threat to wheat production and in severe cases, the crop fails completely. Anmai1350 (AM1350) is moderately resistant to leaf rust and powdery mildew, and highly susceptible to sheath blight and fusarium head blight. We found that the length and area of mycelium in AM1350 cells varied at different time points of Pst infection. To investigate the molecular mechanism of AM1350 resistance to Pst, we performed transcriptome sequencing (RNA-seq). In this study, we analyzed the transcriptomic changes of the seedling leaves of AM1350 at different stages of Pst infection at 0 h post-infection (hpi), 6 hpi, 24 hpi, 48 hpi, 72 hpi, and 120 hpi through RNA-seq. Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) was used to validate RNA-seq data. It was determined that there were differences in the differentially expressed genes (DEGs) of AM1350, and the upregulation and downregulation of the DEGs changed with the time of infection. At different time points, there were varying degrees of enrichment in the response pathways of AM1350, such as the ”MAPK signaling pathway–plant”, the “plant–pathogen interaction” pathway and other pathways. After Pst infected AM1350, the reactive oxygen species (ROS) content gradually increases. The ROS is toxic to Pst, promotes the synthesis of phytoalexins, and inhibits the spread of Pst. As a result, AM1350 shows resistance to Pst race CYR34. The main objective of this study is to provide a better understanding for resistance mechanisms of wheat in response to Pst infections and to avoid production loss. Full article

Fusarium head blight is one of the greatest threats to global wheat production. Despite the special attention paid by researchers to resistance genetics, the stability of resistance and the expression of its epidemiological relationships have not been tested in depth. As most studies only present data on visual symptoms, in this study, we present data from four experiments. Here, 15–40 genotypes were tested with four and eight isolates (inocula) in 3–4-year experiments, with 32, 24, 36, and 12 epidemic situations used to determine the disease index (DI), Fusarium-damaged kernels (FDKs), and DON. All genotypes were tested for stability by the variance across epidemics, and the b value of the linear function was considered. Both indices were suitable for measuring stability/instability, but the variance results were more closely correlated with the experimental data than the b value, known as the stability index (SI). The use of variance is recommended due to its simplicity and reliability. In the first test, the rate of maximum/minimum variance for DI, FDK, and DON differed 15-, 20-, and 120-fold, respectively. In the second test, the same rates were 200, 400, and over 4000, with the other tests exhibiting similar tendencies. The traits differ, the epidemics vary, and a dependence on resistance level can be proven. The genotype ranking varies strongly in different epidemics, with approximately 50% of the correlations between variety responses being insignificant. Therefore, many epidemics are needed to obtain a reliable picture of the adaptation ability of the resistance traits and their stability. Approximately 25% of the genotypes tested belong to the most stable group. About 35% were discarded, and in the 40% medium, we observed both highly unstable and moderately stable genotypes. Principal component analysis (PCA) of the three traits in the experiments showed a confirmatory, nearly uniform distribution of genotypes, with a different footprint or “identity card” present for each genotype. The genotypes for the traits belong to one or two groups, although sometimes individual genotypes seem to be independent. No strict rule was found. This underlines the necessity of considering the plant’s traits (Di, FDK, and DON) in resistance testing. Highly resistant winter wheat lines could also be bred with very low variance and SI values and very high stability (SI values lower than 0.3). Of the traits, DON is the most important. With this methodology, variety registration also becomes possible. The epidemiological aspect has a decisive role in resistance studies, and without identifying stability in FHB resistance, no food safety estimates can be made. Full article

Fusarium head blight (FHB) is an important fungal disease caused by Fusarium graminearum and other Fusarium spp., resulting in significant yield losses across cereal grains. Recently identified F. graminearum isolates in Canada, capable of producing type A trichothecene mycotoxins 3ANX (NX-2, 7-α hydroxy,15-deacetylcalonectrin) and NX (NX-3, 7-α hydroxy, 3,15-dideacetylcalonectrin), demonstrated high levels of genetic diversity. While recent studies have detected this genetic and chemical diversity, little is known of the underlying molecular mechanisms and processes influenced by these distinct chemotypes and regional populations. In the current study, we used an -omics approach coupled with high-resolution mass spectrometry to characterize twenty F. graminearum isolates collected from five distinct regions across Manitoba. These data identified regional F. graminearum populations within Manitoba that demonstrate distinct genomic variation and patterns of gene expression, particularly within pathogenicity-associated processes. Further, we identified genetic variation and differential expression between isolates showing high and low levels of pathogenicity, allowing for the identification of previously characterized and novel putative pathogenicity factors. Lastly, we detected the production of 3ANX and/or NX mycotoxins within the majority of our twenty characterized F. graminearum isolates, suggesting the 3ANX chemotype may be more prevalent than previously expected in Canada. Ultimately, these findings highlight the diversity of F. graminearum across Manitoba and, more importantly, uncover specific genomic regions and candidate pathogenicity factors influenced by this diversity. Full article

Fusarium head blight (FHB) is one of the most devastating diseases in wheat. Besides its negative impact on grain yield, FHB also negatively influences quality. Changes in sugar and free amino acid content were analyzed in flour from Fusarium-infected and non-infected grains of six wheat varieties differing in Fusarium resistance. The concentrations of sugars and free amino acids were determined using a high-performance liquid chromatography device. In flour from FHB-infected grains, the average total amount of fructose, glucose, maltose, total sugars, and total reducing sugars was significantly increased, compared to non-treated flour from the Tika Taka variety, which was the most FHB-susceptible. The total content of free amino acids in flour from FHB-infected varieties increased in proportion to their susceptibility. In Tika Taka, there was a significant increase in free amino acid content of about 46%, while a significant decrease of 16% was observed in the highly resistant Vulkan variety. A highly significant correlation was established between the degree of FHB susceptibility and the content of aspartic acid, glutamic acid, glutamine and histidine, glycine, alanine, methionine, valine, tryptophan, phenylalanine, leucine, and threonine. Most amino acids had strong positive correlations with each other, but among the sugars, only fructose and glucose content showed a strong positive correlation with specific amino acids that were induced by Fusarium infection. Overall, it can be concluded that FHB-susceptible varieties have a high risk of FHB infection, which results in the hydrolysis of sucrose into fructose and glucose, together with an increase in free amino acids, which deteriorates the quality of wheat. Full article

Fusarium head blight (FHB) is an important disease throughout the world due to its strong association with yield reduction, quality deterioration, and mycotoxin contamination in wheat. The use of FHB-resistant genotypes in wheat production can significantly reduce damage. The current study screened a panel of bread wheat from CIMMYT and South Asian countries for FHB resistance to identify promising genotypes useful for wheat breeding and to map the associated genomic regions and linked molecular markers through a genome-wide association study (GWAS). Spray-inoculated field experiments were conducted at CIMMYT, Mexico, over three years, and a wide range of phenotypic variations was observed. Four lines, CIM-39, CIM-29, CIM-9, and CIM-3, exhibited consistent resistance across experiments, with FHB indices ranging from 6.5 to 8.1. Genotyping was conducted using the Illumina Infinium 15 K Bead Chip, and 11,184 high-quality SNP markers were obtained and used for GWAS. Nineteen significant marker-trait associations (MTAs) were detected, among which MTAs at Ra_c58315_265 on 1A and Tdurum_contig102328_129 and Ku_c20136_198 on 7B showed reproducible results, with phenotypic effects on FHB resistance of 6.05%, 3.54%, and 3.92%, respectively. Several genes associated with disease resistance were found near the significant SNPs. The identified resistant genotypes and markers may be useful in future marker-assisted breeding in wheat. Full article

Fusarium graminearum is a common plant pathogen among cereals worldwide. The application of chemical antifungal compounds is the most frequently used method in controlling F. graminearum. However, its excessive use and the genomic plasticity of the fungal genome lead to increased resistance levels to these chemical antifungal compounds. In this context, plant-derived compounds might play a role in protecting against Fusarium head blight (FHB) and crown rot (CR) as an alternative. In this study, we aimed to examine the antifungal effects of an essential oil obtained from Rosa damascena Mill. on the plant pathogen F. graminearum using molecular and analytical methods. The chemical composition of the essential oil was determined by GC-MS. The half effective concentration (EC₅₀) value of R. damascena essential oil (REO) for F. graminearum was determined as 604.25 µg mL⁻¹. Water-soluble tetrazolium 1 (WST-1) analyses revealed that REO caused cytotoxicity in F. graminearum. The potential oxidative stress and autophagic cell death capacity of REO towards F. graminearum was revealed via gene expression analysis and fluorescence microscopy. It was also revealed that, due to the plant-protective effect of REO, the disease severity of treated plants decreased by up to 27.78% in juvenile wheat seedlings infected by F. graminearum. Our data show that R. damascena essential oil might be used as an alternative natural ingredient in the field of plant protection. Full article

Fusarium head blight (FHB), caused by Fusarium graminearum, is a globally significant disease that severely impacts the yield and quality of wheat. Breeding resistant wheat varieties using resistance genes is the most cost-effective strategy for managing FHB, but few markers are available for marker-assisted selection (MAS) of resistance. In this study, we evaluated the resistance of a recombinant inbred line (RIL) population to FHB through single-floret inoculation in four field environments over two years. Combined with quantitative trait loci (QTL) detection through high-density genetic mapping based on wheat 50 K SNP arrays, we identified a total of 21 QTLs influencing FHB resistance. It is worth noting that QFhba-5D.2-1 was detected in two field environments as well as in the multi-environment trial (MET) analysis, explaining phenotypic variation ranging from 1.98% to 18.55%. We also pinpointed thirteen resistance genes within the QTL intervals on chromosomes 4A, 5D, 6B, and 7A associated with FHB defense mechanisms. Furthermore, we developed two Kompetitive Allele-Specific PCR (KASP) markers for the QFhba-5D.2-1 and QFhba-7A regions to validate their specificity within the RIL population. Subsequently, we validated the polymorphism of these two markers in 305 wheat germplasms and analyzed their effect on thousand kernel weight (TKW) and spike length (SL). These markers will accelerate the development of FHB-resistant wheat varieties through MAS, significantly reducing yield losses and strengthening food security. Full article

Fusarium head blight (FHB) is one of the major wheat diseases caused by Fusarium species (mainly Fusarium graminearum and Fusarium asiaticum), resulting in significant global wheat yield losses and risks to food security. Breeding wheat varieties with resistance genes is the most environmentally friendly and economical strategy for controlling FHB. Psathyrostachys huashanica Keng ex P. C. Kuo (2n = 2x = 14, NsNs), which showed abiotic tolerance and biotic resistance, has significant research value and potential as an important genetic resource for wheat improvement. In previous studies, we crossed Psathyrostachys huashanica with common wheat and developed wheat lines containing different N_S chromosomes. In this study, we identified a 4N_S additional line, DA26, from the progenies of wheat-P. huashanica-derived lines using genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) analyses. Line DA26 showed high resistance to Fusarium head blight (FHB) in the greenhouse and field conditions. However, the parental common wheat lines Chinese Spring (CS) and CSph2b mutant showed high susceptibility to FHB. A field evaluation of the agronomic traits showed that the plant height of DA26 was significantly lower than CS, while there were no significant differences in the other agronomic traits. In addition, we also developed eight 4Ns-specific primers to identify the 4Ns chromosome, which can facilitate wheat breeding and FHB resistance gene mapping in the future. Full article

Wheat plays a crucial role in global food security; however, in recent years, Fusarium Head Blight (FHB) has severely impacted both wheat yield and quality. Strong oxidative free radicals, with high oxidation potential and rapid reaction rates, offer an effective approach for pollutant degradation and microbial inactivation. In this study, the control effect of strong oxidizing radicals on FHB was evaluated by comparing the untreated control group (JM23), which was infected with FHB, to the experimental group (FG06), which was treated with strong oxidizing radicals following FHB infection. The results show that FG06 achieved a control effectiveness of 87.87%. The study also assessed grain characteristics and milling quality. Statistical analysis revealed that FG06 had a slightly lower flour extraction rate (71.24%) compared to the control wheat (JM23), but it exhibited competitive flour whiteness (81.30) and a gluten index of 85.50%. The dough stability at 10 min was 27.00 FE, while several gelatinization parameters were significantly lower than JM23. However, FG06 had higher protein content (10.94%), flour protein content (10.70%), ash content (0.58%), wet gluten content (28.70%), dry gluten content (9.40%), and sedimentation value (73.00 mL), all significantly higher than those of JM23. Additionally, FG06 had a gelatinization temperature of 68.61 °C, similar to JM23. Overall, Strong oxidizing radicals as an alternative to conventional pesticides not only effectively controls FHB but also maintains or even enhances wheat milling and processing quality, promoting more sustainable agricultural practices. Full article

The main aim of this study was to discuss and compare the threats associated with F. graminearum in wheat production in Poland and in other Central European countries. Wheat is one of the most widely cultivated crops in the world, and pathogens causing Fusarium head blight (FHB) pose the greatest threat to wheat production. Our knowledge of FHB has to be regularly expanded in order to explore the impacts of climate change, new wheat cultivars, and new fungicides on the prevalence of this disease. The pathogen’s resistance to fungicides was analyzed in a global context due to the relative scarcity of studies examining this problem in Central Europe (excluding Germany). This is an interesting research perspective because, despite a relatively large number of Polish studies on FHB, F. graminearum genotypes and the pathogen’s resistance to fungicides remain insufficiently investigated. The hemibiotrophic pathogen Fusarium graminearum causes particularly high losses in wheat cultivation due to its ability to produce mycotoxins that are dangerous to human health (mainly deoxynivalenol, DON), colonize plant residues in soil in the saprotrophic phase, and produce spores that infect the stem base and spikes throughout the growing season. The infection process is highly dynamic, and it is facilitated by DON. The synthesis of DON (trichothecene) is encoded by Tri genes located in four loci. In Poland, the F. graminearum population is mainly composed of the 15ADON genotype, and the spread of FHB cannot effectively be managed with fungicides during epidemic years. Dynamic gene flows in field populations enable the pathogen to rapidly adapt to environmental changes and overcome wheat resistance to FHB. The emergence of fungicide-resistant F. graminearum strains significantly compromises the quality of wheat crops, but the associated mechanisms have not been sufficiently investigated to date. In addition, although some biopreparations are promising and effective in small-scale field trials, very few have been commercialized. Extensive research into pathogen populations, the development of new resistant wheat varieties, and the use of effective fungicides and biopreparations are required to produce wheat grain that is free of mycotoxins. Full article

Wheat pathogens pose a significant risk to global wheat production, with climate change further complicating disease dynamics. Effective management requires a combination of genetic resistance, cultural practices, and careful use of chemical controls. Ongoing research and adaptation to changing environmental conditions are crucial for sustaining wheat yields and food security. Based on selective academic literature retrieved from the Scopus database and analyzed by a bibliographic software such as the VOSviewer we discussed and focused on various aspects of current and future strategies for managing major wheat pathogens and diseases such as Tan spot, Septoria tritici blotch, Fusarium head blight, etc. Chemical management methods, such as the use of fungicides, can be effective but are not always preferred. Instead, agronomic practices like crop rotation and tillage play a significant role in managing wheat diseases by reducing both the incidence and severity of these diseases. Moreover, adopting resistance strategies is essential for effective disease management. Full article

Accurate detection of soybean diseases is a critical component in achieving intelligent agricultural management. However, traditional methods often underperform in complex field scenarios. This paper proposes a diffusion-based object detection model that integrates the endogenous diffusion sub-network and the endogenous diffusion loss function to progressively optimize feature distributions, significantly enhancing detection performance for complex backgrounds and diverse disease regions. Experimental results demonstrate that the proposed method outperforms multiple baseline models, achieving a precision of 94%, recall of 90%, accuracy of 92%, and mAP@50 and mAP@75 of 92% and 91%, respectively, surpassing RetinaNet, DETR, YOLOv10, and DETR v2. In fine-grained disease detection, the model performs best on rust detection, with a precision of 96% and a recall of 93%. For more complex diseases such as bacterial blight and Fusarium head blight, precision and mAP exceed 90%. Compared to self-attention and CBAM, the proposed endogenous diffusion attention mechanism further improves feature extraction accuracy and robustness. This method demonstrates significant advantages in both theoretical innovation and practical application, providing critical technological support for intelligent soybean disease detection. Full article