Mycotoxins In Grain Research Articles

Rapid, on-site quantitative determination of mycotoxins in grains using a multiple time-resolved fluorescent microsphere immunochromatographic test strip

The label probe plays a crucial role in enhancing the sensitivity of lateral flow immunoassays. However, conventional fluorescent microspheres (FMs) have limitations due to their short fluorescence lifetime, susceptibility to background fluorescence interference, and inability to facilitate multi-component detection. In this study, carboxylate-modified Eu(III)-chelate-doped polystyrene nanobeads were employed as label probes to construct a multiple time-resolved fluorescent microsphere-based immunochromatographic test strip (TRFM-ICTS). This novel TRFM-ICTS facilitated rapid on-site quantitative detection of three mycotoxins in grains: Aflatoxin B1 (AFB1), Zearalenone (ZEN), and Deoxynivalenol (DON). The limit of detection (LOD) for AFB1, ZEN, and DON were found to be 0.03 ng/g, 0.11 ng/g, and 0.81 ng/g, respectively. Furthermore, the TRFM-ICTS demonstrated a wide detection range for AFB1 (0.05–8.1 ng/g), ZEN (0.125–25 ng/g), and DON (1.0–234 ng/g), while maintaining excellent selectivity. Notably, the test strip exhibited remarkable stability, retaining its detection capability even after storage at 4 °C for over one year. Importantly, the detection of these mycotoxins relied solely on simple manual operations, and with a portable reader, on-site detection could be accomplished within 20 min. This TRFM-ICTS presents a promising solution for sensitive on-site mycotoxin detection, suitable for practical application in various settings due to its sensitivity, accuracy, simplicity, and portability.

Contamination and Control of Mycotoxins in Grain and Oil Crops.

Mycotoxins are carcinogenic, teratogenic and mutagenic toxic compounds produced by some filamentous fungi, which are extremely harmful to corn, rice, wheat, peanut, soybean, rapeseed and other grain and oil crops, and seriously threaten environmental safety, food safety and human health. With the rapid increase in the global population and the expansion of the main crop planting area, mycotoxin contamination has increased year by year in agricultural products. The current review aimed to summarize the contamination status and harmful effects of major mycotoxins of grain and oil crops and the environmental factors that impact mycotoxin contamination. Further, control measures of mycotoxin contamination, especially the biological control strategies, were discussed.

Mycotoxins in grains (products), Gansu province, China and risk assessment

ABSTRACT This study aimed to estimate the dietary exposure towards mycotoxins of residents in Gansu province, China, from 2014–2020 through surveillance data on mycotoxins in grains and grain products. Fumonisin B1 (FB1), Deoxynivalenol (DON), 3- and 15-Acetyl-deoxynivalenol (3-ADON and 15-ADON), Tentoxin (TEN), Tenuazonic acid (TeA) and Zearalenone (ZEN) in 863 grains and grain products were detected by HPLC-MS and UPLC-MS. DON was the most detected mycotoxin of all samples. For women, the average dietary exposure to DON was 1.49 μg/kg bw/day, with 55.8% of the individuals eating dried noodles exceeding tolerable daily intake. The hazard quotient values were 1.24–12.60, so greater than 1 for DON at the average, 90th percentile, 95th percentile, and maximum levels: 44.6% of the HQ values for men and 45.7% for women were greater than 1.

Evaluation of fungicidal efficacy of free and nano-encapsulated chitosan against <i>Aspergillus flavus</i> isolated from rice (<i>Oryza sativa</i>) seed

Grains are exposed to contamination by mycotoxins, both in the field and during storage. Aflatoxins produced by Aspergillus species are the most harmful and carcinogenic mycotoxins in grains. Synthetic fungicides are widely used for the control of mycotoxigenic fungi in grains. However, rising public awareness about the toxicological effects of fungicides on human health necessitates the development of non-toxic bio-fungicides. In this connection, reports have shown that chitosan synthesized from shell waste has the potential to serve as an alternative fungicide. Therefore, this study investigated the fungicidal efficacy of free and nano-encapsulated chitosan against aflatoxigenic fungus (Aspergillus flavus). High molecular weight chitosan was purchased, and the in-vitro antifungal efficacy of chitosan against A. flavus was tested using the food poisoning method. Nano-encapsulated chitosan was synthesized using the ionic gelation method, the particle size was determined, and invitro inhibition against A. flavus was investigated. The results revealed that nano-encapsulated chitosan with particle sizes of 525.4 nm, 468.3 nm, and 711.7 nm were obtained. In-vitro mycelial A. flavus growth inhibition of 100% was recorded at 1.5% and 2.0% of free chitosan, while at 0.5% and 1.0% of free chitosan, 45% and 75% inhibition were observed, respectively. Nano-encapsulated chitosan with particle size (nm) of 525.4, 468.3, and 711.7 at 0.50% recorded 61%, 84% and 87% inhibition, respectively. However, at 0.25%, the rate of inhibition was 64%, 78% and 67%, respectively. This study showed that free chitosan and nano-encapsulated chitosan are potential antifungal agents for the control of A. flavus.

Effect of Milling on Reduction of Fusarium Mycotoxins in Barley

Milling can affect the distribution of mycotoxins in small grains. To investigate the effects on barley, seven hulled barley and three naked barley samples naturally contaminated with trichothecenes and zearalenone were obtained and milled at commonly used rates. Both barleys were simultaneously contaminated with deoxynivalenol and its acetyl derivatives (98.1–2,197.8 μg/kg), nivalenol and its acetyl derivative (468.5–3,965.1 μg/kg), and zearalenone (4.1–274.2 μg/kg). Milling hulled barleys at a rate of 67% reduced the mycotoxins in the grain by 90.9% for deoxynivalenol, 87.7% for nivalenol, and 93.2% for zearalenone. The reduction in naked barleys (milled at a rate of 70%) was slightly lower than in hulled barleys, with 88.6% for deoxynivalenol, 80.2% for nivalenol, and 70.1% for zearalenone. In both barleys, the acetyl derivatives of deoxynivalenol and nivalenol were reduced by 100%. However, barley bran had significantly higher mycotoxin concentrations than the pre-milled grains: bran from hulled barley had a 357% increase in deoxynivalenol, 252% increase in nivalenol, and 169% increase in zearalenone. Similarly, bran from naked barley had a 337% increase in deoxynivalenol, 239% increase in nivalenol, and 554% increase in zearalenone. These results show that mycotoxins present in the outer layers of barley grain can be effectively removed through the milling process. As milling redistributes mycotoxins from the grain into the bran, however, it shows that advance monitoring of barley bran is recommended when using barley bran for human or animal consumption.

Evaluation of mycotoxins in grains sold in Idah, Ajaka and Ogbogbo areas of Nigeria.

Mycotoxin contamination in grains is a significant concern due to its adverse effects on human and animal health. Understanding the levels and patterns of mycotoxin contamination in different regions and storage conditions is crucial for developing effective control strategies. This study aimed to assess mycotoxin levels in stored and recently harvested grains in three regions (Idah, Ajaka, and Ogbogbo) and investigate the implications for food safety. The study involved the analysis of mycotoxin levels in maize, rice, sorghum, and millet using appropriate mycotoxin extraction method based on the mycotoxins of interest and a suitable HPLC system. The findings revealed the presence of mycotoxins such as aflatoxins (1±0.2-5±0.4 µg kg-1), deoxynivalenol (520±0.8-700±1.2 µg kg-1), zearalenone (200±0.4-370±0.6 µg kg-1), ochratoxins (2±0.2-4±0.3 µg kg-1), and fumonisin (0±0.0-4±0.3 µg kg-1) in both recently harvested and stored grains. Patulin was absent in most of the samples. Variations in mycotoxin levels were observed among different grains and regions, highlighting the need for targeted interventions. The European Commission mycotoxin standards in grains for human consumption are: aflatoxins 4 µg kg-1 in maize, millet and sorghum while rice is 8 µg kg-1, deoxynivalenal 1750 µg kg-1, zearalenone 100 µg kg-1, ochratoxin A 5 µg kg-1 for maize, rice and millet, then 10 µg kg-1 for sorghum. Fumonisin is 4000 µg kg-1 but no level for rice and patulin is 50 µg kg-1 for rice and none for the other grains. This study demonstrates the persistence of mycotoxin contamination in stored grains and the importance of considering specific crop types and geographical locations when addressing mycotoxin contamination. The findings underscore the significance of implementing effective control measures to mitigate mycotoxin contamination and enhance food safety. The study provides valuable insights into mycotoxin contamination and emphasizes the need for comprehensive risk assessment studies and appropriate regulatory measures.

Interconnectable 3D-printed sample processing modules for portable mycotoxin screening of intact wheat

BackgroundThe increasing demand for food and feed products is stretching the capacity of the food value chain to its limits. A key step for ensuring food safety is checking for mycotoxin contamination of wheat. However, this analysis is typically performed by rather complex and expensive chromatographic methods, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS). These costly methods require extensive sample preparation that is not easily carried out at different points along the food supply chain. To overcome such challenges in sample processing, an inexpensive and portable sample preparation device was needed, that required low skill, for rapid sample-to-result mycotoxin screening. ResultsWe describe 3D-printed and interconnectable modules for simple, integrated and on-site sample preparation, including grinding of wheat kernels, and solvent-based extraction. We characterized these 3D-printed modules for mycotoxin screening and benchmarked them against a laboratory mill using commercial lateral flow device(s) (LFD) and in-house validated LC-MS/MS analysis. Different integrated sieve configurations were compared based on grinding efficiency, and we selected a sieve size of 2 mm allowing grinding of 10 g of wheat within 5 min. Moreover, 10 first time-users were able to operate the grinder module with minimal instructions. Screening for deoxynivalenol (DON) in naturally contaminated samples at the regulatory/legal limit (1.25 mg kg−1) was demonstrated using the developed 3D-printed prototype. The whole process only takes 15 min, from sample preparation to screening result. The results showed a clear correlation (R2 = 0.96) between the LFD and LC-MS/MS. SignificanceOur findings demonstrate the potential of 3D-printed sample handling equipment as a valuable extension of existing analytical procedures, facilitating the on-site implementation of rapid methods for the determination of mycotoxins in grains. The presented prototype is inexpensive with material costs of 2.5€, relies on biodegradable 3D printing filament and can be produced with consumer-grade printers, making the prototype readily available. As a future perspective, the modular character of our developed tool kit will allow for adaptation to other hard food commodities beyond the determination of DON in wheat.

Development and validation of a QuEChERS-LC-MS/MS method for determination of multiple mycotoxins in maize and sorghum from Botswana.

Climatic conditions such as drought, high temperatures, and pre-harvest rainfalls promote the occurrence of mycotoxins in grains. Contamination of staple food sources such as maize and sorghum means that many populations are at risk of being poisoned by mycotoxins. Hence the need for sensitive methods for their simultaneous analysis. Herein, a quick, easy, cheap, effective, rugged, and safe liquid chromatography tandem mass spectrometry (QuEChERS-LC-MS/MS) method for the simultaneous determination of ten mycotoxins in maize and sorghum is presented. The QuEChERS extraction procedure was optimized to maximize extraction recovery and minimize matrix effects while using relatively small quantities of organic solvents and acids. This method was validated according to Commission Implementing Regulation (EU) 2021/808, Commission Regulation (EC) No 1881/2006, and Regulation (EC) no. 401/2006. The developed method met the specified requirements. Recoveries of 80.77% to 109.83% and CVs below 15% were obtained. The correlation coefficient values (R2) were all above 0.98, and low limits of quantification ranging from 0.53 to 89.28 µg/Kg were recorded. The method was applied to 10 maize and 10 sorghum samples collected from markets in Botswana. Half of the samples had detectable mycotoxins, Aflatoxins, Fumonisins, T2-toxin, HT2-toxin, and Zearalenone. Two maize samples had levels of aflatoxin B1 above the maximum permitted level (2.55, 4.07 µg/Kg). These findings point to the necessity of more stringent monitoring of mycotoxins, particularly AFB1 in maize, as well as the value of regular assessment using LC-MS/MS.

Multicolor Visual Detection of Deoxynivalenol in Grain Based on Magnetic Immunoassay and Enzymatic Etching of Plasmonic Gold Nanobipyramids

In this study, a multicolor visual method based on a magnetic immunoassay and enzyme-induced gold nanobipyramids (Au NBPs) etching was developed for deoxynivalenol (DON) detection. The magnetic beads modified with high affinity DON monoclonal antibodies were used as a carrier for target enrichment and signal transformation and the Au NBPs with excellent plasmonic optical properties were served as enzymatic etching substrates. The oxidation state TMB, which was generated through catalysis of horseradish peroxidase (HRP), induced the etching of plasmonic Au NBPs, resulting in the longitudinal peak blue-shift of local surface plasmon resonance (LSPR). Correspondingly, Au NBPs with various aspect ratios displayed a variety of individual colors which were visualized by the naked eye. The LSPR peak shift was linearly related to the DON concentration in the range of 0~2000 ng/mL and the detection limit was 57.93 ng/mL. The recovery for naturally contaminated wheat and maize at different concentrations ranged from 93.7% to 105.7% with a good relative standard deviation below 11.8%. Through observing the color change in Au NBPs, samples with overproof DON could be screened preliminarily by the naked eye. The proposed method has the potential to be applied in on-site rapid screening of mycotoxins in grain. In addition, the current multicolor visual method only used for the simultaneous detection of multiple mycotoxins is in urgent need of a breakthrough to overcome the limitation of single mycotoxin detection.

Different diagnostic approaches for the characterization of the fungal community and Fusarium species complex composition of Italian durum wheat grain and correlation with secondary metabolite accumulation.

The evolution of the fungal communities associated with durum wheat was assessed using different diagnostic approaches. Durum wheat grain samples were collected in three different Italian cultivation macro-areas (north, center and south). Fungal isolation was realized by potato dextrose agar (PDA) and by deep-freezing blotter (DFB). Identification of Fusarium isolates obtained from PDA was achieved by partial tef1α sequencing (PDA + tef1α), while those obtained from DFB were identified from their morphological characteristics (DFB + mc). The fungal biomass of eight Fusarium species was quantified in grains by quantitative polymerase chain reaction (qPCR). Fungal secondary metabolites were analyzed in grains by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Correlations between Fusarium detection techniques (PDA + tef1α; DFB + mc and qPCR) and mycotoxins in grains were assessed. Alternaria and Fusarium showed the highest incidence among the fungal genera developed from grains. Within the Fusarium community, PDA + tef1α highlighted that F. avenaceum and F. graminearum were the most represented members, while, DFB + mc detected a high presence of F. proliferatum. Alternaria and Fusarium mycotoxins, principally enniatins, were particularly present in the grain harvested in central Italy. Deoxynivalenol was mainly detected in northern-central Italy. The adoption of the different diagnostic techniques of Fusarium detection highlighted that, for some species, qPCR was the best method of predicting their mycotoxin contamination in grains. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Assessment of Agricultural Practices for Controlling Fusarium and Mycotoxins Contamination on Maize Grains: Exploratory Study in Maize Farms.

Maize is a significant crop to the global economy and a key component of food and feed, although grains and whole plants can often be contaminated with mycotoxins resulting in a general exposure of the population and animals. To investigate strategies for mycotoxins control at the grain production level, a pilot study and exploratory research were conducted in 2019 and 2020 to compare levels of mycotoxins in grains of plants treated with two fertilizers, F-BAC and Nefusoil, under real agricultural environment. The 1650 grains selected from the 33 samples were assessed for the presence of both Fusarium species and mycotoxins. Only fumonisins and deoxynivalenol were detected. Fumonisin B1 ranged from 0 to 2808.4 µg/Kg, and fumonisin B2 from 0 to 1041.9 µg/Kg, while deoxynivalenol variated from 0 to 465.8 µg/Kg. Nefusoil showed to be promising in regard to fumonisin control. Concerning the control of fungal contamination rate and the diversity of Fusarium species, no significant differences were found between the two treatments in any of the years. However, a tendency for was observed Nefusoil of lower values, probably due to the guaranteed less stressful conditions to the Fusarium spp. present in the soil, which do not stimulate their fumonisins production.

Establishment of non-targeted screening database and confirmation method for 18 mycotoxins in grains using ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry

A mass spectral library of 18 mycotoxins was developed based on ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS), which was used to establish a non-targeted screening method for mycotoxins in rice and wheat matrices. Eighteen mycotoxin standards were separated on an HSS T3 column, and data were collected for both positive and negative ionization under the MSE mode of the UPLC-Q-TOF/MS. Details including formulas, retention times, theoretical exact masses, measured exact masses of the adduct and fragment ions, and ion abundance ratios were recorded to establish the mass spectral library of the 18 mycotoxins in UNIFI Software. Analyte detection was based on a retention time deviation of 0.3 min, and the exact mass deviation of the adduct ions and fragment ions was set to 5×10-6. The screening detection limit (SDL) was used as the main threshold for verifying the screening method. In the validation process, 18 mycotoxins were classified into two types: with maximum levels (MLs) and without MLs. The results showed that the mycotoxins with MLs could be accurately screened at their limited level, and the mycotoxins without MLs had a range of SDL concentration from 2 to 800 μg/kg. The matrix effect results showed that 14 mycotoxins in rice and 11 in wheat had moderate matrix effects. Finally, 25 batches of rice and wheat were purified using QuEChERS and HLB columns after acetonitrile extraction and screening were performed by employing the established method. The results revealed that aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), fumonisins B1 (FB1), and sterigmatocystin (ST) were detected in one batch of rice, FB1 and ST were detected in another batch of rice, FB1 and ochratoxin A (OTA) were detected in two batches of wheat, and no other mycotoxins were detected. This method is characterized by high throughput, simplicity, rapidity, accuracy, and can be applied to accurately screen mycotoxins with concentrations higher than the SDLs and qualitatively screen various mycotoxins in rice and wheat without standards.

Crucial Function of Caveolin-1 in Deoxynivalenol-Induced Enterotoxicity by Activating ROS-Dependent NLRP3 Inflammasome-Mediated Pyroptosis.

Deoxynivalenol (DON) is one of the most pervasive contaminating mycotoxins in grain, and exposure to DON is known to cause acute and chronic intestinal damage. As the gut is the most important target organ of DON, it is essential to identify the pivotal molecules involved in DON-induced enterotoxicity as well as the potential regulatory mechanisms. In the present study, we found that DON treatment dramatically decreased the jejunal villus height and increased the crypt depth in mice. DON exposure induced oxidative stress and NLRP3 inflammasome activation while increasing the levels of pyroptosis-related factors GSDMD, ASC, Caspase-1 P20, and IL-1β and inflammatory cytokines IL-18, TNF-α, and IL-6. In vitro, 0.5-2 μM DON caused cytotoxicity and oxidative stress, as well as NLRP3-mediated pyroptosis in IPEC-J2 cells. Furthermore, DON treatment substantially improved the expression of Caveolin-1 (Cav-1) in vitro and in vivo. Interestingly, Cav-1 knockdown effectively attenuated DON-induced oxidative stress and NLRP3-mediated pyroptosis in IPEC-J2 cells. Meanwhile, treatment with the antioxidant NAC significantly alleviated DON-induced cytotoxicity and pyroptosis in IPEC-J2 cells. Likewise, after inhibiting NLRP3 inflammasome activation with the inhibitor MCC950, DON-induced cytotoxicity, pyroptosis, and inflammatory response were attenuated. However, NLRP3 inhibition did not affect Cav-1 expression. In conclusion, our study demonstrated that pyroptosis may be an underlying mechanism in DON-induced intestinal injury, and Cav-1 plays a pivotal role in DON-induced pyroptosis via regulating oxidative stress, which suggests a novel strategy to overcome DON-induced enterotoxicity.

Comparison of Antifungal Activity of Bacillus Strains against Fusarium graminearum In Vitro and In Planta

Fusarium graminearum (Fg) causes Fusarium head blight (FHB) disease in wheat and barley. This pathogen produces mycotoxins including deoxynivalenol (DON), the T-2 and fumorisin B1. Translocation of the mycotoxins in grains causes important losses in yields and contributes to serious health problems in humans and livestock. We tested the Bacillus strains, two commercial, QST713 (Serenade®) and FZB24 (TAEGRO®) and one non-commercial strain EU07 as microbial biological control agents against the F. graminearum strain Fg-K1-4 both in vitro and in planta. The EU07 strain showed better performance in suppressing the growth of Fg-K1-4. Cell-free bacterial cultures displayed significant antagonistic activity on Fg-K1-4. Remarkably, heat and proteinase K treatment of bacterial broths did not reduce the antagonistic activity of Bacillus cultures. DON assays showed that Bacillus strain was not affected by the presence of DON in the media. Leaf and head infection assays using Brachypodium distachyon (Bd-21) indicated that EU07 inhibits Fg-K1-4 growth in vivo and promotes plant growth. Overall, the EU07 strain performed better, indicating that it could be explored for the molecular investigations and protection of cereal crops against FHB disease.

In-House Validation of an Efficient and Rapid Procedure for the Simultaneous Determination and Monitoring of 23 Mycotoxins in Grains in Korea

A high-performance liquid chromatography tandem mass spectrometry method is described for the simultaneous determination of mycotoxins, including Ergot alkaloids (EAs), in 3 types of grains. The extraction of 23 mycotoxins was evaluated and performed by using a modified QuEChERS-based sample preparation procedure. The proposed method was fully validated on spiked grain samples (barley, wheat and oat) to assess the linearity, limit of detection (LOD) and limit of quantitation (LOQ), matrix effects, precision and recovery. After validation, this method was applied to 143 samples of various types of 3 grains from the Republic of Korea to survey the level of mycotoxin contamination in Republic of Korean grains. A total of 42 grain samples (29%) were contaminated with at least one of these mycotoxins at levels higher than the LOQ. The results demonstrated that the procedure was suitable for simultaneously determining these mycotoxins in cereals and could be performed for their routine analysis in mycotoxin laboratories.

Levels of Deoxynivalenol and Aflatoxin Mycotoxins in Grains in Some Markets of Makurdi Metropolis, Nigeria

This study aimed to estimate deoxynivalenol (DON) and total aflatoxin in two varieties of millet, sorghum and maize, in some markets of Makurdi metropolis, North-Central, Nigeria using direct competitive Enzyme-linked Immunosorbent Assay (ELISA) method. Moisture content, total aerobic microbial count, mould count, Coliform and Escherichia coli were determined using standard analytical methods. Moisture content profile of 9.5032 to 12.9940% (sorghum), 9.5932 to 12.3604% (maize) and 9.0279 to 12.4108% (millet) was considered relatively high. Proliferation of total aerobic microbial count was observed in the samples across the sampling points. Mycotoxins under study were detected in all samples across the sampling points. Whereas total aflatoxins were within permissible limits, DON exceeded thresholds. It was also observed that, these grains were more susceptible to the fungus Fusarium species producer of DON than the producer of aflatoxin, thus susceptibility of the grains to fungus producer of DON was in the order: sorghum > maize > millet, whereas the susceptibility against the fungus producer or producers of total aflatoxin level was in the order: sorghum > millet > maize respectively. This in general, indicated microbial contamination of these cereals in the study location indicting farmers and marketers of poor hygienic handling and processing of the grains. Pearson’s 2-tailed correlation at 0.05 level of significance revealed strong correlation of deoxynivalenol with moisture content of grains across locations.

Mycotoxin Analysis of Grain via Dust Sampling: Review, Recent Advances and the Way Forward: The Contribution of the MycoKey Project.

The sampling protocols for the official control of the levels of mycotoxins in foodstuffs are very costly and time-consuming. More efforts are needed to implement alternative sampling plans able to support official control, or to adapt the current ones. The aim of the research carried out within the European Horizon 2020 MycoKey project was to evaluate the applicability at industrial scale of the dust sampling approach to detect multiple mycotoxins in grains. To this end, two trials were performed on an EU industrial site: (i) control of the unloading of wheat from train wagons; (ii) control of the unloading of wheat from trucks. In line with previous studies, the MycoKey results indicated that dust sampling and mycotoxin analysis represent a fitness for purpose approach for non–destructive and rapid identification of wheat commodities compliant to the maximum permitted levels. Based on reviewed and newly generated results, this article discusses potential applications and limits of the dust sampling methodology, identifying future research needs.

Influence of Structure of Detrital Food Webs on Fusarium Head Blight of Winter Wheat

Conventional methods for Fusarium head blight (FHB) control are ineffective. A better understanding of the mechanisms linking the abundance of Fusarium species in soil before winter wheat flowering and mycotoxin content in mature grain may help to improve the effectiveness of methods for FHB control. In this study, we established a field experiment aimed to trace the impact of three types of organic mulch with different C:N ratios on the structure of detrital food webs and the manifestation of winter wheat FHB. T2-toxin content in grain was significantly higher in N-poor treatment (52.1 ± 0.2 µg g−1) compared to N-rich treatment (40.4 ± 1.6 µg g−1). The structure of detrital food webs in the studied treatments changed significantly after mulch addition; the abundance of soil saprophages and mycophages increased up to 50%. Based on the results of mixed-effects modeling, the abundance of herpetobionts and soil mesofauna were positively associated with an increase in Fusarium biomass in grain. The increase in the content of T2-toxin in the grain was associated with an increase in the abundance of earthworms and phytophagous macrofauna in the soil. Results suggest the existence of a previously undescribed mechanism for FHB infection by transfer of pathogenic spores by soil invertebrates, while the content of mycotoxins in grain can be triggered by the grazing activity of soil phytophagous invertebrates.

Factors affecting the level of Fusarium mycotoxins in grain. Vestsі Natsyyanal’nay akademіі navuk Belarusі

Mycotoxins accumulation in grain is one of the most widely analyzed problem nowadays, as soon as these metabolites are of high danger to health of warm-blooded animals and humans. Producing mycotoxins with Fusarium fungi beaing causal agents of Fusarium head blight, depends on range of factors, and among measures for their accumulation decrease, chemical method is one of the most effective ones. The paper presents the results of study on factors affecting mycotoxins accumulation under the field conditions. During the experiment with artificial inoculation of winter wheat heads by F. culmorum fungi, the influence of triazole fungicides on Fusarium head blight and mycotoxins content had been estimated. Higher biological efficiency (83,2-79,2 %) for disease severity decrease was higher with fungicide Osiris, EC. Use of fungicides led to increase in indicators of economic efficiency in comparison with the option with no treatment, including the yield, by 12.3-12.8%. In the variants with head protection, the DON content was 2.0-2.1 times lower than in the control. Under conditions of natural damage to various varieties of grain crops (winter wheat and triticale, spring barley) by Fusarium head blight, its depressive manifestation had been determined. It had been determined that spring barley, regardless of the variety, was more resistant to accumulation of mycotoxins, in particular ZEN. Level of mycotoxins in winter wheat and triticale grain varied depending on variety and storage duration. The data obtained will serve as the basis for substantiating measures to reduce the level of mycotoxins in grain. Acknowledgments. The research was carried out with the financial support of the Belarusian Republican Foundation for Fundamental Research as a part of the scientific research project “Comprehensive assessment of mycotoxins accumulation during foodstuff storage” (treaty N Б19МЛДГ-009).

Prevalence of Fusarium fungi and Deoxynivalenol Levels in Winter Wheat Grain in Different Climatic Regions of Poland.

Fusarium head blight (FHB) caused by fungi of the genus Fusarium is one of the most dangerous crop diseases, which has a wide geographic distribution and causes severe economic losses in the production of major cereal species. The infection leads to the accumulation of mycotoxins in grains, which compromises its suitability for human and animal consumption. The study demonstrated that grain samples from warmer regions of Poland, including Sulejów and Tomaszów Bolesławicki (results differed across years of the study), were colonized mainly by F. graminearum and were most highly contaminated with deoxynivalenol (DON). Samples from Northeastern Poland, i.e., Ruska Wieś, which is located in a cooler region, were characterized by a predominance of Fusarium species typical of the cold climate, i.e., Fusarium poae and Penicillium verrucosum. A Spearman’s rank correlation analysis revealed that the severity of grain infection with F. avenaceum/F. tricinctum was affected by the mean daily temperature and high humidity in May, and the corresponding values of the correlation coefficient were determined at R = 0.54 and R = 0.50. Competitive interactions were observed between the F. avenaceum/F. tricinctum genotype and DON-producing F. culmorum and F. graminearum, because the severity of grain infections caused by these pathogens was bound by a negative correlation.