Resistance of oat breeding lines to grain contamination with Fusarium langsethiae and T-2/HT-2 toxins

Fusarium disease of oats reduces yield quality due to decreasing germination that is caused by then contamination of grain with mycotoxins produced by Fusarium fungi. The aim of this study was to characterize the resistance of naked breeding lines of oats to fungal grain infection and to contamination with T-2 and HT-2 toxins. Thirteen naked oat breeding lines and two naked varieties, Nemchinovsky 61 and Vyatskiy, as well as a husked variety Yakov, were grown under natural conditions in the Nemchinovka Federal Research Center in 2019–2020. The contamination of grain with fungi was determined by the mycological method and real-time PCR. The analysis of mycotoxins was carried out by ELISA. In oats, Alternaria (the grain infection was 15–90 %), Cochliobolus (1–33 %), Cladosporium (1–19 %), Epicoccum (0–11 %), and Fusarium (3–17 %) fungi prevailed in the grain mycobiota. The predominant Fusarium species were F. poae (its proportion among Fusarium fungi was 49–68 %) and F. langsethiae (29–28 %). The highest amounts of F. langsethiae DNA ((27.9–71.9)×10–4 pg/ng) and T-2/HT-2 toxins (790–1230 μg/kg) were found in the grain of husked oat Yakov. Among the analysed naked oat lines, the amount of F. langsethiae DNA varied in the range of (1.2–42.7)×10–4 pg/ng, and the content of T-2/HT-2 toxins was in the range of 5–229 μg/kg. Two oat breeding lines, 54h2476 and 66h2618, as well as a new variety, Azil (57h2396), can be characterized as highly resistant to infection with Fusarium fungi and contamination with mycotoxins compared to the control variety Vyatskiy.

Determination of uric acid in grain using HPLC

В данной статье показана возможность улучшения определения мочевой кислоты методом высокоэффективной жидкостной хроматографии (ВЭЖХ), с помощью увеличения растворимости ее в 1 %-ном растворе ацетата натрия, повышения удержания мочевой кислоты и тем самым изменения времени выхода, что позволяет повысить точность анализа. Проведено сравнение градуировочных растворов и опытных образцов зерна зараженных вредителями хлебных запасов. В процессе исследования был опробован метод для определения и идентификации мочевой кислоты как одного из загрязняющих зерно веществ с помощью ВЭЖХ в обращенной фазе. Экспериментально опробована и усовершенствована методика анализа мочевой кислоты в зерне с использованием жидкостного хроматографа «Стайер». Описаны оборудование и материалы для ВЭЖХ, условия хроматографического разделения и детектирования, построения калибровочного графика, экстракции, включая методику экстракции, сходимости результатов при экстракции и введении экстракта в хроматограф, а также порядок и расчет измерений. Экспериментально показано, что усовершенствованная методика с применением ВЭЖХ позволяет использовать ее для проведения дальнейших исследований зависимости содержания мочевой кислоты от величины загрязнения зерна насекомыми. This article shows the possibility of improving the determination of uric acid by high-performance liquid chromatography (HPLC), by increasing its solubility in a 1 % solution of sodium acetate, increasing the retention of uric acid, and thereby changing the yield time, which allow to improve the accuracy of the analysis, a comparison of calibration solutions and experimental grain samples of pest-infected bread stocks have been carried out. During the research course a method for the determination and identification of uric acid has been tested as one of the grain polluting substance using HPLC in the reversed phase. The method of uric acid in grain analysis using a liquid chromatograph «Stayer» has been experimentally tested and improved. The equipment and materials for HPLC, the conditions of chromatographic separation and detection, the construction of a calibration graph, extraction, including the extraction method, the convergence of the results during extraction and the introduction of the extract into the chromatograph, as well as the course and calculation of measurements have been described. It has been experimentally shown that the improved method with HPLC allows to use it for further research of the uric acid content dependence on the amount of grain contamination by insects.

DEOXINIVALENOL AS A RISK FACTOR OF FOOD GRAIN CONTAMINATION: MONITORING RESULTS OF 1989–2018 YEARS HARVESTS IN RUSSIAN FEDERATION

The paper dwells on the results obtained via long-term monitoring over food grain (wheat, barley, corn, oats, and rye) contamination with mycotoxin deoxynivalenol (DON). From 1989 to 2018 6,800 grain samples from Central, Southern, Volga, Ural, Siberian, North-Caucasian, Far Eastern, and North-western Federal Districts (FD) of the RF were analyzed. Depending on a year harvest, DON occurrence varied from 0 to 42 % and maximum toxin content reached 6.65 mg/kg. Over the whole examined period 10 % samples turned out to be contaminated and one forth of them contained the toxin in quanti- ties exceeding maximum permissible levels (MPL). DON occurrence amounted to 24–42 % in years of mass epiphytoties (1989, 1992 and 1993) as well as in crops gathered in 2014 and 2017; DON was detected in quantities exceeding MPL in 9–27 % of examined samples in those years. 78 % contaminated samples came from Southern and North-Caucasian FD and another 10 % were from Far Eastern FD. A significant correlation between DON occurrence and a number of rainy and sunny days in May was established on the example of wheat samples from Krasnodar region. Analysis of contamination dy- namics has revealed that over the last years there has been an ascending trend in frequency of DON detection in wheat that came not only from regions where Fusarium head blight was widely spread but also from regions in North-western, Siberian and Volga FD. Health risks related to DON intake with wheat grains processing products were assessed; the assessment revealed that DON intake higher than tolerable daily intake (TDI) for the residents of Southern and North-Caucasian FD in 1992, 1993, 2014 and 2017. Average occurrence of DON was 4.2; 11.9; 3.0 and 0.6 % for barley, corn, rye, and oats samples and its maximum contents amounted to 8.95; 0.95; 0.96 and 0.44 mg/kg accordingly. Just as it was the case with wheat, the most of contami- nated samples came from Southern, North-Caucasian and Far Eastern FD. Contamination tended to grow for all the exam- ined grains and it calls for relevant measures aimed at controlling food grains safety

DEOXINIVALENOL AS A RISK FACTOR OF FOOD GRAIN CONTAMINATION: MONITORING RESULTS OF 1989–2018 YEARS HARVESTS IN RUSSIAN FEDERATION

The paper dwells on the results obtained via long-term monitoring over food grain (wheat, barley, corn, oats, and rye) contamination with mycotoxin deoxynivalenol (DON). From 1989 to 2018 6,800 grain samples from Central, Southern, Volga, Ural, Siberian, North-Caucasian, Far Eastern, and North-western Federal Districts (FD) of the RF were analyzed. Depending on a year harvest, DON occurrence varied from 0 to 42 % and maximum toxin content reached 6.65 mg/kg. Over the whole examined period 10 % samples turned out to be contaminated and one forth of them contained the toxin in quanti- ties exceeding maximum permissible levels (MPL). DON occurrence amounted to 24–42 % in years of mass epiphytoties (1989, 1992 and 1993) as well as in crops gathered in 2014 and 2017; DON was detected in quantities exceeding MPL in 9–27 % of examined samples in those years. 78 % contaminated samples came from Southern and North-Caucasian FD and another 10 % were from Far Eastern FD. A significant correlation between DON occurrence and a number of rainy and sunny days in May was established on the example of wheat samples from Krasnodar region. Analysis of contamination dy- namics has revealed that over the last years there has been an ascending trend in frequency of DON detection in wheat that came not only from regions where Fusarium head blight was widely spread but also from regions in North-western, Siberian and Volga FD. Health risks related to DON intake with wheat grains processing products were assessed; the assessment revealed that DON intake higher than tolerable daily intake (TDI) for the residents of Southern and North-Caucasian FD in 1992, 1993, 2014 and 2017. Average occurrence of DON was 4.2; 11.9; 3.0 and 0.6 % for barley, corn, rye, and oats samples and its maximum contents amounted to 8.95; 0.95; 0.96 and 0.44 mg/kg accordingly. Just as it was the case with wheat, the most of contami- nated samples came from Southern, North-Caucasian and Far Eastern FD. Contamination tended to grow for all the exam- ined grains and it calls for relevant measures aimed at controlling food grains safety

Resistance to Fusarium Head Blight, Kernel Damage, and Concentrations of Fusarium Mycotoxins in the Grain of Winter Wheat Lines

Fusarium head blight (FHB) can contaminate cereal grains with mycotoxins. Winter wheat can also become infected with FHB and is more resistant than durum wheat to head infection but less than other small-grain cereals. The aim of this study was to identify winter wheat lines that combine low levels of head infection and kernel damage with low levels of grain contamination with mycotoxins. Resistance of 27 winter wheat lines (four with resistance gene Fhb1) and cultivars to FHB was evaluated over a three-year (2017–2019) experiment established in two locations (Poznań and Radzików, Poland). At the anthesis stage, heads were inoculated with Fusarium culmorum isolates. The FHB index was scored, and the percentage of Fusarium-damaged kernels (FDKs) was assessed. The grain was analyzed for type B trichothecenes (deoxynivalenol and derivatives and nivalenol) and zearalenone content. The average FHB index of both locations was 12.9%. The proportion of FDK was 6.9% in weight and 8.5% in number. The average content of deoxynivalenol amounted to 3.543 mg/kg, and the average amount of nivalenol was 2.115 mg/kg. In total, we recorded 5.804 m/kg of type B trichothecenes. The zearalenone content in the grain was 0.214 mg/kg. Relationships between the FHB index, FDK, and mycotoxin contents were highly significant for wheat lines; however, these relationships were stronger for FDK than for FHB index. Breeding lines combining all types of FHB resistance were observed, five of which had resistance levels similar to those of wheat lines with the Fhb1 gene.

Image Analysis Methods in Classifying Selected Malting Barley Varieties by Neural Modelling

Quality evaluation of products is a critical stage in the process of production. It also applies to the production of beer and its main ingredients, i.e., hops, yeast, malting barley and other components. The research described in this paper deals with the multifaceted quality evaluation of malting barley needed for the production of malt. The project aims to elaborate on the original methodology used for identifying grain varieties, grain contamination degree and other visual characteristics of malting barley employing new computer technologies, including artificial intelligence (AI) and neural image analysis. The neural modelling and digital image analysis assist in identifying the quality of barley varieties. According to the study, information concerning the colour of barley varieties presented in digital images is sufficient for this purpose. The multi-layer perceptron (MLP)-type neural network generated using a data set describing the colour of kernels presented in digital images was the best model for recognising the analysed malting barley varieties. The proposed procedure may bring specific benefits to malthouses, influencing the beer production quality in the future.

Current postharvest practices and aflatoxin contamination awareness amongst maize producers in Jimma Zone, Southwest of Ethiopia

Grain contamination by mycotoxins can cause significantly negative health and economic impact in areas where poor agricultural practices and food insecurity is prevalent. This study was conducted to investigate the current postharvest practices and aflatoxin contamination awareness level amongst maize producers in Jimma Zone, Ethiopia. Semi-structured questionnaires were used for quantitative and qualitative data collection from 90 randomly selected maize producers in two districts through a cross-sectional study design. The study revealed poor postharvest practices due to lack of proper infrastructure. Maize is harvested after maturation with the use of traditional sun drying. Plastic sheets are commonly used to protect harvested maize from rain during field drying. The majority of the respondents reported the use of traditional storage structures (81.1%) with great potential for possible mould proliferation and aflatoxin production. Maize producers of up to 62.2% were ignorant about aflatoxins and up to 26.7% reported the possible usage of aflatoxin contaminated maize in human food preparation and animal feed production. Up to 53.3% of the respondents were ignorant of aflatoxin risks in human health and stability during food processing hence the usage of mouldy maize for tella brewing. Further investigations on aflatoxin levels in maize-based food and beverages, and human exposure studies are needed. Moreover, there is a need to enhance the maize producers’ knowledge on good agricultural practices and mycotoxicosis through awareness programmes.

Application of analytical methods to identify critical limits of grain infection by Fusarium fungi

Relevance. The scientific community and agricultural producers are looking for a solution to the problem of how to protect consumers from the effects of hazardous mycotoxins in agricultural products. One of the tools, which will be considered in this article, is a screening system that allows determining the quan-titative indicators of wheat grain infection by toxin-producing fungi in a short time.Methods. The method of quantitative PCR with the detection of fungal DNA and the method of enzyme immunoassay with the detection of Fusarium antigens were used to characterize the grain infection.Results. We established the lower critical limit of DNA content which is 3955·10-4 pg/ng and the lower critical limit of Fusarium antigens which is 596 U/g based on the analyzes of grain fungi contamination in model experiments. Grain should be subjected to mycotoxins analysis upon detection of these critical lim-its. All batches of grain can be used in production without additional analyzes if their values determined by analytical methods are below that critical points. The obtained values can be quantitative benchmarks corresponding to the standard visual analysis of grain contamination currently described in GOST 31646-2012

Natural Occurrence of Maize Gibberella Ear Rot and Contamination of Grain with Mycotoxins in Association with Weather Variables

Gibberella ear rot (GER) severity (percent area of the ear diseased) and associated grain contamination with mycotoxins were quantified in plots of 15 to 16 maize hybrids planted at 10 Ohio locations from 2015 to 2018. Deoxynivalenol (DON) was quantified in grain samples in all 4 years, whereas nivalenol, 3-acetyldeoxynivalenol, and 15-acetyldeoxynivalenol (15ADON) were quantified only in the last 2 years. Only DON and 15ADON were detected. The highest levels of GER and DON contamination were observed for 2018, followed by 2016 and 2017. No GER symptoms or DON were detected in 2015. Approximately 41% of the samples from asymptomatic ears had detectable levels of DON, and 7% of these samples from 2016 had DON > 5 ppm. Associations between DON contamination and 43 variables representing summaries of temperature (T), relative humidity (RH), rainfall (R), surface wetness, and T-RH combinations for different window lengths and positions relative to R1 growth stage were quantified with Spearman correlation coefficients (r). Fifteen-day window lengths tended to show the highest correlations. Most of the variables based on T, R, RH, and T-RH were significantly correlated with DON for the 15-day window, as well as other windows. For moisture-related variables, there generally was a negative correlation before R1, changing to a positive correlation after R1. Results showed that GER and DON can be frequently found in Ohio maize fields, with the risk of DON being associated with multiple weather variables, particularly those representing combinations of T between 15 and 30°C and RH > 80 summarized during the 3 weeks after R1.

Tilletia species on winter wheat grain

Goal. To determine the species composition of the complex of pathogens of bunt diseases of the genus Tilletia on winter wheat grain. Methods. The research was conducted during 2017—2020. 315 samples of winter wheat grain from different soil and climatic zones were analyzed. Seed contamination was determined by washing the grains and centrifuging the spore suspension, followed by counting their number in the Goryaev chamber. Identification of the pathogen was performed in the laboratory by microscopic examination, taking into account the morphological features of teliospores. Results. In 2017 and 2018, the presence of spores of fungi of the genus Tilletia was detected in 23.5 and 28.6% of the analyzed wheat grain samples, respectively. The number of spores per grain varied between 11—388.9 and 2.8—214.8 and averaged 72.5 and 33.7 correspondingly. The largest number of infected samples was observed in 2019 — 47.4%. In the same period, the highest level of seed contamination was observed — up to 1089 spores per grain, in average — 124.6 spores per grain. The lowest level of grain contamination was detected in 2020 — 6.3% of samples with an average of 3.7 spores per grain. Mostly spores of bunt pathogens were found in grain samples from Ternopil, Kyiv, Chernihiv, Lviv, Vinnytsia regions. The following species have been identified: Tilletia caries, T. controversa, T. laevis. Pathogen T. caries was detected annually. It dominated in 2020 and ranked second in detection rate in 2017—2019. T. controversa was found on grain in 2017—2019 and prevailed among other species. Its part in the complex of pathogens varied from 77.1 to 87.5%. In 2018, T. laevis was also detected. Conclusions. In most samples, spores of fungi of the genus Tilletia were not detected. On average, according to the years of research, grain contamination by bunt fungi were detected in 6.3—47.4% of samples with an average spore load of 3.7—124.6 of grain. The highest number of infected samples and the level of contamination were observed in 2019, the lowest — in 2020. The complex of pathogens is represented by three species: T. caries, T. laevis, T. controversa. T. controversa dominated in 2017—2019 and T. caries — in 2020. T. laevis occurred sporadically.