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An electronic device based on the detection of volatile substances was developed in response to the need to distinguish between fungal infestations in food and was applied to wheat grains. The most common pathogens belong to the fungi of the genus Fusarium: F. avenaceum, F. langsethiae, F. poae, and F. sporotrichioides. The electronic nose prototype is a low-cost device based on commercially available TGS series sensors from Figaro Corp. Two types of gas sensors that respond to the perturbation are used to collect signals useful for discriminating between the samples under study. First, an electronic nose detects the transient response of the sensors to a change in operating conditions from clean air to the presence of the gas being measured. A simple gas chamber was used to create a sudden change in gas composition near the sensors. An inexpensive pneumatic system consisting of a pump and a carbon filter was used to supply the system with clean air. It was also used to clean the sensors between measurement cycles. The second function of the electronic nose is to detect the response of the sensor to temperature disturbances of the sensor heater in the presence of the gas to be measured. It has been shown that features extracted from the transient response of the sensor to perturbations by modulating the temperature of the sensor heater resulted in better classification performance than when the machine learning model was built from features extracted from the response of the sensor in the gas adsorption phase. By combining features from both phases of the sensor response, a further improvement in classification performance was achieved. The E-nose enabled the differentiation of F. poae from the other fungal species tested with excellent performance. The overall classification rate using the Support Vector Machine model reached 70 per cent between the four fungal categories tested. [ABSTRACT FROM AUTHOR]

The massive import of uncontrolled technical grain from the East into the European Community poses a risk to public health when it ends up in the mills to be used as flour for food purposes instead of being burnt (biofuel). In fungal infections of wheat, the most dangerous species belong to the genus Fusarium. F. poae is a pathogen that is most commonly isolated from cereals worldwide and causes various types of diseases in animals and humans due to the numerous toxins it produces. The manuscript reports an attempt to distinguish between four species of Fusarium, F. avanceum, F. langsethiae, F. poae, and F. sporotrichioides, in wheat grains by measuring the volatiles emitted. The patterns obtained from the signals captured by the electronic nose PEN3 were used to build the Random Forests classification model. The recall and precision of the classification performance for F. poae reached 91 and 87%, respectively. The overall classification accuracy reached 70%. Gas chromatography coupled with mass spectrometry (GC–MS) was used to analyze the chemical composition of the emitted volatiles. The patterns found in the GC–MS results allowed an explanation of the main patterns observed when analyzing the electronic nose data. The mycotoxins produced by the Fusarium species analyzed were detected. The results of the reported experiment confirm the potential of the electronic nose as a technology that can be useful for screening the condition of the grain and distinguishing between different pathogenic infestations. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the susceptibility of oats to Fusarium langsethiae infection, as measured by combined HT‐2 and T‐2 mycotoxin concentration (HT2 + T2) in harvested oat grain samples. Over 10 years (2004–2013), samples from single replicates of each UK Recommended List oat trial were analyzed for HT‐2 and T‐2. For spring oats, there were small but statistically significant differences between varieties, whereas for winter oats, they had a broader range and higher mean of HT2 + T2 concentration compared with spring oats. For winter oats, the short‐strawed varieties had consistently high HT2 + T2 levels compared with other varieties, whereas naked varieties were at the lower end of the range, and short, naked varieties had intermediate levels. A separate set of harvested oat grain samples of eight common varieties from 17 field experiments were analyzed by modified joint regression analysis. Results showed that environment had the strongest impact on HT‐2 and T‐2 concentrations but that the varietal susceptibility to HT‐2 and T‐2 contamination was highly stable across environments. This methodology can be used to calculate a Fusarium (HT2 + T2) resistance score for oats to aid grower selection of suitable varieties, as is available for Fusarium (DON) resistance for wheat varieties in many countries. [ABSTRACT FROM AUTHOR]

An electronic device based on the detection of volatile substances was developed in response to the need to distinguish between fungal infestations in food and was applied to wheat grains. The most common pathogens belong to the fungi of the genus Fusarium: F. avenaceum, F. langsethiae, F. poae, and F. sporotrichioides. The electronic nose prototype is a low-cost device based on commercially available TGS series sensors from Figaro Corp. Two types of gas sensors that respond to the perturbation are used to collect signals useful for discriminating between the samples under study. First, an electronic nose detects the transient response of the sensors to a change in operating conditions from clean air to the presence of the gas being measured. A simple gas chamber was used to create a sudden change in gas composition near the sensors. An inexpensive pneumatic system consisting of a pump and a carbon filter was used to supply the system with clean air. It was also used to clean the sensors between measurement cycles. The second function of the electronic nose is to detect the response of the sensor to temperature disturbances of the sensor heater in the presence of the gas to be measured. It has been shown that features extracted from the transient response of the sensor to perturbations by modulating the temperature of the sensor heater resulted in better classification performance than when the machine learning model was built from features extracted from the response of the sensor in the gas adsorption phase. By combining features from both phases of the sensor response, a further improvement in classification performance was achieved. The E-nose enabled the differentiation of F. poae from the other fungal species tested with excellent performance. The overall classification rate using the Support Vector Machine model reached 70 per cent between the four fungal categories tested.

The massive import of uncontrolled technical grain from the East into the European Community poses a risk to public health when it ends up in the mills to be used as flour for food purposes instead of being burnt (biofuel). In fungal infections of wheat, the most dangerous species belong to the genus Fusarium. F. poae is a pathogen that is most commonly isolated from cereals worldwide and causes various types of diseases in animals and humans due to the numerous toxins it produces. The manuscript reports an attempt to distinguish between four species of Fusarium, F. avanceum, F. langsethiae, F. poae, and F. sporotrichioides, in wheat grains by measuring the volatiles emitted. The patterns obtained from the signals captured by the electronic nose PEN3 were used to build the Random Forests classification model. The recall and precision of the classification performance for F. poae reached 91 and 87%, respectively. The overall classification accuracy reached 70%. Gas chromatography coupled with mass spectrometry (GC–MS) was used to analyze the chemical composition of the emitted volatiles. The patterns found in the GC–MS results allowed an explanation of the main patterns observed when analyzing the electronic nose data. The mycotoxins produced by the Fusarium species analyzed were detected. The results of the reported experiment confirm the potential of the electronic nose as a technology that can be useful for screening the condition of the grain and distinguishing between different pathogenic infestations.

Oats (Avena sativa L.) are well known for their nutritional properties but are susceptible to the growth of different Fusarium fungi resulting in mycotoxin contamination of harvested oats. In this study, oat samples from harvest years 2011 to 2017 were preselected for their suitability as milling oats for food purposes with DON contents below 1750 µg/kg. The reduction of DON, T-2 and HT-2 toxins during the commercial de-hulling process was analysed. While the average reduction for the sum of T-2 and HT-2 toxins in large oat kernels was 85%, the reduction for thin kernels was 66%. The reduction for DON was about 60% and did not differ for the two kernel fractions. In laboratory de-hulling experiments, milling oat samples and de-hulled oat kernels with known DON, T-2 and HT-2 toxin content were correlated with the associated DNA amount of Fusarium graminearum, Fusarium culmorum and Fusarium langsethiae. The reduction of the Fusarium DNA amount after de-hulling was comparable to the reduction of the associated mycotoxins. Notably, the correlation between F. langsethiae DNA amounts and the sum of T-2 and HT-2 toxin contents was R2 = 0.69 in milling oats and it rose to R2 = 0.85 in de-hulled oat kernels. In laboratory tests, at least one third of the initial levels of DON and the sum of T-2 and HT-2 toxins could be removed by polishing off the first parts of the outer layers; two thirds remained in the polished oat kernels. These observations indicate that de-hulling alone may not be completely sufficient to remove mycotoxin contamination in oats. These findings are of high importance in the discussion of determining legal maximum levels for DON or the sum of T-2 and HT-2 toxins in intermediate and final products. [ABSTRACT FROM AUTHOR]

Over recent decades, the Norwegian cereal industry has had major practical and financial challenges associated with the occurrence of Fusarium head blight (FHB) pathogens and their associated mycotoxins in cereal grains. Deoxynivalenol (DON) is one of the most common Fusarium-mycotoxins in Norwegian oats, however T-2 toxin (T2) and HT-2 toxin (HT2) are also commonly detected. The aim of our study was to rank Nordic spring oat varieties and breeding lines by content of the most commonly occurring Fusarium mycotoxins (DON and HT2 + T2) as well as by the DNA content of their respective producers. We analyzed the content of mycotoxins and DNA of seven fungal species belonging to the FHB disease complex in grains of Nordic oat varieties and breeding lines harvested from oat field trials located in the main cereal cultivating district in South-East Norway in the years 2011–2020. Oat grains harvested from varieties with a high FHB resistance contained on average half the levels of mycotoxins compared with the most susceptible varieties, which implies that choice of variety may indeed impact on mycotoxin risk. The ranking of oat varieties according to HT2 + T2 levels corresponded with the ranking according to the DNA levels of Fusarium langsethiae, but differed from the ranking according to DON and Fusarium graminearum DNA. Separate tests are therefore necessary to determine the resistance towards HT2 + T2 and DON producers in oats. This creates practical challenges for the screening of FHB resistance in oats as today's screening focuses on resistance to F. graminearum and DON. We identified oat varieties with generally low levels of both mycotoxins and FHB pathogens which should be preferred to mitigate mycotoxin risk in Norwegian oats. [ABSTRACT FROM AUTHOR]

Over recent decades, the Norwegian cereal industry has had major practical and financial challenges associated with the occurrence of Fusarium head blight (FHB) pathogens and their associated mycotoxins in cereal grains. Deoxynivalenol (DON) is one of the most common Fusarium-mycotoxins in Norwegian oats, however T-2 toxin (T2) and HT-2 toxin (HT2) are also commonly detected. The aim of our study was to rank Nordic spring oat varieties and breeding lines by content of the most commonly occurring Fusarium mycotoxins (DON and HT2 + T2) as well as by the DNA content of their respective producers. We analyzed the content of mycotoxins and DNA of seven fungal species belonging to the FHB disease complex in grains of Nordic oat varieties and breeding lines harvested from oat field trials located in the main cereal cultivating district in South-East Norway in the years 2011–2020. Oat grains harvested from varieties with a high FHB resistance contained on average half the levels of mycotoxins compared with the most susceptible varieties, which implies that choice of variety may indeed impact on mycotoxin risk. The ranking of oat varieties according to HT2 + T2 levels corresponded with the ranking according to the DNA levels of Fusarium langsethiae, but differed from the ranking according to DON and Fusarium graminearum DNA. Separate tests are therefore necessary to determine the resistance towards HT2 + T2 and DON producers in oats. This creates practical challenges for the screening of FHB resistance in oats as today’s screening focuses on resistance to F. graminearum and DON. We identified oat varieties with generally low levels of both mycotoxins and FHB pathogens which should be preferred to mitigate mycotoxin risk in Norwegian oats.

Ежегодный мониторинг зараженности зерна грибами рода Fusarium и определение их видового состава свидетельствуют о массовом распространении Fusarium langsethiae, способного продуцировать опасные Т-2 и НТ-2 токсины, в Северо-Западном и Центральном Федеральных округах (ФО) России. Микологический анализ урожая зерна 2018−2019 гг. позволил выявить новые места обнаружения F. langsethiae, в том числе в трёх областях Уральского ФО, где ранее этот вид был отмечен единично. Максимальная установленная заражённость F. langsethiae зерна овса достигала в 2019 г. 14 %. Видовая идентификация выделенных из образцов зерна штаммов, проведённая с помощью ПЦР со специфичными праймерами, подтвердила их принадлежность к F. langsethiae. С помощью высокоэффективной жидкостной хроматографии в сочетании с масс-спектрометрией подтверждена способность гриба продуцировать значительные количества Т-2 и НТ-2 токсинов. В образцах зерна, заражённых этим видом, выявлены значительные суммарные количества Т-2 и НТ-2 токсинов (165−1230 мкг/кг). Необходимо дальнейшее уточнение ареала F. langsethiae и его внутривидового разнообразия для понимания путей распространения этого токсинопродуцирующего гриба.

Analysis of survey data from 804 spring-oat fields divided into five climatic regions suggested that low inoculum level of Fusarium langsethiae was a major limiter of T-2 + HT-2. A 30-year climate with a cool and rainy 10-day period preceding estimated mid-anthesis and a warm 3-week period following anthesis were positively associated with T-2 + HT-2 contamination. In 12 survey years, warm weather from 4 weeks before GS65 until harvesting increased T-2 + HT-2, except in the 1–2 weeks preceding mid-anthesis, when the requirement for high humidity dominated. F. langsethiae and F. sporotrichioides were consistently promoted by high temperature from mid-anthesis onwards. A positive response of T-2 + HT-2 to high humidity peaked 5–10 days earlier and was shorter and weaker than the responses of DON and F. graminearum. The probability of high concentration and regional mean concentration of T-2 + HT-2 tended to be lower under ploughing than under non-ploughing, and they tended to increase with increasing cereal intensity. T-2 + HT-2 was positively associated with zero tillage when compared with minimum tillage. The responses of F. langsethiae and F. sporotrichioides to ploughing and cereal intensity varied by region. In contrast to T-2 + HT-2, DON was the same or higher under ploughing than under non-ploughing, not consistently affected by cereal intensity and not associated with zero tillage. F. graminearum was consistently more common under ploughing than under non-ploughing, and decreased with increasing cereal intensity in four regions. Also, F. culmorum and F. poae tended to be more common under ploughing. F. culmorum increased with cereal intensity in three regions. [ABSTRACT FROM AUTHOR]

Fusarium langsethiae is one of the common Fusarium species infecting small grain cereals in the Nordic region and the UK. It is usually described as a weak pathogen, and with a strong preference for oats, although no studies have yet addressed the explanations for this at the microscopic level. Using microscope techniques we have studied the early steps of colonization of oat and wheat grain by F. langsethiae particularly addressing the role of pollen in the infection process and the fungal ability to penetrate plant cell wall. The aim was to better understand its non-aggressive colonization picture and why oat is preferred over wheat as a host. Spray inoculated oat and wheat plants were scored for fungal progression at 3, 6, 10 and 14 days post inoculation (dpi) using light microscopy and scanning electron microscopy (SEM). Fungal hyphae entered the grain at the apex, or along the sides in the overlapping zone between palea wings and lemma, then spread basipetally and laterally, with a clear directional growth towards the caryopsis. Hyphal growth was clearly aided by the presence of pollen. On oat proliferating hyphae developed a variety of penetration structures on all internal surfaces. F. langsethiae infection on wheat progressed along the same routes, however slower and overall with less hyphal mass. Interestingly, hyphae closely associated to the wheat caryopsis seemed to undergo degradation, and profuse conidiation was observed at 14 dpi. Explanations for the differences in F. langsethiae colonization of oat versus wheat are suggested in light of the results. [ABSTRACT FROM AUTHOR]

High occurrence of Fusarium poae (FP) and Fusarium langsethiae (FL) and their mycotoxins nivalenol (NIV) and T‐2/HT‐2 have been observed in Swiss oats. Early prediction of mycotoxin levels is important for farmers and the cereal industry to minimize the risk of contaminated food and feed. Therefore, climate chamber experiments were conducted to investigate the influence of different temperatures (10, 15, 20 °C) and durations (4, 8, 12 h) at 99% relative humidity (RH) on the infection of oats with FP and FL. In addition, to discover the most susceptible period of oats, artificial FL inoculations were conducted at different growth stages. Field experiments were performed to observe the dispersal of these fungal species within the field and to investigate the weather conditions that influence the dispersal. The climate chamber experiments revealed higher contamination with NIV and T‐2/HT‐2 in the 10 °C treatments and with a prolonged humidity duration of 12 h 99% RH. Inoculations of oat plants at early (DC 61) and mid (DC 65) anthesis, led to higher FL infection and T‐2/HT‐2 accumulation in the grains compared with treatments at earlier growth stages, which might be due to an increased susceptibility during anthesis. No indication for spore dispersal was observed in the field experiments. The results obtained, together with the cropping factors that influence infection and mycotoxin production, could be used as a first step in developing forecasting models to predict the contamination of oats with the mycotoxins NIV and T‐2/HT‐2. [ABSTRACT FROM AUTHOR]

To assess the in vitro activity of three phenolic acids (ferulic acid, p-hydroxybenzoic acid, vanillic acid) and two flavonols (quercetin, rutin) on mycelial growth and mycotoxin accumulation of Fusarium graminearum (FG), F. langsethiae (FL) and F. poae (FP), two different approaches were chosen. First, grains from oat varieties were inoculated with a suspension of three FL isolates to determine the influence of phenolic compounds on the accumulation of mycotoxins. The oat variety Zorro showed a tendency for lower accumulation of T-2/HT-2, diacetoxyscirpenol and neosolaniol. Second, a mycelium growth assay was conducted to follow FG, FL and FP growth on cereal based media supplemented with phenolic compounds. Increasing concentrations of ferulic acid substantially inhibited growth of FG and FL, while FP growth was reduced to 57%. In contrast, p-hydroxybenzoic acid, vanillic acid, quercetin, and rutin slightly stimulated mycelium growth. Results about mycotoxin production in cereal based media were less conclusive. [ABSTRACT FROM AUTHOR]

Between 2013 and 2015, 325 samples of commercially grown oats were collected in Switzerland along with data on respective cropping factors. The incidence of different Fusarium species was determined using a seed health test and quantitative PCR was used to measure the amount of F. poae and F. langsethiae DNA. Mycotoxins were quantified by LC–MS/MS. Among all Fusarium species, F. poae was found to be dominant whereas T-2/HT-2 toxins were the major mycotoxins. Samples from fields with the previous crop cereal showed the highest concentrations of T-2/HT-2. Higher amounts of nivalenol (NIV) and T-2/HT-2 were detected in samples from fields with reduced tillage compared with samples from ploughed fields. Furthermore, we observed a higher contamination with NIV and T-2/HT-2 in winter sown varieties compared with spring sown varieties. Results from the current study are highly valuable to develop recommendations for optimised cropping systems that reduce the risk of mycotoxin contamination of oat grains. [ABSTRACT FROM AUTHOR]

Phytopathogenic fungi can lead to significant cereal yield losses, also producing mycotoxins dangerous for human and animal health. The fungal control based on the use of synthetic fungicides can be complemented by "green" methods for crop protection, based on the use of natural products. In this frame, the antifungal activities of bergamot and lemon essential oils and of five natural compounds recurrent in essential oils (citronellal, citral, cinnamaldehyde, cuminaldehyde and limonene) have been evaluated against three species of mycotoxigenic fungi (Fusarium sporotrichioides, F. graminearum and F. langsethiae) responsible for Fusarium Head Blight in small-grain cereals. The natural products concentrations effective for reducing or inhibiting the in vitro fungal growth were determined for each fungal species and the following scale of potency was found: cinnamaldehyde > cuminaldehyde > citral > citronellal > bergamot oil > limonene > lemon oil. Moreover, the in vitro mycotoxin productions of the three Fusaria strains exposed to sub-lethal concentrations of the seven products was evaluated. The three fungal species showed variability in response to the treatments, both in terms of inhibition of mycelial growth and in terms of modulation of mycotoxin production that can be enhanced by sub-lethal concentrations of some natural products. This last finding must be taken into account in the frame of an open field application of some plant-derived fungicides. [ABSTRACT FROM AUTHOR]

Fusarium langsethiae, a toxigenic fungus known to contaminate small-grain cereals with type A trichothecene mycotoxins, HT-2 and T-2 was described as a new species in 2004. HT-2 and T-2 are some of the most potent Fusarium toxins in eukaryotes, capable of inhibiting protein synthesis. The epidemiology of F. langsethiae is not well understood and with the intent of the European Commission to set maximum levels of contamination of cereals with these toxins, importance is currently placed in trying to understand the fungal infection process and its favorable growth conditions. A field study was carried out to investigate the effect of artificially inoculated oats straw, ploughing and minimum tillage with and without incorporated crop debris (straw) on infection and mycotoxin production by F. langsethiae on oats cultivar Gerald. The results indicated that cultural field practices had effects on the infection of oats by F. langsethiae. Fusarium langsethiae DNA was quantified in significantly larger amounts (p<0.05) in minimum tilled with incorporated straw plot samples than in other plot samples. It was also shown that inoculated straw had no significant effect (p>0.05) on oat infection by F. langsethiae as quantified by DNA concentration. HT-2+T-2 quantification and analysis, gave no good evidence that either inoculation or cultural practice had any significant influence on the concentration of mycotoxins in the samples (p>0.05), but samples from minimum tillage with incorporated straw plots resulted in 2.5 times more HT-2+T-2 toxins than samples from ploughed with removed straw. These findings indicate the importance of tillage and crop debris management in the mitigation in an effort to prevent F. langsethiae infection, colonization and possible contamination of oats with HT-2 and T-2 toxins. [ABSTRACT FROM AUTHOR]

The increased occurrence of Fusarium-mycotoxins in Norwegian cereals over the last decade, is thought to be caused by increased inoculum resulting from more cereal residues at the soil surface as a result of reduced tillage practices. In addition, weather conditions have increasingly promoted inoculum development and infection by Fusarium species. The objective of this work was to elucidate the influence of different tillage regimes (autumn plowing; autumn harrowing; spring plowing; spring harrowing) on the inoculum potential (IP) and dispersal of Fusarium spp. in spring oats. Tillage trials were conducted at two different locations in southeast Norway from 2010 to 2012. Oat residues from the previous year’s crop were collected within a week after sowing for evaluation. IP was calculated as the percentage of residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. F. avenaceum and F. graminearum were the most common Fusarium species recovered from oat residues. The IP of Fusarium spp. was significantly lower in plowed plots compared to those that were harrowed. Plowing in either the autumn or spring resulted in a low IP. Harrowing in autumn was more effective in reducing IP than the spring harrowing, and IP levels for the spring harrowed treatments were generally higher than all other tillage treatments examined. Surprisingly low levels of F. langsethiae were detected in the residues, although this species is a common pathogen of oat in Norway. The percentage of the residues infested with F. avenaceum, F. graminearum, F. culmorum and F. langsethiae generally related to the quantity of DNA of the respective Fusarium species determined using qPCR. Fusarium dispersal, quantified by quantitative PCR analysis of spore trap samples collected at and after heading, generally corresponded to IP. Fusarium dispersal was also observed to increase after rainy periods. Our findings are in line with the general understanding that plowing is a means to reduce the IP of Fusarium spp. in cereal fields. The main inoculum source for F. langsethiae remains unclear. Our results will be useful in the development of forecasting tools to calculate the risk of Fusarium in cereals.

T-2 and HT-2 toxins are two of the most toxic members of type-A trichothecenes, produced by a number of Fusarium species. The occurrence of these mycotoxins was studied in barley samples during a survey carried out in the 2011-2014 growing seasons in climatically different regions in Italy. The percentage of samples found positive ranges from 22% to 53%, with values included between 26 and 787 μg/kg. The percentage of samples with a T-2 and HT-2 content above the EU indicative levels for barley of 200 μg/kg ranges from 2% to 19.6% in the 2011-2014 period. The fungal species responsible for the production of these toxins in 100% of positive samples has been identified as Fusarium langsethiae, a well-known producer of T-2 and HT-2 toxins. A positive correlation between the amount of F. langsethiae DNA and of the sum of T-2 and HT-2 toxins was found. This is the first report on the occurrence of F. langsethiae—and of its toxic metabolites T-2 and HT-2—in malting barley grown in Italy. [ABSTRACT FROM AUTHOR]

The increased occurrence of Fusarium-mycotoxins in Norwegian cereals over the last decade, is thought to be caused by increased inoculum resulting from more cereal residues at the soil surface as a result of reduced tillage practices. In addition, weather conditions have increasingly promoted inoculum development and infection by Fusarium species. The objective of this work was to elucidate the influence of different tillage regimes (autumn plowing; autumn harrowing; spring plowing; spring harrowing) on the inoculum potential (IP) and dispersal of Fusarium spp. in spring oats. Tillage trials were conducted at two different locations in southeast Norway from 2010 to 2012. Oat residues from the previous year's crop were collected within a week after sowing for evaluation. IP was calculated as the percentage of residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. Fusarium avenaceum and F graminearum were the most common Fusarium species recovered from oat residues. The IP of Fusarium spp. was significantly lower in plowed plots compared to those that were harrowed. Plowing in either the autumn or spring resulted in a low IP. Harrowing in autumn was more effective in reducing IP than the spring harrowing, and IP levels for the spring harrowed treatments were generally higher than all other tillage treatments examined. Surprisingly low levels of F langsethiae were detected in the residues, although this species is a common pathogen of oat in Norway. The percentage of the residues infested with F avenaceum, F graminearum, F culmorum, and F langsethiae generally related to the quantity of DNA of the respective Fusarium species determined using quantitative PCR (qPCR). Fusarium dispersal, quantified by qPCR analysis of spore trap samples collected at and after heading, generally corresponded to the IP. Fusarium dispersal was also observed to increase after rainy periods. Our findings are in line with the general understanding that plowing is a means to reduce the IP of Fusarium spp. in cereal fields. The main inoculum source for F langsethiae remains unclear. Our results will be useful in the development of forecasting tools to calculate the risk of Fusarium in cereals. [ABSTRACT FROM AUTHOR]

The effect of natural phenolic acids was tested on the growth and production of T-2 and HT-2 toxins by Fusarium langsethiae and F. sporotrichioides, on Mycotoxin Synthetic medium. Plates treated with 0.5 mM of each phenolic acid (caffeic, chlorogenic, ferulic and p-coumaric) and controls without phenolic acid were incubated for 14 days at 25 °C. Fungal biomass of F. langsethiae and F. sporotrichioides was not reduced by the phenolic acids. However, biosynthesis of T-2 toxin by F. langsethiae was significantly reduced by chlorogenic (23.1%) and ferulic (26.5%) acids. Production of T-2 by F. sporotrichioides also decreased with ferulic acid by 23% (p < 0.05). In contrast, p-coumaric acid significantly stimulated the production of T-2 and HT-2 toxins for both strains. A kinetic study of F. langsethiae with 1 mM ferulic acid showed a significant decrease in fungal biomass, whereas T-2 production increased after 10 days of incubation. The study of gene expression in ferulic supplemented cultures of F. langsethiae revealed a significant inhibition for Tri5, Tri6 and Tri12 genes, while for Tri16 the decrease in gene expression was not statistically significant. Overall, results indicated that phenolic acids had a variable effect on fungal growth and mycotoxin production, depending on the strain and the concentration and type of phenolic acid assayed. [ABSTRACT FROM AUTHOR]

Fusarium langsethiae is a widespread pathogen of small grain cereals, causing problems with T-2 and HT-2 toxin contamination in grains every year. In an effort to better understand the biology of this fungus, we present a draft genome sequence of F. langsethiae Fl201059 isolated from oats in Norway. The assembly was fragmented, but reveals a genome of approximately 37.5 Mb, with a GC content around 48%, and 12,232 predicted protein-coding genes. Focusing on secondary metabolism we identified candidate genes for 12 polyketide synthases, 13 non-ribosomal peptide synthetases, and 22 genes for terpene/isoprenoid biosynthesis. Some of these were found to be unique compared to sequence databases. The identified putative Tri5 cluster was highly syntenic to the cluster reported in F. sporotrichioides . Fusarium langsethiae Fl201059 produces a high number of secondary metabolites on Yeast Extract Sucrose (YES) agar medium, dominated by type A trichothecenes. Interestingly we found production of glucosylated HT-2 toxin (Glu-HT-2), previously suggested to be formed by the host plant and not by the fungus itself. In greenhouse inoculations of F. langsethiae Fl201059 on barley and oats, we detected the type A trichothecenes: neosolaniol, HT-2 toxin, T-2 toxin, Glu-HT-2 and numerous derivatives of these. [ABSTRACT FROM AUTHOR]

Phytopathogenic fungi can lead to significant cereal yield losses, also producing mycotoxins dangerous for human and animal health. The fungal control based on the use of synthetic fungicides can be complemented by "green" methods for crop protection, based on the use of natural products. In this frame, the antifungal activities of bergamot and lemon essential oils and of five natural compounds recurrent in essential oils (citronellal, citral, cinnamaldehyde, cuminaldehyde and limonene) have been evaluated against three species of mycotoxigenic fungi (Fusarium sporotrichioides, F. graminearum and F. langsethiae) responsible for Fusarium Head Blight in small-grain cereals. The natural products concentrations effective for reducing or inhibiting the in vitro fungal growth were determined for each fungal species and the following scale of potency was found: cinnamaldehyde > cuminaldehyde > citral > citronellal > bergamot oil > limonene > lemon oil. Moreover, the in vitro mycotoxin productions of the three Fusaria strains exposed to sub-lethal concentrations of the seven products was evaluated. The three fungal species showed variability in response to the treatments, both in terms of inhibition of mycelial growth and in terms of modulation of mycotoxin production that can be enhanced by sub-lethal concentrations of some natural products. This last finding must be taken into account in the frame of an open field application of some plant-derived fungicides.

We report a case of keratitis due to Fusarium langsethiae in a 56-year-old man. The patient presented with pain and tearing of 10 days duration in the right eye, which had sustained a paddy stalk injury. On examination, a hypopyon corneal ulcer was noted in the right eye. Multiple scrapings were obtained from the affected part of the cornea. A lactophenol cotton blue wet mount and a Gram-stained smear of scrapings were made. Scrapings were also inoculated on various culture media, including Sabouraud dextrose agar (SDA). A fungal etiology was sought by conventional microbiological techniques and polymerase chain reaction. In vitro susceptibility testing was performed by an agar dilution method. Direct microscopy of corneal scrapings revealed septate hyphae, leading to initiation of intensive topical therapy with natamycin (5 %). However, the keratitis progressed, necessitating therapeutic penetrating keratoplasty. White, powdery-like colonies, with abundant aerial mycelium, were recovered on SDA from corneal scrape material. Based on macroscopic and microscopic morphological features, the isolated fungus was initially identified as a Fusarium species. Sequence analysis of the 28S rRNA region of the fungal genome led to a specific identification of F. langsethiae. Antifungal susceptibility testing results suggested that the strain isolated was susceptible to voriconazole, ketoconazole, and itraconazole. To our knowledge, this is the first reported case of keratitis due to F. langsethiae; attention is drawn to the unique characteristics of the fungal isolate, difficulties in identification and non-responsiveness to medical therapy. [ABSTRACT FROM AUTHOR]

T-2 and HT-2 toxins are two of the most toxic members of type-A trichothecenes, produced by a number of Fusarium species. The occurrence of these mycotoxins was studied in barley samples during a survey carried out in the 2011–2014 growing seasons in climatically different regions in Italy. The percentage of samples found positive ranges from 22% to 53%, with values included between 26 and 787 μg/kg. The percentage of samples with a T-2 and HT-2 content above the EU indicative levels for barley of 200 μg/kg ranges from 2% to 19.6% in the 2011–2014 period. The fungal species responsible for the production of these toxins in 100% of positive samples has been identified as Fusarium langsethiae, a well-known producer of T-2 and HT-2 toxins. A positive correlation between the amount of F. langsethiae DNA and of the sum of T-2 and HT-2 toxins was found. This is the first report on the occurrence of F. langsethiae—and of its toxic metabolites T-2 and HT-2—in malting barley grown in Italy.

The effect of natural phenolic acids was tested on the growth and production of T‐2 and HT‐2 toxins by Fusarium langsethiae and F. sporotrichioides, on Mycotoxin Synthetic medium. Plates treated with 0.5 mM of each phenolic acid (caffeic, chlorogenic, ferulic and p‐coumaric) and controls without phenolic acid were incubated for 14 days at 25 °C. Fungal biomass of F. langsethiae and F. sporotrichioides was not reduced by the phenolic acids. However, biosynthesis of T‐2 toxin by F. langsethiae was significantly reduced by chlorogenic (23.1%) and ferulic (26.5%) acids. Production of T‐2 by F. sporotrichioides also decreased with ferulic acid by 23% (p < 0.05). In contrast, p‐coumaric acid significantly stimulated the production of T‐2 and HT‐2 toxins for both strains. A kinetic study of F. langsethiae with 1 mM ferulic acid showed a significant decrease in fungal biomass, whereas T‐2 production increased after 10 days of incubation. The study of gene expression in ferulic supplemented cultures of F. langsethiae revealed a significant inhibition for Tri5, Tri6 and Tri12 genes, while for Tri16 the decrease in gene expression was not statistically significant. Overall, results indicated that phenolic acids had a variable effect on fungal growth and mycotoxin production, depending on the strain and the concentration and type of phenolic acid assayed.

Abstract: The health-beneficial properties of oats have led to an increase in the consumption of oats and oat-based food products in recent years. Fusarium langsethiae grows on small grain cereals, especially oats and can result in contamination with type A trichothecenes (T-2 toxin (T-2) and HT-2 toxin (HT-2)) in crops pre- and post-harvest. The aim of this work was to assess the efficacy of three fungicides (fenpropimorph, prochloraz and tebuconazole) on temporal growth of two F. langsethiae strains and the accumulation of T-2 and HT-2 in oat grains, under different water activities (a w; 0.95 and 0.98) and temperatures (15 and 25 °C). All the antifungal agents reduced growth rates when compared to controls, and this increased with increasing fungicide dose. The ranges of ED50 values (mg/kg) were 65–270 for fenpropimorph, 0.25–4.2 for prochloraz, and 0.3–14 for tebuconazole. The ED90 values (mg/kg) ranged from 170 to > 800, 0.5 to > 10 and 0.5 to > 15 for these three fungicides respectively. The ED50 values were not statistically significantly affected by the factors a w, temperature or strain. However, there were significant differences among the fungicides. Fenpropimorph proved less efficient that the two azoles, which do not differ significantly. In general, levels of HT-2 were higher than T-2 in all cultures regardless of environmental conditions. Overall, HT-2 concentration was always higher at 25 than 15 °C and increased from day 14 to day 21. Levels of both toxins generally decreased with increasing fungicide dose regardless of fungicide type, strain and incubation time. No toxins were detected in cultures at 0.95 a w in the presence of any of the three fungicides. Also under wetter conditions at 0.98 a w neither mycotoxin was found in cultures treated with prochloraz at doses >1 mg/kg (15 °C) or >3 mg/kg (25 °C) or tebuconazole at doses >6 mg/kg (15 or 25 °C). ANOVA showed that in treatments with each fungicide the factors dose, time and temperature significantly affected toxin production while there was no difference between the strains. [Copyright &y& Elsevier]

Fusarium langsethiae is a toxigenic fungal species that has been reported in European small-grain cereal crops such as oats, wheat and barley. Although its relative contribution to fusarium head blight ( FHB) symptoms is not well understood, it is reported to contaminate these cereals with high levels of HT-2 and T-2 trichothecenes mycotoxins that are currently under consideration for legislation by the European Commission. Ten commercial oat fields in Shropshire and Staffordshire (two adjacent counties in the Midlands) in the UK were surveyed in the 2006/2007 growing season. Samples were taken from predetermined field locations at Zadoks growth stages 32/33, 69, 77-85 and 90-92 for F. langsethiae biomass and HT-2 and T-2 toxins quantification. The results from this study showed that oats can be heavily infected with F. langsethiae and have high concentrations of HT-2 and T-2 toxins with no apparent FHB symptoms. The regression of HT-2 + T-2 toxins on F. langsethiae DNA concentration was highly significant (P < 0.001, r2 = 0.55). The results indicated that although F. langsethiae had no direct effect on crop yield, it may result in indirect economic losses where the grain can be rejected or downgraded as a result of intolerable levels of HT-2 and T-2 toxins, which are of human food and animal feed safety concern. The influence of cultural field practices on the infection and HT-2 and T-2 toxins accumulation in oats was not clear and warrants further studies to identify the sources of F. langsethiae inoculum and conditions favourable for infection and mycotoxin production. [ABSTRACT FROM AUTHOR]

Fusarium langsethiae is a toxigenic fungus that was formally described as a new species in 2004. This fungus was first detailed in the 1990s but was initially referred to as 'powdery Fusarium poae' having a spore morphology similar to F. poae but a mycotoxin profile like that of Fusarium sporotrichioides. The species has been isolated from infected oat, wheat and barley grains but has been reported as more problematic in the former crop rather than the latter two. Whilst the epidemiology of F. langsethiae remains unclear, the fungus has been shown to produce high levels of type- A trichothecenes HT-2 and T-2 toxins in small-grain cereals. HT-2 and T-2 toxins are two of the most potent trichothecenes capable of inhibiting protein synthesis in eukaryotes. In this regard, mycotoxin contamination caused by F. langsethiae is clearly a food and feed safety hazard. With the European Commission considering legislation of HT-2 and T-2 toxins, more information is required not only on the producer and conditions favouring mycotoxin production, but also on reliable methods of pathogen detection and reduction of cereal contamination. This review describes recent research concerning the known epidemiology of F. langsethiae and suggestions of what needs to be known about the fungus in order to be able to understand and employ measures for preventing its infection and contamination of cereals with HT-2 and T-2 toxins. [ABSTRACT FROM AUTHOR]

Abstract: This article reports an extraction–purification of napins from an industrial rapeseed meal and the assessment of their antimicrobial activity against Fusarium langsethiae. The best extraction conditions are observed at pH 2, 12% (w/w) of rapeseed meal after 15min of extraction in water at room temperature. Under these conditions the extraction is highly selective, allowing a simple purification process (ammonium sulfate precipitation followed by desalting size exclusion chromatography) to get purified napins. These napins possessed significant anti-Fusarium activity (IC50 =70μM) and a compact secondary structure rich in α-helix, which may explain this bioactivity. [Copyright &y& Elsevier]

Abstract: High levels of Fusarium mycotoxins HT-2 and T-2 have been detected in UK oats since surveys started in 2002. Fusarium langsethiae and the closely related species F. sporotrichioides have previously been associated with the contamination of cereals with type A trichothecenes HT-2 and T-2 in Nordic countries. Preliminary microbiological analysis of UK oat samples with high concentrations of HT-2 and T-2 detected and isolated F. langsethiae and F. poae but not the other type A trichothecene producing species F. sporotrichioides, F. sibiricum and F. armeniacum. Two hundred and forty oat flour samples with a known mycotoxin profile were selected from a previous four year study (2002–2005) to cover the full concentration range from below the limit of quantification (<20μg/kg) to 9990μg/kg HT-2+T-2 combined. All samples were analysed for the DNA of F. langsethiae, F. poae and F. sporotrichioides based on previously published PCR assays. F. langsethiae was detectable in nearly all samples; F. poae was detected in 90% of samples whereas F. sporotrichioides was not detected in any sample. A real-time PCR assay was developed to quantify F. langsethiae DNA in plant material. The assay could quantify as low as 10−4 ng F. langsethiae DNA/μl. Based on this assay and a previously published assay for F. poae, both species were quantified in the oat flour samples with known HT-2+T-2 content. Results showed a good regression (P<0.001, r2 =0.60) between F. langsethiae DNA and HT-2+T-2 concentration. F. poae DNA concentration was not correlated to HT2+T2 concentration (P=0.448) but was weakly correlated to nivalenol concentration (P<0.001, r2 =0.09). Multiple regression with F. langsethiae and F. poae DNA as explanatory variates identified that both F. langsethiae and F. poae DNA were highly significant (P<0.001) but F. poae DNA only accounted for an additional 4% of the variance and the estimate was negative, indicating that higher concentrations of F. poae DNA were correlated with slightly lower concentrations of HT2+T2 detected. A stronger regression (P<0.001, r2 =0.77) between F. langsethiae DNA and HT-2+T-2 was obtained after extraction and quantification of DNA and mycotoxins from individual oat grains. The results from this study provide strong evidence that F. langsethiae is the primary, if not sole, fungus responsible for high HT-2 and T-2 in UK oats. [Copyright &y& Elsevier]

Abstract: Fusarium langsethiae has been isolated from infected cereals in central and northern Europe where it has been identified in the last decade as the main species involved in the occurrence of high levels of T-2 and HT-2 toxins, mainly in oats. The efficacy of three fungicides (prochloraz, tebuconazole, fenpropimorph) for controlling growth of two strains of F. langsethiae isolated from oats was examined at 0.96 and 0.98 aw at 15, 20 and 25°C on oat-based media. The concentrations necessary for 50 and 90% growth inhibition (ED50 and ED90 values) were determined. The effect on the trichothecene type A mycotoxins T-2 and HT-2 was also determined. Without fungicides both strains grew faster at 0.98 than at 0.96 aw and the influence of temperature on growth rates was 25>20>15°C. Prochloraz and tebuconazole were more effective than fenpropimorph against F. langsethiae. Strain, temperature and type of fungicide significantly influenced the ED50 and ED90 values for growth. The concentration ranges under different environmental conditions were: prochloraz (0.03–0.1 and 0.3–1.5), tebuconazole (0.06–0.9 and 1.3–8.2), and fenpropimorph (22–59 and 125–215mgl−1). Production of T-2 and HT-2 toxins was influenced by temperature, aw, type of fungicide and dose. Levels of T-2 were usually higher than those of HT-2 under the same conditions. The biosynthesis of T-2 toxin increased after 10day incubation, but was reduced with decreasing temperature and increasing fungicide dose. At 0.98 aw T-2 levels increased in cultures containing fenpropimorph while at 0.96 aw the toxin concentrations increased in response to the other two fungicides. Low doses of prochloraz or tebuconazole enhanced toxin production when compared with untreated cultures for strain 2004-59 at 0.96 aw and 20–25°C. HT-2 was hardly detectable in the treatments with prochloraz or tebuconazole at 0.98 aw. This is the first study on the effect of these anti-fungal compounds on control of growth of F. langsethiae and on production of T-2 and HT-2 toxins in oat-based media. [Copyright &y& Elsevier]

Abstract: Production of type A trichothecenes has been reported in the closely related species Fusarium langsethiae and F. sporotrichioides. Here, we characterized a collection of Fusarium isolates from Siberia and the Russian Far East (hereafter Asian isolates) that produce high levels of the type A trichothecene T-2 toxin and are similar in morphology to the type A trichothecene-producing F. langsethiae, and to F. poae which often produces the type B trichothecene nivalenol. The Asian isolates possess unique macroscopic and microscopic characters and have a unique TG repeat in the nuclear ribosomal intergenic spacer (IGS rDNA) region. In Asian isolates, the TRI1–TRI16 locus, which determines type A versus type B trichothecene production in other species, is more similar in organization and sequence to the TRI1–TRI16 locus in F. sporotrichioides and F. langsethiae than to that in F. poae. Phylogenetic analysis of the TRI1 and TRI16 gene coding regions indicates that the genes in the Asian isolates are more closely related to those of F. sporotrichioides than F. langsethiae. Phylogenetic analysis of the beta-tubulin, translation elongation factor, RNA polymerase II and phosphate permease gene sequences resolved the Asian isolates into a well-supported sister lineage to F. sporotrichioides, with F. langsethiae forming a sister lineage to F. sporotrichioides and the Asian isolates. The Asian isolates are conspecific with Norwegian isolate IBT 9959 based on morphological and molecular analyses. In addition, the European F. langsethiae isolates from Finland and Russia were resolved into two distinct subgroups based on analyses of translation elongation factor and IGS rDNA sequences. Nucleotide polymorphisms within the IGS rDNA were used to design PCR primers that successfully differentiated the Asian isolates from F. sporotrichioides and F. langsethiae. Based on these data, we formally propose that the Asian isolates together with Norwegian isolate IBT 9959 comprise a novel phylogenetic species, F. sibiricum, while the two subgroups of F. langsethiae only represent intraspecific groups. [Copyright &y& Elsevier]

Wheat is the most important cereal produced in Iran. A mycological survey was carried out for the first time, on the stored wheat samples in Tehran, East Azarbayejan and Mazandaran provinces in 2007. Exogenous and endogenous fungi, were isolated by the method of flotation with Malachite green agar (MGA 0.25) and Freeze blotter techniques respectively. In this study, 46 species belonging to 23 different genera were isolated. Cladosporium spp. (57.1–89.2%) and Alternaria spp. (82.4–100%) species were the predominant fungal species identified as endogenous mycoflora. The predominant exogenous fungi were Penicillium spp. (78.4–92.8%) and Aspergillus spp. (71.4–85.7%) species. Fusarium proliferatum was the most prevalent species of Fusarium isolates. Aspergillus niger (39.4%) and Aspergillus flavus (36.7%) were the predominant Aspergillus species identified as exogenous mycoflora. Aspergillus flavus (26.6%) was the predominant Aspergillus species identified as endogenous mycoflora. Flotation method with MGA 0.25 recommended for isolating of hyaline fungi from wheat cereals. In this study one isolate from Fusarium species was isolated on the basis of morphology and ribosomal internal transcribed spacer classified as Fusarium langsethiae but on the basis of partial translation elongation factor-1alpha gene grouped with Fusarium sporotrichioides. To our knowledge, this is the first report about F. cf. langsethiae in Iran and Asia. [ABSTRACT FROM AUTHOR]

In a series of field experiments in eastern England over 5 years, severe ear blight developed only in plots of winter wheat that were inoculated by spraying with conidial suspensions ofFusarium culmorumduring anthesis, and in which infection was encouraged by rainfall or mist irrigation. In the absence of artificial inoculation of the ears,F. culmorumcaused less extensive ear blight, and only where soil-surface inoculum was available after its application on infested plant material (colonized oat grains) up to 3–4 weeks before anthesis; it then developed most where significant rainfall occurred close to the time of anthesis. A warm, dry period following application of inoculum to the ground in late March contributed to increased infection of grain byF. culmorum, although ear blight was not increased. Ear infection therefore depended on adequate viable inoculum on infested plant debris within the crop, and conditions tending to favour brown foot rot development as well as, subsequently, rainfall and moist conditions during anthesis. These conditions did not occur together naturally during this period. Seedling infection byF. culmorumorMicrodochium nivalemade no significant contribution to ear blight. Inoculation of ears at anthesis withM. nivaleor a locally obtained isolate ofF. langsethiaedid not produce ear blight symptoms. Possibilities for minimizing the availability of inoculum ofF. culmorumand the implications for various options for ear-blight control are discussed. [ABSTRACT FROM AUTHOR]

Fusarium langsethiae was recently described as a new toxigenic Fusarium species, which morphologically resembles Fusarium poae, but exhibits a mycotoxin pattern related to Fusarium sporotrichioides. To develop tools for early and specific detection of F. langsethiae and distinguishing it from related species of section Sporotrichiella and Discolor (F. poae, F. sporotrichioides, Fusarium kyushuense, Fusarium robustum, Fusarium sambucinum and Fusarium tumidum) sequence variations in their β-tubulin-encoding (tub1) gene were employed to design two PCR-based methods, denaturing gradient gel electrophoresis (DGGE) and amplification refractory mutation system (ARMS)-PCR. DGGE reliably separated all these strains, even from mixtures and in the presence of DNA from their natural hosts Zea mais, Triticum aestivum and Avena sativa. In addition, a tetraprimer ARMS-PCR, which employs two primer pairs to amplify, respectively, two different fragments of tub1 in a single PCR reaction resulted in rapid differentiation between F. langsethiae, F. sporotrichioides and F. poae according to the number of amplicons (four, two and one, respectively). These two methods will thus be worthwhile tools in the specific detection of F. langsethiae in infected crops. [Copyright &y& Elsevier]

A new species of Fusarium, Fusarium langsethiae, is described, illustrated and discussed. This species is isolated from kernels of oats, wheat and barley in several European countries. Morphologically, the species resembles Fusarium poae. It is differentiated from F. poae by slower growth, less aerial mycelium and absence of odour; its napiform or globose conidia are borne in the aerial mycelium on the agar surface on often bent phialides which exhibit sometimes more than one opening, whereas those of F. poae are produced on straight monophialides mostly in the aerial mycelium. No sporodochial conidia are formed by F. langsethiae even under near-UV light (nUV). Based on morphological characters, the species is placed in the section Sporotrichiella. [Copyright &y& Elsevier]