Reduction Of Deoxynivalenol Content Research Articles

The expedient application of microbial fermentation after whole-wheat milling and fractionation to mitigate mycotoxins in wheat-based products

The effect of whole milling and fractionation of wheat grains from the 2017 and 2018 harvests on the mycotoxin transfer into milling products and the influence of microbial fermentation of such products on mycotoxin levels were analysed. Additionally, the identification and occurrence of fungal contamination in grains with different mycotoxin contamination levels was evaluated. The mycotoxin contents were determined by chromatography (HPLC-TOF-HRMS). The distribution of mycotoxins in wheat wholemeal fractions depended on wheat kernel contamination level. The flour fractions contained zearalenone (ZEN) from 59 to 92%, and deoxynivalenol (DON) and deoxynivalenol-3-glucoside (D3G) at levels on average 60% of those in unprocessed wheat grains. The highest contents of enniatin B (ENNB) (84–86%) and ENNB1 (80–99%) were distributed within the flour fractions. Prolonged sourdough fermentation (48 h) allowed a reduction in DON content in the sourdough by 44–69% and a removal of 15-acetyldeoxynivalenol (15-AcDON), alternariol (AOH), deoxynivalenol-3-glucoside (D3G), toxins H-2 and HT-2, while the enniatin removal levels were in a range 5–70%, with the complete removal of only ENNB1. The study on the retention of mycotoxins during secondary grain processing (sourdough fermentation) is important for the risk assessment of wheat-based products.

Impact of microalgal phenolic extracts on the control of Fusarium graminearum and deoxynivalenol contamination in wheat

In this study, microalgal phenolic extracts (MPE) of Nannochloropsis sp. and Spirulina sp. were tested in in vitro experiments and, in comparison with synthetic fungicides, in field experiments, for their ability to control Fusarium graminearum development and limit deoxynivalenol (DON) contamination. In in vitro experiments, the Nannochloropsis and Spirulina extracts inhibited fungal biomass by 34 and 25%, respectively, compared with the untreated control. This effect was confirmed by a reduction in ergosterol production (-80% for Nannochloropsis and -75% for Spirulina) and in DON content (-97% for Nannochloropsis and -62% for Spirulina). In field experiments, application of the fungicide prothioconazole and prothioconazole + tebuconazole resulted in control of Fusarium head blight (FHB) and foliar disease, leading to a significant increase in grain yield (+13%) and a reduction in DON content (-46%) compared to the untreated control. The application of MPE at wheat flowering reduced the severity of FHB compared with the control (-35% for Spirulina and -39% for Nannochloropsis). However, the MPE did not significantly control foliar diseases (Septoria tritici blotch) and therefore did not enhance the grain yield. Moreover, no effect in reducing the DON content in comparison to the control was observed in the field. In view of that, the use of MPE in wheat fields as real alternatives to conventional fungicides requires the discovery of solutions to empower their persistence and efficacy.

QTL mapping of Fusarium head blight resistance and deoxynivalenol accumulation in the Kansas wheat variety ‘Everest’

Fusarium head blight (FHB) reduces grain yield and accumulates mycotoxins in wheat kernels and flour and thus compromise the end-use quality. In this study, quantitative trait loci (QTL) associated with components of FHB resistance were mapped in the Kansas wheat variety Everest. A doubled haploid (DH) population with 176 lines was developed from a cross between Everest and WB-Cedar, which are moderately resistant and moderately susceptible to FHB, respectively. Two-year field evaluations were conducted using a randomized complete block design with three replications. Deoxynivalenol (DON) accumulation and Fusarium-damaged kernels (FDK) were estimated using a single-kernel near-infrared (SKNIR) system. Four QTL from Everest were identified on 1BS, 3DS, 4BL, and 5AS, indicating that this variety is a source of native FHB resistance conditioned by multiple loci. A large-effect QTL (Qksu-fhbE-5AS) from Everest explained up to 13% of the DON variation in the 2-year experiment average. A single QTL from WB-Cedar, Qksu.fhbC-1AS, was identified contributing FHB resistance. QTL grouping analysis showed that individuals containing multiple QTL were significantly more resistant, indicating that QTL pyramiding enhances FHB resistance. A 36% reduction in DON content was observed in DH lines carrying all mapped QTL for DON accumulation. Further validation of the QTL mapped here will allow breeding programs to increase FHB resistance in other genetic backgrounds. This is the first study that identified QTL associated with low DON accumulation in multiple years of field experiment using the SKNIR technology, supporting the use of this methodology in future genetics and breeding studies.

Masked mycotoxins: does breeding for enhancedFusarium head blight resistance result in more deoxynivalenol-3-glucoside in new wheat varieties?

From economic and environmental points of view, enhancing resistance toFusarium head blight (FHB) in wheat is regarded as the best option to reduce fungal colonisation and the concomitant mycotoxin contamination. This review focuses on the effect of FHB resistance on deoxynivalenol (DON) and the masked metabolite deoxynivalenol-3-glucoside (DON-3-glucoside) in wheat. Based on published information complemented with our own results we draw the following conclusions: (1) All investigated wheat cultivars can convert DON to DON-3-glucoside. Hence, detoxification of DON to DON-3-glucoside is not a new trait introduced by recent resistance breeding against FHB. (2) The amount of DON-3-glucoside relative to DON contamination can be substantial (up to 35%) and is among other things dependent on genetic and environmental factors. (3) Correlation analyses showed a highly significant relationship between the amount of FHB symptoms and DON contamination: breeding for FHB resistance reduces DON contamination. (4) DON contamination data are highly correlated with DON-3-glucoside concentration data: in other words, reduction of DON content through resistance breeding results in a concomitant reduction in DON-3-glucoside content. (5) The DON-3-glucoside/DON ratio increases with decreasing DON contamination: the most resistant lines with the lowest DON contamination show the highest relative level of DON-3-glucoside to DON. In summary, introgressing FHB resistance reduces both DON and DON-3-glucoside levels in the grain, but the reduction is lower for the masked toxin. DON-3-glucoside can represent a possible hazard to human and animal health, especially in wheat samples contaminated with DON close to permitted limits.

From wheat to sourdough bread: a laboratory scale study on the fate of deoxynivalenol content

The effect of wheat processing by scouring, milling and sourdough bread making on the fate of deoxynivalenol was studied using wheat samples artificially contaminated with Fusarium graminearum. The scourer assures an intensive treatment of grain surface, allowing the reduction of deoxynivalenol content by 34.6-46.2%. After milling, the deoxynivalenol was found in all wheat mill fractions. The highest deoxynivalenol contents were found in bran fractions (bran and shorts). Concerning the flour fractions, those with low ash content, resulting from the first break and first reduction flours, were found to have higher deoxynivalenol concentrations than other flour fractions. The sourdough fermentation with selected lactic acid bacteria allowed the significant decrease (58.6-66.5%) of deoxynivalenol content of flour, while the spontaneous fermentation induced a much lower decrease (26.2-29.1%). The baking process caused the reduction of deoxynivalenol content by 11.4-15.5% compared to fermented dough.

Effect of prothioconazole-based fungicides on Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat under field conditions

The effect of triazole-based treatments on Fusarium head blight (FHB), grain yields and the accumulation of deoxynivalenol (DON) in harvested wheat kernels was evaluated by means of twenty multi-site field experiments performed during five consecutive growing seasons (from 2004‒2005 to 2008‒2009) in Italy. Fungicide treatments were carried out on different cultivars of common wheat (cv. Serio, Blasco, Genio and Savio) and durum wheat (cv. Orobel, Saragolla, San Carlo, Levante, Duilio, Karur and Derrik) after artificial inoculation with a mixture of toxigenic Fusarium graminearum and F. culmorum strains. The application of fungicides containing prothioconazole (Proline® or Prosaro®) at the beginning of anthesis (BBCH 61) resulted in a consistent reduction of FHB disease severity (by between 39 and 93%) and DON levels in wheat kernels (by between 40 and 91%) and increased wheat yields (from 0.4 to 5.6 t ha-1, average 2.2 t ha-1), as compared to the untreated/inoculated control. Fungicides containing tebuconazole (Folicur® SE) and cyproconazole plus prochloraz (Tiptor® Xcell) showed a reduced effectiveness compared with prothioconazole-based treatments. All fungicide treatments were more effective in reducing DON and increasing grain yields of common wheat than durum wheat. Results showed that the application of fungicides containing prothioconazole at the beginning of anthesis provided a strong reduction of FHB disease, allowing both an increase in grain yields and a considerable reduction of DON content in wheat kernels.

Effectiveness of marker-based selection for Fusarium head blight resistance in spring wheat

The effect of selection for two donor-QTL from Fusarium head blight (FHB) resistant spring wheat variety Sumai 3 on the reduction of deoxynivalenol (DON) content and FHB index was evaluated in field trials over two years (2008, 2009) following artificial inoculation with Fusarium culmorum. This study was conducted on populations of recombinant inbred lines derived from two crosses, Sumai 3/Swedget and Sumai 3/SG-S 191-01. DON content and FHB index were significantly reduced in both crosses in the genotype classes with two stacked donor QTL on chromosomes 3B and 5A in comparison to genotype classes with no donor QTL. In the cross Sumai 3/Swedget the selection for QTL alleles from 3B and 5A resulted in a 63.4% reduction in DON content, and a 51.8% reduction in the FHB index. Similarly, there was a 35.9% and 31.9% reduction, respectively, in the cross Sumai 3/SG-S 191-01. The single effect of the donor-QTL allele from 3B was significant only in the cross Sumai 3/Swedjet. The presence or absence of awns affected both DON content and FHB index in both populations, but was only significantly in the cross Sumai 3/SG-S 191-01. In this cross the effect of selection for fully awned genotypes was particularly evident on a reduction of both DON and FHB index in classes with neither donor QTL, or the 3B QTL. However, the data indicate that the “awnedness” effect on FHB resistance may be highly variable and is probably greater on reducing FHB symptoms than on DON content. The results confirmed that marker-based introgression of resistance QTLs on chromosomes 3B and 5A in traditional breeding materials can enrich populations for resistance types, but it was also shown that the effect of marker-based selection need not be large in all crosses and a similar effect can probably be reached by indirect selection for some FHB-related traits.

Effects of genotype, environment and fungicide treatment on development of Fusarium head blight and accumulation of DON in winter wheat grain

Reactions to artificial infection with <i>Fusarium culmorum</i> and (metconazole- or tebuconazole-based) fungicides were studied in nine winter wheat cultivars that were evaluated in field experiments at the location Prague-Ruzyne for four years (2001−2004) for deoxynivalenol (DON) content in grain, pathogen DNA content (Ct) by real-time quantitative PCR, percentage of Fusarium damaged grains (FDG), symptom scores and reductions in grain yield components. All examined traits were highly affected by conditions of experimental years and interactions with cultivars and treatments. Moderately resistant cultivars Arina and Petrus were included in the first homogeneous group in all traits, including the pathogen DNA content. To predict cultivar resistance to Fusarium head blight and accumulation of DON, the examination of the percentage of FDG in different environments appeared to be useful from practical aspects. The pathogen DNA content was significantly related to the content of DON under different conditions, however, the correlation coefficients ranged between 0.42 and 0.92. Different levels of DON could be detected at similar pathogen contents. The higher colonization of grain by the fungus was mostly connected with a strongly reduced amount of DON per pathogen unit (DON/Ct ratio). The fungicide treatment had a significant effect on a reduction in all traits except DON/Ct, but the effects on different traits were not often proportional and they were highly variable in the particular years (range 10−69%) and cultivars (range < 0−60%). While the application of fungicide caused a reduction in DON content in all cultivars, an increase in pathogen content after the application of fungicides was not exceptional. The low fungicide effect on a reduction in pathogen content was connected with higher temperatures (temperature extremes) in a 30-day period of disease development. The efficacy of fungicide treatment for DON was low at high pathogen content and late heading. The use of the collected data to improve control measures is discussed.

Effect of Fusarium Head Blight on Mycotoxin Content in Grain of Spring Barley Cultivars

The results are based on field infection experiments with six spring barley cultivars registered in the Czech Republic and resistance sources Chevron and CI 4196. One of the four Fusarium isolates used for inoculations was a predominant nivalenol producer, while the other isolates were deoxynivalenol (DON) producers. Out of the other mycotoxins 3-AcDON was found in grain at a relatively higher concentration. Significant cultivar differences in DON content, examined yield traits, percentage of Fusarium colonies and percentage of non-germinating seeds were detected after inoculum spraying on two dates and mist irrigation of infected plots. When inoculated with aggressive isolate of F. culmorum Chevron and CI 4196 cvs. showed high resistance and the cultivars Jersey, Olbram and Scarlett moderate resistance to DON accumulation in grain. Treatment with fungicide Horizon 250 EW (active ingredient tebuconazole) led on average to a 52.5% reduction of DON content, but the efficacy of fungicide treatment was highly influenced by year and cultivar. Fungicide treatment did not have a significant effect on grain weight per spike and, in general, the influence of infection on examined yield traits was low in these experiments. DON content was closely related only with the parameter C<sub>T </sub>Fus (transformed) from quantitative real time PCR analysis. Using the developed PCR system it was possible to specify clearly cultivar responses to infection and effects of fungicide treatment on DON content.