Aflatoxin B1, zearalenone and deoxynivalenol production by Aspergillus parasiticus and Fusarium graminearum in interactive cultures on irradiated corn kernels

The influence of inoculum size in the production of aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON) was determined when Aspergillus parasiticus NRRL 3000 and Fusarium graminearum ITEM 124 were cultured alone and in pairs on irradiated corn kernels at 28 °C and 0.97 water activity (aw). The highest levels of AFB1 produced by A. parasiticus were produced at the lowest levels of the inoculum (103 spores/ml). No significant differences were observed in ZEN and DON production at any inoculum level during the experimental period. When A. parasiticus was co-inoculated with F. graminearum both to the same inocula (106 spores/ml), AFB1 inhibition percentage were 60, 72 and 56% at 10, 20 and 35 days of incubation respectively, while at 106 spores/ml the percentages of inhibition were 34, 84 and 93% at 10, 20 and 35 days. In the mixture cultures A. parasiticus 103 × F. graminearum 106 spores/ml the percentage of inhibition of AFB1 oscillated in 99% during all the incubation. In the interaction A. parasiticus 106 spores/ml × F. graminearum 103 spores/ml the accumulation of AFB1 decreased in 80, 94 and 86% at 10, 20 and 35 days of incubation respectively. In single culture F. graminearum was inoculated with 10³ or 106 spores/ml and the highest levels of ZEN and DON were detected at 35 days of incubation. The levels oscillated in 538–622 μg/kg for ZEN and 870–834 μg/kg for DON respectively. In paired cultures there were no significant differences in the levels regardless of the spore concentrations during the incubation time. This revised version was published online in June 2006 with corrections to the Cover Date.     

Mycotoxin-producing Fusarium Species Occurring in Winter Wheat in Belgium (Flanders) During 2002–2005

Deoxynivalenol (DON) content and Fusarium spp. ( Fusarium graminearum , Fusarium culmorum , Fusarium avenaceum , Microdochium nivale and Fusarium poae ) of mycotoxin-producing Fusarium species in winter wheat in Belgium (Flanders) were determined. Field trials were set up in the varietal testing network of Flanders Agricultural Centre for Small Grains (Roeselare – Beitem, Belgium) and followed up during growing seasons 2001–2002, 2002–2003, 2003–2004 and 2004–2005. Fusarium infection and DON contamination were mainly influenced by location and environmental parameters. Mean DON levels ranged from 0 to 15 mg/kg. Over the period of four growing seasons cvs Deben, Ordeal and Napier had the highest DON contamination. Seasonal and local weather conditions before and during flowering together with local crop husbandry measures (crop rotation, soil preparation) seemed to be of great importance in explaining the variation in results obtained. At Bottelare a positive correlation between disease index and DON content was found for the growing seasons 2001–2002 and 2002–2003, but not the season 2003–2004. Fusarium graminearum and F. culmorum were in general the most frequently occurring Fusarium spp. in Flanders over the 4 years but the composition of the Fusarium population varied strongly from location to location and from year to year. Fusarium graminearum predominated in areas especially where maize was cultivated, whereas in areas with more small cereals in the crop rotation more F. culmorum was present. Also temperature played a role in the composition of Fusarium spp.     

Differences in susceptibility of winter wheat varieties for Fusarium species under Belgian growing conditions

Fusarium head blight is an important disease of cereal crops caused by Fusarium species. It causes not only a reduction in yield, but most Fusarium species (F. graminearum. F. culmorum, F. avenaceum. F. poae) produce also a range of toxic metabolites such as deoxynivalenol (DON) and zearalenone (ZEA). The evaluation of Fusarium species was followed up under natural infection conditions during the growing seasons 2001--2002 and 2002--2003 in two varietal winter wheat experiments on the experimental farm of the Hogeschool Gent at Bottelare. Disease pressure, DON and ZEA content, different Fusarium species as well as growth and yield parameters were determined. In both years there were significant differences between the varieties concerning the susceptibility to Fusarium and the DON content. ZEA was not found in the kernels. The mean deoxynivalenol (DON) content was in 2002 (1,126 mg/kg) higher than in 2003 (0.879 mg/kg) although the mean disease severity was bigger in 2003 than in 2002 what means that the DON content was not always correlated with the disease severity. The Fusarium species most frequently identified in our two field trials (Bottelare) were F. graminearum and F. culmorum Varietal differences in susceptibility to Fusarium species and DON contamination could be detected.     

Response to Fusarium culmorum inoculation in barley

In field tests replicated in 2004 and 2005, 32 cultivars of spring barley were assessed for resistance to Fusarium head blight (FHB) by single floret inoculation and spray inoculation with Fusarium culmorum (W. G. Smith) Sacc. It was found that the weather conditions in individual years affect to a large extent the progression of FHB and production of mycotoxin deoxynivalenol (DON). At the same time, in both years the cultivars reacted to F. culmorum infection similarly with respect to areas under disease progress curve (AUDPC) values and content of mycotoxin DON. Spraying inoculation led to stronger infection. The biggest differences in AUDPC values were observed between the cultivars Brise and Celinka, and weak reaction was found in the cultivars Kompakt and Madonna. The cultivars Kompakt and Tolar were most resistant towards FHB. In both monitored years the variety Ludan contained the lowest amounts of mycotoxin DON. Cultivars with high infection and low DON content (r = 0.78) showed weak positive relationship between resistance to FBH and accumulation of DON (concentration 70–200 mg/kg). This is the first information on FHB and in vivo concentrations of DON in certificated barley cultivars in Slovakia.     

Analysis of Fusarium Graminearum Mycotoxins in Different Biological Matrices by LC/MS

The purpose of this study was to develop an LC/MS assay to accurately detect three mycotoxins produced by Fusarium graminearum in various matrices. Using different LC conditions, deoxynivalenol (DON), 15-acetyldeoxynivalenol (15-ADON), and zearalenone (ZEN) were detected in four different matrices (fungal liquid cultures, maize grain, insect larvae and pig serum). The sensitivity of MS detection allowed us to detect concentrations as low as 8 ppb of DON and 12 ppb of ZEN. A very small quantity of matrix was therefore necessary for successful analysis of these toxins and a variety of experimental situations were successfully investigated using this technique. Production of 15-ADON and butenolide was monitored in a liquid culture of F. graminearum under controlled conditions. Using simple extraction procedures, the differential accumulation of DON and 15-ADON was followed in inoculated maize genotypes varying in susceptibility to F. graminearum. Toxicokinetic studies were carried out with maize insect pests reared continually on artificial diets containing ZEN and suggested that larvae may possess the ability to degrade ZEN. Finally, persistence of DON was assessed in pigs fed diet supplemented with DON, results indicated that DON accumulates quickly in pig blood and then levels decline progressively for 12 hours thereafter. The LC/MS study reported here is very useful and flexible for the detection of these mycotoxins in different media and at very low concentrations.     

Plasma kinetics and matrix residues of deoxynivalenol (DON) and zearalenone (ZEN) are altered in endotoxaemic pigs independent of LPS entry site

This study aimed to investigate a potential modulatory effect of E. coli lipopolysaccharide (LPS) on the kinetics of deoxynivalenol (DON) and zearalenone (ZEN) after pre- or post-hepatic LPS administration to unravel the putative role of the liver. Fifteen barrows were fed a diet containing mycotoxin-contaminated maize (4.59 mg DON/kg feed, 0.22 mg ZEN/kg feed) for 29 days and equipped with pre-hepatic catheters (portal vein, “po”) and post-hepatic catheters (jugular vein, “ju”), facilitating simultaneous infusion of LPS (“LPS group”, 7.5 μg/kg body weight) or 0.9% sterile NaCl solution (control, “CON group”, equivolumar to LPS group) and blood sampling. This resulted in three infusion groups, depending on infusion site: CON_ju-CON_po, CON_ju-LPS_po, and LPS_ju-CON_po. On day 29, pigs were fed their morning ration (700 g/pig) (?15 min), and blood samples were collected at regular intervals relative to infusion start. At 195 min, pigs were sacrificed and bile, urine, liquor, and liver samples collected. DON concentrations in jugular and portal blood decreased in both LPS-infused groups, whereas the ZEN concentrations increased, regardless of the treatment site. In liver tissue, a decrease of both toxin concentrations was observed in endotoxaemic pigs as well as a drop in hepatic conjugation, regardless of LPS entry site. In contrast to our hypothesis, DON and ZEN were not differently altered depending on the LPS-entry site. Neither the absorption nor the accumulation of DON and ZEN in different tissues differed significantly between animals which were infused with LPS via either the jugular or portal vein.     

Detoxification of Fusarium-contaminated maize with sodium sulphite – in vivo efficacy with special emphasis on mycotoxin residues and piglet health

A feeding experiment with piglets was performed to examine the efficacy of a wet preservation of Fusarium (FUS)-contaminated maize with sodium sulphite (SoS) based on deoxynivalenol (DON) and zearalenone (ZEN) residue levels in urine, bile and liquor and health traits of piglets. For this purpose, 80 castrated male piglets (7.57 ± 0.92 kg BW) were assigned to four treatment groups: CON? (control diet, with 0.09 mg DON and <0.01 mg ZEN/kg diet), CON+ (diet CON?, wet-preserved with 5 g SoS/kg maize; containing 0.05 mg DON and <0.01 mg ZEN/kg diet), FUS? (diet with mycotoxin-contaminated maize; containing 5.36 mg DON and 0.29 mg ZEN/kg diet), and FUS+ (diet FUS?, wet-preserved with 5 g SoS/kg maize; resulting in 0.83 mg DON and 0.27 mg ZEN/kg diet). After 42 d, 40 piglets (n = 10 per group) were sampled. A clear reduction of DON levels by approximately 75% was detected in all specimens of pigs fed diet FUS+. ZEN was detected in all urine, bile and liquor samples, while their metabolites were only detectable in urine and bile. Additionally, their concentrations were not influenced by SoS treatment. Among the health-related traits, feeding of FUS diets increased the total counts of leukocytes and segmented neutrophil granulocytes irrespective of SoS treatment. SoS treatment increased the total blood protein content slightly with a similar numerical trend in albumin concentration. These effects occurred at an obviously lower level in FUS-fed groups. Moreover, SoS treatment recovered the reduction of NO production induced by feeding diet FUS? indicating an effect on the redox level. As this effect only occurred in group FUS+, it is obviously related to the adverse effects of the Fusarium toxins. In conclusion, treatment of FUS-contaminated maize with SoS decreased the inner exposure with DON as indicated by the lower DON levels in various piglet specimens. However, health-related traits did not consistently reflect this decreased exposure.     

Mycotoxins in cereal grain (part 15). Distribution of deoxynivalenol in naturally contaminated wheat kernels

The analysis of deoxynivalenol (DON) in naturally infected wheat samples, after having been separated into four fractions through laboratory sieves, showed very low levels of DON in the fraction of largest kernels >2.8 mm (0 up to 1 mg/kg). The highest concentration of DON was found in fractions 2.2 to 2.5 mm and <2.2mm with up to 14mg/kg and 15mg/kg DON, respectively. In two samples (fractions <2.2mm) nivalenol was detected in concentrations up to 1,4mg/kg.     

Relationship between Fusarium graminearum and Alternaria alternata contamination and deoxynivalenol occurrence on Argentinian durum wheat

A mycological survey was carried out on durum wheat (Triticum durum) samples from the main production area of Argentina. The isolation frequency and relative density of species of dematiaceous fungi, and genus Fusarium were calculated. Alternaria alternata and Fusarium graminearum were the predominant fungal species. An analysis of deoxynivalenol (DON) natural contamination was also performed on a limited number of samples (60). DON contamination levels in positive samples ranged from 26 to 6400 μg/kg. The non-parametric techniques applied showed that there is a positive relationship between DON contamination and F. graminearum relative densities and a negative relationship between DON contamination and A. alternata relative densities. This revised version was published online in August 2006 with corrections to the Cover Date.     

Response of Barley Genotypes to Fusarium Head Blight under Natural Infection and Artificial Inoculation Conditions

Forty-eight spring barley genotypes were evaluated for deoxynivalenol (DON) concentration under natural infection across 5 years at Harrington, Prince Edward Island. These genotypes were also evaluated for Fusarium head blight (FHB) severity and DON concentration under field nurseries with artificial inoculation of Fusarium graminearum by the grain spawn method across 2 years at Ottawa, Ontario, and one year at Hangzhou, China. Additionally, these genotypes were also evaluated for FHB severity under greenhouse conditions with artificial inoculation of F. graminearum by conidial suspension spray method across 3 years at Ottawa, Ontario. The objective of the study was to investigate if reactions of barley genotypes to artificial FHB inoculation correlate with reactions to natural FHB infection. DON concentration under natural infection was positively correlated with DON concentration (r = 0.47, P < 0.01) and FHB incidence (r = 0.56, P < 0.01) in the artificially inoculated nursery with grain spawn method. Therefore, the grain spawn method can be used to effectively screen for low DON. FHB severity, generated from greenhouse spray, however, was not correlated with DON concentration (r = 0.12, P > 0.05) under natural infection and it was not correlated with DON concentration (r = −0.23, P > 0.05) and FHB incidence (r = 0.19, P > 0.05) in the artificially inoculated nursery with grain spawn method. FHB severity, DON concentration, and yield were affected by year, genotype, and the genotype × year interaction. The effectiveness of greenhouse spray inoculation for indirect selection for low DON concentration requires further studies. Nine of the 48 genotypes were found to contain low DON under natural infection. Island barley had low DON and also had high yield.     

Mycotoxins in laboratory rodent feed

Twenty-one batches of fixed-formula rodent diets from three feed manufacturers were tested for the presence of five mycotoxins: deoxynivalenol (DON), nivalenol (NIV), HT-2 toxin, T-2 toxin and ochratoxin A (OTA). Five batches were also tested for the presence of zearalenone (ZEN) and six batches for aflatoxins. Detectable levels of DON (up to 298 microg/kg), NIV (up to 118 microg/kg), OTA (up to 3.1 microg/kg) or ZEN (up to 26.7 microg/kg) were found in samples from all manufacturers. Three batches contained two (DON or NIV and OTA or ZEN) and one batch contained three (DON, OTA and ZEN) different mycotoxins. Aflatoxins, T-2 and HT-2 were not detected in any of the batches. The concentrations of mycotoxins detected in the feed were low, but indicated that feed ingredients, probably the cereal ingredients, were contaminated by mycotoxins. Since mycotoxins are known to have toxic and/or immunosuppressive effects, non-contaminated ingredients should be used for production of laboratory animal feed. The results imply that an improved quality control of ingredients used for laboratory rodent feed should be implemented.     

Resistance to Fusarium head Blight and Deoxynivalenol Accumulation in Chinese Barley

Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe is a devastating barley disease world-wide, causing significant yield losses and contaminating cereal products with mycotoxins. Barley grain contaminated with deoxynivalenol (DON) is associated with gushing and may be rejected by the malting and brewing industry. Genetically inherited resistance is the most effective option for the control of the disease. A total of 266 barley cultivars and breeding lines originating from China were evaluated for FHB resistance and concentration of DON in grain. Plants were inoculated with isolates of F. graminearum under field conditions by injecting conidia into a single spikelet of each spike. FHB symptoms were evaluated by visual inspection, and DON content was analysed by HPLC. Significant differences in FHB ratings and DON levels were observed among cultivars. Visual symptoms of FHB varied from 4.88 to 71.75% of infected spikelets 21 days after inoculation and from 7.86 to 113.33 area under the disease progress curve units (AUDPC). Twenty-seven lines were more resistant to FHB than the control resistant cultivar Zhedar 2 and with fewer than 12% infected spikelets. Twenty-one of the above lines originated from the area in the mid to low valley of Yangtze River, where FHB epidemics are frequent. DON levels ranged from 0.05 to 24.39 mg/kg among the tested barley lines. Correlation coefficients were significant between FHB symptom ratings and DON levels. However, there was no significant correlation between symptom rating and plant height and no significant correlation between symptom rating and heading date.     

Haematological,clinical–chemical and immunological consequences of feeding <Emphasis Type="Italic">Fusarium</Emphasis> toxin contaminated diets to early lactating dairy cows

Dairy cows experience a negative energy balance at the onset of lactation which results in an enhanced vulnerability for infectious diseases. Any dietary imbalances, including Fusarium toxin contamination, might therefore exacerbate this situation. The aim of the present investigations was to study the effects of increasing dietary concentrations of deoxynivalenol (DON) and zearalenone (ZEN) on clinical-chemical, haematological and immunological traits up to week 14 of lactation. For this purpose, ten cows each were assigned to a control group (CON; 0.02 mg ZEN and 0.06 mg DON per kg diet at 88 % DM), toxin level 1 (TOX-1; 0.29 mg ZEN and 2.31 mg DON per kg diet at 88 % DM) and toxin level 2 (TOX-2; 0.58 mg ZEN and 4.61 mg DON per kg diet at 88 % DM). The measured values of most parameters were affected by parturition but only a few of them were further modified by dietary treatment. For example, the time-dependent decrease in haemoglobin concentration, haematocrit and erythrocyte counts occurred at a significantly higher level for group TOX-2 while a serum glucose increase was missing in this group. Proportions of CD4+ and CD8+ cells decreased significantly over time solely in group TOX-2 while the CD4+/CD8+ ratio remained uninfluenced. Ability of granulocytes to mount an oxidative burst tended to increase at the end of the study in groups TOX-1 and TOX-2 while the opposite was observed in group CON. The results of this time-limited study indicate that feeding of Fusarium-toxin contaminated diets in early lactation affects health related parameters without compromising milking performance. However, long-term consequences of the observed effects on health need to be addressed in further studies.     

Decontamination ofFusarium mycotoxins,nivalenol, deoxynivalenol,and zearalenone,in barley by the polishing process

Korean dehusked and unhusked barley naturally contaminated withFusarium mycotoxins were polished using a Satake Grain Testing Mill. The pearled barley and bran fractions with different degrees of polishing were analyzed for nivalenol (NIV) and deoxynivalenol (DON) by gas chromatography with an electron capture detector, and for zearalenone (ZEN) by high-performance liquid chromatography with a fluorescence detector. NIV was detected in all the pearled barley fractions, but DON and ZEN were not detected in ≥27 % pearled barley fractions from dehusked barley and ≥36% pearled barley fractions from unhusked barley. However, for all degrees of polishing, NIV, DON, and ZEN were detected in bran fractions. The levels of NIV, DON, and ZEN in the bran fractions increased several fold over the original barley. Polishing was effective in removing DON and ZEN from the naturally contaminated barley, but not NIV.     

Trichothecene mycotoxins in kernels and head fusariosis susceptibility in winter triticale

A single isolates ofFusarium graminearum Schwabe KF 366 andFusarium culmorum (W.G.Sm.) Sacc. KF 365 were used to infect 10 genotypes (9 lines and one cultivar) of winter triticale, 1 rye cultivar and 1 wheat cultivar, and amounts of mycotoxins in kernels were analysed at the same stage of development. One genotype of triticale CHD 353/79 and rye “Chodan” were found to be most resistant towards both species infection with lowest amount of mycotoxins (deoxynivalenol) content in kernels and also the lowest yield reduction. The most susceptible line CZR 142 cumulated in kernels about ten times higher amount of mycotoxins (up 53 mg DON/kg and 16 mg 3AcDON/kg, and 5 mg zearalenone/kg). GenerallyF, culmorum formed higher level of mycotoxins in kernels of infected heads thanF. graminearum. In kernels of more susceptible genotypes except deoxynivalenol, 3 acetyldeoxynivalenol and zearalenone also were present.     

Influence of organically or conventionally produced wheat on health, performance and mycotoxin residues in tissues and bile of growing pigs

From 1999-2001 three different varieties of wheat [Contur (susceptible to Fusarium), Batis and Petrus (less susceptible to Fusarium)] were cultivated under organic and conventional conditions in order to determine mycotoxin burden. Soil quality, preceding crop and weather conditions were comparable in the different production systems. The wheat batches were analysed for moulds, and the contents of zearalenone (ZEN) and deoxynivalenol (DON). Feeding trials were carried out with growing pigs (n = 96; average initial live weight 22.2 +/- 1.5 kg [mean +/- SD]) to examine a possible influence on the animal performance and on mycotoxin residues. The data recorded were clinical conditions, performance, biochemical and hematological data. Residues of ZEN, alpha- and beta-zearalenol (ZEL) and of DON were determined in bile, liver and muscle after slaughtering. Conventionally cultivated wheat was more frequently contaminated with Fusarium and contained more frequently ZEN and DON in higher concentrations than the organically produced wheat. Hematological and biochemical parameters of pigs fed with organically cultivated diets were not different from those of conventionally fed pigs. Pigs fed with organically produced wheat showed a slightly higher daily weight gain, but a lower carcass yield than the conventionally fed animals. The highest residues of DON and total-ZEN (ZEN + alpha-ZEL + beta-ZEL) were found in bile. Bile samples of organically fed pigs contained lower concentrations of total-ZEN than those of conventionally fed pigs. Altogether, these data suggest that wheat from an organic farming does not have higher mycotoxin-contamination than wheat from the conventional farming system.     

Reduced susceptibility to Fusarium head blight in Brachypodium distachyon through priming with the Fusarium mycotoxin deoxynivalenol

The fungal cereal pathogen Fusarium graminearum produces deoxynivalenol (DON) during infection. The mycotoxin DON is associated with Fusarium head blight (FHB), a disease that can cause vast grain losses. Whilst investigating the suitability of Brachypodium distachyon as a model for spreading resistance to F. graminearum, we unexpectedly discovered that DON pretreatment of spikelets could reduce susceptibility to FHB in this model grass. We started to analyse the cell wall changes in spikelets after infection with F. graminearum wild‐type and defined mutants: the DON‐deficient Δtri5 mutant and the DON‐producing lipase disruption mutant Δfgl1, both infecting only directly inoculated florets, and the mitogen‐activated protein (MAP) kinase disruption mutant Δgpmk1, with strongly decreased virulence but intact DON production. At 14 days post‐inoculation, the glucose amounts in the non‐cellulosic cell wall fraction were only increased in spikelets infected with the DON‐producing strains wild‐type, Δfgl1 and Δgpmk1. Hence, we tested for DON‐induced cell wall changes in B. distachyon, which were most prominent at DON concentrations ranging from 1 to 100 ppb. To test the involvement of DON in defence priming, we pretreated spikelets with DON at a concentration of 1 ppm prior to F. graminearum wild‐type infection, which significantly reduced FHB disease symptoms. The analysis of cell wall composition and plant defence‐related gene expression after DON pretreatment and fungal infection suggested that DON‐induced priming of the spikelet tissue contributed to the reduced susceptibility to FHB.     

Fusarium graminearum gene deletion mutants map1 and tri5 reveal similarities and differences in the pathogenicity requirements to cause disease on Arabidopsis and wheat floral tissue

The Ascomycete pathogen Fusarium graminearum can infect all cereal species and lower grain yield, quality and safety. The fungus can also cause disease on Arabidopsis thaliana. In this study, the disease-causing ability of two F. graminearum mutants was analysed to further explore the parallels between the wheat (Triticum aestivum) and Arabidopsis floral pathosystems. Wild-type F. graminearum (strain PH-1) and two isogenic transformants lacking either the mitogen-activated protein kinase MAP1 gene or the trichodiene synthase TRI5 gene were individually spray- or point-inoculated onto Arabidopsis and wheat floral tissue. Disease development was quantitatively assessed both macroscopically and microscopically and deoxynivalenol (DON) mycotoxin concentrations determined by enzyme-linked immunosorbent assay (ELISA). Wild-type strain inoculations caused high levels of disease in both plant species and significant DON production. The map1 mutant caused minimal disease and DON accumulation in both hosts. The tri5 mutant, which is unable to produce DON, exhibited reduced pathogenicity on wheat ears, causing only discrete eye-shaped lesions on spikelets which failed to infect the rachis. By contrast, the tri5 mutant retained full pathogenicity on Arabidopsis floral tissue. This study reveals that DON mycotoxin production is not required for F. graminearum to colonize Arabidopsis floral tissue.     

Deoxynivalenol and Acetyldeoxynivalenol Accumulation in Field Maize Inoculated with Fusarium graminearum

Seven selected maize hybrids (Smolimag, Ruten, KLG 2210, Zenit, Betulisa, RAH BE 86101 and RAH BE 90102) were toothpick inoculated in the ear (at ∼ 10 days after midsilk) with a single isolate of Fusarium graminearum in order to determine their reaction to infection and susceptibility to mycotoxin accumulation in the tissues. Deoxynivalenol (DON), 15-acetyldeoxynivalenol (15-AcDON), and 3-acetyldeoxynivalenol (3-AcDON) were detected in differing amounts in kernels, husks, stalks (nodes and internodes) and roots. DON was recovered from stems, husks and damaged kernels at levels of 864, 278 and 93mg/kg, respectively, while 15-AcDON was recovered at 235, 55 and 11mg/kg and 3-AcDON was recovered at 3, 2 and 0.5 mg/kg, respectively. Maize hybrids Smolimag and Ruten were most resistant to infection and contained the lowest amounts of mycotoxins in the tissues while Zenit, RAH BE 90102, RAH BE 86101 and Betulisa were most susceptible to infection and accumulated higher amounts of mycotoxins.     

Distribution of deoxynivalenol inFusarium-infected forage maize

A time course study was carried out to assess the appearance and distribution of DON in different organs of forage maize cultivated in the field. DON was produced after the flowering period and increased until harvest to high amounts in the rudimentary ears and leaf sheaths/leaf blades deriving from nodes located below the ear node, whereas nodes and internodes were either not or only slightly contaminated with DON. Genrally, DON was not detected in the ears, including husks, during the whole cultivation time.Fusarium biomass determined in the infected organs confirmed these findings. It seems that the contribution of DON containing rudimentary ears, leaf sheaths and leaf blades to the total DON contamination of forage maize is so far widely underestimated. Therefore advanced evaluation procedures are recommended to get a better understanding of the infection and contamination process and to prove genotypic differences in the resistance of forage maize genotypes againstFusarium infection.