Mycotoxin Accumulation Research Articles

Early sowing and harvesting as effective measures to reduce stalk borer injury, Fusarium verticillioides incidence and associated fumonisin production in maize

Maize cultivation in Tanzania is hampered by the presence of maize stalk borer (Busseola fusca) and Fusarium verticillioides, causing ear, kernel and stalk damage. Furthermore, accumulation of fumonisin mycotoxins deteriorates grain quality. Optimized agronomic practices remain the primary line of defense against pests and diseases. Therefore, the aim of this study was to gain insight into the effects of hybrid, sowing and harvest date on injuries due to maize stalk borer, Fusarium verticillioides symptoms and fumonisin contamination in maize grown in Tanzania. The analyses of the data collected during two growing seasons (2013 and 2014) showed early sowing and early harvesting as important measures for minimizing these problems. Although the impact of hybrid was not always significant, the early maturing hybrid STUKA M1 was consistently less susceptible compared to the hybrid STAHA. Correlation analysis revealed that stalk borer injuries, Fusarium symptoms and fumonisin levels were positively associated. The associations between yield and stalk borer injuries, Fusarium symptoms and fumonisin levels were negative, indicating that besides the mycotoxin issues, the insect and fungal pathogen also contribute to yield losses.

Resistance against Fusarium graminearum and the relationship to \u03b2-glucan content in barley grains

Fusarium head blight (FHB) caused by Fusarium graminearum (FG) is a destructive disease impacting barley worldwide. The disease reduces the grain yield and contaminates grains with mycotoxins, such as the trichothecene deoxynivalenol (DON). Although the infection mainly affects the grain yield, little is known about its impact on grain structural and biochemical properties. Yet, such information is instrumental to characterize the facets of resistance in the grains. After artificial inoculation of six barley cultivars with FG in a 2 years field test, different levels of symptoms on spikes, of colonisation of grains and of DON content were observed. The infections caused a reduction in grain weight and an average decrease of 10% of the β-glucan content in grains, indicating alterations of grain filling, composition and structure. According to our results, we postulate the presence of two distinct resistance mechanisms in the grain, tolerance to grain filling despite infection as well as the inhibition of mycotoxin accumulation. Differently to wheat, in barley, type IV resistance (tolerance of the grain to infection) is directly linked with type III resistance (resistance against kernel infection). The resistance against toxin accumulation (named type V resistance in wheat) appeared to be independent to all other resistance types. Generally, the resistance was significantly influenced by the environment and by genotype x environment interactions explaining the generally weak stability of resistance in barley. Interestingly, a significant and inverse relationship between DON contamination and β-glucan content in grains suggests that high β-glucan content in grains contributes to type V resistance.

Cell wall features transferred from common into durum wheat to improve Fusarium Head Blight resistance

Durum wheat is naturally more susceptible to Fusarium graminerum infection in comparison to common wheat. The improvement of durum wheat resistance against F. graminearum is a challenge due to the lack of resistance sources in its gene pool. FHB-resistance factors were introduced in durum wheat by generating recombinant inbred lines (RILs), obtained by crossing the hexaploid resistant accession 02-5B-318 with the susceptible durum wheat cv. Saragolla. In this work we explored the possible contribution of cell wall (CW) in RILs with improved FHB resistance. We thoroughly studied CW components, mycotoxins content and the expression of related genes in different RILs selected for their extremely high and low resistance to FHB. Differences were found in resistant and susceptible lines in the degree of pectin methylesterification and in deoxynivalenol (DON) accumulation after fungal infection. Genes involved in biochemical modification of CW structure (WheatPme-1, Glu-1) and mycotoxins accumulation (ns-LTP-1) were analyzed as putative candidates for FHB resistance. Our results indicate that durum wheat plants with cell wall structure and gene response acquired from common wheat displayed an increased resistance to FHB.

Accumulation of toxigenic Fusarium species and Stenocarpella maydis in maize grain grown under different cropping systems

Mycotoxigenic fungi such as Fusarium graminearum, Fusarium verticillioides and Stenocarpella maydis infecting maize grain can be detrimental to both humans and animals due to the toxins they produce. Disease management strategies include tillage practices and crop rotations, however, these have not been sufficiently evaluated in South Africa. The effect of cropping systems on ear rot accumulation and mycotoxin contamination in maize grain was investigated in two localities over a four and six-year period. Cropping systems evaluated were: 1) monoculture maize conventional tillage, 2) monoculture maize no-till, 3) two, and 4) three-year rotation systems consisting of maize/cowpea and maize/cowpea/babala (all no-till), respectively. In Buffelsvallei, two additional crop rotations, maize/sunflower and maize/sunflower/babala (all no-till) were included. Naturally infected trials were visually evaluated for disease severity or incidence while fungal and mycotoxin contamination of maize grain was quantified. Disease incidence and mycotoxin contamination were inconsistent throughout the study period due to seasonal and geographical differences. In Buffelsvallei, cropping system had a significant effect (P < 0.05) on the accumulation of fumonisins and F. graminearum for 2010/11, deoxynivalenol (2011/12) and S. maydis incidence (2013/14). Fusarium graminearum and fumonisin accumulation was significantly higher in the three-year maize/cowpea/babala rotation and two-year sunflower rotation in the 2010/11 season, respectively. Deoxynivalenol levels in monoculture maize, using conventional tillage (2011/12) was significantly higher when compared to all other cropping systems and S. maydis incidence was significantly higher in maize conventionally tilled, no-till and two-year maize/cowpea and maize/sunflower cropping systems in the 2013/14 season. Cropping systems had no significant effects on fungal infection or mycotoxin accumulation in maize grain obtained from trials conducted at Erfdeel. The results of this study indicate that Conservation Agriculture systems under the environments evaluated, did not increase the risk of maize ear rots and mycotoxin production.

Changes in Phenylpropanoid and Trichothecene Production by Fusarium culmorum and F. graminearum Sensu Stricto via Exposure to Flavonoids.

Flavonoids are a group of hydroxylated polyphenolic compounds widely distributed in the plant kingdom. Biosynthesis of these compounds involves type III PKSs, whose presence has been recently predicted in some fungal species through genome sequencing efforts. In this study, for the first time it was found that Fusaria produce flavonoids on solid YES medium. Naringenin, as the central precursor of all flavonoids, was produced at highest quantities, followed by quercetin, kaempferol, apigenin and luteolin. In plants, flavonoids are involved in the protection of cereals to a wide range of stresses, including host defense against Fusaria. Under in vitro conditions, strains of Fusarium culmorum and F. graminearum sensu stricto were incubated at levels of flavonoids close to amounts produced by cereals in response to fungal infection. The amounts of exogenous naringenin, apigenin, luteolin, kaempferol and quercetin were reduced and converted by fungi to the other flavonoid derivatives. Treatment of fungi with naringenin derivatives led to the inhibition of naringenin production. Correspondingly, the production of fungal-derived phenolic acids decreased in flavonoid treated samples, although this effect appeared to be dependent on the strain, flavonoid molecule and its concentration. Fusaria showed high variability in trichothecene production in response to flavonoids. With emphasis on quercetin, mycotoxin accumulation in the media was significantly decreased by luteolin, kaempferol, naringenin and apigenin. However, in some cases, apigenin led to the increase of mycotoxin content in the media. Gene expression experiments of Tri genes responsible for trichothecene biosynthesis (Tri4, Tri5 and Tri10) proved that the inhibition of mycotoxin production by flavonoids occurred at the transcriptional level. However, the changes in Tri transcript levels were not significant in most apigenin and all kaempferol-treated cultures. In this study, a link was established between antioxidant and antiradical properties of flavonoids and their effects on fungi.

Tolerance and Excretion of the Mycotoxins Aflatoxin B₁, Zearalenone, Deoxynivalenol, and Ochratoxin A by Alphitobius diaperinus and Hermetia illucens from Contaminated Substrates.

This study aimed to investigate the potential accumulation of mycotoxins in the lesser mealworm (Alphitobius diaperinus, LMW) and black soldier fly (Hermetia illucens, BSF) larvae. Feed was spiked with aflatoxin B1, deoxynivalenol (DON), ochratoxin A or zearalenone, and as a mixture of mycotoxins, to concentrations of 1, 10, and 25 times the maximum limits set by the European Commission for complete feed. This maximum limit is 0.02 mg/kg for aflatoxin B1, 5 mg/kg for DON, 0.5 mg/kg for zearalenone and 0.1 mg/kg for ochratoxin A. The mycotoxins and some of their metabolites were analysed in the larvae and residual material using a validated and accredited LC-MS/MS-based method. Metabolites considered were aflatoxicol, aflatoxin P1, aflatoxin Q1, and aflatoxin M1, 3-acetyl-DON, 15-acetyl-DON and DON-3-glycoside, and α- and β-zearalenol. No differences were observed between larvae reared on mycotoxins individually or as a mixture with regards to both larvae development and mycotoxin accumulation/excretion. None of the mycotoxins accumulated in the larvae and were only detected in BSF larvae several orders of magnitude lower than the concentration in feed. Mass balance calculations showed that BSF and LMW larvae metabolized the four mycotoxins to different extents. Metabolites accounted for minimal amounts of the mass balance, except for zearalenone metabolites in the BSF treatments, which accounted for an average maximum of 86% of the overall mass balance. Both insect species showed to excrete or metabolize the four mycotoxins present in their feed. Hence, safe limits for these mycotoxins in substrates to be used for these two insect species possibly could be higher than for production animals. However, additional analytical and toxicological research to fully understand the safe limits of mycotoxins in insect feed, and thus the safety of the insects, is required.

Comparative Transcriptome Profiles of Near-Isogenic Hexaploid Wheat Lines Differing for Effective Alleles at the 2DL FHB Resistance QTL.

Fusarium head blight (FHB), caused by the fungus Fusarium graminearum, represents one of the major wheat diseases worldwide, determining severe yield losses and reduction of grain quality due to the accumulation of mycotoxins. The molecular response associated with the wheat 2DL FHB resistance QTL was mined through a comprehensive transcriptomic analysis of the early response to F. graminearum infection, at 3 days post-inoculation, in spikelets and rachis. The analyses were conducted on two near isogenic lines (NILs) differing for the presence of the 2DL QTL (2-2618, resistant 2DL+ and 2-2890, susceptible null). The general response to fungal infection in terms of mRNAs accumulation trend was similar in both NILs, even though involving an higher number of DEGs in the susceptible NIL, and included down-regulation of the primary and energy metabolism, up-regulation of enzymes implicated in lignin and phenylpropanoid biosynthesis, activation of hormons biosynthesis and signal transduction pathways and genes involved in redox homeostasis and transcriptional regulation. The search for candidate genes with expression profiles associated with the 2DL QTL for FHB resistance led to the discovery of processes differentially modulated in the R and S NILs related to cell wall metabolism, sugar and JA signaling, signal reception and transduction, regulation of the redox status and transcription factors. Wheat FHB response-related miRNAs differentially regulated were also identified as putatively implicated in the superoxide dismutase activities and affecting genes regulating responses to biotic/abiotic stresses and auxin signaling. Altered gene expression was also observed for fungal non-codingRNAs. The putative targets of two of these were represented by the wheat gene WIR1A, involved in resistance response, and a gene encoding a jacalin-related lectin protein, which participate in biotic and abiotic stress response, supporting the presence of a cross-talk between the plant and the fungus.

What influences the composition of fungi in wheat grains?

Wheat grains are inhabited by different fungi, including plant pathogens and fungi – mycotoxin producers. The composition of seed mycobiota can be influenced by different factors, including agronomic practices, but the results are still contradictory. The aim of this study was to evaluate the mycobiota of wheat grains depending on agroecological conditions. Wheat grains were obtained from a two-factorial field trial: A – tillage system (A1 – ploughing at a depth of 22–24 cm; A2 – harrowing at a depth of up to 10 cm); B – crop rotation (B1 – continuous wheat; B2 – oilseed rape and wheat; B3 – crop rotation). The mycobiota of grain were determined by mycological and molecular methods. The most abundant and widespread of the mycobiota were &lt;em&gt;Pyrenophora tritici-repentis&lt;/em&gt;, &lt;em&gt;Alternaria&lt;/em&gt; spp., &lt;em&gt;Arthrinium&lt;/em&gt; spp., and &lt;em&gt;Fusarium avenaceum&lt;/em&gt;. Higher amounts of precipitation increased the infection of grains with &lt;em&gt;Fusarium&lt;/em&gt; fungi. Seven species of &lt;em&gt;Fusarium&lt;/em&gt; were identified in the grain samples: &lt;em&gt;F. avenaceum&lt;/em&gt;, &lt;em&gt;F. poae&lt;/em&gt;, &lt;em&gt;F. graminearum&lt;/em&gt;, &lt;em&gt;F. culmorum&lt;/em&gt;, &lt;em&gt;F. acuminatum&lt;/em&gt;, &lt;em&gt;F. sporotrichioides&lt;/em&gt;, and &lt;em&gt;F. tricinctum&lt;/em&gt;. The soil tillage method and crop rotation did not influence the total incidence of &lt;em&gt;Fusarium&lt;/em&gt; spp., but the abundance of a particular species differed depending on agronomic practice. The research suggests that continuous wheat sowing under conditions of reduced soil tillage can increase the level of risk of grain infection with &lt;em&gt;F. graminearum&lt;/em&gt; and, consequently, the accumulation of mycotoxins.

Fusarium head blight incidence and mycotoxin accumulation in three durum wheat cultivars in relation to sowing date and density

Durum wheat (Triticum turgidum var. durum) is an important crop in Europe, particularly in the Mediterranean countries. Fusarium head blight (FHB) is considered as one of the most damaging diseases, resulting in yield and quality reduction as well as contamination of grain with mycotoxins. Three winter durum wheat cultivars originating from Austria, Slovakia, and Poland were analyzed during 2012–2014 seasons for FHB incidence and Fusarium mycotoxin accumulation in harvested grain. Moreover, the effects of sowing density and delayed sowing date were evaluated in the climatic conditions of Southern Poland. Low disease severity was observed in 2011/2012 in all durum wheat cultivars analyzed, and high FHB occurrence was recorded in 2012/2013 and 2013/2014 seasons. Fusarium graminearum was the most abundant pathogen, followed by Fusarium avenaceum. Through all three seasons, cultivar Komnata was the most susceptible to FHB and to mycotoxin accumulation, while cultivars Auradur and IS Pentadur showed less symptoms. High susceptibility of cv. Komnata was reflected by the number of Fusarium isolates and elevated mycotoxin (deoxynivalenol, zearalenone, and moniliformin) content in the grain of this cultivar across all three seasons. Nivalenol was identified in the samples of cv. Komnata only. Genotype-dependent differences in FHB susceptibility were observed for the plants sown at optimal date but not at delayed sowing date. It can be hypothesized that cultivars bred in Austria and Slovakia show less susceptibility towards FHB than the cultivar from Poland because of the environmental conditions allowing for more efficient selection of breeding materials.

The effect of ambient pH modulation on ochratoxin A accumulation byAspergillus carbonarius

Aspergillus carbonarius, the main cause of severe post-harvest decay of vine fruit, is considered the major source of ochratoxin A (OTA) contamination of grapes and derived products. The factors inducing OTA accumulation byA. carbonarius and its contribution to pathogenicity remain unclear. Present findings indicate that the production of organic acids, such as D-gluconic acid (GLA) and citric acid, byA. carbonarius in the growth medium or in the decayed fruit tissue was directly related to ambient pH reduction. Under these conditions, induced transcript expression of genes involved in OTA biosynthesis occurred concurrently with mycotoxin accumulation. The high accumulation of OTA during acidification process raised the question of its importance in host-pathogen interactions during the fungal colonisation. Treatment of colonised grapes with sodium bicarbonate reduced accumulation of organic acid and OTA with a concomitant reduction in decay development, suggesting that tissue acidification is a significant factor inA. carbonarius pathogenicity. The present findings suggest that ambient pH is a regulatory signal for induction of mycotoxin production byA. carbonarius under the dynamic nutritional growth conditions occurring in culture. Yet the molecular mechanisms of OTA biosynthesis induction during colonisation of the acidic host environment are still unclear and should be further investigated.

Behaviour of durum wheat cultivars towards deoxynivalenol content: A multi-year assay in Italy

The deoxynivalenol (DON) occurrence in durum wheat (Triticum durum Desf.) kernels is a key food safety issue, hence more and more attempts have been made to increase the availability of resistant cultivars. Within this framework, this work focused on the analysis of the behaviour of several durum wheat cultivars widely grown in Italy in relation to the level of deoxynivalenol contamination in whole milled kernels. A total of 2844 samples were submitted for deoxynivalenol analysis by enzyme-linked immuno-sorbent assay. The statistical analysis by generalised linear models provided a trend ranking of durum wheat cultivars on the basis of the deoxynivalenol contamination level, depending on each cultivation area assayed. This study provided a better understanding of cultivar susceptibility to mycotoxin accumulation in grains. The role of the factor cultivar has clearly emerged. However, other environmental factors, such as growing area, have a great influence on the DON concentration levels in the cultivars tested.

Phenotypic and biochemical characterization of new advanced durum wheat breeding lines from Algeria that show resistance to fusarium head blight and to mycotoxin accumulation

Durum wheat (Triticum turgidum L. var. durum) is a crop highly susceptible to Fusarium head blight (FHB), which results in yield losses and downgrades the quality of grains mostly due to mycotoxin contamination. Although breeding for resistance to FHB is one of the most promising strategy for minimizing crop damage, the attempts to obtain durum wheat resistant lines have been limited so far. Two potentially interesting lines were recently delivered by a breeding program based on crosses involving cultivars from Europe and Syria. Using a field experiment in Algeria with four different Fusarium culmorum strains and a spray inoculation method, we demonstrated that the two breeding lines were significantly less affected than a set of commercial cultivars. The two breeding lines were shown to exhibit a higher resistance to both initial fungal infection and disease spread , and to mycotoxin contamination. In addition, a detailed analysis of 2 phenolic acid composition of grains indicates significant differences in p-coumaric acid between the FHB-resistant breeding lines and the sensitive genotypes. Our results corroborate the importance of cell wall composition in preventing the diffusion of F. culmorum and therefore contributing to the resistance of cereals to FHB.

Visual assessment and computer–assisted image analysis of Fusarium head blight in the field to predict mycotoxin accumulation in wheat grains

Phenotypic traits are regularly used to diagnose the development of Fusarium head blight (FHB) in the field, whereas mycotoxin accumulation in wheat grains can only be accurately evaluated through costly methods, such as high–performance liquid chromatography (HPLC). The aim of this study was to determine whether: (i) the results provided by existing commercial decision support tools could be anticipated using phenotypic measurements, including a novel technique of computer–assisted image analysis of spikes; and (ii) these measurements could avoid using HPLC. We monitored the FHB development during two consecutive years in highly contaminated plots in the Burgundy region (France). Contamination by crop residues was simulated through a field inoculation with barley grains artificially colonized by Fusarium graminearum. The development of the disease on spikes and harvested grains was assessed on one tolerant and two susceptible wheat varieties. The accumulated amounts of mycotoxins were measured in harvested grains using HPLC. As expected, the measured traits revealed that the inoculum responsible for infection on spikes mainly came from residues left on the soil surface, and the susceptible varieties were more diseased than the tolerant variety. Weather conditions had a strong effect on disease development. The novel computer–assisted image analysis technique had a better prediction power of deoxynivalenol accumulation, was more objective and time–saving than classical visual symptom assessments. This assessment method could be suitable to supplement the use of existing prediction tools and might avoid systematic and costly mycotoxin measurements in likely infected plots.

Does the Host Contribute to Modulation of Mycotoxin Production by Fruit Pathogens?

Storage of freshly harvested fruit is a key factor in modulating their supply for several months after harvest; however, their quality can be reduced by pathogen attack. Fruit pathogens may infect their host through damaged surfaces, such as mechanical injuries occurring during growing, harvesting, and packing, leading to increased colonization as the fruit ripens. Of particular concern are fungal pathogens that not only macerate the host tissue but also secrete significant amounts of mycotoxins. Many studies have described the importance of physiological factors, including stage of fruit development, biochemical factors (ripening, C and N content), and environmental factors (humidity, temperature, water deficit) on the occurrence of mycotoxins. However, those factors usually show a correlative effect on fungal growth and mycotoxin accumulation. Recent reports have suggested that host factors can induce fungal metabolism, leading to the synthesis and accumulation of mycotoxins. This review describes the new vision of host-factor impact on the regulation of mycotoxin biosynthetic gene clusters underlying the complex regulation of mycotoxin accumulation in ripening fruit.

Sinapic Acid Affects Phenolic and Trichothecene Profiles of F. culmorum and F. graminearum Sensu Stricto.

Plant-derived compounds for reducing the mycotoxin load in food and feed have become a rapidly developing research field of importance for plant breeding efforts and in the search for natural fungicides. In this study, toxigenic strains of Fusarium culmorum and F. graminearum sensu stricto were exposed to sinapic acid on solid YES media at levels close to those reported in wheat bran. Fusaria produced phenolic acids, whose accumulation was decreased by exogenous sinapic acid. Strains exposed to the lowest doses of sinapic acid showed more efficient reduction of phenolic acid production than fungi kept at higher concentrations of this compound. Fungi reduced exogenous sinapic acid, leading to the formation of syringic aldehyde. Treatment with sinapic acid led to a dramatic accumulation of its parent compound ferulic acid, presumably due to inhibition of the further conversion of this phenolic compound. Exogenous sinapic acid decreased the production of trichothecenes by fungi. Higher doses of sinapic acid resulted in more efficient reduction of mycotoxin accumulation in the media. Gene expression studies of Tri genes responsible for trichothecene biosynthesis (Tri4, Tri5 and Tri10) proved that the inhibition of mycotoxin production by sinapic acid occurred at the transcriptional level. Fusaria respond to sinapic acid by stimulation of ergosterol biosynthesis.

Nicotinamide mononucleotide and related metabolites induce disease resistance against fungal phytopathogens in Arabidopsis and barley

Nicotinamide mononucleotide (NMN), a precursor of nicotinamide adenine dinucleotide (NAD), is known to act as a functional molecule in animals, whereas its function in plants is largely unknown. In this study, we found that NMN accumulated in barley cultivars resistant to phytopathogenic fungal Fusarium species. Although NMN does not possess antifungal activity, pretreatment with NMN and related metabolites enhanced disease resistance to Fusarium graminearum in Arabidopsis leaves and flowers and in barley spikes. The NMN-induced Fusarium resistance was accompanied by activation of the salicylic acid-mediated signalling pathway and repression of the jasmonic acid/ethylene-dependent signalling pathways in Arabidopsis. Since NMN-induced disease resistance was also observed in the SA-deficient sid2 mutant, an SA-independent signalling pathway also regulated the enhanced resistance induced by NMN. Compared with NMN, NAD and NADP, nicotinamide pretreatment had minor effects on resistance to F. graminearum. Constitutive expression of the NMNAT gene, which encodes a rate-limiting enzyme for NAD biosynthesis, resulted in enhanced disease resistance in Arabidopsis. Thus, modifying the content of NAD-related metabolites can be used to optimize the defence signalling pathways activated in response to F. graminearum and facilitates the control of disease injury and mycotoxin accumulation in plants.

Relationship of Mycotoxins Accumulation and Bioactive Components Variation in Ginger after Fungal Inoculation.

Ginger has got increasing worldwide interests due to its extensive biological activities, along with high medical and edible values. But fungal contamination and mycotoxin residues have brought challenges to its quality and safety. In the present study, the relationship of content of mycotoxins accumulation and bioactive components variation in ginger after infection by toxigenic fungi were investigated for the first time to elucidate the influence of fungal contamination on the inherent quality of ginger. After being infected by Aspergillus flavus and Aspergillus carbonarius for different periods, the produced mycotoxins was determined by an immunoaffinity column clean-up based ultra-fast liquid chromatography coupled with tandem mass spectrometry, and the main bioactive components in ginger were analyzed by ultra performance liquid chromatography-photodiode array detection. The results showed that consecutive incubation of ginger with A. flavus and A. carbonarius within 20 days resulted in the production and accumulation of aflatoxins (especially AFB1) and ochratoxin A, as well as the constant content reduction of four bioactive components, which were confirmed through the scanning electron microscope images. Significantly negative correlation was expressed between the mycotoxins accumulation and bioactive components variation in ginger, which might influence the quality and safety of it. Furthermore, a new compound was detected after inoculation for 6 days, which was found in our study for the first time.

Occurrence of mycotoxins in aquaculture: preliminary overview of Asian and European plant ingredients and finished feeds

Concern about mycotoxins in aquaculture has been growing, partly due to the gradual replacement of animal-derived proteins, such as fish meal, by plant sources. Over a period of one year, 2,176 samples of different plant protein sources and 25 samples of finished aquaculture feeds were analysed. Samples were tested for aflatoxins (AF; sum of aflatoxin B1, B2, G1 and G2), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB; sum of fumonisin B1 and B2), T-2 toxin and ochratoxin A (full toxin screen). The following plant-based meals were analysed: soybean meal (SBM), wheat (WH), wheat bran (WB), maize (C), corn gluten meal (CGM), cottonseed meal (CSM), rapeseed/canola meal (R/CM) and rice bran (RB). The plant raw materials and aquaculture finished feeds were obtained from Asia and Europe. Finished feed samples from Asia were acquired from Vietnam, Indonesia and Myanmar, while from Europe they were sampled from Denmark, Austria, the Netherlands and Germany. Mycotoxins were found in most of the commodities and finished feeds analysed, showing that mycotoxins represent a risk for the development of the aquaculture sector. Generally, in Asian samples we observed that SBM, WH, WB, C, CGM, R/CM and RB were mostly contaminated withFusarium mycotoxins (ZEA, DON and FB). CSM was contaminated primarily by AF andFusarium toxins (ZEA and DON) at lower concentrations. European samples were contaminated mainly byFusarium mycotoxins. The co-occurrence of mycotoxins in all commodities was high, raising the probability of co-occurrence in finished feeds. An accumulation of mycotoxins on the processed plant-based ingredients (e.g. CGM and WB) was observed when compared to the respective whole grains (C and WH, respectively). Compared to results obtained in 2014, finished feeds presented lower contamination levels, but the co-occurrence risk increased.

Saccharomyces cerevisiae YE-7 reduces the risk of apple blue mold disease by inhibiting the fungal incidence and patulin biosynthesis

The yeast strain, Saccharomyces cerevisiae YE-7, was tested to control the apple blue mold disease caused by Penicillium expansum and the accumulation of patulin mycotoxin. Compared with control, pre-treatment of pathogen-infected apples with YE-7 significantly reduced the incidence of blue mold diseases and patulin accumulation in rotten apple tissue by 48% and 42.6%, respectively. Interestingly, late treatment of pathogen-infected apples with YE-7 did not decrease patulin accumulation in the rotten tissue compared with pre-treatment or simultaneous-treatment. Independently, patulin amount and gene expression of isoepoxydon dehydrogenase were also measured. YE-7 pre-treated apples showed 75% and four times reduction in patulin accumulation and IDH gene expression, respectively. The results indicated that YE-7 directly affected patulin biosynthesis and did not affect accumulated patulin. On the other hand, cold storage enhanced the effect of YE-7 on apple blue mold disease incidence. Practical applications Postharvest blue mold decay caused by Penicillium expansum was important postharvest disease of apples. In addition, under favorable conditions, P. expansum can cause severe losses in apple fruits due to the production of patulin. In this study, a strain of S. cerevisiae (YE-7) was assessed for its efficacy not only in controlling apple blue mold diseases, but also in reducing patulin accumulation in fruit tissue. The research will give a practical way to control the decay in a bio-control way instead of the chemical.

The Reaction of some Maize Hybrids, Created at ARDS TURDA, to Fusarium spp. Infection

The most important disease of maize in Romania are stalk and ear rot, which caused yield losses in average of 20%. The resistant hibrids represent one of the most efficient solution for reducing the field loses caused by Fusarium spp. on the maize (Nagy et al., 2006). Diseases caused by Fusarium spp. can affect the yield and grain quality of maize because of contamination with numerous mycotoxins produced by these fungi (Czembor et al., 2015). The purpose of this paper was to know more about the reaction of different maize hybrids to Fusarium and the evaluating the effect of ear rot on the yield ability and mycotoxins accumulation. The experiments carried out at ARDS Turda, during four years (2012-2015). The biological material was represented by 8 hybrids, from different maturity groups, tested in two infection conditions with Fusarium spp. (natural and artificial infections). The temperature and rainfalls of the four years of experiments corresponding to the vegetation of maize (april-september) are influenced favourably the pathogenesis of stalk and ear rot caused by Fusarium spp. and a good discrimination of the resistance reaction of genotypes. Fusarium ear rot has significantly affected production capacity and chemical composition of corn hybrids tested. In conditions of artificial infection with Fusarium spp. was a decrease in the content of starch, fat and increased protein content compared with artificially inoculated variants. The quantity of fumonizin B1+B2 has reached to 5630 μg/kg in conditions of artificial infection. There are negative correlations between production capacity and degree of attack of fusarium ear rot; depending on the reacting genotypes tested increasing disease causes production decrease. The response of maize hybrids to Fusarium infection is influenced by infection and climatic conditions. These factors affect production both in terms of quantity and quality and accumulation of mycotoxins.