小麦赤霉病及呕吐毒素的分析检测

采集赤霉病含量不同的小麦样品为检验组,用赤霉病粒小麦配制成不同病粒含量的梯度小麦样品为对照组,用酶联免疫法测定感染赤霉病后的小麦中呕吐毒素含量,结果显示,控制小麦赤霉病含量≤3%,可确保小麦呕吐毒素含量符合国家粮食卫生指标规定,由此指导基层粮库小麦的收购工作。     

小麦赤霉病粒含量与呕吐毒素含量关系研究

采用胶体金快速定量法,对不同梯度赤霉病粒含量的小麦样品进行呕吐毒素的检测,并绘制曲线。结果表明,当小麦赤霉病粒含量超过2.5%时,呕吐毒素存在一定的超标风险。本研究对基层粮库小麦入库,以及通过测定赤霉病麦粒含量来判断呕吐毒素超标程度提供了参考依据,有助于粮库提高呕吐毒素检测效率,提高收粮速度。     

小麦呕吐毒素含量与赤霉病粒含量的相关性研究

该文通过大量数据的积累与分析,建立了小麦呕吐毒素含量与赤霉病粒含量的相关性曲线y=297.6x+135.96,并通过数十组实验数据加以验证曲线的正确性。所建立的相关性曲线在辅助仓库进仓小麦呕吐毒素定性筛查上具有较好的应用价值。     

小麦中呕吐毒素研究进展

小麦是全球三大谷物之一。由镰刀菌引起的小麦赤霉病是我国最主要的小麦病害之一,能造成小麦严重减产、品质下降,而且镰刀菌还能产生多种真菌毒素,进一步危害小麦及其制品的质量安全,其中,呕吐毒素(deoxynivalenol, DON)是小麦中检出率最高、危害最严重的真菌毒素之一,已成为关系小麦及其制品食用安全的重要问题。DON在小麦等谷物及其制品中的污染和防控是全球面临的严峻挑战,对DON进行定期检测和污染分析,研究高效、安全的降解技术,确保消费者安全,已成为目前世界各国政府和公众广泛关注和高度重视的热点问题。本文综述了DON的理化性质及毒性、影响产生的因素、污染现状及防控与脱毒方面的研究进展情况,以期为小麦中DON的风险评估及防控策略的制定提供有利参考。     

小麦收购过程中呕吐毒素检测方法的探讨

目前对呕吐毒素国内常用的检测方法主要有高效液相色谱法、酶联免疫检测试剂盒和胶体金快速定量法等。胶体金快速定量法无需大型仪器、检测速度快、成本较低,但精度较低,这在小麦收购现场是可以接受的,比较适合于收购粮食过程中呕吐毒素的现场快速检测,控制好入库小麦的呕吐毒素含量。     

小麦中呕吐毒素和玉米赤霉烯酮与赤霉病粒关系研究

采用受赤霉病污染小麦样品,检测赤霉病粒、呕吐毒素和玉米赤霉烯酮含量,研究分析三者之间的关系。结果显示,2种真菌毒素和赤霉病粒均存在显著线性关系,随赤霉病粒数量的增加,2种真菌毒素含量均呈现增加的趋势。对过赤霉病粒数量快速可以判断2种真菌毒素是否超过国家限定值,为基层粮食生产经营有现实意义。     

呕吐毒素在小麦正常粒和赤霉病粒中的分布情况研究

选用不同梯度呕吐毒素含量的小麦样品10份,通过测定样品赤霉病粒去除前后的呕吐毒素含量,以确定呕吐毒素在正常小麦和赤霉病粒中的分布比例情况。结果表明:小麦中的呕吐毒素60%左右分布在赤霉病粒中,在正常麦粒中也有一定分布。     

小麦中呕吐毒素降解的研究进展

呕吐毒素,又名脱氧雪腐镰刀菌烯醇(DON),是镰刀菌产生的一种真菌毒素,广泛存在于世界各地的谷物,特别是小麦中。不但给全球粮食产业造成巨大经济损失,也给人类健康带来潜在威胁,因此对小麦中的DON进行降解显得非常重要和迫切。本文对清除小麦中脱氧雪腐镰刀菌烯醇的物理、化学和生物方法进行了综述,为有效控制其水平提供了思路。     

呕吐毒素污染小麦气流分级分离技术研究

研究了水平气流速度、分级隔板高度和供料时间等因素对呕吐毒素污染小麦水平气流分级装置性能的影响。在单因素试验的基础上设计了正交试验,得出影响呕吐毒素含量高的小麦(即轻质小麦)分级性能主次因素为:分级隔板高度、供料时间、水平气流速度;小麦呕吐毒素含量最高时的最佳分级条件为:水平气流速ua=11.65m/s,分级隔板高h=100mm,供料时间t=12s。影响呕吐毒素含量高的小麦分级质量百分比的主次因素为:供料时间、分级隔板高度、水平气流速度;呕吐毒素含量高的小麦质量百分比最高的最佳分级条件为水平气流速度ua=11.65m/s,分级隔板高度h=70mm,供料时间t=15s。     

食品中呕吐毒素检测方法的研究进展

呕吐毒素是一种毒性较高的真菌次级代谢产物,常见于粮食、饲料及食品中,对人类健康具有潜在的风险和危害.呕吐毒素作为三级致癌物,其检测方法一直是食品检测领域研究的重点.文章阐述了呕吐毒素的理化性质、毒性作用、污染情况及限量标准,重点分析综述了各种检测技术在呕吐毒素检测分析方面的研究进展,以期为呕吐毒素快速检测技术的研究和检...     

Effect of fungicides on the development of Fusarium head blight,yield and deoxynivalenol accumulation in wheat inoculated under field conditions with Fusarium graminearum and Fusarium culmorum

The effect of different fungicide treatments on Fusarium head blight (FHB) development, grain yields and deoxynivalenol (DON) accumulation in wheat was evaluated after artificial inoculation under field conditions with a mixture of Fusarium graminearum and F culmorum. The trials were carried out using commercially available products on five different cultivars of soft and durum wheat (Serio, Genio, Bracco, Duilio and Orobel) in two separate experimental fields located in the North of Italy. Treatments with Tiptor^® S (cyproconazole plus prochloraz) and a mixture of Horizon^® 250 EW (tebuconazole) plus Amistar^® 250 SC (azoxystrobin) significantly reduced the FHB disease severity (by between 25 and 77%) and DON content (by between 32 and 89%) in the grain as compared with the inoculated control. Yields (tonne ha^?1) and thousand grain weight (TGW) were higher in plots subjected to fungicide treatments. Tetraconazole (Eminent^® 40 EW) showed a markedly reduced effectiveness compared with the other treatments. Regression analysis showed a strong correlation of disease severity with DON levels (positive correlation) and with yields or TGW (negative correlation) for individual cultivars and locations. Fusarium graminearum, F culmorum and F poae were the species most commonly isolated from all trials, including inoculated and non‐inoculated control plots. Copyright © 2004 Society of Chemical Industry     

Analysis of deoxynivalenol and deoxynivalenol-3-glucosides content in Canadian spring wheat cultivars inoculated with Fusarium graminearum

Contamination of wheat grains with Fusarium mycotoxins and their modified forms is an important issue in wheat industry. The objective of this study was to analyse the deoxynivalenol (DON) and deoxynivalenol-3-glucosides (D3G) content in Canadian spring wheat cultivars grown in two locations, inoculated with a mixture of 3-acetyldeoxynivalenol (3-ADON)-producing Fusarium graminearum strains and a mixture of 15-acetlyldeoxynivalenol (15-ADON)-producing F. graminearum strains. According to the analysis of variance, significant differences were observed among the cultivars for Fusarium head blight (FHB) disease index, Fusarium-damaged kernel percentage (%FDK), DON content and D3G content. When the effect of chemotype was considered, significant differences were observed for FHB disease index, FDK percentage and DON content. The D3G content and D3G/DON ratio were not significantly different between the chemotypes, except for D3G content at the Winnipeg location. The Pearson correlation coefficient between DON and D3G was 0.84 and 0.77 at Winnipeg and Carman respectively. The highest D3G/DON ratio was observed in cultivars Carberry (44%) in Carman and CDC Kernen (63.8%) in Winnipeg. The susceptible cultivars showed lower D3G/DON ratio compared with the cultivars rated as moderately resistant and intermediate. The current study indicated that Canadian spring cultivars produce D3G upon Fusarium infection.     

Molecular survey of trichothecene genotypes of Fusarium graminearum species complex from barley in southern Brazil

Fusarium head blight is a disease of primary concern to small-grain cereals of Brazil, including barley. Its main causal agent, Fusarium graminearum species complex (Fg complex)¸ is able to produce mycotoxins, especially deoxynivalenol (DON) and nivalenol (NIV), that usually contaminate grain. Strains that produce DON may also produce its acetylated derivatives: 3-acetyl-DON (3-ADON) and 15-acetyl-DON (15-ADON). Ninety two isolates were obtained from samplings of barley grain during three years (2007, 2008 and 2009) from several fields in both southern and northern production regions of Rio Grande do Sul state, Brazil. These isolates were examined for polymerase chain-reaction-based (PCR) trichothecene genotype based on the amplification of portions of Tri3 and Tri12. There was no effect of year or region on the proportion of trichothecene genotypes. Overall, 66% of the strains (61/92) were 15-ADON, 4.4% (4/92) were 3-ADON and 29.3% (27/92) were NIV. The overall NIV/DON ratio estimated (0.41) was five times higher than that found in previous studies with strains from wheat grown in the same region. Species identification of nine strains representing the trichothecene genotypes, based on comparisons of DNA sequences of portions of the PHO, RED and URA genes with sequences from curated reference isolates of Fusarium from GenBank, revealed that they belong to F. graminearum sensu stricto (four 15-ADON and one 3-ADON strain), F. meridionale (three NIV strains) and F. austroamericanum (one 3-ADON strain). These results add to the current regional knowledge of trichothecene genotypes and species within the Fg complex affecting barley in the region.     

Reduction of Fusarium head blight and deoxynivalenol in wheat with early fungicide applications of prothioconazole

Numerous studies have identified the benefit of fungicides applied at flowering (Zadoks Growth Stage (GS) 59–69) in the reduction of Fusarium head blight and the reduction of deoxynivalenol (DON) in harvested wheat grain. Two experiments were performed to identify the ability of prothioconazole (Proline®) at three timings to reduce Fusarium head blight and resulting DON in harvested grain of wheat. Prothioconazole (150 g ha^?1) was applied to plots of wheat at GS31, GS39, and GS65 in a full-factorial design. Plots were inoculated with Fusarium-infected oat grain at GS30 and mist-irrigated at GS65 to encourage head blight development. Plots were assessed for head blight symptoms at GS77 and harvested grain was analysed for yield, specific weight, thousand grain weight, and DON. Factorial analysis of variance (ANOVA) identified prothioconazole applications at each timing that resulted in significant reductions in Fusarium head blight and DON. The control achieved with combinations of spray timings was additive with no significant interactions. The control of Fusarium head blight at GS31, GS39, and GS65 was 50, 58 and 83%, respectively. The reduction in Fusarium head blight achieved by all three timings combined was 97% compared to the fully untreated control plots. The reduction of DON after application of prothioconazole at GS31, GS39, and GS65 was 27%, 49%, and 57%, respectively. The application of prothioconazole at all three timings achieved 83% reduction of DON compared with the fully untreated control plots. These experiments have determined, for the first time, significant additional head blight disease control and mycotoxin reduction with applications of a fungicide before flowering.     

Reaction of winter wheat (Triticum aestivum L.) cultivars to infection with Fusarium spp.: mycotoxin contamination in grain and chaff

This study compares the susceptibility of winter wheat (Triticum aestivum L.) cultivars to Fusarium head blight (FHB) and accumulation of mycotoxins in kernels and chaff under different climatic conditions in two locations–Cerekwica near Poznan (Central West Poland) and Sitaniec, near Zamosc, Lublin region (South East Poland). Very high variations were found in the concentrations of mycotoxins (zearalenone, ZEA; nivalenol, NIV; deoxynivalenol, DON; moniliformin, MON) in examined fractions: Fusarium-damaged kernels (FDK) and healthy looking kernels (HLK) and in chaff for individual cultivars in both locations. In most cases, significantly higher concentrations of investigated toxins were recorded in wheat from the area of Lublin than from Poznan (p < 0.05). The highest Fusarium infection rates and mycotoxin biosynthesis levels were observed in the Lublin location, with the percentage of the FDK fraction ranging 8.1–81.6. In this region, ZEA concentration (µg g^?1) after inoculation with F. culmorum and F. graminearum ranged from 0.02–0.48 and 0.32–1.04, respectively. In the Poznan area, the toxin concentrations were considerably lower, ranging 0.01–0.10 and 0.03–0.13 µg g^?1 for both isolates, respectively. The concentration of DON was significantly higher than ZEA or NIV levels. The levels of MON accumulation (µg g^?1) in the FDK fraction were between 0.14 and 1.73 (Poznan area) and ND (not detected) to 2.51 (Lublin area). F. avenaceum infection rate ranged 7–35% in samples where the toxin was detected.     

Influence of inoculum and climatic factors on the severity of Fusarium head blight in German spring and winter barley

Fusarium head blight (FHB) of small cereals is a disease of global importance with regard to economic losses and mycotoxin contamination harmful to human and animal health. In Germany, FHB is predominantly associated with wheat and F. graminearum is recognised as the major causal agent of the disease, but little is known about FHB of barley. Monitoring of the natural occurrence of FHB on Bavarian barley revealed differences for individual Fusarium spp. in incidence and severity of grain infection between years and between spring and winter barley. Parallel measurement of fungal DNA content in grain and mycotoxin content suggested the importance of F. graminearum in winter barley and of F. langsethiae in spring barley for FHB. The infection success of these two species was associated with certain weather conditions and barley flowering time. Inoculation experiments in the field revealed different effects of five Fusarium spp. on symptom formation, grain yield and mycotoxin production. A significant association between fungal infection of grain and mycotoxin content was observed following natural or artificial infection with the type B trichothecene producer F. culmorum, but not with the type A trichothecene-producing species F. langsethiae and F. sporotrichioides. Trichothecene type A toxin contamination also occurred in the absence of significant damage to grain and did not necessarily promote fungal colonisation.     

Suppression of Fusarium graminearium growth by differently structured starch types

We investigated the growth behavior and amylolytic enzymes of Fusarium graminearum cultivated on different types of native starch granules including barley (A‐type crystalline polymorph), potato and Curcuma zedoaria (B‐type crystalline polymorph), cassava (C‐type crystalline polymorph), and high AM maize (A + Vh‐type crystalline polymorphs). F. graminearum grew poorly on B‐type starches and the accumulation of biomass was similar to that obtained for fungi cultivated under carbohydrate starvation conditions. In comparison, three‐ to fivefold higher accumulation of fungal biomass was observed for growth on the A‐, C‐ and A + Vh‐type starches. Fungal glucoamylase and α‐amylase activity increased over time in the presence of native starch granules. Interestingly, resistant B‐type starches induced the highest amylolytic activity indicating that F. graminearum interacts with B‐type granules although only limited degradation occur. Starch degradation products maltose and malto‐oligosacharides was found to increase glucoamylase and α‐amylase activity, whereas glucose acted as a catabolite repressor.     

Assessment of Fusarium infection in wheat heads using a quantitative polymerase chain reaction (qPCR) assay

The accuracy of a quantitative polymerase chain reaction assay in quantifying the DNA of trichothecene-producing F. culmorum and F. graminearum within harvested wheat grains and head tissue was evaluated in comparison with incidences of infected kernels and deoxynivalenol levels. In a first experiment, six durum and bread wheat varieties were grown in randomized plots for a 2-year period, and inoculated with Fusarium macroconidia at six growth stages between heading and dough ripening, to obtain a wide range of Fusarium head blight incidences. There was a close relationship between fungal DNA and the amount of deoxynivalenol, and this relationship was consistent over Fusarium species, wheat species and varieties, and over a wide range of Fusarium head blight infection. In a second experiment potted wheat plants were grown under environmentally controlled conditions and inoculated with the two Fusarium species at full flowering; head samples were collected before inoculation and after 6 h to 12 days, and processed by the quantitative polymerase chain reaction assay. This assay made it possible to detect the dynamic of fungal invasion in planta after infection had occurred, and to single out the presence of infection before the onset of the disease symptoms: A robust detection of the infection occurred within 18-24 h for F. culmorum, and within 2-9 days for F. graminearum.     

On the effects of graded levels of Fusarium toxin contaminated wheat in diets for gilts on feed intake, growth performance and metabolism of deoxynivalenol and zearalenone

A total of 36 gilts (103 +/- 6 kg) were divided into four groups and fed diets with increasing proportions of a Fusarium toxin contaminated wheat over a period of 35 days. The concentrations of the indicator toxins deoxynivalenol (DON) and zearalenone (ZON) which were analyzed by HPLC methods were 210 and 4, 3070 and 88, 6100 and 235 and 9570 and 358 mug.kg(-1) diet fed to groups 1-4 respectively. Feed was partially refused during the first 21 days of the experiment by groups 2, 3 and 4 where two, three and six out of nine gilts were affected. No signs of hyperestrogenism or uterotrophic effects were observed due to dietary treatments. Blood serum, urine, bile and liver were analyzed for residues of DON, ZON and their metabolites. DON and its de-epoxidized metabolite (de-epoxy-DON) were detected in all analyzed specimens and increased in a significantly linearly related fashion. Alpha-zearalenol (alpha-ZOL) and beta-ZOL could be detected besides the parent toxin ZON, but only in bile and urine. In conclusion, the impact of dietary treatments on the performance parameters was most pronounced in the highest exposed group. The maximum ratio between DON concentration in liver and diet was 0.0013, and suggests that a possible contamination of pig liver with DON is negligible and does not contribute significantly to human DON exposure.