小麦中呕吐毒素与玉米赤霉烯酮相关性探讨

正呕吐毒素又称脱氧雪腐镰刀菌烯醇(DON),化学名为3a 7a 15-三羟基草镰孢菌-9-烯-8-酮,属单端孢霉烯族化合物。玉米赤霉烯酮(ZEN)又称F-2毒素,化学名为6-(10-羟基-6氧基-1-碳烯基)β-雷琐酸-μ-内酯,是由玉米赤霉菌、禾谷镰刀菌(F.graminearum)、三线镰刀菌(F.tricinctum)及串珠镰刀菌等产生的一类真菌毒素。有研究显示,DON和ZEN广泛污染农作物、食品及饲料等植物性产品,     

山东省小麦赤霉病菌的种群组成及毒素化学型分析

为了明确其在山东的种群组成及毒素类型,在2014,2015年从山东11个地区的28县、市共采集小麦病穗标本300余份,采用常规的组织分离方法,得到小麦赤霉病菌菌株338株。根据采集地点随机选取120株作为测试菌株,采用鉴定种和鉴定B型毒素化学型的特异性引物对选取菌株进行鉴定。结果表明,120个供试菌株均为禾谷镰孢菌进化宗系群,分为两种进化类型:禾谷镰孢菌和亚洲镰孢菌,分别为108株和12株,其中禾谷镰孢菌占90%,是优势致病型。亚洲镰孢菌是长江中下游麦区的优势种,此类型是首次在山东境内被检测到,且其在山东的分布与前茬作物种类无明显的相关性。毒素化学型鉴定结果表明,供试的120个菌株中有118株属脱氧雪腐镰孢菌烯醇(DON)毒素化学型,仅有2个菌株产生雪腐镰孢菌烯醇(NIV)毒素。其中,DON毒素化学型菌株又进一步划分为15-乙酰脱氧雪腐镰孢菌烯醇(15-AcDON)和3-乙酰脱氧雪腐镰孢菌烯醇(3-AcDON)。其对应菌株分别为101株和17株。     

赤霉病毒素（DON）去毒技术的研究

将天然污染赤霉病毒素脱氧雪腐镰刀菌烯醇(deoxynivalenol)的小麦,用清水淘洗浮选后再经过加工制粉,可以使毒素含量为2.3mg/kg的小麦中脱氧雪腐镰刀菌烯醇(DON)的量减少75％,使毒素含量为1.2mg/kg的降低60％;6％的过氧化氢(加1％NaOH)去毒效果较明显,DON的含量可降低59％;用1％的亚硫酸氢钠处理的小麦,可去除毒素约30％;20％水分的小麦在100％氨气(加10％Na_2CO_3)中放置18小时,在10％氯气中暴露0.5小时,均可使毒素含量降低30％。     

小麦粉中单端孢霉烯族毒素的检测方法

使用GC/MS建立了小麦粉中脱氧雪腐镰刀菌烯醇和雪腐镰刀菌烯醇2种毒素同时检测的方法。前处理0.5倍浓缩,外标法定量,回收率超过70%,定量下限为0.01 mg/kg,0.005～0.5 mg/L标准溶液的相关系数大于0.99。该方法操作简单、重现性和准确度高,非常适用于脱氧雪腐镰刀菌烯醇和雪腐镰刀菌烯醇的检测。     

酶联免疫吸附法快速检测谷物中的脱氧雪腐镰刀菌烯醇

应用ELISA法快速检测麦类、谷物及其制品中脱氧雪腐镰刀菌烯醇(DON),最低检出限为10μg/L,检测范围为10-1 000μg/L。用10%甲醇水溶液提取含DON的小麦及玉米样品,回收率为86～93%,变异系数为4.1%～17.4%。     

浙江大学生物所赤霉病防控研究团队发现ATP结合蛋白在病菌致病中的新作用

正6月23日,浙江大学生物所赤霉病防控研究团队在国际知名期刊New Phytologist上发表论文,揭示了赤霉病菌中ATP结合蛋白(ATP-binding cassette transporter)在病菌致病和生长中的新机制。近年来,由禾谷镰孢菌复合种(Fusarium graminearium complex)引起的赤霉病已经成为威胁我国小麦安全生产最重要的病害,病菌产生的脱氧雪腐镰刀菌烯醇(DON,也称呕吐毒素)也严重危害人畜健康,严重影响农产品质量安全。为此,深入理解病菌的致病机理和毒素合成机制对病害防控     

新西兰玉米中的霉菌毒素

新西兰研究者最近对1992～1994年收获的玉米作霉菌菌相和霉菌毒素污染量的普查,普查结果,1992～1994年收获的玉米普遍感染了镰刀菌。玉米中带有的霉菌毒素主要是镰刀菌烯醇、脱氧雪腐镰刀菌烯醇以及玉蜀赤霉烯醇,1992年收获的玉米样品中镰     

小麦镰刀菌毒素DON积累抗性研究进展

赤霉病是影响小麦生产的重要病害。小麦赤霉菌侵染寄主后,不仅影响小麦产量和品质,感病子粒中的真菌毒素（主要为脱氧雪腐镰刀菌烯醇,Deoxynivalenol,DON）还对人畜安全造成危害,培育抗病特别是抗DON积累品种是减轻赤霉病危害的有效途径。目前,在赤霉病5种抗性类型中仅抗侵染（类型Ⅰ）和抗扩展（类型Ⅱ）的研究较为深入,随着近年来对食品安全的重视,对毒素DON积累抗性类型（类型Ⅲ）的许多研究也陆续展开。本文系统地综述了抗毒素DON积累种质资源筛选、抗性遗传和抗病基因的分子标记等方面的进展。     

中科院揭示禾谷镰孢侵染植物的分子策略

<正>近期,中科院上海生命科学研究院植生生态所研究人员揭示了禾谷镰孢侵染植物的分子策略。禾谷镰孢是一种丝状真菌,能引起小麦赤霉病、玉米茎腐病等多种农作物病害,还能产生脱氧雪腐镰刀菌烯醇等真菌毒素。禾谷镰孢的基因组编码约14000个基因,已有上百个基因被证明与其致病性相关,但禾谷镰孢致病机制的全貌仍不清楚。     

制粉对小麦中脱氧雪腐镰刀菌烯醇(DON)的迁移作用

以自然污染脱氧雪腐镰刀菌烯醇(DON)的小麦为材料,通过筛理、水洗、制粉等加工工艺处理后,对小麦中的DON含量进行测定,得到了DON在小麦籽粒中的分布情况及小麦加工对其中DON迁移的影响。实验结果表明:1小麦中的DON主要分布在皮层,虽然小麦粉中DON含量有随染病程度增加而上升的趋势,但就总体而言,小麦粉中DON含量明显低于全麦粉;2筛理和水洗都能不同程度地降低小麦粉中DON的含量。筛理对于降低小麦粉中毒素的作用较明显,水洗对于降低麸皮中DON含量的作用较明显;3由于心粉和皮粉之间,粗麸和细麸之间的DON含量差异微小,因此,提高加工精度或控制出粉率对进一步降低小麦粉中DON含量的作用不大;4当小麦的DON含量在1.56mg/kg以下时,经筛理、水洗、制粉加工后的含量有较大可能性达到限量值1mg/kg以下。     

Estimation of deoxynivalenol (DON) content by symptom rating and exoantigen content for resistance selection in wheat and triticale

Fusarium head blight (FHB) in wheat and triticale leads to contamination of the grain with the mycotoxin deoxynivalenol (DON) that is harmful to animal and man. A fast, low-cost, and reliable method for quantification of the DON content in the grain is essential for selection. We analysed 113 wheat and 55 triticale genotypes for their symptom development on spikes, Fusarium exoantigen (ExAg) and DON content in the grain after artificial inoculation with a highly aggressive isolate of F. culmorum in three (wheat) and six (triticale) location-by-year combinations. Additionally, in triticale the amount of Fusarium damaged kernels (FDK) was assessed. ExAg content was analysed by a newly developed Fusarium-specific plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA) and DON content by an immunoassay. A moderate disease severity resulted in an ExAg content of 0.87 optical density (OD) units in wheat and 1.02 OD in triticale. DON content ranged from 12.0 to 105.2 mg kg^–1 in wheat and from 24.2 to 74.0 mg kg^–1 in triticale. Genotypic and genotype-by-environment interaction variances were significant (P < 0.01). Coefficient of phenotypic correlation between DON content analysed by the immunoassay and ExAg content was r = 0.86 for wheat and r = 0.60 for triticale. The highest correlation between DON content and symptom rating was found by FHB rating in wheat (r = 0.77) and by FDK rating in triticale (r = 0.71). In conclusion, selection for reduced FHB symptoms should lead to a correlated selection response in low fungal biomass and low DON content in the grain.     

小麦/玉米/大豆和小麦/玉米/甘薯套作对土壤氮素含量及氮素转移的影响

为探讨小麦/玉米/大豆套作对氮素营养的种间促进机制, 采用叶片¹⁵N富积标记法研究了小麦/玉米/大豆(A1)和小麦/玉米/甘薯(A2) 2种套作系统中不同施氮水平下的土壤培肥效果和氮素转移规律。结果表明,施氮可以提高小麦、玉米的土壤总氮含量,以施纯氮150~300 kg hm^-2处理最高;大豆较甘薯更有利于保持土壤肥力,施氮0、150、300和450 kg hm^-2水平下种植大豆后的土壤总氮含量比种植大豆前(小麦收获后)高38.6%、20.2%、9.4%和16.7%,而种植甘薯则降低总氮含量3.1%、1.8%、14.0%和3.8%。A1系统中小麦和玉米季土壤中NO₃-N含量低于A2系统,且随施氮量的增加而增加;大豆季土壤中NO₃-N含量高于甘薯季。A1和A2系统均存在¹⁵N的双向转移,¹⁵N转移量随施氮量的增加而降低,且A1的¹⁵N净转移量和转移强度高于A2;A1系统中小麦、玉米和大豆的¹⁵N净转移量比A2系统的¹⁵N净转移量分别高3.3%~12.1%、27.0%~166.2%和26.2%~78.7%。玉米与小麦之间的¹⁵N净转移方向为从玉米向小麦,玉米与大豆之间的¹⁵N净转移方向为从大豆向玉米,玉米与甘薯之间的¹⁵N净转移方向为从玉米向甘薯。     

Genetic variation for head blight resistance in triticale caused by Fusarium graminearum isolates of different deoxynivalenol production

Summary Fusarium head blight infection causes severe yield losses and contamination of the grain with mycotoxins in triticale (× Triticosecale Wittmack) grown in temperate and semihumid areas. In a two-year experiment thirty-six genotypes were inoculated separately with two isolates of Fusarium graminearum differing fivefold in their in vitro deoxynivalenol (DON) production and the effect on various traits was studied. All traits were significantly affected by head blight. The two isolates differed considerably in their aggressiveness resulting in a mean reduction of grain weight per spike of almost 25% and 50%, respectively. Inter-annual correlation was high for average disease rating (r=0.63, P<-0.01) and low for the other traits. Therefore, disease rating, averaged from two to three records, was regarded a suitable criterion for screening purposes. The effect of isolates on genotypes was not stable over years. The mean DON content of five genotypes with diverse resistance levels was 68 mg kg^-1. In vitro DON production of the two isolates used for inoculation did not correspond to their aggressiveness and DON contamination of the grain.     

用化学方法脱除赤霉病麦毒素的研究

对天然污染脱氧雪腐镰刀菌烯醇（ＤＯＮ）毒素的小麦,进行机械加工去皮和化学试剂处理脱毒。结果机械加工去皮可以去除２３．６％～３４．７％的ＤＯＮ毒素。化学试剂处理中,对麦粒的脱毒效果以０．１ｍｏｌ／Ｌ碳酸钠为最好,去毒效果达到８２．１％～８５．０％,平均为８３．９％;其次是１％亚硫酸氢钠,其ＤＯＮ降低率为６９．９％;４％过氧化氢和５％石灰水对ＤＯＮ降低率分别为４５．１％和２１．８％;对麸皮的脱毒效果也     

Effects of genotype and genotype—environment interaction on deoxynivalenol accumulation and resistance to Fusarium head blight in rye, triticale, and wheat

Fusarium culmorum is one of the most important Fusarium species causing head blight infections in wheat, rye, and triticale. It is known as a potent mycotoxin producer with deoxynivalenol (DON), 3‐acetyl deoxynivalenol (3‐ADON), and nivalenol (NIV) being the most prevalent toxins. In this study, the effect of winter cereal species, host genotype, and environment on DON accumulation and Fusarium head blight (FHB) was analysed by inoculating 12 rye, eight wheat, and six triticale genotypes of different resistance levels with a DON‐producing isolate at three locations in 2 years (six environments). Seven resistance traits were assessed, including head blight rating and relative plot yield. In addition, ergosterol, DON and 3‐ADON contents in the grain were determined. A growth‐chamber experiment with an artificially synchronized flowering date was also conducted with a subset of two rye, wheat and triticale genotypes. Although rye genotypes were, on average, affected by Fusarium infections much the same as wheat genotypes, wheat accumulated twice as much DON as rye. Triticale was least affected and the grain contained slightly more DON than rye. In the growth‐chamber experiment, wheat and rye again showed similar head blight ratings, but rye had a somewhat lower relative head weight and a DON content nine times lower than wheat (3.9 vs. 35.3 mg/kg). Triticale was least susceptible with a five times lower DON content than wheat. Significant (P = 0.01) genotypic variation for DON accumulation existed in wheat and rye. The differences between and within cereal species in the field experiments were highly influenced by environment for resistance traits and mycotoxin contents. Nevertheless, mean mycotoxin content of the grain could not be associated with general weather conditions in the individual environments. Strong genotype‐environment interactions were found for all cereal species. This was mainly due to three wheat varieties and one rye genotype being environmentally extremely unstable. The more resistant entries, however, showed a higher environmental stability of FHB resistance and tolerance to DON accumulation. Correlations between resistance traits and DON content were high in wheat (P = 0.01), with the most resistant varieties also accumulating less DON, but with variability in rye. In conclusion, the medium to large genotypic variation in wheat and rye offers good possibilities for reducing DON content in the grains by resistance selection. Large confounding effects caused by the environment will require multiple locations and/or years to evaluate FHB resistance and mycotoxin accumulation.     

普通小麦籽粒DON含量的配合力分析

为了选育抗赤霉病且籽粒毒素含量低的小麦品种以减轻赤霉病危害,在对我国南方麦区地方品种进行赤霉病抗性鉴定的基础上,选用8个籽粒中脱氧雪腐镰刀菌烯醇（deoxynivalenol, DON）含量水平不同的小麦品种作亲本,按8×8半双列杂交配制28个杂交组合,以接种后成熟籽粒中DON含量、病小穗数、病小穗率和病粒率为指标,进行赤霉病抗性、一般配合力（GCA）和特殊配合力（SCA）遗传分析,以及不同鉴定指标间比较和相关性分析。结果表明,8个品种中籽粒DON含量以苏麦3号最低(0.5715 mg kg^-1),Alondra’s最高(13.5560 mg kg^-1),各组合F1的籽粒DON含量均低于感病品种Alondra’s。品种间GCA和SCA存在显著差异,籽粒DON含量以加性效应为主,存在部分显性效应。苏麦3号、望水白和翻山小麦表现出较好的一般配合力效应。以苏麦3号为亲本的5个组合、望水白为亲本的4个组合特殊配合力效应较大。扬麦158一般配合力效应较小,但有4个组合表现较好的特殊配合力效应。籽粒DON含量和病小穗数、病小穗率、病粒率呈极显著的正相关关系。感病品种Alondra’s和绵阳8545的各个抗性鉴定指标的一般配合力在8个品种的排序中表现一致,抗病品种各个抗性指标的一般配合力在8个参试材料间的排序有所差异。DON含量的狭义遗传力为74.54%,因此以抗DON积累为指标的赤霉病抗性育种,可以在早期世代进行选择。     

Studies on somaclonal variants for resistance to scab in bread wheat (Triticum aestivum L.) through in vitro selection for tolerance to deoxynivalenol

This study was conducted to develop an efficient in vitro selection system for scab resistance by using in vitro screening for tolerance to deoxynivalenol (DON). Immature embryos of two wheat varieties, a scab-resistant variety Sumai 3 and a susceptible variety Mianyang 11, and their reciprocal F₁ hybrids were cultured on MS medium supplemented with 2,4-D 2 mg/l and 0.6 × 10^-4 M DON for callus induction. The responses of callus induction and plant regeneration to 0.6 × 10^-4 M DON differed significantly between resistant and susceptible varieties, according to observed scab resistance levels at the plant level in the field. The percentage of callus formation of resistant variety Sumai 3 on induction medium containing DON was higher than that of susceptible variety Mianyang 11. Regeneration of DON-tolerant calli on DON-containing differentiation medium differed significantly between Sumai 3 and Mianyang 11. Averaged across the DON-tolerant calli of two varieties and their reciprocals, regeneration of DON-tolerant calli was decreased 3-fold on DON-containing medium. By an inoculation test with conidiospores of Fusarium graminearum Schw, we obtained several resistant lines from progenies of regenerated plants from DON-tolerant calli. These somaclonal lines had lower disease scoring (reaction index, infected spikelets and disease incidence), shorter plants and better yield components than Sumai 3, a famous Chinese resistant variety. This revised version was published online in July 2006 with corrections to the Cover Date.     

不同贮藏条件下小麦和玉米种子的水分变化规律及其建模验证

种子平衡水分(EMC)是评价种子吸湿或解吸动态变化的重要指标。本研究以不同初始水分(IMC)小麦和玉米种子为试材,研究了不同贮藏条件下的吸湿解吸规律,并建模验证。结果表明,玉米种子在8.0%IMC、15℃、相对湿度(RH)<18.8%, 25°C或40℃和RH<48.1%条件下; 以及在13.5%IMC或18.0%IMC、15°C、25°C或40℃、RH<48.1%条件下呈解吸变化; 而在其他条件下均呈吸湿变化。小麦种子在贮温15、25和40℃时,8.0%IMC在RH≤18.8%、18.0%IMC在RH≤48.1%时解吸,其他条件下吸湿; 13.5%IMC在15℃和RH<48.1%以及25、40℃和RH<18.8%时解吸,其他条件下吸湿。小麦种子在15℃和RH=53.0%、25℃和RH=48.0%以及40℃和RH=43.0%时的安全水分(SWC)依次为13%、11%和9%; 玉米种子在15℃和RH=55.0%、25℃和RH=50.0%以及40℃和RH=40.0%时,其SWC依次为14%、12%和9%。小麦种子EMC在15℃和RH>50.0%、25℃和RH>50.0%、40℃和RH>48.0%时超过其对应条件下的SWC; 玉米种子EMC在15℃和RH>50.0%、25℃和RH>47.0%以及40℃和RH>47.0%时超过其对应条件下的SWC。玉米郑单958的平衡时间(d)与IMC(x)、RH(y)和温度(z)的预测模型为d = 35.34 + 4.32x - 0.28y - 0.35z - 0.031xy - 0.012xz - 0.0011yz + 0.003y²,农大108为d = 39.76 + 2.35x - 0.39y - 0.27z - 0.022xy - 0.014xz - 0.0057yz + 0.008y²,小麦山农15为d = 25.69 + 7.65x - 0.27y - 0.89z - 0.12xy - 0.07xz - 0.007yz + 0.006y²+ 0.04z²,泰农18为d = 46.67 + 0.39x - 0.28y - 1.72z - 0.006yz + 0.006y²+ 0.017z²。模型经验证,预测性良好。     

Comparison of rye,triticale, durum wheat and bread wheat genotypes for Fusarium head blight resistance and deoxynivalenol contamination

Small-grain winter cereal crops can be infected with Fusarium head blight (FHB) leading to mycotoxin contamination and reduction in grain weight and quality. Although a number of studies have investigated the genetic variation of genotypes within each small-grain cereal, a systematic comparison of the winter crops rye, triticale, durum and bread wheat for their FHB resistance, Fusarium-damaged kernels (FDK) and deoxynivalenol (DON) contamination across species is still missing. We have therefore evaluated twelve genotypes each of four crops widely varying in their FHB resistance under artificial infection with one DON-producing F. culmorum isolate at constant spore concentrations and additionally at crop-specific concentrations in two environments. Rye and triticale were the most resistant crops to FHB followed by bread and durum wheat at constant and crop-specific spore concentrations. On average, rye accumulated the lowest amount of DON (10.08 mg/kg) in the grains, followed by triticale (15.18 mg/kg) and bread wheat (16.59 mg/kg), while durum wheat had the highest amount (30.68 mg/kg). Genotypic variances within crops were significant (p ≤ .001) in most instances. These results underline the differing importance of breeding for FHB resistance in the different crops.     

Validation of two major quantitative trait loci for fusarium head blight resistance in Chinese wheat line W14

Identity of quantitative trait loci (QTL) governing resistance to fusarium head blight (FHB) initial infection (type I), spread (type II), kernel infection, and deoxynivalenol (DON) accumulation was characterized in Chinese wheat line W14. Ninety‐six double‐haploid lines derived from a cross of W14 × ’Pion2684’ were evaluated for FHB resistance in two greenhouse and one field experiment. Two known major QTL were validated on chromosomes 3BS and 5AS in W14 using the composite interval mapping method. The 3BS QTL had a larger effect on resistance than the 5AS QTL in the greenhouse experiments, whereas, the 5AS QTL had a larger effect in the field experiment. These two QTL together explained 33%, 35%, and 31% of the total phenotypic variation for disease spread, kernel infection, and DON concentration in the greenhouse experiments, respectively. In the field experiment, the two QTL explained 34% and 26% of the total phenotypic variation for FHB incidence and severity, respectively. W14 has both QTL, which confer reduced initial infection, disease spread, kernel infection, and DON accumulation. Therefore, marker‐assisted selection (MAS) for both QTL should be implemented in incorporating W14 resistance into adapted backgrounds. Flanking markers Xbarc133 and Xgwm493 on 3BS and Xbarc117 and Xbarc56 on 5AS are suggested for MAS.