文章以江苏省农业科学院为例,结合农业科研试验基地规范化管理的实践,归纳总结出规范化管理的经验和做法,分析了规范化管理中存在的问题,并从思想、制度、管理等方面提出了加强农业科研试验基地规范化管理的建议,以期不断提高基地的管理服务效能,为创建规范有序的现代化农业科研试验基地提供管理思路.

Staphylococcus aureus is a common food-borne pathogenic microorganism that poses a serious threat to food quality and safety, and can do harm to human health. In the past, researchers relied on antibiotics to control Staphylococcus aureus, though very effective, yet it was also worrying in the aspect of bio-safety. In fact, anti-idiotypic antibody (Anti-Id) shows its potential to mimic some of the structural and biological functions of antigens. Therefore, in this study, based on Anti-Id theory and technology, we expect to obtain the vancomycin Anti-Id which can mimic vancomycin against Staphylococcus aureus from a human phage display domain antibody library. After four rounds of bio-panning, a total of 18 positive Anti-Ids were obtained. Among them, two Anti-Ids named Anti-Id-2C12 and Anti-Id-1F5 were identified as “β” type Anti-Ids, and afterwards they were selected for gene cloning and protein expression in prokaryotic expression system. As a result, a concentration of purified proteins with 568.6 μg/mL (Anti-Id-2C12) and 602.3 μg/mL (Anti-Id-1F5) were successfully obtained, and their minimum inhibitory concentration (MIC) values for Staphylococcus aureus were 125 and 200 μg/mL, respectively. As they are human heavy-chain domain antibodies, which were theoretically harmless to humans, they have the potential application value as preservatives in food and edible agricultural products.

Dihydroxyacid dehydratase (DHAD), encoded by ILV3, catalyses the third step in the biosynthetic pathway of branched-chain amino acids (BCAAs), which include isoleucine (Ile), leucine (Leu), and valine (Val). Enzymes involved in BCAA biosynthesis exist in bacteria, plants, and fungi but not in mammals and are therefore attractive targets for antimicrobial or herbicide development. In this study, three paralogous ILV3 genes (FgILV3A, FgILV3B, and FgILV3C) were identified in the genome of Fusarium graminearum, the causal agent of Fusarium head blight (FHB). Deletion of FgILV3A alone or combined with FgILV3B or FgILV3C indicated an important role for FgILV3A in BCAA biosynthesis. FgILV3A deletion mutants lost the ability to grow on medium lacking amino acids. Exogenous supplementation of 1 mM Ile and Val rescued the auxotrophy of ΔFgIlv3A, though 5 mM was required to recover the growth defects in ΔFgIlv3AB and ΔFgIlv3AC strains, indicating that FgIlv3b and FgIlv3c exhibit redundant but accessory roles with FgIlv3a in BCAA biosynthesis. The auxotrophy of ΔFgIlv3A resulted in pleiotropic defects in aerial hyphal growth, in conidial formation and germination, and in aurofusarin accumulation. In addition, the mutants showed reduced virulence and deoxynivalenol production. Overall, our study demonstrates that FgIlv3a is crucial for BCAA biosynthesis in F. graminearum and a candidate fungicide target for FHB management.

研究NaOH浓度、液料比、乙酸乙酯萃取时间和萃取次数对小麦籽粒中酚酸提取量的影响,并优化提取条件;运用高效液相色谱-质谱联用法分析不同产区主栽小麦品种差异对酚酸含量的影响.结果表明:NaOH浓度、液料比、乙酸乙酯萃取时间和萃取次数对小麦籽粒中酚酸提取量影响显著,经响应面优化获得小麦籽粒中酚酸提取条件为:NaOH溶液浓度1.56 mol/L、液料比15.53:1(mL/g)、萃取时间17.33 min、萃取2次.在此提取条件下,小麦籽粒中酚酸提取量达到1055.99 mg/kg.小麦中主要有9种酚酸,分别为没食子酸、原儿茶酸、4-羟基苯甲酸、香草酸、咖啡酸、丁香酸、p-香豆酸、芥子酸和阿魏酸,其中阿魏酸为主要酚酸,占总酚酸的73.07％～89.01％.江淮麦区宁麦14中总酚酸含量最高,达1001.12 mg/kg,与该产区的保麦6号、淮麦33有显著性差异;黄淮麦区的新麦26中总酚酸含量最高,为1016.03 mg/kg,与该产区的矮抗58、百农207有显著性差异.由此可见,不同产区主栽小麦品种的差异对酚酸含量的影响极大.

近年来,百姓生活水平不断提高,食用植物油的使用量逐年增加[1].食用植物油在日常环境条件下由于氧化会发生变质.为了阻止或延缓食用植物油的氧化,食品生产企业会人为添加抗氧化剂,延长食用植物油的保质期.目前,使用最为广泛的人工合成抗氧化剂为特丁基对苯二酚(TBHQ)、叔丁基羟基茴 香 醚 (BHA )和 2,6-二 叔 丁 基-4-甲 基 苯 酚(BHT),这 3 种抗氧化剂都具有一定的毒性,过量食用会对人体健康造成损害[2-4],我国在 国 家 标 准GB 2760-2014 [5]中规定 TBHQ、BHA 和 BHT 在食用植物 油 中 的 最 大 使 用 量 均 不 能 超 过 0.2 g ?kg-1 .因此,准确测定食用植物油中 TBHQ、BHA和 BHT 的含量,对保障百姓餐桌安全具有十分重要的意义.

Deoxynivalenol (DON), a notorious mycotoxin mainly found in Fusarium-contaminated crops, causes great loss in livestock farming and severe safety risks to human health. Here we report the isolation of a Gram-negative bacterial strain with effective biodegrading abilities on DON and its derivatives including 3-acetyl-DON and 15-acetyl-DON. The strain was identified as Devosia insulae A16 on the basis of morphological and physiological characteristics and 16S rRNA-based phylogenetic analysis. D. insulae A16 was able to degrade 88% of 20 mg/l DON within 48 h under aerobic conditions at 35 degrees C and neutral pH. The major degradation product of DON and its derivatives was 3-keto-DON by the oxidation of the hydroxyl group at C-3. Both 3-acetyl-DON and 15-acetyl-DON underwent a deacetylation reaction to generate DON prior to the degradation to 3-keto-DON. The results provide the potential use of D. insulae A16 as a biodegradation agent to control DON contamination in cereals.

Deoxynivalenol (DON) is a major mycotoxin found in wheat infected withFusarium fungi. DON can be converted by plant detoxification into a form of ‘masked mycotoxin’ termed deoxynivalenol-3-glucoside (DON-3G). To recommend appropriate wheat cultivars for planting in order to reduce DON contamination in Jiangsu province, where a traditionalFusarium head blight (FHB) epidemic area is located in the lower reaches of Yangtze-Huaihe, we evaluated the capacity of various wheat cultivars to transform DON into DON-3G under field conditions. We collected and evaluated samples from 11 major wheat cultivars grown in 63 experimental stations in Jiangsu province in 2015 and 2016. All samples were contaminated with DON, with an average concentration of 2,087±112 and 2,601±126 µg/kg in 2015 and 2016, respectively. DON-3G was detected in 425 (96%) and 405 (97%) samples in 2015 and 2016, with an average concentration of 545±28 and 819±44 µg/kg, respectively. The DON-3G/DON ratio ranged from 5 to 84% (average, 30%) in 2015 and from 0 to 71% (average, 31%) in 2016. DON levels were highly correlated with DON-3G concentrations (P<0.01), and the FHB resistance of the wheat cultivars was proportional to their capacity to convert DON to DON-3G. Importantly, region, cultivar, and region × cultivar interaction all significantly affected DON and DON-3G concentrations and DON-3G/DON ratios. In general, FHB-resistant cultivars, such as Sumai 188 and Ningmai 13, had lower levels of DON and DON-3G than the others. However, additional factors, including the growing region and environmental variables, were important for wheat management when other wheat cultivars were evaluated.

Zearalenone (ZEN), mainly produced by Fusarium species, is an estrogenic mycotoxin which causes reproductive disorders in livestock. In this study, we described a simple and rapid method for screening of ZEN-degrading bacteria by esterase activity assay. Soil bacteria strains were first tested for their esterase activities, then active strains were further evaluated for their ZEN-degrading potentials. A bacterial strain named Bacillus pumilus ES-21 was detected to be able to eliminate ZEN in the culture medium. ZEN degradation conditions were optimized through response surface methodology and the result showed that the degradation rate of ZEN by Bacillus pumilus ES-21 was up to 95.7% at the ZEN concentration of 17.9 g/ml within 24 h. One of the degradation product was proposed to be 1-(3,5-ihydroxypheny1)-6'-hydroxy-F-undecen-10'-one according to LC-TOF-MS/MS analysis. This study provided a strategy for the isolation of ZEN degrading microbes and a promising degrading strain. (C) 2017 Elsevier Ltd. All rights reserved.

BACKGROUND: The Fusarium graminearum species complex infects several cereals and causes the reduction of grain yield and quality. Many factors influence the extent of Fusarium infection and mycotoxin levels. Such factors include crop rotation. In the present study, we explored the effect of rice or maize as former crops on mycotoxin accumulation in wheat grains.RESULTS: More than 97% of samples were contaminated with deoxynivalenol (DON). DON concentrations in wheat grains from rice and maize rotation fields were 884.37 and 235.78 tg Zearalenone (ZEN) was detected in 45% of samples which were mainly collected from maize-wheat rotation systems. Fusarium strains were isolated and more F. graminearum sensu stricto (s. str.) isolates were cultured from wheat samples obtained from maize rotation fields. DON levels produced by Fusarium isolates from rice rotation fields were higher than those of samples from maize rotation fields.CONCLUSIONS: Rice-wheat rotation favours DON accumulation, while more ZEN contamination may occur in maize-wheat rotation models. Appropriate crop rotation may help to reduce toxin levels in wheat grains. (C) 2016 Society of Chemical Industry

The present study was performed to identify prevailing Fusarium species and the environmental factors affecting their frequencies and the contamination of grain with major mycotoxins in Jiangsu province. The precipitation levels were 184.2mm, 156.4mm, and 245.8mm in the years 2013-2015, respectively, and the temperature fluctuated by an average of 10.6±7.2°C in 2013, 10.9±7.2°C in 2014, and 10.6±6.3°C in 2015. Co-occurrence of deoxynivalenol (DON), 3-acetyldeoxynivalenol (3ADON), and 15-acetyldeoxynivalenol (15ADON) were observed in wheat. The average concentrations of DON were 879.3±1127.8, 627.8±640.5, and 1628.6±2,168.0μg/kg in 2013-2015, respectively. The average concentrations of 3ADON were 43.5±59.0, 71.2±102.5, and 33.5±111.9μg/kg in 2013-2015, respectively. We found that the average concentration of DON in wheat was positively correlated with precipitation (r=0.998, p<0.01), and 3ADON was negatively correlated with precipitation (r=-0.887, p<0.05). However, there was no correlation between precipitation and 15ADON or nivalenol (NIV). The differences in temperature were not as significant as the differences in rainfall amount over a short time period. Therefore, there were no correlations between temperature and the concentrations of trichothecenes, excluding 3ADON (r=0.996, p<0.01). Our data indicated that Fusarium asiaticum is the primary pathogenic fungus prevalent in the Fusarium head blight disease nursery. The trichothecene chemotype composition differed between Fusarium graminearum sensu stricto (s. str.) and F. asiaticum isolates. The 3ADON chemotype was found only among strains of F. asiaticum. The NIV chemotype was not observed among strains of F. graminearum, while the 15ADON chemotype represented 100% of the F. graminearum strains collected. The results of this study indicated no correlations between environmental conditions and the species or genetic chemotype composition of pathogens in Jiangsu province in 2013-2015.

Trichothecene genotype composition, mycotoxin production, genetic diversity, and population structure were analyzed, using 185 Fusarium strains collected from wheat (Triticum aestivum L.) throughout the Jiangsu province during 1976, 1983, 1998, 2006, and 2014. The results showed that 3-acetyldeoxynivalenol (3ADON) was consistently the predominant type in this region over 40 years, and the nivalenol (NIV) type has emerged since 1998. Long-term rotation of wheat and rice (Oryza sativa L.), rather than fungicide application, crop fitness, or weather conditions, might be the main cause of this phenomenon. The genetic diversity results from two toxin synthetic genes, Pks4 and Tri10, and variable number of tandem repeat (VNTR) markers revealed the largest variance within the population in 1998, which was also the year with the highest production of mycotoxins. Population differentiation analysis indicated that major temporal population comparisons from the same area were not significantly differentiated. Our results showed that dominant species could maintain genetic stability for a long time, and Pks4 would be of utility in genetic and population studies.

近年来,小麦赤霉病在我国小麦产区高频率流行,尤其在长江中下游、淮河流域以及黄淮南部,导致小麦中镰刀菌毒素严重污染,不仅影响小麦产量,还危害人畜健康.镰刀菌毒素包括脱氧雪腐镰刀菌烯醇(DON,又称呕吐毒素)、玉米赤霉烯酮(ZEN)、雪腐镰刀菌烯醇(NIV)以及伏马毒素(FB)等,可以引起动物消化、神经、免疫以及生殖系统异常,有的还具有致癌作用.本文对我国小麦镰刀菌毒素的发生情况与影响因素进行了分析,同时对镰刀菌毒素的风险评估与防控研究的迫切性进行了探讨,以期提高人们对小麦镰刀菌毒素污染的认识,保障我国小麦产业的健康发展.

研究含水量分别为11．5％、12．8％、15．7％的小麦在4℃冷库、25℃恒温室、常温库、地下仓库4种环境下储藏0～90 d镰刀菌毒素DON、NIV含量的变化情况，并对不同储存环境下小麦含水量变化情况进行分析。结果表明：90 d内，3种含水量的小麦在4℃冷库和25℃恒温室条件下，DON、NIV毒素均未发生显著变化。储存在常温库和地下仓库2种不可控环境下的3种含水量小麦在60 d后DON毒素含量降低，NIV毒素含量未发生显著变化。

A quantitative real-time PCR system for the detection of the number of Polymyxa graminis was established in this study. In the system, the standard curve showed a linear correlation between the input DNA and the CT values, with PCR efficiency of 95% and the correlation coefficient of 0. 999, and the melting curve presented a single peak, indicative of the feasibility of the system. The quantity of P. graminis in the rhizosphere soil of transgenic wheat N12-1 and its paren-tal material Yangmai158 during growth stages was detected using the system. No significant difference was detected in the quantity of P. graminis between transgenic wheat N12-1 and Yangmai158. The results suggested that the planting of trans-genic wheat N12-1 had few adverse effects on the quantity of P. graminis in rhizosphere soil.

The transgenic wheat line N12-1 containing the WYMV-Nib8 gene was obtained previously through particle bombardment, and it can effectively control the wheat yellow mosaic virus (WYMV) disease transmitted by Polymyxa graminis at turngreen stage. Due to insertion of an exogenous gene, the transcriptome of wheat may be altered and affect root exudates. Thus, it is important to investigate the potential environmental risk of transgenic wheat before commercial release because of potential undesirable ecological side effects. Our 2-year study at two different experimental locations was performed to analyze the impact of transgenic wheat N12-1 on bacterial and fungal community diversity in rhizosphere soil using polymerase chain reaction-denaturing gel gradient electrophoresis (PCR-DGGE) at four growth stages (seeding stage, turngreen stage, grain-filling stage, and maturing stage). We also explored the activities of urease, sucrase and dehydrogenase in rhizosphere soil. The results showed that there was little difference in bacterial and fungal community diversity in rhizosphere soil between N12-1 and its recipient Y158 by comparing Shannon's, Simpson's diversity index and evenness (except at one or two growth stages). Regarding enzyme activity, only one significant difference was found during the maturing stage at Xinxiang in 2011 for dehydrogenase. Significant growth stage variation was observed during 2 years at two experimental locations for both soil microbial community diversity and enzyme activity. Analysis of bands from the gel for fungal community diversity showed that the majority of fungi were uncultured. The results of this study suggested that virus-resistant transgenic wheat had no adverse impact on microbial community diversity and enzyme activity in rhizosphere soil during 2 continuous years at two different experimental locations. This study provides a theoretical basis for environmental impact monitoring of transgenic wheat when the introduced gene is derived from a virus.