陕西省小麦不同部位镰刀菌分离鉴定及毒素化学型分析

为明确陕西省小麦不同部位镰刀菌种群结构及其毒素化学型，于2022年小麦灌浆期分别从陕西省渭南市、宝鸡市、咸阳市、西安市采集小麦穗部、茎秆以及茎基部具有明显病状的样品，采用单孢分离法获得镰刀菌菌株，并使用分子生物学鉴定其种群结构及毒素化学型。结果表明，从采集的样本中共分离到156株镰刀菌菌株，其中发生在穗部的赤霉病以及发生在茎秆的秆腐病的优势病原菌均为禾谷镰刀菌（Fusarium graminearum），主要以15-ADON化学型为主；发生在茎基部的茎基腐病的优势病原菌为假禾谷镰刀菌（F.pseudograminearum），其15-ADON和3-ADON化学型占比差异不大；未检测到NIV毒素化学型的镰刀菌。以上结果说明，小麦不同部位对镰刀菌毒素化学型可能不存在选择性，小麦茎基部与穗部和茎秆的镰刀菌毒素化学型不同，原因可能是由优势病原菌不同造成的。     

AFLA-maize,a mechanistic model for Aspergillus flavus infection and aflatoxin B1 contamination in maize

A mechanistic weather-driven model was developed based on the infection cycle of Aspergillus flavus on maize to predict the risk of aflatoxin contamination in field on a daily basis from silk emergence to harvest; hourly data of temperature, relative humidity and rain were used as model input. The work was done in four steps: (i) development of the model prototype; (ii) collection of Italian field data on aflatoxin contamination in maize with related crop and weather data; (iii) development of a probability index to exceed the legal limit of 5 μg of aflatoxin B₁ per kg of unprocessed maize by combining model predictions and field data in a logistic regression; and (iv) validation with Italian data of the probability index and release of the predictive model, named AFLA-maize. Predictions of maize contamination above the threshold of 5 μg/kg in the data set used for parameterization of the regression equation were correct for 73% of field samples; 59% and 14%, respectively, were not contaminated and contaminated. In a second independent data set, 68% of samples were correctly predicted. The model AFLA-maize provides prediction of A. flavus infection and aflatoxin contamination along the growing season and at harvest. This information is useful to support decision-making for (i) crop management, (ii) harvest timing, (iii) maize lots cleaning and logistic, and (iv) maize sampling for aflatoxin analysis at consignment.     

山东省玉米真菌毒素风险排序研究

连续两年对山东省主产区的玉米进行采样和主要真菌毒素的测定,采用期望值排序法对真菌毒素进行排序。以毒性(致癌性)和毒效用以判定真菌毒素危害的严重性,用风险控制程度、检出率和残留水平判定真菌毒素风险发生的可能性。风险排序结果表明,山东省玉米生产过程中必须关注的真菌毒素为黄曲霉毒素B_1,重点关注的为黄曲霉毒素B_2、G_1,AFG_2为一般关注指标,FB_S、DON、ZEN为暂不关注指标。山东省玉米真菌毒素污染水平处于低风险水平。     

High feeding and growth rates in common octopus (Octopus vulgaris) fed formulated feeds with an improved amino acid profile and mixture of binders

Four semi‐moist formulated feeds were supplied to Octopus vulgaris subadults (664 ± 70 g; 18.4 ± 0.7°C) in two different experiments. In the experiment #1, two diets were prepared with a new mixture of binders (gelatine 150 g kg^?1, starch 100 g kg^?1 and gum 50 g kg^?1). The GEL15‐Squid and GEL15‐Hake feeds included 100 g kg^?1 freeze‐dried squid (Todarodes sagittatus) or hake (Merluccius sp.) respectively. Both feeds showed low water disintegration rates at 24 h (13.6–15.0% dry weight). The specific feeding rate was higher in animals fed GEL15‐Hake (2.7%BW day^?1), but the growth and feed efficiency were significantly better in animals fed GEL15‐Squid (1.4%BW day^?1 and 61.2% respectively; P < 0.05). The proximate composition of the digestive gland, carcass and whole animals was similar. In the experiment #2, the GEL15‐Squid amino acid profile was improved by replacing 50 g kg^?1 gelatine by 50 g kg^?1 freeze‐dried squid (GEL10‐Squid) or freeze‐dried fish (GEL10‐Fish). These feeds showed higher water disintegration rates (31.7–36.3% dry weight). The feeding rates (2.2–2.3%BW day^?1), growth (1.5%BW day^?1) and feed efficiency were similar for both diets. Total lipids were higher in the digestive gland and whole animals fed GEL10‐Fish diet (P < 0.05). Future effort could be directed towards alternative binders that allow improve amino acid balance with a minimum gelatine content or even supplementation trials including essential amino acids.     

玉米中霉菌毒素对仔猪疫苗免疫应答的影响（摘要）

[目的]研究霉变的玉米中的毒素对仔猪免疫应答的影响。[方法]使用ELISA方法测定了霉变玉米中黄曲霉毒素B1和赭曲霉毒素A的含量;将霉变玉米饲喂仔猪,并测定仔猪血清中相应的抗体效价。[结果]试验组抗体水平明显低于对照组,免疫器官的组织切片也表明霉菌毒素可以明显抑制仔猪的免疫应答反应。[结论]玉米霉菌毒素对仔猪内脏器官和免疫应答具有重要影响。     

奶牛养殖中霉菌毒素的危害及其防控方法研究进展

近年来,霉菌毒素污染饲料已经引起饲料行业的高度重视。奶牛采食被霉菌毒素污染的饲料后很容易引发各种疾病,有些霉菌毒素还会代谢进入牛奶中对人们的健康造成威胁。本文主要就霉菌毒素对奶牛的危害及其防控方法的研究进行综述,以期为生产实践中降低霉菌毒素的危害提供理论参考。     

Aflatoxin in maize,a multifaceted answer of Aspergillus flavus governed by weather,host-plant and competitor fungi

Aspergillus section Flavi is able to produce aflatoxins (AFs) in vitro down to 0.85 a_w with a potential maximum occurring between 0.95 and 0.99 a_w, while in the field AFs increased significantly with kernel humidity below 0.95 a_w. In order to clarify this apparent discrepancy, a 3-year field trial with artificial inoculation of maize ears with Aspergillus flavus strains was organised. The co-occurrence of Aspergillus section Flavi and Gibberella fujikuroi species complex (Gfsc) was observed. The incidence of A. flavus was significantly influenced by the year and negatively related to Gfsc incidence. In 2012, when the highest temperature and the lowest rain were registered, aflatoxin B₁ (AFB₁) content was the highest and a_w < 0.95 in kernels was measured early throughout the growing season. In 2013 and 2014, the temperature was lower and rain more abundant, and a_w decreased below 0.95 only close to harvest and AFB₁ contamination was limited. The possibility of describing/predicting reasonably well a_w dynamic based on temperature, (degree day) was confirmed. With a_w > 0.95, a positive correlation between AFB₁ production rate and a_w was found, but a negative correlation resulted with a_w < 0.95. Other factors than a_w play a role, but a_w = 0.95 should be considered as an indicator of suitable conditions for rapid aflatoxin accumulation.     

脱霉剂对种公猪精液品质的影响

饲料霉变及霉菌毒素严重影响饲料工业和畜牧业生产。本试验以种公猪作为试验对象,在公猪日粮中添加G1和G2脱霉剂,试验开始后每周对公猪精液品质进行品质检测,G2见效要比G1快;两种脱霉剂使用后对采精量、每次射精精子总数、精子活力均有所提高,精子畸形率也有下降。综上所述,这两种脱霉剂均可有效提高霉菌毒素引起的公猪生殖性能抑制,从而提高公猪的精液品质,G2效果要更佳。     

贮藏时间对饲用燕麦种子寄藏真菌及真菌毒素的影响

为明确贮藏时间对饲用燕麦种子中寄藏真菌和真菌毒素的影响，本研究通过平板培养法、形态学观察和rDNA-ITS序列分析法，对3个燕麦（Avena sativa）品种种子携带的真菌进行了分离鉴定；通过高效液相色谱质谱联用法对优势菌属产生的毒性较强的3种真菌毒素细交链孢酮酸（TeA）、黄曲霉毒素B₁（AFB₁）和桔青霉素（CIT）进行了检测和分析。结果表明：饲用燕麦种子的带菌量随贮藏时间的增加总体呈降低趋势。从供试材料中共检出真菌16属34种，优势属为链格孢菌属、曲霉菌属和青霉菌属；带菌种类和分离率随贮藏年限的变化差异显著，不同品种的带菌情况也差异显著；3种真菌毒素随贮藏年限的延长基本呈先升后降的趋势，贮藏年限和品种间的互作对毒素含量的影响最大。综上，贮藏时间对饲用燕麦种子的带菌情况和真菌毒素检出量影响显著。     

植物油基油墨连结料的制备

植物油基油墨连结料是以大豆油和桐油为原料,蒽醌和氧化锌为催化剂进行制备的,研究大豆油和桐油的比例、催化剂用量、反应温度、反应时间对植物油基连结料酸值和粘度的影响以及连结料性能的测试。桐油和大豆油质量比为9∶1,蒽醌和Zn O的质量比1∶1,催化剂的用量为4%,在310℃反应2 h条件下制备的植物油基油墨连结料粘度达到10.85 Pa·s,酸值为13.3 KOH mg·g-1。结果表明,以大豆油和桐油组成的混合油制备的植物油基油墨连结料能够用于油墨的生产,具有良好的油墨性能。