建兰花叶病毒广东分离物的全基因组序列分析

【目的】建兰花叶病毒(Cymbidium mosaic virus,CymMV)是最主要的兰花病毒病原之一,其广泛传播对兰花产业发展造成严重威胁。探究CymMV遗传信息和进化,为广东省兰花病毒病的监测预警和兰花抗病毒病基因工程提供重要科学依据。【方法】对采自广州地区的墨兰疑似病毒病叶片进行CymMV的RT-PCR及DA-SELISA检测鉴定,利用相关分子生物学软件对CymMV分离物进行基因组序列组装、注释、系统进化及选择压力分析。【结果】首次在广东省发现2个CymMV分离物GZV013和ZC-29,基因组全长均为6227 nt,编码5个功能蛋白;GZV013与台湾分离物M2的核苷酸序列一致性为97.03%;ZC29与南京分离物NJ-1的核苷酸序列一致性为97.11%;CymMV各分离物的全基因组序列一致性为86.85%～98.31%,且多样性种群的分化与寄主种类和地理隔离关系密切;CymMV基因组每个区域均受到负选择的影响,并符合中性进化模型;编码RdRp、TGB1和TGB2的基因在基因组中变异率最高。【结论】GZV013与台湾分离物M2的亲缘关系最近,ZC29与南京分离物NJ-1的亲...     

Fluorescence localization of epidermal cathepsins L and B in the Japanese eel

Histochemical localization of proteolytic activities in the dorsal epidermis of Japanese eel was demonstrated by fluorescent microscopy utilizing 4-methoxy-2-naphthylamide (4M$\beta$NA) derivatives as substrates and 5-nitrosalicylaldehyde as a trapping agent. Carbobenzoxy-L-phenylalanyl-L-arginyl-4M$\beta$NA (Cbz-Phe-Arg-4M$\beta$NA) and Cbz-Arg-Arg-4M$\beta$NA were used for direct detection of cathepsins L and B activities, respectively, in fresh frozen sections and unfixed cells of the eel epidermis. The fluorescing areas, where Cbz-Phe-Arg-4M$\beta$NA was hydrolyzed by cathepsin L, were shown in mucus secretory cells and club cells and broadly around skin surface. The fluorescing areas due to Cbz-Arg-Arg-4M$\beta$NA hydrolysis by cathepsin B were localized similarly in these tissues. The fluorescing intensity for both catheptic activities in mucus secretory cells was higher than that in club cells, where small fluorescing granules were distributed. These results indicate that eel cathepsins L and B are stored in epidermal secretory cells at different levels and probably serve as defense factors before or after secretion by these cells. Abbreviations: Cbz – carbobenzoxy; 4M$\beta$NA – 4-methoxy-2-naphthylamide; NSA – 5-nitrosalicylaldehyde.     

Production of polyclonal antiserum against recombinant VP28 protein and its application for the detection of white spot syndrome virus in crustaceans

The VP28 gene of white spot syndrome virus (WSSV) was cloned into pRSET B expression vector. The VP28 protein was expressed as a protein with a 6-histidine taq in Escherichia coli GJ1158 with NaCl induction. Antiserum was raised against this recombinant-VP28 protein in rabbits and it recognized VP28 protein in naturally and experimentally WSSV-infected shrimp, marine crabs, freshwater prawns and freshwater crabs. The antiserum did not recognize any of the other known WSSV structural proteins. Various organs such as eyestalks, head muscle, gill tissue, heart tissue, haemolymph, tail tissue and appendages were found to be good materials for detection of WSSV using the antiserum and detection of WSSV was successful in experimentally infected Penaeus monodon and P. indicus at 12 and 24 h post-infection (p.i.), respectively. The antiserum was capable of detecting WSSV in 5 ng of total haemolymph protein from WSSV-infected shrimp.     

洋葱提取物抗氧化作用的研究

绿色饲料添加剂是当前研究的方向,本实验以红皮洋葱为原料,研究其抗氧化作用。用95%乙醇作溶剂,通过微波辅助法提取洋葱精油,料液比为1∶5,微波功率160W,微波时间160s,微波处理之后浸泡2h,浸泡温度55℃,抽滤后减压旋转蒸发除去溶剂得洋葱精油。然后将其加入猪油和花生油中,添加浓度分别为0、0.07%、0.1%、0.2%和对照组0.05%的BHT(二叔丁基羟基甲苯)。采用烘箱贮藏法,以过氧化值(POV)和酸价(AV)为指标研究其对猪油和花生油的抗氧化作用。结果表明:洋葱提取物对猪油和花生油有一定的抗氧化作用,且具有剂量关系。     

白斑综合征病毒环介导等温扩增快速检测方法的建立

根据对虾白斑综合征病毒(WSSV)囊膜蛋白VP28基因保守序列,利用Primer Explorerv 4.0软件设计了4条引物,建立了白斑综合征病毒环介导等温扩增快速检测方法,对反应温度和反应时间等参数进行了优化,同时将建立的LAMP检测方法与巢式PCR进行了比较分析。结果表明,LAMP最适反应在64℃恒温条件60min内完成,凝胶电泳呈现梯型条带;反应体系中添加SYBR Green I荧光染料后,绿色的阳性结果明显区别于橙色阴性结果。LAMP方法的最低检出限为100拷贝/μL,灵敏度较巢式PCR高100倍,而且LAMP方法在1h内即可完成检测,操作简单,无需复杂仪器,肉眼可直接观察检测结果。用建立的LAMP方法对临床发病南美白对虾样品进行了检测,结果表明,LAMP方法适合对虾白斑综合征病毒的现场快速检测。     

我国食品中农药残留研究进展

随着人们安全健康意识的提高,食品中农药残留问题更加受到重视。为此,对样品预处理研究进展及农药残留快速检测技术研究进展进行综述,并简单介绍各种方法的优缺点。     

基于改进Hough变换的农田作物行快速检测算法

选取苗期农田作为研究对象,采集了包含行栽作物和土壤背景的农田图像,针对现有作物行定位方法易受外界干扰和处理速度较慢的不足,提出将投影法和直接Hough变换法相结合检测作物行的算法.采用2G-R-B 法和OTSU法将图像二值化,通过快速中值滤波算法去除噪声,再利用垂直直方图投影将图像进行水平条划分获取作物垄平均定位点,最后通过Hough变换检测垄定位点,得到作物行中心线.试验结果表明:基于垂直直方图投影的Hough变换检测作物行中心线的算法在保证高定位精度的同时,算法处理速度比直接Hough变换检测法提高了3倍,得到的定位基准线能代表作物行走向.     

采用施奈德重合器实现馈线自动化的实践研究

针对基于传统重合器的馈线自动化原理及存在问题,提出基于施奈德重合器的馈线自动化方案。以大连庄河炮台变电所石山线-龙王庙变电所水泥线为例,分析施奈德重合器的馈线自动化工作原理,指出该馈线自动化系统在实践中的优点和不足。     

基于阵列芯片现场高灵敏同步快速检测粮油中氨基甲酸酯类农药残留混合污染

The quality and safety of agricultural products is the technique focus of the strategy of rural vitaliza⁃tion. Carbamate pesticide residues are seriously threatening the safety of agricultural product and human life and health. Nowadays, the common detection methods are instrument-based for carbamate pesticide residue, which dis⁃ satisfy the request of an on-site rapid, sensitive and simultaneous detection for multiple carbamate pesticide resi⁃ dues. Based on the home-made monoclonal antibodies against carbofuran and carbaryl respectivity, a microarray for rapid and simultaneous detection of multiple carbamate pesticide residues was developed within 30 min. Under the optimized conditions, the limits of detection（LODs）were found to be 0.11 and 0.09 ng/g, while the linear ranges were 0.33-3000 and 0.18-1500 ng/g for carbofuran and carbaryl respectively. By using spiked peanut samples, it recorded recoveries of 88.4%-98.3%, 90.1%-118.8% for carbofuran and carbaryl respectively. The RSD of intraarray were found at 9.0%, 3.5%, while the RSD of inter-array were recorded at 12.3%, 16.3% respectively. The de⁃ tection results of the microarray were highly consistent with that of HPLC-MS/MS. This proposed microarray provid⁃ ed an on-site high-sensitivity, simultaneous and rapid detection of carbofuran and carbaryl, and could be widely used in the fields of agricultural product quality safety, food safety and environmental monitoring.     

槟榔黄化病病原及检测方法研究进展

黄化病是一种严重威胁槟榔生产种植的毁灭性传染性病害,目前主要在印度和我国槟榔主产区发生。本文从非生物与生物因素两方面对槟榔黄化病病原认识过程及检测方法进行详细的综述。