Monoclonal-antibody-mediated enzyme-linked immunosorbent assay for detection of reticuloendotheliosis viruses

An enzyme-linked immunosorbent assay (ELISA) is described for the detection of reticuloendotheliosis viruses (REVs). The assay uses a mixture of monoclonal antibodies (MCAs) prepared against a 62-kilodalton REV envelope glycoprotein (gp62) to capture antigen, rabbit anti-REV serum as detection antibody, and peroxidase-conjugated anti-rabbit IgG as indicator antibody. The MCAs were reactive with REV strain T, chick syncytial virus, and duck infectious anemia virus but unreactive against Marek's disease and avian leukosis viruses. The ELISA was compared with complement fixation test and REV immunofluorescent assay of infected fibroblasts, plasmas, and egg albumen from infected chickens. The lower limit of gp62 detection was about 120 ng of REV protein. Limit dilution of infectious REV was detected after 7-8 days of cultivation of infected fibroblasts.     

已知抗白粉病基因的小麦品种在贵州的表现简报

 国外对小麦抗白粉病基因的研究比较深入,已经分析了很多品种具有的抗性基因,并确知其所在位置。而且还利用了近等基因系于研究工作中。     

Protective immunity induced by a recombinant pseudorabies virus expressing the GP5 of porcine reproductive and respiratory syndrome virus in piglets

Pseudorabies virus (PRV) has been developed as a vaccine vector for expressing foreign immunogens. Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), continues to be a major problem to the pork industry worldwide. Many vaccine strategies have been developed to control the disease but most of them turn out to be unsuccessful. The objective of this research was to explore the feasibility of PRV-based vector vaccine in protection against PRRSV. A live attenuated vaccine-based PRV recombinant expressing the envelope protein GP5 of PRRSV was generated using recombinant DNA techniques. The Bartha-K61-derived recombinant virus, named rPRV-GP5, was shown to express PRRSV GP5 efficiently. Sixteen healthy piglets were assigned to one of four groups (one to four, four pigs per group). Animals in Groups 1 and 2 were each inoculated intramuscularly and intranasally with 10(7.0) PFU of rPRV-GP5 and its parent Bartha-K61, respectively; Group 3 were vaccinated intramuscularly with one-dose of PRRS inactivated vaccine; Group 4 was served as non-vaccinated control. One month later, all animals were all challenged with 10(6.5) TCID(50) of virulent PRRSV CH-1a. All animals in Groups 1 and 3 remained clinically healthy before and after challenge, with only a short period of fever (no more than 41 degrees C and 3 days), mild and gradually improving lung and kidney lesions, and short-term viremia (2 and 3 week, respectively) in spite of no detectable anti-PRRSV antibody before challenge. On the other hand, all animals in the other two groups showed evident clinical signs with higher temperatures (more than 41 degrees C) after challenge, and severe lung, kidney and spleen lesions and extended viremia (4 weeks). The results indicate that the rPRV-GP5 is safe for vaccinates and able to confer significant protection against clinical disease and reduce pathogenic lesions induced by PRRSV challenge in vaccinated pigs.     

<Emphasis Type="Italic">N</Emphasis>-acyl-homoserine lactone-mediated quorum sensing blockage,a novel strategy for attenuating pathogenicity of Gram-negative bacterial plant pathogens

Quorum sensing is a bacterial communication mechanism by which bacteria sense their own population size and couple specific gene expression to cell density. In Gram-negative bacteria, the most commonly used quorum sensing signals are N-acyl homoserine lactones (AHLs). It is now apparent that many pathogenic bacteria employ quorum sensing to control premature expression of virulence factors. This control is thought to decrease the likelihood that the plant host would detect the pathogens presence and activate its defense system. Novel strategies that target bacterial quorum sensing systems in order to control plant bacterial diseases are discussed.     

姜曲海母猪发情周期性腺激素及其子宫受体含量的变化规律

以长白猪为对照,测定了姜曲海母猪发情周期血浆中雌二醇和孕酮及其子宫受体含量。发现发情期血浆雌二醇的峰值为58.3±3.9pg/ml,与长白猪比差异不显著。间情期孕酮的最高水平和平均水平均比长白猪高(23.25±1.36对14.28±1.42ng/ml和18.56±1.42对11.76±0.57ng/ml,P<0.01)。发情期和间情期的细胞质雌二醇受体(CER)分别为 410±30.3和367±14.2fmol/mgDNA,其kd值分别为4.8±0.65和4.0±0.8nmol;细胞核雌二醇受体(NER)分别为1390±195.3和620±28.9fmol/mgDNA,其kd值为6.6±2.1和4.4±1.3nmol;细胞质孕酮受体(CPR)分别为364±56.0和147±46.0 fmol/mgDNA;细胞核孕酮受体(NPR)分别为337±51.8和184±67.0fmol/mgDNA。发情期和间情期子宫NER含量较长白猪高(P<0.05),说明此时姜曲海母猪子宫对雌二醇具有较高的敏感性。     

哈密瓜花叶病毒病的研究——Ⅰ、病原学

 1958年以来新疆哈密瓜由于花叶病毒的发生,使产量和含糖量严重降低。由病株分离出三种病毒,称谓哈密瓜病毒2、3和5。简称HMV2、HMV3和HMV5。     

大豆地膜覆盖——大豆稀、少、覆栽培法研究

我所于1985—1986年在所内外开展了大豆地膜覆盖试验——大豆稀、少、覆栽培法的研究工作。试验分为地膜覆盖和露地直播(对照,参考对照)密植栽培三个处理,供试品种为密枝1号和嫩丰11,三次重复,随机排列。研究结果表明,覆盖栽培,由于提高地温,(0—25cm平均地温比直播增温1.56—3.04℃)提前成熟9—14天。覆膜保墒节水,提高水的利用率,生育期水分生产效率比对照增加53.1—75.0％,对抗御干旱起到了卓有成效的作用。覆膜使土壤微生物数量增加,有利于养分分解,苗期的碱解氮、速效磷分别比直播增加50.0％和14.9％。为大豆生长发育提供了充足的养分。协调大豆生长发育环境中的热量、水分、养分、气体的组合,这些综合因素作用,使大豆生长发育沿着最佳的生物轨道运转。经济产量每公顷达到2630.8—4317.0kg,比露地直播增产62.4—72.7％。     

窄冠杨树品种评选及其类型划分

本文通过对１８个杨树品种无性系在９个试验点的Ｇ×Ｅ互作分析，用８个参数评价生产力，遗传稳定性和生长适应性，并经综合评定，从村冠积比（材积／冠积）方面将１８个品系划分为不同类型，为各试验区评选出了适合栽培的优良品系。     

化龙山南坡上部亚高山草地成因初探

本文从南北坡差异、人为影响、森林火灾、地形、土壤等方面研究分析了化龙山南坡上部亚高山草地的成因,结果表明,风是草地形成的主因。     

秦川牛保种情况的分析 Ⅰ群体规模、年龄结构与迁移

采用群体遗传学理论与方法研究了陕西省秦川牛场秦川牛保种群30多年来的保种情况,详细地分析了保种群的规模、年龄结构及迁移情况。研究发现,该保种群规模变化剧烈,总的来说规模偏小,尤其是公牛群远小于保种遗传学基本法则规定的最小值;畜群结构不稳定,迁入不规则,该研究结果将为今后采取适当的措施提高保种效果提供科学的参考依据。