猪伪狂犬病的流行病学、临床症状及防控措施

猪伪狂犬病由伪狂犬病毒引起,临床上以妊娠母猪流产、产死胎,新生仔猪出现共济失调、神经症状,并造成仔猪大量死亡为特征.自伪狂犬病毒毒株变异以来,病猪数量不断增加,严重威胁了养猪业健康发展,并造成巨大的经济损失.文章将从流行病学、临床症状、病理变化、鉴别诊断、防控措施等几个方面对猪伪狂犬病进行概述,希望能够对猪伪狂犬病的防...     

Anatid herpesvirus 1 CH virulent strain induces syncytium and apoptosis in duck embryo fibroblast cultures

Anatid herpesvirus 1 (AHV-1) CH virulent strain was first isolated from an infected duck and it was found that this virus strain could induce cytopathic effect (CPE) in duck embryo fibroblast (DEF). Following AHV-1 infection, DEF showed morphological changes such as cell rounding, improved refractivity and detachment from the culture surface. However, its pathological characteristics were not adequately known. Related studies were performed and the results showed that syncytium formation could be observed as the other type of CPE in AHV-1 infection. Hematoxylin-eosin staining and 4’, 6-diamidino-2-phenylindole (DAPI) staining of infected DEF were each used to visualize the shape and distribution of chromatin within nuclei and nuclear fragmentation was observed. Chromatin condensation and margination, as well as formation of apoptotic bodies were observed by transmission electron microscopy (TEM). DNA ladder formation was detected in AHV-1 infected cells and apoptosis of the infected DEF was also detected by flow cytometry analysis of Annexin V-FITC/PI staining method. Therefore, it was suggested that AHV-1 virulent strain can induce syncytium and apoptosis in DEF. Syncytium formation and apoptosis observed in this study may contribute to the elucidation of AHV-1 pathogenesis.     

我国出口观赏鸟新城疫病毒血清抗体的监测

2001年月11月-2002年12月间，用血凝抑制试验(HI)对28种出口观赏鸟的600份血清进行了NDV血清抗体监测。结果：阳性抗体1：2滴度的检出率为69．8％、1：4的为15．3％、1：8(含1：8以上)的为4．8％；冬春两季的检出率比夏秋两季高。被检雀形目的10个科28种观赏鸟中全部检出不同程度的NDV血清阳性抗体，抗体滴度在1：4以上的有9个科，分别是雀科、梅花雀科、绣眼科、鸫亚科、鹎科、巫鸟科、书眉画科和百灵科，其中以梅花雀科和百灵科的检出率最高。     

Inconspicuous restraint of rice seedling growth by root-infecting fungi in soil of a rice paddy field

 Rice seedling growth, estimated by plant height and root development and discoloration, was better in pasteurized soil than in unpasteurized soil obtained from a flooded rice field. Rice seedlings also grew better in sterilized soil modified by adding roots harvested from the pasteurized soil than in soil modified by adding roots harvested from the unpasteurized soil. The results demonstrate that seedling growth in the rice field soil was inhibited by soil microorganisms, even though no typical symptoms such as seedling blight or damping-off appeared. Pythium aristosporum is suggested to be involved in the inhibition. Thus, it appears that inconspicuous restraint of rice seedling growth could occur in soils of rice paddy fields. Received: May 20, 2002 / Accepted: October 16, 2002 Acknowledgments The authors thank Dr. T. Ichitani, former professor at Osaka Prefectural University, for providing an isolate of Pythium aristosporum for comparison, and Mr. Mitsuaki Sato of Akita Prefectural College of Agriculture for technical assistance.     

基于SRAP标记的黄瓜霜霉菌遗传多样性分析

本研究对来自黑龙江、辽宁、河北、山东、江苏5个省12个黄瓜主产区的77个黄瓜霜霉菌菌株,采用SRAP分子标记进行了遗传多样性分析。从35对SRAP引物中筛选出10对引物,共产生9 554条扩增条带,其中9 132条表现多态性,占95.6%。基于SRAP分子标记,77个黄瓜霜霉菌菌株的遗传距离为0.60~1.00,表明黄瓜霜霉菌具有丰富的遗传多样性。通过聚类分析,77个黄瓜霜霉菌菌株聚类为8个类群,并且来自相同地区的菌株大多数聚集于同一类群中,表明黄瓜霜霉菌群体的遗传多样性与其地理来源密切相关。     

小耳花猪蛔虫ITS及5.8S rDNA序列扩增与分析

以分离自小耳花猪消化道内的蛔虫为研究对象,提取虫体的DNA片断,然后用引物对核糖体DNA(rDNA)的内转录间隔区ITS-1、ITS-2及5.8S序列进行PCR扩增。结果显示,目的片段ITS总长为1441 bp,2个不同样品之间的I TS序列没有差异。通过BLAST检索,与相关蛔虫I TS序列进行比较,发现与拜林蛔线虫(Bayl i sascari s t ransfuga)、猪蛔虫(Ascari s suum)和人蛔虫(Ascari s l umbri coi des)的ITS序列相似性分别为88%、98%和86%,与其他蛔虫的相似性均小于90%。     

外引内研 创新发展中国养猪业——国家级重点种畜企业北京养猪育种中心

2004年末,我国生猪存栏4.7亿头,占世界总存栏9.5亿头的49%;出栏商品猪6.2亿头,占世界出栏商品猪12.78亿头的49.5%,猪肉产量4775万t,占世界猪肉产量10039万t的47.5%,而且,猪肉产量占全国肉类总产量的65.7%。数字表明,中国是世界名副其实的养猪和猪肉消费大国。     

水杨酸对湖北海棠活性氧代谢及超微弱发光的影响

 以50 μg·mL ^{- 1}水杨酸( SA) 喷施湖北海棠(Malus hupehensis Rehd. ) 幼苗, 结果显示: 超氧阴离子O^·₂ 的产生速率在处理后12～48 h明显高于对照, 而在72 h以后明显低于对照; H₂O₂ 含量在水杨酸处理后, 始终高于对照, 并在处理后第12和48小时出现两次峰值。POD活性在处理12 h后逐渐增加,SOD活性则在处理48 h后才有显著的增加, 而CAT在处理后24 h内活性高于对照, 48 h后明显低于对照。SA还明显促进了脂过氧化产物丙二醛(MDA) 的产生, 也明显促进了叶片的超微弱发光, 超微弱发光值在处理后的120 h内始终高于对照, 但在整个试验过程中超微弱发光的变化趋势与H₂O₂ 含量及O^·₂ 的产生速率的变化趋势明显不同。     

绿色管理在园林绿化产业中的运用

从绿色管理的概念出发,在研究园林绿化产业巨大的环境保护与生态效益的基础之上,探讨了将绿色管理思想运用到园林绿化产业中,并从园林绿化设计、施工、养护、废弃物处理4个环节具体分析了绿色管理在园林绿化产业的运用.     

对森林生态共享数据问题的初探

共享数据可以为我国经济社会可持续发展指标研究提供丰富的支撑。可持续发展指标的系统调查已经成为各级行政主管部门的经常性工作,数据的获得成为很容易的事情,并且形成惯例成为数字化产品序列,使指标的实施有了可操作的定量化方法。