水稻高产优质高效栽培的基础生理研究

本文对双季稻高产优质高效栽培途径与传统栽培法的生理基础进行了比较研究。结果表明,采用“双高一优”法栽培,水稻根系特别发达,对氮、磷、钾的吸收能力及根系过氧化物酶活力均明显优于对照;功能叶的碳氮同化协调,呼吸消耗少,谷粒灌浆启动快,速率大;尤以以下三方面的结果更具有意义。(1) 水稻每克鲜根的氧化力低于对照17.5%—36.1%。(2) 叶片的叶绿素b含量及叶绿素溶液在430nm附近的O.D值分别比对照高49%—68%,67%—106%,剑叶透光率较对照低22.2%。(3) 功能叶及根系的硝酸还原酶活力比对照低,表现出与高产耐肥品种一样的生理特性。此外,本文还对根系活力及其与土壤环境的关系,作物根系及田间杂草对改良土壤、提高地力的作用,提出了新的看法。     

复合RT-PCR快速鉴别鹅副粘病毒与鸡新城疫病毒

对新近分离的鹅副粘病毒SF02株通过自行设计的3条引物建立了复合RT-PCR方法。该方法对鹅源副粘病毒SF02株和GPV2株均可检测到215bp和401bp2条带，对12株(其中7株参考株，5株野毒)鸡源新城疫、2株鸽源新城疫、1株鸭源新城疫病毒的检测只出现1条401bp带，与预期的大小一致，对H5、H9亚型禽流感病毒、鸭病毒性肝炎病毒、传染性支气管炎病毒、SPF鸡胚尿囊液均未检测到特异性条带。     

鸡传染性支气管炎病毒N基因片段的RT-PCR扩增及限制性内切酶分析

根据鸡传染性支气管炎病毒 (IBV)的已报道基因序列设计了 1对可扩增 N基因片段的引物 ,并得到了预期的 438bp扩增产物 ;将目的条带纯化并回收后 ,克隆到 PMD18- T质粒载体中 ,对插入片段进行序列测定 ,并与已发表的 IBV N基因序列进行了比较 ,证实扩增和克隆的产物是正确的 ;根据扩增的 N基因的序列 ,选择了 Bst X 酶对 IBV进行分析 ,发现 M41和澳大利亚 T株 Bst X 酶切图谱存在明显的差异 ,从而建立了一种新的鉴定 IBV病毒的方法。     

Rapid diagnosis of duck plagues virus infection by loop-mediated isothermal amplification

Duck virus enteritis is a serious disease among farmed and free-living ducks (Anatidae) and a constant threat to the commercial duck industry in China. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed to rapidly detect and diagnose duck plague virus (DPV) in both farmed and wild waterfowl, and compared with polymerase chain reaction (PCR) method and real-time PCR method in accuracy, sensitivity and specificity. A set of four specific primers was successfully designed to recognize six distinct genomic sequences of UL6 protein from DPV, including one forward inner primer, one back inner primer and two outer primers. The optimum reaction temperature and time were verified to be 61.5 °C and 60 min, respectively. Comparative experiments showed that LAMP assay was a simple, rapid, accurate, sensitive and specific method for detecting DPV, and was superior to PCR assay in sensitivity and specificity for DNA amplification. In addition, challenge tests indicated the newly developed LAMP method was more sensitive for the diagnosis of DPV infection than virus isolation and PCR. LAMP assay would be a good alternative method for on-farm disease diagnosis.     

Koi herpesvirus epizootic in cultured carp and koi, Cyprinus carpio L., in Taiwan

Koi herpesvirus (KHV) poses a significant threat to cultured koi and common carp, both Cyprinus carpio L. Since the first reported case in Israel in 1998, KHV has rapidly spread worldwide. This study investigates the spread of KHV to Taiwan by collecting 49 cases of suspected common carp and koi infections from 2003 to 2005 for analysis. Clinical signs included lethargy, anorexia, increased respiratory movements and uncoordinated swimming. Hyperaemia, haemorrhage on body surface and necrotic gill filaments were recorded. Gill epithelial hyperplasia, necrosis and eosinophilic intranuclear inclusion bodies were observed by histological examination, while virions were detected using transmission electron microscopy. By detecting the presence of the KHV thymidine kinase (TK) gene and the KHV 9/5 gene using polymerase chain reaction (PCR), 37 cases were identified as KHV-positive, and the cumulative mortality of infected fish was 70-100%. Positive cases showed identical sequences for the genes analysed, implying that they were of the same origin. For the KHV 9/5 gene sequence, these cases exhibited 100% identity with the Japanese strain (TUMST1, accession number AP008984) and 99% identity with the Israeli (KHV-I, DQ177346) and US (KHV-U, DQ657948) strains. Additionally, a loop-mediated isothermal amplification (LAMP) assay was performed and found to be more sensitive than PCR tests, suggesting its potential use as a rapid diagnostic method for KHV. This is the first epidemiological study of KHV infection in cultured common carp and koi in Taiwan.     

鲍疱疹病毒原位LAMP检测方法的建立与初步应用

为精确定位鲍疱疹病毒(HaHV-1)在宿主不同组织器官中的分布,明确HaHV-1的组织亲嗜性和侵染进程,实验基于环介导等温扩增技术(LAMP)和原位杂交技术建立了HaHV-1的原位LAMP检测方法。利用该方法研究了HaHV-1人工感染实验不同时间节点,病毒在杂色鲍主要器官的分布规律和组织亲嗜性。并对已报道的HaHV-1 LAMP扩增引物进行优化,实现对载玻片上原位固定靶组织内病毒DNA的稳定、特异扩增,筛选最佳显色时间等原位杂交反应条件,最后通过免疫酶标技术分析HaHV-1在组织样本内的分布情况。结果显示,HaHV-1原位LAMP检测方法最适显色时间为60 min。利用该方法对攻毒后24、36、48、60和72 h,HaHV-1在杂色鲍外套膜、鳃、肝胰腺和腹足神经节4种样本的组织分布情况进行检测和分析。病毒阳性信号最早于36 h出现在腹足神经节,48 h在部分外套膜样本中观察到病毒阳性信号,分布局限于外周神经中。在感染实验后期,病毒阳性信号出现在肝胰腺结缔组织中。病毒阳性信号出现的部位常有大量细胞渗出和浸润,渗出的细胞中可见被病毒感染的血淋巴细胞。本研究建立的HaHV-1原位LAMP检...     

猪繁殖—呼吸道综合征病毒（PRRSV）CH—1a株基因型鉴定

根据猪繁殖－呼吸道综合征病毒（ＰＲＲＳＶ）美洲型毒株和欧洲型毒株的基因组序列设计合成了２对引物,即１００８ＰＳ／１００９ＰＲ和１０１０ＰＬＳ／１０１１ＰＬＲ。我国分离的ＣＨ－１ａ株用这２对引物均能扩增出与预期大小相符的ＲＴ－ＰＣＲ产物,分别与美洲型代表株（ＶＲ－２３３２）的ＲＴ－ＰＣＲ产物大小相当。特异性试验表明,这２对引物均不能扩增其他常见的繁殖障碍相关病毒的ＲＮＡ或ＤＮＡ以及未感染的ＭＡＲＣ－１４５细胞ＲＮＡ。间接免疫荧光试验也证明,ＣＨ－１ａ株与ＰＲＲＳＶ核衣壳蛋白特异性单克隆抗体以及美洲型毒株抗血清均呈阳性反应。因此初步证实ＣＨ－１ａ株为美洲型ＰＲＲＳＶ。     

非洲猪瘟病毒环介导等温扩增快速检测方法的建立

本试验利用环介导等温扩增技术（LAMP）建立了一种快速高效检测非洲猪瘟病毒的方法。整个反应在水浴锅中恒温进行,不需要其他昂贵仪器,30 min即可得到阳性结果,灵敏度是OIE标准PCR方法的100倍,并且与其他常见猪DNA病毒无交叉反应。该方法非常适合在野外现场或缺乏试验条件的边远地区检测非洲猪瘟病毒。     

核酸扩增新技术

核酸扩增技术广泛应用于生命科学及其相关的各个领域,对生命科学的发展发挥着重要的作用。论文对核酸扩增的一些新技术进行综述,包括环介导等温扩增(LAMP)技术,赖解旋酶恒温基因扩增(HDA)技术,固相PCR技术,指数富集配体的系统进化(SELEX)技术,SOLEXA高通量测序技术。这些新技术具有重要的应用价值,随着技术的不断完善,将会有广阔的应用前景。     

猪细环病毒LAMP检测方法的建立

为建立一种特异和快速的猪细环病毒(TTSuV)检测方法,本研究通过比对TTSuV的全基因序列,选择其保守区域,设计了针对TTSuV检测的LAMP引物,利用LAMP Real Time Turbidimeter LA-320仪对反应体系及条件进行了优化,建立TTSuV环介导等温扩增的检测方法.结果表明:该方法最佳反应条件为64℃恒温50 min,病毒的最低检出限为5.5拷贝/μL,并且与其他相关传染病无交叉反应.临床样品检测结果显示,猪繁殖与呼吸综合征病毒-(PRRSV)和2型猪圆环病毒(PCV2)阳性的样品中TTSuV呈高阳性率,分别为92％和87.3％,显著高于非PRRSV和PCV2阳性的猪群.该方法的建立为快速及特异性的检测猪TTSuV提供了有效的方法.