猪流行性腹泻病毒荧光定量PCR检测方法的建立与应用     

于长青  林树伯  刘乐荣  王庆博  李继良 《北京农学院学报》2015,30(3):44-47

用RT-PCR方法扩增猪流行性腹泻病毒(PEDV)的M基因片段,并克隆到PUC-T载体中,构建含有PEDV M基因片段的重组质粒。以系列稀释后的重组质粒为模板,基于SYBR GreenⅠ进行PEDV检测的实时荧光定量PCR扩增。结果显示,扩增效率为100.4%,相邻扩增曲线之间间距均匀,所有产物的熔解曲线具有单一整齐的峰,标准曲线具有优良的线性关系,最低可准确检测520拷贝/μL的核酸模板,重复性试验的变异系数小于3%。用所建立方法对3种常见猪源RNA病毒的检测结果均为阴性,对临床样品的检出率显著(P0.05)高于常规PCR方法。研究结果表明,建立了一种灵敏度高、特异性强、重复性好的检测PEDV的SYBR GreenⅠ实时荧光定量PCR方法,可用于PEDV的定量检测和猪流行性腹泻的早期快速诊断。  相似文献   

麦后移栽棉氮素营养诊断与追肥模型     

谭京红  吴启侠  朱建强  佘子浩  柯鑫瑶  马泓雨 《新疆农业科学》2021,58(7):1225-1235

【目的】基于江汉平原麦后移栽棉花适宜氮素诊断指标建立追肥模型,为棉花氮素精准管理提供依据。【方法】于2019年采用田间小区试验,设置6个施氮量处理(0、90、180、270、360、450 kg N/hm²),分析蕾期、花铃期倒4叶叶绿素含量(SPAD值)、叶柄硝酸盐含量(NIT)及24个高光谱参数与前期施氮量的关系,研究麦后移栽棉适宜氮素营养诊断关键指标,结合氮肥效应函数建立氮素追肥模型。【结果】随施氮量的增加,棉花倒4叶SPAD值、叶柄NIT含量显著增大,棉花冠层光谱绿光波段形成的反射峰变缓,但当氮肥增加到360 kg/hm²时不再显著增加(蕾期NIT除外)。蕾期、花铃期倒4叶SPAD值、叶柄NIT含量、冠层高光谱参数(RSI和mND705)与前期施氮量均呈极显著一元二次方程关系(R²＞0.8,RMSE＜1),可作为江汉平原麦后移栽棉氮素营养诊断指标,以产量潜力的95%为临界值,蕾期麦后移栽棉SPAD值、叶柄NIT含量、冠层RSI和mND705临界值分别为34.802、2.307、1.526和0.549,花铃期相应为34.841、4.174、1.589和0.619。【结论】4个指标为江汉平原麦后移栽棉氮素营养诊断指标。麦后移栽棉最适宜施氮量为310.64 kg/hm²,产量潜力为4 662.53 kg/hm²。  相似文献   

Piscirickettsia salmonis: a Gram-negative intracellular bacterial pathogen of fish   总被引：2，自引：0，他引：2  

Fryer JL  Hedrick RP 《Journal of fish diseases》2003,26(5):251-262

Piscirickettsia salmonis is the first Gram-negative, intracellular bacterial pathogen isolated from fish and is a significant cause of mortality in salmonid fish. Recent reports of P. salmonis or P. salmonis-like organisms from new fish hosts and geographic regions have increased the interest in the bacterium. In this review, the important characteristics of the bacterium including recent taxonomic changes, features of the disease caused by the bacterium including transmission, hosts, reservoirs, diagnostic procedures, and current approaches for prevention and treatment have been discussed. The reader is also directed to other reviews concerning the bacterium and the disease it causes (Fryer & Lannan 1994, 1996; Almendras & Fuentealba 1997; Lannan, Bartholomew & Fryer 1999; House & Fryer 2002; Mauel & Miller 2002).  相似文献   

DNA hybridization assays for the detection of Piscirickettsia salmonis in salmonid fish     

Venegas CA  Contreras JR  Larenas JJ  Smith PA 《Journal of fish diseases》2004,27(7):431-433

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Studies on epizootic iridovirus infection among red sea bream,Pagrus major (Temminck & Schlegel), cultured in Taiwan     

Wang CS  Shih HH  Ku CC  Chen SN 《Journal of fish diseases》2003,26(3):127-133

Since 1993, an epizootic viral disease has occurred in net-cage cultured red sea bream, Pagrus major (Temminck & Schlegel), in Peng-hu Island located on the south-western coast of Taiwan. The diseased fish exhibited abnormal swimming and were lethargic, but few visible external signs were observed. The cumulative mortality because of the disease sometimes reached 50-90% over 2 months. Histopathogical studies of the affected fish showed enlarged basophilic cells in the gill, kidney, heart, liver and spleen. These necrotic cells were Feulgen-positive and stained blue using Giemsa. Transmission electron microscopy revealed icosahedral virions in the cytoplasm of the necrotic cells. The viral particles consisted of a central nucleocapsid (75-80 nm) and envelope, and were 120-150 nm in diameter. These results suggest that the virus belongs to the Iridoviridae. Using polymerase chain reaction (PCR), approximately 570 bp fragments were produced from the viral DNA using as a template 1-F and 1-R primers derived from red seabream iridovirus (RSIV) from red sea bream in Japan. Similar results were also obtained using nested-PCR with different primer sets (1-F, 2-R and 2-F, 1-R). Although the size and some features of epizootics of this virus differed from RSIV in Japan, it shows close genetic affinities with the latter and it is suggested that RSIV has been introduced to Taiwan.  相似文献   

对虾的主要疾病及其诊断方法   总被引：3，自引：0，他引：3  

王吉桥  徐锟 《水产科学》2002,21(5):23-28

诊断对虾病原的方法有传统的形态病理学（光镜和电镜直接观察和组织病理学等）、扩增和生物测定、微生物学和血清学方法，对皮下及造血组织坏死病毒病（IHHNV）、肝胰脏细小病毒病（HPV）、拖拉症（Taura syndrome,TS）、白斑综合症（WSSV）、斑节对虾型杆状病毒病（MBV）和杆状对虾病毒病（BP）等病原均采用非放射性的基因组探针目前已研制出了NHP、某些弧菌（Vibrio spp）和微孢子虫的传统基因探针，根据聚合酶链式反应（PCR），采用DNA扩增方法确立的检测某些病原的高敏感性方法也应用在对虾病原诊断上。  相似文献   

Isolation in cell culture and detection by PCR-based technology of IPNV-like virus from leucocytes of carrier turbot, Scophthalmus maximus (L.)   总被引：1，自引：0，他引：1  

Cutrín JM  López-Vázquez C  Olveira JG  Castro S  Dopazo CP  Bandín I 《Journal of fish diseases》2005,28(12):713-722

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An evaluation of current diagnostic tests for the detection of infectious salmon anaemia virus (ISAV) following experimental water-borne infection of Atlantic salmon,Salmo salar L     

Snow M  Raynard RS  Murray AG  Bruno DW  King JA  Grant R  Bricknell IR  Bain N  Gregory A 《Journal of fish diseases》2003,26(3):135-145

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Rapid and sensitive detection of Streptococcus iniae by loop-mediated isothermal amplification (LAMP)     

Han HJ  Jung SJ  Oh MJ  Kim DH 《Journal of fish diseases》2011,34(5):395-398

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咖啡-荔枝混农林系统中小粒咖啡营养诊断及平衡施肥效应研究   总被引：2，自引：0，他引：2       下载免费PDF全文

蔡传涛  姚天全  刘宏茂  周庆辉  王华 《中国生态农业学报》2006,14(2):92-94

定位试验研究咖啡-荔枝混农林系统中N、P、K不同用量及配比咖啡营养状况结果表明,缺N对小粒咖啡产量影响最大,其次为K,而P的影响较小;喷施微量元素B、Zn可明显增加咖啡产量。N、P、K肥配比为1∶0.5∶1,咖啡产量随N、P、K用量的增加而提高,鲜果产量为15~30t/hm2。建议思茅地区小粒咖啡营养诊断指标为N25~30g/kg,P1.0~1.5g/kg,K15~25g/kg,Ca10~12g/kg,Mg2.5~5.0g/kg,Zn10~15mg/kg和B40~50mg/kg;N、P2O5和K2O平衡施肥年最佳用量为N50~100g/株、P2O525~50g/株和K2O50~100g/株。  相似文献