羊附红细胞体PCR诊断方法的建立及应用

根据羊附红细胞体16S rRNA基因序列设计特异性引物,建立了羊附红细胞体的PCR诊断方法.该方法能扩增羊附红细胞体16S rRNA基因片段,对大肠杆菌、羊无形体、羊源支原体、猪附红体和假单孢菌基因组DNA没有扩增出条带,所能检测羊附红细胞体DNA的最低量为1.82 pg/mL.运用所建立的方法对从重庆市荣昌县采集的110份羊血样进行附红细胞体检测,其中13份羊附红体感染阳性,表明该方法特异性和灵敏度高,可用于急性羊附红细胞体病和临床带菌羊的检测.     

猪附红细胞体PCR诊断方法的建立

据猪附红细胞体重庆株16S rRNA基因的序列特点设计合成种特异性引物,建立了猪附红细胞体PCR诊断方法.该方法能特异性扩增840 bp的猪附红细胞体16S rRNA基因片段,而对牛温氏附红细胞体、羊附红细胞体、猫血巴尔通氏体CA株、绵羊肺炎支原体、猪肺炎支原体、假单孢茵、大肠杆茵、沙门氏茵、肝片吸虫、葡萄球菌等的基因组DNA没有扩增条带出现.对猪附红细胞体基因组DNA的最小检测量为0.16 fg.通过对30份临床样品的检测,21份猪附红细胞体感染为阳性,其余为阴性.结果表明:建立的PCR诊断方法具有很高的敏感性和特异性,可用于猪附红细胞体的临床诊断和流行病学调查.     

重庆市羊附红细胞体感染情况研究

参考GenBank登录的羊附红细胞体16S rRNA序列设计引物,建立检测羊附红细胞体16S rRNA的特异性PCR方法,对重庆市14个区县山羊进行附红细胞体感染的分子流行病学调查.结果表明:重庆市附山羊红细胞体感染率为16.1%;其中1周岁以下羊附红细胞体感染率为13.9%,低于1周岁以上羊附红细胞体感染率(17.0%).重庆黑山羊、波尔山羊、南江黄羊和板角山羊的附红细胞体感染率分别为15.9%,16.3%,16.6%和17.6%.     

The Finding and Phylogenetic Evolution Analysis of Bovine Piroplasms in the Rasǒn Area of North Korea

The objective of this study was to investigate the epidemiology of bovine Piroplasms infections in the Rasǒn area of North Korea.The survey was carried out by light microscopic examination of Giemsa-stained blood smears,PCR,and phylogenetic evolution analysis of 128 blood samples collected from the Rasǒn area.The results showed that the infection rates of the small and large parasites were about 2.5 and 1.5% on average,respectively,in all Theileria sergenti and Babesia ovatapositive blood smears by microscopic examination of blood smears.The detection rate of T.sergenti Giemsa-stained smears was 43.75%,while that with PCR was 67.97%.The detection rate of B.ovata Giemsa-stained smears was 49.21%,while that with PCR was 71.88%.The sequence and phylogenetic analysis of DNA showed 98.84% homology between the 18S rRNA gene sequences of T.sergenti isolates from North Korean and that of Yanbian state from China,indicating the closest genetic relationship between both of them.Moreover,100% homology was shown between the 18S rRNA gene sequence of B.ovata isolates from North Korea and the published sequence AY081192 of GenBank,indicating the closest genetic relationship between both of them.This survey confirmed that Ras n is the endemic area of T.sergenti and B.ovata in North Korea.     

Comparison of PCR, DIA and Pathogenicity Assay for Detection of Xanthomonas axonopodis pv. citri, the Causal Agent of Citrus Bacterial Canker Disease

Polymerase chain reaction (PCR) approach based on newly designed primers, JYF5/JYR5, was applied for specific detection of Xanthomonas axonopodis pv.citri(Xac). The efficiency and reliability of PCR method were compared with dot immunobinding assay (DIA) and classical pathogenicity test techniques for detecting suspensions of pure cells of Xac and soaking sap of citrus tissues. Detection sensitivity of PCR was about 4.5 cells or 1.56 pg target DNA per reaction which was higher than that of DIA (ca.450 cells per dot).These three techniques (PCR assay, DIA and Pathogenecity test) could always detect Xac from symptomatic citrus samples. Different performances were obtained from citrus materials without symptoms, and the positive detection frequency was PCR, DIA and pathogenicity test.     

A New Disease of Cherry Plum Tree with Yellow Leaf Symptoms Associated with a Novel Phytoplasma in the Aster Yellows Group

A novel phytoplasma was detected in a cherry plum（Prunus cerasifera Ehrh） tree that mainly showed yellow leaf symptom. The tree was growing in an orchard located in Yangling District, Shaanxi Province, China. The leaves started as chlorotic and yellowing along leaf minor veins and leaf tips. Chlorosis rapidly developed to inter-veinal areas with the whole leaf becoming pale yellow in about 1-4 wk. Large numbers of phytoplasma-like bodies（PLBs） were seen under transmission electron microscopy. The majority of the PLBs was spherical or elliptical vesicles, with diameters in range of 0.1-0.6 μm, and distributed in the phloem cells of the infected tissues. A 1 246-bp 16 S ribosomal RNA（rRNA） gene fragment was amplified from DNA samples extracted from the yellow leaf tissues using two phytoplasma universal primer pairs R16mF2/R16mR1 and R16F2n/R16R2. Phylogenetic analysis using the 16 S rRNA gene sequence suggested that the phytoplasma associated with the yellow leaf symptoms belongs to a novel subclade in the aster yellows（AY） group（16SrI group）. Virtual and actual restriction fragment length polymorphism（RFLP） analysis of the 16 S rRNA gene fragment revealed that the phytoplasma was distinguishable from all existing 19 subgroups in the AY group（16SrI） by four restriction sites, Hinf I, Mse I, Sau3 A I and Taq I. The similarity coefficients of comparing the RFLP pattern of the 16 S rRNA gene fragment of this phytoplasma to each of the 19 reported subgroups ranged from 0.73 to 0.87, which indicates the phytoplasma associated with the cherry plum yellow leaf（CPYL） symptoms is probably a distinct and novel subgroup lineage in the AY group（16SrI）. In addition, the novel phytoplasma was experimentally transmitted to periwinkle（Catharanthus roseus） plants from the tree with CPYL symptoms and then back to a healthy 1-yr-old cherry plum tree via dodder（Cuscuta odorata） connections.     

羊附红细胞体巢式PCR检测方法的建立与应用

为了建立一种更加准确、敏感的羊附红细胞体检测方法,根据Gen Bank上发表的羊附红细胞体16S rRNA基因序列(登录号:AF338268),设计内、外2对特异性引物,建立了巢式PCR检测方法。筛选该方法的最佳反应条件,并进行了特异性、敏感性、重复性试验及临床样本检测。结果表明,该方法能扩增出大小为506 bp的羊附红细胞体特异性片段,与Gen Bank收录的相关参考序列同源性为97.8%~99.6%;与猪附红细胞体、嗜吞噬细胞无浆体、绵羊无浆体、莫氏巴贝斯虫、吕氏泰勒虫基因组DNA均无交叉反应;DNA最低检测量为0.654 fg·μL~(-1);具有良好的重复性;对77份羊临床血液样品检测结果表明,羊附红细胞体感染率为71.43%,高于常规PCR和已报道的巢式PCR检测结果。     

猪附红细胞体特异性基因的克隆和序列分析

为分析吉林省流行的猪附红细胞体基因序列,根据发表的猪附红细胞体16S rRNA基因序列设计引物,扩增出长度约为541 bp的基因片段,并成功地将该基因克隆到pGEM-T Easy载体.将经Not Ⅰ酶切鉴定和PCR鉴定为阳性的重组质粒进行测序,与发表的附红细胞体基因序列进行比较,试验所获得的核苷酸序列与猪附红细胞体16S rRNA基因序列非常相近,同源性为97.8%～100%,从而证明吉林省所流行的猪附红细胞体属于16S rRNA基因群.     

E.tenella吉林株单卵囊的分离及PCR鉴定(英文)

[Objective] In order to get a purified strain to carry out the relative molecular biology research about E.tenella. [Method] The single-oocyst isolation method was improved and the isolated single-oocyst which was put into capsule was fed to chickens. At the same time, the collected oocysts were identified by PCR method. [Result] The oocysts were isolated from feces of 15 chickens among that of 20 chickens and the infection rate was 75%. The PCR results demonstrated that the single-oocyst strain was E.tenella. [Conclusion] The inoculation of single oocyst capsule was simple, besides, this method did not only save time but also declined inoculation difficulty, increased infection rate and provided good materials for biological research of coccidian.     

Detection of Herbicide-tolerant Canola by Multiplex PCR

[Objective]This study aimed to establish a multiplex PCR detection method of herbicide-tolerant canola.[Method] An endogenous reference gene(CruA) and three exogenous genes(T-CaMV 35 S, P-CaMV 35 S and pat) were selected for multiplex PCR. Specific primers were designed based on national standards or related literature. The annealing temperature, ratio of primer concentration and sensitivity of the established multiplex PCR system were optimized. The optimal multiplex PCR system was verified with known samples. [Result] The experimental results showed that the optimal annealing temperature of multiplex PCR was 58 ℃; the optimal ratio of primer concentration(μmol/L) was T-CaMV 35S: CruA: P-CaMV 35S: pat=0.1: 0.2: 0.2: 0.2;the detection sensitivity of the established multiplex PCR method was 0.3 ng. The amplified bands of known samples were completely consistent with the molecular characteristics. [Conclusion] This study provided a rapid, accurate and effective multiplex PCR technique for detection of herbicide-tolerant canola.     

浅谈饲料中有效能的测定技术

饲料中有效能是供动物生长发育的基础.不同动物所用的有效能体系不同,目前大多数动物采用消化能、代谢能体系,但随着研究的发展与深入,发现最能反映饲料有效能的是净能体系.无论哪种体系,采用合理的测定技术准确测定饲料中的有效能值显得尤其重要,通过对饲料有效能值的准确测定可以实现动物所需能量的精确供给,减少养殖成本,使经济效益最大化.文章综述了几种有效能评价体系的测定技术.     

高校贫困生认定工作面面观

国家贫困生资助政策实施以来,对贫困生帮助很大,同时在实际运行中还存在着一些问题。本文提出贫困生认定工作仍需要进一步采取各种相关配套措施,以推动和保障贫困生资助工作更好地开展。     

《河北农业大学学报》创刊年代考

清光绪二十八年(1902)河北农业大学前身—直隶农务学堂诞生,经几易其名,于1958年更名为河北农业大学至今。清光绪三十一年(1905)直隶高等农业学堂时期创办了《北直农话报》,清光绪三十四年(1908)更名为《直隶农务官报》,中华民国七年(1918)改出《农学月刊》,中华民国十七年(1928)易名为《河大农刊》,中华民国二十三年(1934)更名为《河北通俗农刊》,中华民国二十四年(1935)易名为《河北农林学刊》,1948年更名为《河北农学院研究专刊》,1959年更名为《河北农业大学学报》至今。《河北农业大学学报》前身诸刊都与现时的《河北农业大学学报》有着一脉相承的历史渊源,各刊之间联系紧密,连续性、继承性强。因此,《河北农业大学学报》的创刊时间应追溯至1905年创办的《北直农话报》。     

生态旅游潜在客源市场特征的调查研究--以湖南永州金洞森林旅游开发为例

为探明客源市场生态旅游消费的潜在特征,采用问卷调查的形式,就长沙市居民对湖南金洞生态旅游开发的意向等问题进行抽样调查．结果显示,生态旅游符合人们“回归自然”的旅游新时尚,有着极大的开发空间,指出生态旅游的开发要注重环境保护和可持续发展．开发的产品要以休闲度假类的大众产品为主,开发生态旅游都市客源市场还要多种渠道并用,尤其是要注重媒体的宣传．     

探究板栗的科学贮藏方法

板栗属壳斗科栗属(Castanea mollisima Blume),其种子属于顽拗型种子,不耐贮藏。基于近年来板栗贮藏保鲜技术研究成果,从合理采收、贮前处理、贮藏方法等方面进行论述。     

动物疫苗接种异常反应的处理

动物疫病是畜牧业生产的大敌,要发展畜牧业生产就要防治动物疫病。但在疫苗接种时,经常出现正常反应外的其他不利于机体的反应,如废食、皮疹、休克、死亡等,正确处理或避开这些问题,对推行动物疫病的计划免疫,实施强制免疫,保护人畜安全具有十分重要的现实意义和作用。     

厚胶合板弹性模量预测模型

为了预测厚胶合板弹性模量,通过简化层合板理论,该文建立了胶合板弹性模量预测模型,并以单板条、经过涂胶热压处理的单板条和相同工艺条件下的单板层积材的弹性模量,采用4种不同铺层方式的19层桉树胶合板对模型进行了验证。结果表明:3种预测值与实测值的趋势一致,相关系数R2顺纹在0.86以上,横纹在0.88以上,但是精度不同。采用单板条弹性模量预测的胶合板弹性模量比实测值偏低;采用经过涂胶热压处理后的单板条弹性模量预测的胶合板弹性模量比实测值偏高;采用相同工艺条件下的单板层积材弹性模量预测的胶合板弹性模量与实测值偏差较小,顺纹平均误差为4.64%,横纹平均误差10.94%。因此,采用相同工艺条件下的单板层积材的弹性模量来预测胶合板的弹性模量是可行的。      

增强我国水果业出口竞争力的思考

分析了入世4年来,我国水果出口在量上实现了突破,但并没有实现质变的主要原因,指出我国水果业存在的问题。论述了引进外资对发展我国水果业的意义,并提出了具体可行的对策与建议。     

山茱萸多糖提取工艺优化及马钱苷含量测定

采用L（934）正交设计试验,对山茱萸浸提液中山茱萸多糖的酶水解法提取工艺进行了优化研究,并对浸提液的中有效成分马钱苷含量进行了HPLC法分析。结果表明,山茱萸多糖浸提的最佳工艺为：液料比1∶5,浸提时间4 h,浸提温度80℃,果胶酶添加量0.55 g/L。用HPLC法测定出的山茱萸浸提液中马钱苷平均含量为0.512 ...     

甘肃省日光温室生产发展对策的探讨

甘肃省设施农业发展历史悠久,古代创造了麦草覆盖生产韭 黄及泥碗护苗等传统设施农业技术,至今仍然受到农民欢迎,在 甘肃省中部应用面积约5万多hm2。建国后,甘肃设施农业获得 了新生,大致经历了三个阶段;第一阶段为引进应用北京改良式 温室阶段,时间在20世纪50-60年代;第二个阶段为塑料拱棚 与地膜覆盖栽培阶段,时间在20世纪70-80年代:第三阶段为