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1.
广州桑树植原体分子检测及多样性初探   总被引：3，自引：1，他引：2  
采用植原体16S-23S rDNA区段的通用引物对P1/P7和巢式引物对Rm16F2/Rm16R1,建立了快速准确的桑树植原体巢式PCR检测技术。对广州的两个桑树品种资源圃中的部分桑树品种进行了植原体分子检测,结果在两个资源圃中均发现有植原体存在。对巢式PCR的扩增产物(16S rDNA片段)进行了限制性片断长度多态性(RFLP)分析,显示出3种RFLP带型,暗示桑树植原体存在多样性。对所得植原体16S rDNA片段进行序列测定,并与其它植物植原体作亲缘关系分析,结果表明该植原体的16S rDNA序列与其它植物病原植原体之间的同源性为83.3%~99.9%,并初步判断所检测到的桑树植原体属于16S rI组。  相似文献   

2.
从浙江省蚕区的桑园内采集表现桑黄化型萎缩病症状的植株叶片,并提取叶脉总DNA,通过巢式PCR和常规PCR方法对桑黄化型萎缩病植原体分离物(MYD-ZJ)的16S r DNA、延伸因子基因tuf和核糖体蛋白基因rp进行扩增及克隆,分别得到大小为1 239 bp、842 bp和1 240 bp的序列。对这些基因片段序列进行系统进化分析,结果表明,MYD-ZJ的16S r DNA序列与来自山东、安徽等省感病桑树分离桑黄化型萎缩病植原体的同源序列的相似度为98%,在进化树中位于同一进化支;MYD-ZJ的tuf基因序列与来自山东省的桑黄化型萎缩病植原体的同源序列的相似度为89%~100%,并与该同源序列以及同样来自山东省的枣疯病植原体、苦楝丛枝病植原体等聚为一支;MYD-ZJ的rp基因序列与来自山东省、安徽省的桑黄化型萎缩病植原体的同源序列的相似度为100%,在进化树中位于同一进化支。研究结果明确了MYD-ZJ属于翠菊黄化植原体组的16SrⅠ-B亚组、tufⅠ-B亚组及rpⅠ-B亚组。  相似文献   

3.
山东蚕区桑黄化型萎缩病病原物的分子鉴定   总被引：3，自引：1，他引：2  
以采自山东省宁阳市桑园的桑黄化型萎缩病发病植株叶脉组织为材料,通过PCR扩增植原体16S rRNA基因及延伸因子基因(tuf)和核糖体蛋白基因(rp),分别得到大小约为1.4、0.8和1.2 kb的目的片段并测定序列。以该病原物的16S rRNA基因与GanBank中相关的植原体16S rRNA基因序列构建系统发育树并进行RFLP分析,结果显示该病原物属于翠菊黄化组的16SⅠr-B亚组,与翠菊黄化组16SⅠr-B亚组典型成员的同源性为99.9%。进一步对延伸因子基因和核糖体蛋白基因构建系统发育树并做RFLP分析,结果显示该病原物与翠菊黄化组的tuⅠf-B亚组典型成员和rpⅠ-B亚组典型成员的同源性分别达到99.6%、99.9%。由此在3个基因水平确定该植原体的分类地位属于16SrⅠ-B、tuⅠf-B和rpⅠ-B亚组。  相似文献   

4.
柑橘黄龙病是目前危害柑橘产业的重要危险性病害，实验室中通过PCR技术检测柑橘黄龙病是最有效的方法，因此，确定一组特异性好、灵敏度高的引物至关重要。本文通过荧光定量PCR标定柑橘黄龙病菌核酸浓度的方法，对目前各实验室常规PCR应用比较广泛的4对引物（P400F/R、P535F/R、OI1/OI2，16SF/R）做了特异性和灵敏度的比较。结果发现4对引物均能排除其它来源核酸的干扰，表现出明显的特异性，但在灵敏度方面4对引物差别很大，灵敏度结果是依次为：16SF/R＞P400F/R ＞P535F/R=OI1/OI2，灵敏度最高的16SF/R引物检测柑橘黄龙病菌核酸含量约为1.87×10﹣2 ng/μl。本研究结果为实验室开展检测柑橘黄龙病研究提供了很好的理论与实践基础  相似文献   

5.
本研究采用目标起始密码子多态性(Start codon targeted,SCoT)标记,对600份不同紫花苜蓿(Medicago sativa L.)材料(共6个种质)的基因组DNA进行扩增,分析了不同取样数量下(10,15,20,30,40,50,60,70,80,90和100)紫花苜蓿的遗传多样性,旨在筛选出代表紫花苜蓿种群遗传多样性的最佳取样单株数。结果发现,6条SCoT引物共扩增出80个条带,平均每条引物的扩增条带数为13.3个,多态性条带百分率为100%。在评价不同取样梯度下的紫花苜蓿遗传多样性覆盖度时发现,当取样数量增加至40时,6个供试紫花苜蓿种质的遗传多样性覆盖率均达到95%以上。此外,本试验采用UPGMA与STRUCTURE聚类分析方法,分析了不同取样梯度下紫花苜蓿的遗传结构。结果表明,样本量为40时能够有效反映紫花苜蓿群体间差异。  相似文献   

6.
本试验筛选了新孢子虫病PCR检测的引物,运用《新孢子虫病检疫技术规范》(SN/T 3499-2013)对根据犬新孢子虫Nc2和Nc5基因设计的PCR引物进行了评价。此外,同时运用F1/R1、F2/R2和SN/T 3499 F/SN/T 3499 R共同对14份荷斯坦牛和19份西门塔尔牛全血DNA进行PCR检测,旨在筛选出特异性较好的引物,建立新孢子虫病PCR检测方法和了解当地不同品系牛患新孢子虫病的感染率。结果显示,3对引物分别扩增出105、128和231 bp目的片段,均与预期目的片段大小相符;其中,F1/R1与SN/T 3499 F/SN/T 3499 R的最低检测量相同,为19.9 fg/μL,F2/R2最低检测量为199 fg/μL,说明F1/R1和SN/T 3499 F/SN/T 3499 R引物的敏感性更好;运用F1/R1、F2/R2引物分别对19.9 pg/μL和199 fg/μL模板重复进行4次扩增,均出现了较明亮的扩增条带,证明两对引物重复性较好。33份血液样品共检出6份阳性DNA,阳性率分别为21.43%和15.79%,检出复合率为100%。以上结果说明F1/R1和F2/R2引物均可作为新孢子虫病PCR的诊断引物,本试验初步建立了新孢子虫PCR方法,同时初步了解了当地牛群中新孢子虫感染情况,为有效预防和控制新孢子虫病提供了科学的理论依据。  相似文献   

7.
针对牛冠状病毒(BCoV)N基因保守序列设计合成了1对特异性引物,以体外转录法制备的cDNA标准品为模板,建立了检测BCoV的SYBR GreenⅠ实时荧光定量PCR方法。在1个反应体系中模板最低检测限为7.8 copies/μL,比普通RT-PCR更加灵敏;与牛主要消化道和呼吸道病毒病病原均无交叉反应;批内、批间重复变异系数均低于1.5%;应用定量PCR检测了39份疑似临床病料,阳性检出率为51.28%(20/39),普通RT-PCR为41.03%(16/39)。结果表明,该方法特异性强、稳定性好、准确率高,本方法将为BCoV的临床诊断和流行病学调查提供技术保障。  相似文献   

8.
采用正交设计优化紫花苜蓿(Medicagosativa L.)SSR-PCR反应体系,从17对SSR引物中筛选出6对扩增产物具有稳定多态性的引物,检测第1代植株的基因多态性。结果表明:4个紫花苜蓿品种德福(Defi)、德宝(Derby)、阿尔刚金(Algonguin)、三得利(Sanditi)共检测到25个等位基因,每对引物检测出2～8个等位基因,平均为4.17个。结合植株较高、叶色较深、叶片较大、多叶4个表型突变指标,检测经过表型变异筛选的植株等位基因频率及每个位点的多态性信息量(PIC),PIC在0.2216～0.8328之间变化,平均为0.6366。分析多态基因植株与表型变异的相关性,根据检测结果初步确定了13株突变植株,为后继世代遗传变异的多代跟踪及选育奠定基础。  相似文献   

9.
为建立牛传染性鼻气管炎病毒(IBRV)的TaqMan荧光定量PCR检测方法,本研究根据IBRVgB基因保守区域设计特异性引物和MGB探针,并采用矩阵法优化了PCR反应条件。结果显示,标准曲线相关系数(R2)为0.998,103拷贝/μL~108拷贝/μL内具有较好的线性关系。对牛呼吸道合胞体、牛病毒性腹泻粘膜病1型、牛副流感病毒3型的cDNA进行检测,结果均为阴性,特异性良好。该方法对IBRV检测的灵敏度可达到1.49×101拷贝/μL,是常规PCR灵敏度的100倍,重复性试验表明该方法的组内和组间变异系数均小于1.5%。应用建立的方法与普通PCR方法分别对17份疑似临床呼吸道症状牛鼻黏液拭子样品进行检测,该方法检测的阳性率比传统PCR法检测的阳性率提高了约12%。研究表明建立的IBRV TaqMan-MGB荧光定量PCR方法灵敏、快速、特异性强、重复性好,适用于临床疑似样品的快速定量检测。  相似文献   

10.
研究了在佳木斯地区建植紫花苜蓿单播人工草地和混播人工草地时紫花苜蓿的最佳播种量。3年试验结果表明,在佳木斯地区建植紫花苜蓿单播人工草地的最佳播种量为15.0 kg/hm2;建植紫花苜蓿和无芒雀麦混播人工草地的紫花苜蓿+无芒雀麦最佳播种量为18.8 kg/hm2(紫花苜蓿和无芒雀麦播种量比例为2∶1)。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
Tropical Animal Health and Production -  相似文献   

14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

17.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

18.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

19.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

20.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

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