桃红叶植原体检测及鉴定

对表现红叶的桃植株进行植原体16SrRNA基因PCR扩增,得到1.2kb的特异片段.将此片段与pGEM T Easy载体连接并转化到大肠杆茵DH5α感受态细胞中.通过酶切、PCR鉴定,对筛选得到的重组阳性克隆进行序列测定及同源性比较分析,确定该株系属于翠菊黄化植原体组(Aster yellows group,16SrI).在国内首次报道了翠菊黄化组中的植原体侵染桃树.     

磺胺嘧啶钠在鸡体内过程的房室法分析

本文运用经典的房室分析法进行磺胺嘧啶对15只鸡静注、内服单剂量(0.2g/kg)和多剂量动力学研究,应用重氮化一偶合比色法测定血药浓度。试验除指出静注、内服的药时曲线符合无吸收二室开放模型和有吸收一室开放模型外,还对主要特征参数作了统计和表述。最后根据试验结果及药效学资料拟定的鸡连续静注、内服磺胺嘧啶钠的方案。     

The use of atropine to control heart rate responses during detomidine sedation in horses

Detomidine is a sedative-analgesic which has a pharmacological profile similar to xylazine. There is evidence that the sedative effects are mediated through alpha-2 adrenoceptors.Cardiopulmonary responses were determined using detomidine as the principal agent and as a preanesthetic prior to the induction of general anesthesia. Compatibility with guaifenesin, sodium thia-mylal and halothane were determined.As in the case of xylazine, detomidine produces a slowing of heart rates. This was found to be either sinus bradycardia or heart block. There may be a corresponding increase in systolic blood pressures. The respiratory pattern is altered through the arterial blood gases and pH data supported evidence of adequate ventilation. The heart rate response to detomidine without anticholinergic treatment was transient and related to he duration of drug action.Atropine sulfate, 0.02 mg/kg i.v. was effective in preventing or treating bradycardia or heart block from detomidine. Heart rates also increased during the administration of guaifenesin and sodium thia-mylal when given 50 min poisit-detomidine.     

鲈鲤肌肉脂肪酸组成分析

对鲈鲤肌肉脂肪酸进行测定,结果显示:鲈鲤肌肉中含有7种脂肪酸,饱和脂肪酸有3种,不饱和脂肪酸有4种。3种饱和脂肪酸(SFA)总量为28.22%,4种不饱和脂肪酸(UFA)为71.75%,以不饱和脂肪酸中油酸C18∶1含量最高,为44.28%。鲈鲤鱼体肌肉脂肪酸主要由油酸C18∶1、棕榈酸C16∶0、亚油酸C18∶2和棕榈油酸C16∶14种脂肪酸组成,这4种脂肪酸质量分数总和占脂肪酸总质量分数的93.58%。鲈鲤肌肉脂肪酸种类组成与其它几种淡水鱼类比较,存在明显差异。     

Epizootic haematopoietic necrosis virus—An assessment of the likelihood of introduction and establishment in England and Wales

Epizootic haematopoietic necrosis virus (EHNV) is an iridovirus that affects perch (Perca fluviatilis) and rainbow trout (Oncorhynchus mykiss). It emerged in Australia in the 1980s and has not been discovered elsewhere. It causes a high level of mortality in perch resulting in steep population declines. The main possible routes of introduction of the virus to England and Wales are the importation of infected live fish or carcasses. However, no trade in live susceptible species is permitted under current legislation, and no importation of carcasses currently takes place. The virus is hardy and low levels of challenge can infect perch. Therefore, mechanical transmission through the importation of non-susceptible fish species should be considered as a potential route of introduction and establishment. Carp (Cyprinus carpio) have been imported to the UK from Australia for release into still-water fisheries. A qualitative risk assessment concluded that the likelihood of EHNV introduction and establishment in England and Wales with the importation of a consignment of carp was very low. The level of uncertainty at a number of steps in the risk assessment scenario tree was high, notably the likelihood that carp become contaminated with the virus and whether effective contact (resulting in pathogen transmission) is made between the introduced carp and susceptible species in England and Wales. The virus would only establish when the water temperature is greater than 12 °C. Analysis of 10 years of data from two rivers in south-west England indicated that establishment could occur over a period of at least 14 weeks a year in southern England (when average water temperature exceed 12 °C). Imports of live fish from Australia need to be evaluated on a case-by-case basis to determine which, if any, sanitary measures are required to reduce the assessed risk to an acceptable level.     

2016-2020年华北地区猪繁殖与呼吸综合征病毒分子流行病学调查

利用RT-PCR方法对2016-2020年华北地区692份疑似猪繁殖与呼吸综合征(PRRS)临床样本进行检测,获得368份阳性样品,阳性率为53.18%,并对其进行了ORF5基因扩增和测序,开展遗传变异和分子流行病学分析。结果显示,共获得33条完整的ORF5基因序列,除了HB-XT株为600 bp,其余全长均为603 bp。ORF5基因遗传进化分析表明33株均为Ⅱ型,其中有9株分布在Lineage 8,24株分布在Lineage 1。33株之间的氨基酸序列同源性为80.1%～99.5%,与JX-A1株和NADC30株的同源性分别为81.1%～99.5%和85.6%～94.5%。氨基酸分析结果表明,33株均在诱骗表位和中和表位发现了突变;在33株中共发现7个N-糖基化位点,其中包括相对保守的N44和N51位点,以及主要位于抗原表位的N30,N32,N33,N34和N35位点。结果表明,2016-2020年华北地区HP-PRRSV毒株逐渐被类NADC30毒株所取代,成为优势毒株,且ORF5基因变异差异较大,使PRRSV流行变得更加复杂。因此,本研究对PRRS分子流行病学以及疫苗的选择和防控...     

兰州大学草地农业科技学院硕士学位论文引文分析

摘要：以兰州大学草地农业科技学院8个专业（2007-2009年）的48篇硕士学位论文为统计源,运用文献计量学方法对其所引文量、类型、语种、年代分布等项进行初步统计分析,探讨了研究生文献需求的规律和特点,提出了加强图书馆馆藏建设的建议,并发现了一些亟待解决的问题。     

早实核桃不同品种抗旱性综合评价

以12 个早实核桃品种苗木为试材,采用自然干旱胁迫及复水的方法,测定了复水后各品种与抗旱性有关的生长指标、生理生化指标、光合指标及叶绿素荧光指标。对复水后各指标进行主成分分析,筛选出影响抗旱性的5 个主要指标,利用隶属函数对早实核桃品种的抗旱性进行了综合评价。结果表明：12 个早实核桃品种抗旱性强弱依次为：辽核1 号 > 中林5 号 > 新早丰 > 温185 > 鲁光 > 中林1 号 > 辽核4 号 > 扎343 > 强特勒 > 香玲 > 西林2 号 > 西扶1 号。此评价结果与大田试验结果基本一致。     

呼伦贝尔地区6种禾本科牧草养分对应分析

本研究运用对应分析方法对呼伦贝尔地区种植的6种禾本科牧草营养价值进行综合评定,结果表明:牧草品种间营养成分存在差异,且养分含量与品种间存在一定的相关性。‘阿坝'垂穗披碱草(Elymus nutans‘Aba')的粗蛋白与粗脂肪含量最高(P0.05),多花黑麦草(Lolium multiflorum Lamk)最低;披碱草(Elymus dahuricus Turcz)的吸附水含量最高,老芒麦(Elymus sibiricus Linn)最低;偃麦草(Elytrigia repens(L.)Nevski.)的粗纤维和粗灰分含量最高,蒙农杂种冰草(Agropyron cristatum×A.desertorum‘Hycrest Mengnong')最低;老芒麦钙和磷的含量最高,蒙农杂种冰草钙含量最低,偃麦草磷的含量最低。     

植物激素在园林植物中的作用

以生长素、赤霉素、细胞分裂素、脱落酸、乙烯为例,介绍了植物激素在园林植物中的调控作用,为植物激素的应用提供参考。