鸭链球菌的分离与耐药性监测     

赵瑞宏  张丹俊  潘孝成  程宝艳  胡晓苗 《中国畜牧兽医》2010,37(1):169-170

本研究利用鲜血琼脂和营养琼脂培养基,从自然发病的鸭体内成功分离出链球菌19株,革兰氏染色镜检可见革兰氏阳性球菌呈长链状排列,生化试验和动物接种试验结果表明,所分离的细菌对鸭有致病性。药敏试验结果表明,分离的菌株耐药性均很强,除7株对丁胺卡那中度敏感外,其余菌株对丁胺卡那、头孢曲松钠、氧氟沙星等14种药物低度敏感或不敏感。说明鸭链球菌耐药性在不断增强,给鸭链球菌病的防治带来了一定的困难。  相似文献   

不同品系欧洲报春的抗寒性研究     

王建强  胡力  史红文  钟汉冬 《辽宁林业科技》2012,(4):9-11

在不同低温处理下,分别对引进的3个品系欧洲报春叶片和花进行相对电导率及游离脯氨酸含量测定,分析其抗寒性的差异,结果表明:3个品系的欧洲报春花叶片伤害度、半致死温度和游离脯氨酸含量变化较为相符,其叶片和花的耐寒性强弱为:丹若娃的叶片>里拉的叶片>妃纯的叶片;妃纯的花>丹若娃的花>里拉的花,与其在露地栽培中观察到的结果相符。  相似文献   

关于骆驼抗逆性的思考     

额尔敦木图  达尔嘉  刘图雅 《畜牧与饲料科学》2012,33(2):29

从探险家发现南极鱼到科学家在南极鱼体内找到抗冷冻蛋白,联想到如何挖掘骆驼所具有的抗逆性。围绕骆驼特有的耐热、耐渴、耐寒、耐饿、耐粗饲料等生物学特性,对驼产业的开发与利用提出了新的思路。  相似文献   

23个欧美杨无性系苗期叶锈病抗性测定   总被引：2，自引：0，他引：2  

潘姝慧  孙佳音  刘春华  吕晓亮  滕文飞 《辽宁林业科技》2010,(1):5-7,46

以引进23个欧美杨无性系为研究对象,通过对苗木叶锈病感病指数的调查,借助SPSS统计软件对调查数据进行统计分析,结果表明:对叶锈病的抗性表现超过对照品种I108的有19个,其中02-36-1、02-36-4、N177、N197和N195这5个无性系对叶锈病完全免疫;无性系02-34-334对叶锈病表现为高度抗病;02-01-119、324、03-04-111、03-04-97和02-34-278表现为抗病;03-04-141、03-04-170、02-34-347和03-05-184表现为感病;02-01-219、03-04-167、03-04-288和02-34-228表现为高感;对叶锈病的抗性表现不及对照品种I108的有3个,即03-05-206、03-04-171和03-05-156,均表现为高感。  相似文献   

多功能电话电路设计     

曾健平  欧古平  陈迪平  王镇道  夏辉 《湖南农业大学学报(自然科学版)》1999,26(4)

设计了一种多功能电话电路，能够防止他人非法串线盗打和窃听电话，通过单片机控制自动存储并显示电话号码和所打电话的时刻及用时，且可通过打印机接口打印以上信息。  相似文献   

Reactions on Nicotiana species to potato viruses A,X and Y and tobacco mosaic virus in relation to their taxonomy and geographical origin     

P. Van Dijk  C. Cuperus 《European journal of plant pathology / European Foundation for Plant Pathology》1989,95(6):343-356

When testing the response of species of the genusNicotiana to 14 isolates of potato viruses A (PVA), X (PVX) and Y (PVY) and tobacco mosaic virus (TMV), sections and section parts of the genus could be divided into five groups according to the overall reaction of their species. Species from arid regions of australia and belonging to the sectionSuaveolentes (subgenusPetunioides) were most sensitive and least resistant, whereas the sectionsPaniculatae (subgenusRustica),Tomentosae (Tabacum) andNoctiflorae (Petunioides) appeared least sensitive and most resistant. Sixty-one percent of the accessions of the latter sections proved resistant to at least two of the viruses. The most resistant species have their main geographical distribution in the central Andes (southern Peru, Bolivia and north-western Argentina), where the viruses may have originated. One other resistant species wasN. africana (Suaveolentes) indigenous to south-western Africa. The most sensitive American sections, viz.Genuinae (Tabacum) andTrigonophyllae, Alatae, Acuminatae andBigelovianae (Petunioides), were generally more sensitive than species of theSuaveolentes section from outside the arid regions of Australia. The remaining part of the genus, viz. the American sectionsThyrsiflorae andRusticae (Rustica) andUndulatae, Repandea andNudicaules (Petunioides) was intermediate between the latter group ofSuaveolentes species and the resistant group of sections with regard to sensitivity and resistance, but had a high rate of tolerance to PVA, PVX and PVY and of hypersensitivity-associated resistance to TMV. The results indicate that the viral respons in the genusNicotiana is mainly determined geographically and to a lesser extent taxonomically.Samenvatting Na inoculatie van een grote collectieNicotiana-soorten met 14 isolaten van de aardappelvirussen A (PVA), X (PVX) en Y (PVY) en tabaksmozaïekvirus (TMV), konden de secties of sectiedelen van het genus op basis van de gemiddelde reactie van hun soorten in vijf groepen worden verdeeld. Soorten uit Australische woestijngebieden en taxonomisch behorend tot de sectieSuaveolentes (subgenusPetunioides) bleken het meest gevoelig en het minst resistent, terwijl de sectiesPaniculatae (subgenusRustica),Tomentosae (Tabacum) enNoctiflorae (Petunioides) het minst gevoelig en het meest resistent waren. Van de collectienummers van de laatstgenoemde secties bleek 61% resistentie tegen minstens twee van de virussen te bezitten. De meest resistente soorten hebben hun verspreidingsgebied vooral in het centrale deel van het Andesgebergte (het zuidelijk deel van Peru, Bolivia en noord-westelijk Argentinië). Mogelijk is dit het ontstaansgebied van deze virussen. De einge andere resistente soort wasN. africana (Suaveolentes) uit zuid-westelijk Afrika. De meest gevoelige Amerikaanse secties, te wetenGenuinae (Tabacum) enTrigonophyllae, Alatae, Acuminatae enBigelovianae (Petunioides), waren gemiddeld gevoeliger danSuaveolentes-soorten die niet uit de Australische woestijnen afkomstig zijn. Het resterende deel van het genus, bestaande uit de Amerikaanse sectiesThyrsiflorae enRusticae (Rustica) enUndulatae, Repandae enNudicaules (Petunioides), stond met betrekking tot gevoeligheid en resistentie tussen laatstgenoemd deel van de sectieSuaveolentes en de groep resistente secties in, maar vertoonde in hoge mate tolerantie voor PVA, PVX en PVY en met overgevoeligheid samengaande resistentie voor TMV. Uit de resultaten blijkt dat de reacties van het genusNicotiana op virussen vooral geografisch bepaald zijn en in mindere mate taxonomisch.  相似文献   

Morphological Basis of Resistance in Cotton to the WhiteflyBemisia Tabaci     

N. S. Butter  B. K. Vir 《Phytoparasitica》1989,17(4):251-261

The morphological basis of resistance to the whiteflyBemisia tabaci Genn. (Aleyrodidae: Hemiptera) was studied. The plant characters examined were leaf area, thickness of leaf lamina, hair density, hair length, angle of insertion of leaf hair, and density of gossypol glands. Hair density and leaf thickness were positively correlated with the population ofB. tabaci, and a positive correlation was obtained between the adult whitefly population and gossypol glands on stem internodes. Cotton genotype USA-22 (sparsely hairy) was found to be more tolerant toB. tabaci than was genotype USA-13 (velvety hairy). The use of thinner and glabrous leaved cotton varieties is suggested to minimize the whitefly menace in cotton.  相似文献   

Laboratory selection of resistance by the red flour beetle,tribolium castaneum (Herbst), to an atmosphere of low oxygen concentration     

E. Donahaye 《Phytoparasitica》1990,18(3):189-202

Adult populations of the red flour beetle,Tribolium castaneum (Herbst), were exposed for 40 generations to an atmosphere containing 99.5% N₂ and 0.5% O₂ at 95% RH, in order to select a strain resistant to the low oxygen concentration (LOC) atmosphere. Selection pressure was maintained at between 50% and 70% mortality. At the 40th generation comparison of sensitivity between the selected strain and the original non-selected strain indicated a resistance factor at the 50% mortality level (LT50) of x 5.2. However, throughout the selections, log-time against probit-mortality curves remained roughly parallel from generation to generation and the slope remained low. These findings indicate a multiplicity of genetic factors that at a high level of selection contribute together towards an adaptation of the insects to survival in the LOC atmosphere. Removal of selection pressure from a sub-population of the selected strain from the 13th to 21st generation revealed that resistance was partially retained with a decrease in resistance factor of 23%. Although the study revealed that the insects were able to develop a strain resistant to hypoxia, exposures were at 95% RH to minimize the desiccation effect. This does not reflect field situations, where ambient relative humidities are generally below 70%.  相似文献   

小麦赤霉病菌对多菌灵抗药性测定方法的探讨     

顾宝根  刘经芬 《植物保护学报》1990,17(3):275-278

  相似文献   

稻瘟菌水平抗性稳定性的研究——品种与小种适合度的分析   总被引：2，自引：0，他引：2  

孔平  岩野正敬 《植物保护学报》1991,18(2):103-108

在温室条件下,对9个无垂直抗性基因粳稻品种×8个日本标准稻瘟菌株组合测定了侵染几率(IP)、病斑型比例(PB)、病斑扩展速率(LR)和产孢能力(SPC)组分,并据此确定了品种与小种的适合度。方差分析结果表明,除SPC的互作项外,其它组分及类型,方差均达到显著或极显著水平。但品种和小种主效应所占方差更大,从而证实了品种的抗性类型为水平抗性。某些品种在IP、PB及LR组分上反映了小种的专化作用,但因为不同品种在各组分上的抗性反应不同,因此,品种水平抗性的稳定性不能由组分的小种专化作用确定,而须由各组分组成的适合度的小种专化性确定。对品种X小种的适合度进行了互作的多重比较,未发现专化性互作,说明供试品种的水平抗性是稳定的。  相似文献