直接药敏试验在肉鸡生产中的临床应用意义

以信阳市和谐动物医院在2012²013年间接诊的112个细菌病例为研究对象,选取18种常见的抗菌素药敏片,运用纸片扩散法来分析直接药敏试验在临床上的应用效果。结果表明:从112个细菌病例中选出92个病例做研究,36个病例可筛选出3种以上的高敏药物,28个病例可筛选出2种以上的高敏药物,39个病例只能筛选出1种高敏药物,16个病例只能筛选出中敏药物,4个病例对常规的18种药物全部耐药。     

输卵管炎种鸭大肠杆菌的分离鉴定及生物学特性分析

为分析表现输卵管炎种鸭体内分离的大肠杆菌的致病性、药敏试验、血清型及毒力基因携带情况,无菌采集表现输卵管炎的种鸭肝脏,进行大肠杆菌的分离鉴定,经易感鸭皮下注射,测定其致病性;纸片法进行药敏试验;凝集试验确定血清型;PCR法检测毒力基因.结果共分离鉴定大肠杆菌16株,其中强毒菌株11株.70％以上菌株表现敏感的药物有丁胺卡那霉素、氟苯尼考、头孢唑啉、左氧氟沙星和壮观霉素,70％以上菌株表现耐受的药物有复方新诺明、卡那霉素、庆大霉素、恩诺沙星和氟哌酸.16株大肠杆菌分属于4个血清型,078占56.3％,为主要血清型.毒力基因irp2、yuA、imC和pa pC的检出率分别为68.8％、87.5％、75％和100％.总结说明,从表现输卵管炎的种鸭体内共分离到16株大肠杆菌,078是主要的血清型,首选壮观霉素和氟苯尼考等敏感药物进行治疗.     

河北省北部马铃薯早疫病菌对嘧菌酯敏感性的测定与分析

选取2009~2011年采集自河北省张家口、承德两地的74株马铃薯早疫病菌(Alternaria solani),用抑制分生孢子萌发的方法,进行嘧菌酯敏感性测定,旨在为生产上科学使用嘧菌酯提供理论依据。结果表明,嘧菌酯的EC50介于0.01~0.13μg/m L之间,平均EC50为0.04μg/m L。处于敏感基线的菌株(EC500.01~0.07μg/m L)占总数的87.84%。2009~2011年所采集的早疫病菌对嘧菌酯敏感性随年度略微有所下降,不同地区采集的菌株对嘧菌酯的敏感性也有差异。因此,河北省北部地区马铃薯早疫病的防控仍可以使用嘧菌酯,但不可盲目,并实时检测菌株的抗药性。     

杀菌温度对优质巴氏杀菌乳中热敏感和生物活性物质的影响

选取我国东南某乳品企业特优级(A+)生乳,采用不同巴氏杀菌温度74℃、75℃、76℃、77℃、78℃、79℃和80℃(15 s保持时间),检测杀菌乳中的热敏感物质糠氨酸、碱性磷酸酶、乳过氧化物酶和乳中生物活性物质免疫球蛋白、乳铁蛋白、ɑ-乳白蛋白、β-乳球蛋白的含量.试验结果显示,优质乳在74℃和75℃杀菌条件下活性物...     

籼型光温敏核不育系广占63S生育特性的研究

1999～ 2 0 0 1年籼型光温敏核不育系广占 63S在合肥种植 ,其主茎叶片数 14 .5～ 12 .9叶 ,播始历期 91～ 69d ,平均播始期有效积温 10 5 8.9℃ ,播始历期与有效积温呈极显著正相关 (r=0 .761 ) ,表明广占 63S为感温性强的早熟中籼两系核不育系     

sch蚕胚胎期温敏性的mRNA差异显示研究

采用mRNA差异显示技术对不同催青处理的伴性赤蚁sch系统进行研究 ,并以普通黑蚁系统夏芳作为对照。实验中分别抽提高温和常温催青处理 36h后的sch蚕卵和夏芳蚕卵的总RNA进行DDRT -PCR分析 ,其产物于变性聚丙烯酰胺凝胶上电泳展示 ,得到大量的差示片段。对高温催青处理后在夏sch蚕卵中特异表达的 2条能稳定重复的带进行了克隆 ,得到了长度分别为 2 73和 199bp的cDNA片段 ,并对其进行了序列分析。Northern杂交证实HAP82 80仅在高温催青处理的夏sch蚕卵中有转录 ,表明其为sch蚕卵经高温催青处理后特异表达的产物     

光敏、温敏核不育水稻核不育基因等位性及基因对数的研究

以光敏核不育系农垦58S及其衍生的光敏核不育系7001S、温敏核不育系W6154S、增矮64S，以及温敏核不育系安农S－1及其衍生的温敏核不育系810S、安湘S、香125S为材料进行相互杂交，在长日高温条件下观察F1的育性，根据其可育性和不育性确定核不育基因的等位性。结果表明：7001S、W6154S、培矮64S与核不育基因供体农垦58S之间有等位点的核不育基因；但温敏核不育系W6154S与培矮64S之间，不具等位点的温敏核不育基因。该结果说明光敏核不育系农垦58S至少存在一对光敏核不育基因和两对温敏核不育基因，而且各对温敏核不育基因可独立遗传，在夏季高温条件下其不育性得到充分表达。安农S－1与其衍生的不育系之间以及衍生的不育系与不育系之间都具有等位点的温敏核不育基因。农垦58S及衍生的核不育系与安农S－1及衍生的核不育系之间没有等位点的核不育基因。     

Characterization of the durable resistance to yellow rust in old winter wheat cultivars in the Netherlands

Summary Winter wheat cultivars released in the Netherlands before 1930 carried durable resistance to yellow rust. Cultivars released in the period between 1930 and 1950 often were durably resistant while recent cultivars infrequently showed durable resistance. This durable resistance was not difficult to transfer to new cultivars. Twenty nine older cultivars with durable resistance and eight recent non-durably resistant cultivars were tested in the seedling stage and in the adult plant stage against 12 West-European yellow rust races and against some non-European races in the seedling stage only. The adult plant tests were carried out in race nursery tests in the Flevopolder. Per race nursery all 37 cultivars, planted in hills of about 20 plants on both sides of the highly susceptible cv. Michigan Amber, were exposed to one race.The infection type of each cultivar-race combination was scored on 0 to 9 scale once in the seedling stage and twice in the adult plant stage. In the race nurseries the percentage leaf area affected was evaluated three times to be used to calculate the area under the disease progress curve (AUDPC). This AUDPC multiplied with the mean infection type in the field gave the susceptibility index (SI).The infection types were classified into resistant (R), intermediate (I) or susceptible (S) when the infection types were 0 to 3, 4 to 6 or 7 to 9, respectively. Four categories of resistance were discerned on the basis of the three infection type scores: 1) RRR, overall resistance; complete or near-complete resistant at all stages. 2) SRR, adult plant resistance, complete- or near-complete resistant at the adult plant stage only. 3) SRS and SSR, temperature sensitive resistance, the resistance changed from the one evaluation data to the other. 4) SSS and an SI lower than that of Michigan Amber, partial resistance.The frequencies of overall, adult plant and temperature sensitive resistance were 1.4, 52 and 54% in the older cultivars and 40, 62 and 22% in the recent ones, respectively. Among the older cultivars all had a fair to high level of partial resistance, the SI being on average only 20% of that of Michigan Amber, while most cultivars also seemed to carry temperature sensitive resistance. The partial resistance of the recent cultivars was of a much lower level with a mean SI compared to that of Michigan Amber of 61%. Partial resistance was highly correlated (r = –0.94) with the mean resistance scores from the Dutch Recommended Cultivars Lists. It was concluded that partial resistance and temperature sensitive resistance were the major components of the durable resistance in the older cultivars.     

辐射敏化剂对离子注入小麦生物学效应的影响

采用中国科学院兰州近代物理研究所 2 0 0kV离子注入机产生的不同剂量Fe1+ ,对春小麦新品系 81 52 9种子进行注入并用辐射敏化剂后处理 ,研究其注入效应。结果表明 :①离子注入随注入剂量的增加染色体畸变率呈上升趋势 ;②不同辐射敏化剂后处理对萌发力、染色体畸变率影响程度不同 ;③不同辐射敏化剂对同一剂量Fe1+ 离子注入小麦的染色体畸变率影响的总趋势 :EDTA >秋水仙素 >咖啡因。     

水稻两用核不育系育性转换与温度的相关分析

在贵阳对8个籼型水稻两用核不育系进行了间期为10－15d的分期播种，以套袋自交结实性作为育性考查指标，结果所有核不育系都有稳定不育期和可育或部分可育期表现，且育性转换明显。稳定不育期的长短因不育系不同而有差异，范围在5－33d。自交结实率与日平均气温之间的相关性表明，所有不育系都在幼穗发育的一定阶段内对温度表现敏感，大多数不育系的温度敏感时期在抽前7－24d，培矮64S在抽穗前17－30d。不同不育基因供体来源的不育系对温度敏感时期和持续时间长短存在着差异，同一不育基因供体来源的不同不育系之间，其育性对温度敏感时期和持续时间长短也不相同。