不同培养条件对苏棉12号茎尖组织培养的影响

将苏棉12号无菌种子放于不同的培养基上培养5～7 d成苗,然后制备茎尖分别放在不同的激素和不同添加物的培养基上培养,探索出适合茎尖生长成苗的一套比较完整的体系.结果表明:0.1 mg/LIBA对植株再生的效果最佳;在使用的糖源中,葡萄糖明显好于蔗糖;80 mg/L卡那霉素的筛选效果最好.     

柱花草编码CP12蛋白的cDNA克隆及其序列分析

叶绿体蛋白12(chloroplast protein 12,CP12)是一个存在于叶绿体与光合作用相关的蛋白。以亲本柱花草热研2号叶片为材料,根据豌豆CP12及柱花草响应低温的cDNASSH文库中CP12克隆片段设计引物,采用RT-PCR,从柱花草cDNA中克隆获得柱花草热研2号CP12基因全长序列,并在GenBank登陆(登录号:HQ906668),命名为SgCP12。柱花草热研2号CP12基因全长426bp,包含399 bp的ORF。通过生物信息学分析结果表明,CP12的C端具有高度保守的结构域。同源性分析表明,该基因与豌豆的CP12基因氨基酸序列同源性最高。     

Molecular Characterization of Equine Rotavirus Group A Detected in Argentinean Foals During 2009–2014

Equine rotavirus group A (RVA) has been detected in several countries worldwide since its first detection in 1975. Currently, equine RVA is considered the major cause of dehydrating diarrhea in foals younger than 3 months, and the frequency of detection in clinical cases varies from 20% to 77%. The genotypes of epidemiologic relevance found in horses are G3P[12] and G14P[12]. In a survey conducted in Argentina from 1992 to 2008, equine RVA was detected in 21% and 39% of the fecal samples and outbreaks, respectively. Genotype distribution was 51% G3P[12] and 33% G14P[12]. In continuation with the surveillance, the aim of the present study was to characterize the equine RVA detected in Thoroughbred foals in Argentina from 2009 to 2014. A total of 436 stool samples (corresponding to 177 single diarrhea cases or outbreaks) were analyzed. Equine RVA was detected in 31% (135 of 436) of the samples, which corresponded to 42% (74 of 177) of outbreaks. From the positive cases, 42% (57 of 135) were genotyped. Of this, 63% were G3 (36 of 57) and 37% (21 of 57) were G14 genotype. Considering the whole data (1992–2014), equine RVA was detected in 25% (300 of 1,207) of the stool samples and 41% (119 of 293) of the diarrhea outbreaks. The results of this study also show a cyclic pattern of the G3 and G14 prevalence in the horse population with a change in G3:G14 frequencies from year to year. Furthermore, clustering in the phylogenetic tree suggests evolutionary and geographic relationships between the Argentinean strains compared with the strain circulating worldwide.     

(111)晶面暴露的NiO纳米催化剂的制备及其CO催化氧化性能

采用溶剂热法,以Ni(NO_3)_3·6H_2O、均苯三甲酸以及N,N-二甲基甲酰胺(DMF)为原料快速合成金属有机骨架材料Ni_3(BTC)_2·12H_2O晶体。以Ni_3(BTC)_2·12H_2O为前体,通过焙烧得到具有(111)面的NiO颗粒用于CO催化氧化反应,并与由硝酸镍热解得到的NiO(R)催化剂进行对比。通过X射线衍射(XRD)、N_2物理吸附-脱附、透射电子显微镜(TEM)以及X射线光电子能谱(XPS)等方法对具有(111)面的NiO颗粒的组成、结构和形貌进行表征。CO催化氧化结果表明,具有(111)面的NiO颗粒的催化活性优于普通NiO催化剂的催化活性。     

转基因抗虫棉种质资源GK12性状与利用情况分析

采用比较方法,对GK12的遗传基础、产量、农艺性状及其利用情况进行了分析,总结了以GK12为亲本育成转基因抗虫棉新品种的情况,为GK12的进一步利用提供了重要参考依据。     

“十二五”期间农业推广硕士教育与管理问题探讨

农业推广硕士专业学位教育的求真性、务实性和灵活性等特点,决定农业推广硕士教育是＂十二五＂期间我国高等教育支持新农村建设的一个契合点。针对当前农业推广硕士教育和管理中存在的不足,需要从广开招生门路,提高生源质量;优化课程设置,创新教学方式;强化导师责任,提升师资力量;规范论文设计,严格答辩程序等方面来加以改进。     

Resistance mechanisms and farm-level distribution of fecal Escherichia coli isolates resistant to extended-spectrum cephalosporins in pigs in Spain

Introduction

Fecal Escherichia coli isolates showing a phenotype of reduced susceptibility or resistance to extended-spectrum cephalosporins are common among pigs in Spain. The aim of this study was to describe the main beta-lactam resistance mechanisms carried by these strains and their distribution at farm-level.

Materials and methods

Twenty-nine E. coli isolates showing reduced susceptibility or resistance to extended-spectrum cephalosporins were collected from a sampling frame of 80 pig farms distributed over 13 Spanish provinces. The survey was carried out at the slaughterhouse level in 2004.

Results

Of the 29 isolates, 21 (72%) met the criteria for a positive phenotypic confirmatory test for extended-spectrum beta-lactamases (ESBL). The following ESBLs were detected: SHV-12 (12 isolates, 41%), CTX-M-1 (three isolates, 10%), CTX-M-9 (three isolates, 10%), and CTX-M-14 (three isolates, 10%). The remaining eight isolates (28%) were phenotypically non-ESBL, with seven of them (24%) showing mutations on the chromosomal ampC gene promoter at positions −42 (C → T), −18 (G → A), −1 (C → T), and +58 (C → T). A multiplex PCR for detection of plasmidic class C beta-lactamases was negative for all isolates.

Conclusion

Different ESBLs and other mechanisms linked to extended-spectrum cephalosporin resistance are widely distributed among fecal E. coli from slaughter pigs in Spain.     

IL-12及其免疫调节作用

IL-12是一种具有多种生物学活性的免疫细胞生长刺激因子,它能促进T淋巴细胞和NK细胞的分化与增殖,调控细胞免疫,提高NK/LAK细胞的杀伤功能和特异性CTL细胞的应答能力,诱导γ干扰素产生;能与其他细胞因子协同成为重要的免疫治疗因子。     

高香乌龙茶新品种鸿雁12号的选育

对高香乌龙茶新品种鸿雁12号的选育过程、多年品比和区试试验结果进行了介绍和分析。结果表明:鸿雁12号属灌木型,中叶早芽,无性系新品种,其生长势强,产量高,品比试验3年平均产量比对照福建水仙增产41.3%,在4个省份区试点产量表现均较好,分别比对照种黄棪增产2.22%、10.29%、29.64%和32.76%。适制高香乌龙茶和花香绿茶,品质优异。高香乌龙茶外形绿润,花香高浓持久,滋味浓滑爽口,汤色黄绿明亮,感官审评比福建水仙高8.1分,比黄棪高2.55～4.2分;花香绿茶滋味浓爽,香气高长,汤色叶底绿明亮,香气品质优于福鼎大白茶。该品种抗寒旱和抗虫能力强,易扦插,种植成活率高,适宜广东、湖南、广西、福建等省生产应用。     

添加V_(B_(12))、V_E、V_C对无角道塞特绵羊精液冷冻效果的影响

探讨在无角道塞特绵羊冷冻精液稀释液中添加VB12、VE、VC对精子冷冻品质的影响。在无角道塞特绵羊冷冻精液稀释液中添加不同质量浓度的VB12、VE、VC制作细管冻精,解冻后观察精子的成活率和顶体完整率等指标。结果显示,VB12添加0.003 g/L时能够显著提高解冻后的精子活率(P0.05)和精子顶体完整率(P0.05);VE添加2.5 g/L时,能够极显著提高解冻后的精子活率(P0.01)和顶体完整率(P0.01);VC的添加4.4 g/L时能够显著提高解冻后的精子活率(P0.05),但对冷冻后精子的顶体完整率无影响。在稀释液中添加VB12、VE和VC能使解冻后精子品质得到提高。VE添加后能够极显著提高冷冻精子的顶体完整率,应该优先考虑添加。