早熟桃、油桃胚培养研究     

赵艳华  程和禾  吴永杰  李玉生  刘国俭  吴雅琴 《河北农业科学》2008,12(8):12-13

以早熟桃、油桃杂交胚为试材，调查了胚发育动态，研究了影响胚培养的主要因子，并建立了胚培养技术体系。  相似文献   

奶牛粪中致病性大肠杆菌的分离鉴定及生物学特性的研究   总被引：2，自引：0，他引：2  

于俊娥  敖日格乐  王纯洁  张爱荣  格日勒图  程佳 《畜牧兽医杂志》2007,26(5):1-3

对呼和浩特市地区不同奶牛场共20头健康荷斯坦奶牛的鲜粪便进行了病原性大肠杆菌的分离提取,共分离到大肠杆菌40株,经鉴定病原性大肠杆菌6株,均为强毒株,占分离菌数的15.0%,而34株为非致病性大肠杆菌,占分离菌数的85.0%。同时对6株病原性大肠杆菌进行了病原性特性的研究,发现病原性菌的生化特性基本一致,与资料报道相符。对6株病原性大肠杆菌进行了抗"O"血清鉴定,除1株有自凝现象,其余5株分属O1、O2、O83个血清型,分别占定型菌株的20%、40%和40%。  相似文献   

Construction of Drought and Salt Resistance Gene P5CS in Plant Expression Binary Vector     

CHENG Ji-dong  AN Yu-lin  SUN Rui-fen 《华北农学报》2008,23(6)

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Characterization of Competitive Mycelial Growth in Pleurotus eryngii     

SHANG Xiaodong  CHENG Jihong  TAN Qi 《食用菌学报》2007,(4)

Competitive mycelial growth(CMG)between Pleurotus eryngii isolates is genetically controlled,and stable CMG responses(positive,neutral or negative)were recorded among the strains tested.Correlations between CMG responses and mycelial growth rate were observed.CMG simultaneously reflects information relating to somatic incompatibility and mycelia growth rate in edible mushrooms,and can be readily and reliably applied to studies on genetic polymorphism among this group of fungi.  相似文献   

赤霉酸涂布剂在绿宝石梨上的应用效果研究     

程亚樵  薛丽丰  乔宝营  黄海帆  秦莉红  朱运钦  李道德 《北方园艺》2009,(2)

试验证明,应用赤霉酸涂布剂涂抹果柄,可以有效地减少绿宝石梨裂果率(较对照减少裂果25.38%),增大果个、提高产量(较对照增长14.15%),明显提高经济效益,并使可溶性固形物的含量增加2.55%,果心减小3.48%.用3%赤霉酸脂膏于花后10d涂抹果柄基部长度1.5cm,对减轻绿宝石梨裂果的作用和提高果实其他性状效果最好.  相似文献   

浅析中国木材产业的国际化经营问题     

印中华  宋维明  程宝栋 《林业资源管理》2007,(4):5-9

国际化经营是影响中国木材产业的重要因素,对于中国木材产业的成长具有重大意义。该文介绍了国际化经营的相关概念,分析了中国木材产业国际化经营的现状,研究了进出口和对外直接投资对中国木材产业的影响,提出了中国木材产业国际化经营的演化路径。  相似文献   

鸭肿头出血症病毒强毒的致病性及感染组织细胞的超微病理变化     

张舍郁朱德康  程安春汪铭书沈婵娟  李传峰张娜 《中国兽医科技》2007,37(12):1017-1023

将鸭肿头出血症病毒（DSHDV）强毒株以不同途径接种10日龄鸭胚，研究了病毒在鸭胚中的繁殖规律，并用透射电镜观察了感染鸭胚各组织器官的超微结构变化，同时用DSHDV人工感染不同日龄雏鸭，比较了不同感染途径对雏鸭的致病性和对不同日龄雏鸭的致病性。结果显示，尿囊腔和卵黄囊2种途径均能使病毒在鸭胚上繁殖并传代，对鸭胚的半数致死量分别为10^-7.24／0．2mL和10^-6.4／0．2mL。病毒感染鸭胚后，电镜下可观察到肝和尿囊膜中的病毒粒子，病毒粒子呈球形或椭圆形，大小为60～80nm，无囊膜；病毒在细胞浆内复制，可形成特征性包涵体；病毒侵害的主要靶器官为尿囊膜与肝，细胞器的变化主要表现为粗面内质网扩张以及线粒体肿胀和嵴断裂、消失。病毒经肌肉注射、口服和滴鼻均能使28日龄鸭感染发病，致死率分别为86％、89％和97％。研究表明，DSHDV能很好地在鸭胚上生长并致鸭胚各组织器官超微结构发生变化，不同感染途径均能使雏鸭感染发病且致病性强。  相似文献   

环境因素对淡水浮丝藻生长及产生嗅味的影响          下载免费PDF全文

成建国  马力通  赵文渊  刘云颖 《水生态学杂志》2022,43(2):70-76

浮丝藻(Planktothrix) 是一种在我国水域中普遍存在, 可以引起蓝藻水华的水华藻之一,其代谢生成的二-甲基异莰醇 (2-methylisoborneol, 2-MIB) 可导致水体产生令人厌恶的嗅和味,从而使饮用水感官质量下降。本文探讨了温度 (15-30℃),BG11营养盐浓度 (20-100% (w/v))和光照强度 (1000-4000 Lux)对分离于巢湖的浮丝藻(Planktothrix sp.) FACHB-1372生长密度,总2-MIB生成量及胞外2-MIB分泌量的影响。研究结果表明在所述实验条件范围内,温度对浮丝藻生长密度,总2-MIB生成量及胞外2-MIB分泌量影响最显著。25 ℃是浮丝藻最适宜的生长温度,最高细胞密度可达6.04×10_⁵ cell?ml_^-1,30 ℃是其最适宜的产2-MIB温度,总2-MIB生成量和胞外2-MIB分泌量最高分别可达3.64×10_³ ng?L_^-1和2.78×10_³ ng?L_^-1；其次为营养盐浓度,增大BG-11营养盐浓度,浮丝藻生长密度和总2-MIB生成量会随之增加,但实验发现低浓度营养盐时,胞外2-MIB分泌量所占比例较高,表明低浓度营养盐更有利于浮丝藻进行胞外2-MIB分泌；光照对浮丝藻生长及产嗅味物质影响较小,强光照可促进2-MIB胞外释放,4000 Lux时其胞外2-MIB分泌量达最高。最后,依据实验结果为控制和预警浮丝藻过渡繁殖和嗅味物质释放提出了应对方法。  相似文献   

Evaluation of Joint Toxicity of Enrofloxacin and Three Antimicrobials on MRC-5 Cells     

LUAN Yehui  CHENG Linli  ZHAO Junjie  DING Yuli  WANG Wenhao  HUANG Jiamo 《中国畜牧兽医》2007,47(11):3722-3730

The aim of this study was to evaluate the combined toxicity of enrofloxacin with each of three antimicrobials (ciprofloxacin,florfenicol and sulfamethazine).MRC-5 cells were used as a cell model to simulate the damage of lung cells caused by mixed contamination of antimicrobials.Multiple concentration gradients and mixing ratios were set.CCK-8 method was used to determine the inhibition rate of cell growth caused by four antimicrobials and the inhibition rate of cell growth caused by enofloxacin mixed with three antimicrobials,respectively.Then Chou-Talalay method was used to fit the median effect plot and to calculate the combination index (CI) value.The results showed that the growth inhibition rates of MCR-5 cells caused by four single drugs went up in a step-like manner with the increase of drug concentration in the tested concentration range,among them,the growth inhibitory rate of MCR-5 cells by florfenicol was low (<4.5%).The combined toxicity of the three binary combinations showed a concentration-dependent and mixing-ratio dependence.Mixing enrofloxacin and ciprofloxacin showed synergistic toxicity (CI<1) on MRC-5 cells at high and middle concentration groups,and antagonistic toxicity (CI>1) at the very-low-concentration groups.Mixing ciprofloxacin and florfenicol mainly showed an inhibited toxicity (CI>1).Binary combination enrofloxacin and sulfamethazine might present either a synergistic joint toxicity (CI<1) or an antagonistic joint toxicity (CI>1) as the concentration and mixing ratio changing.This study showed that it was necessary to assess the combined toxicity of antimicrobials in the toxicity evaluation of antimicrobials.Using Chou-Talalay method,the joint toxicity of multiple antimicrobials could be quickly and efficiently determined at cellular level.  相似文献   

Effects of felodipine on atherosclerosis in high cholesterol-diet apolipoprotein E knock-out mice     

YAO Rui  CHENG Xiang  LIAO Yu-hua  CHEN Yong  XIE Jiang-jiao  YU Xian  DING Ying-jun  TANG Ting-ting 《园艺学报》2008,24(11):2092-2096

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