麻疯树水浸液对两种经济作物的化感作用研究

以麻疯树种子的萌发率、胚根长度、根活力指数、叶绿素及光合作用作为测量指标,以化感效应敏感指数RI为评价指标,研究了麻疯树对2种经济作物烟草和玉米的化感作用。结果表明:不同的麻疯树器官水浸液对烟草和玉米的抑制程度不同:种子>叶>枝。烟草和玉米对低浓度麻疯树水浸液的反应不同:烟草种子萌发与幼苗生长没有受到明显抑制,而玉米种子萌发及幼苗生长则受到促进;玉米地下部分对麻疯树化感物质较地上部分敏感,烟草则无明显区别。麻疯树水浸液对玉米和烟草幼苗生长的抑制作用在生理上表现为:抑制光合作用、减少气孔开放和胞间CO2浓度、降低根活力指数和叶绿素含量,以及种子吸胀过程中的主动吸收,增强呼吸作用。     

4株猪圆环病毒2型凉山州分离株全基因组进化分析

为了解猪圆环病毒2型(PCV2)凉山州分离株的基因型,本研究采用PCR方法对采自凉山州3个发病猪场的4个PCV2阳性样品进行全基因组序列的扩增、克隆、测序分析,并绘制遗传进化树.结果显示:4个PCV2凉山州分离株全基因组序列长度均为1767 bp,核苷酸同源性为99.4％～99.8％,与国内外101株PCV2参考毒株核...     

低山丘陵岗地齿叶山杨引种研究

本文介绍了齿叶山杨、响叶杨、毛白杨、山杨在长江中游丘陵岗地的物候期、林木高生长节律。调查了造林成活率、12 a 生林木保存率、速生性及林分的抗病抗虫性。研究了小×大叶杨、齿叶山杨杂交种(株系)在高海拔(1 500 m)地区的抗病性和速生性。     

鸡IFIT5对J亚群禽白血病病毒在DF-1细胞内复制的影响

【目的】制备鸡干扰素诱导蛋白含三角形四肽重复5(IFIT5)多克隆抗体,以探究IFIT5对J型禽白血病病毒(ALV-J)在鸡胚成纤维细胞(DF-1)内复制的影响。【方法】以感染ALV-J的鸡脾脏组织细胞提取的RNA反转录获得的cDNA作为模板,对IFIT5基因进行PCR扩增,利用重组酶将纯化后的PCR产物和线性化载体进行连接,构建重组质粒pET-28a-IFIT5和pcDNA5-flag-IFIT5并测序。将测序正确的重组质粒pET-28a-IFIT5转化大肠杆菌BL21感受态细胞进行诱导表达,表达的融合蛋白His-IFIT5纯化后免疫6周龄BALB/c雌鼠制备多克隆抗体,通过Western blotting鉴定抗体的特异性,利用间接ELISA测定抗体的效价。将测序正确的重组质粒pcDNA5-flag-IFIT5转染DF-1细胞,24 h后接种ALV-J,通过Western blotting检测DF-1细胞中过表达IFIT5对ALV-J复制的影响。【结果】试验成功扩增到大小为1 440 bp的IFIT5基因,并成功构建重组质粒pET-28a-IFIT5和pcDNA5-flag-IFIT...     

Antibacterial Meroterpenoids,Merochlorins G–J from the Marine Bacterium Streptomyces sp.

Four new chlorinated meroterpenoids, merochlorins G−J (1−4), and 10, a dihydronaphthalenedione precursor, along with known merochlorins A (5) and C−F (6−9), were obtained from cultivation of the bacterium strain Streptomyces sp. CNH-189, which was isolated from marine sediment. The planar structures of compounds 1−4 and 10 were elucidated by interpretation of MS, UV, and NMR spectroscopic data. The relative configurations of compounds 1−4 were determined via analysis of nuclear Overhauser effect (NOE) spectroscopic data, after which their absolute configurations were established by comparing the experimental electronic circular dichroism (ECD) spectra of compounds 1−4 to those of previously reported possible enantiomer models and DP4 calculations. Compound 3 displayed strong antibacterial activities against Bacillus subtilis, Kocuria rhizophila, and Staphylococcus aureus, with MIC values of 1, 2, and 2 μg/mL, respectively, whereas compound 1 exhibited weak antibacterial effects on these three strains, with a 16−32 μg/mL MIC value range.     

苦丁茶不同提取物抗氧化活性比较及其GC-MS分析

利用气相色谱-质谱联用技术（GC-MS）,对苦丁茶超声辅助不同有机溶剂（乙醇、乙酸乙酯、石油醚）提取物及超临界CO₂萃取物的体外抗氧化活性（DPPH自由基清除能力、羟基自由基清除活性、超氧阴离子自由基清除活性和ABTS ⁺自由基清除能力）进行比较分析。结果表明,苦丁茶不同提取物DPPH清除能力和超氧阴离子自由基清除活性依次为：超声-乙醇提取物>超临界CO₂萃取物>超声-乙酸乙酯提取物>超声-石油醚提取物,羟基自由基和ABTS ⁺自由基清除能力依次为：超声-乙醇提取物>超声-乙酸乙酯提取物>超临界CO₂萃取物>超声-石油醚提取物。GC-MS结果显示,苦丁茶不同提取物中主要有5类物质,共有49种化学成分,7种共有成分。     

H9亚型禽流感病毒免疫磁珠分离方法初步建立

禽流感病毒(AIV)严重危害世界养禽业,是举世瞩目的重大人畜共患病原,环境中微量病原是潜在的重要传染源,很难进行监测。为了提高畜禽环境中微量病原的监测效率,样品的必要预处理非常重要。制备了粒径约30~100 nm的Fe_3O_4纳米粒子,并利用戊二醛二步法偶联H9-HA单抗和磁珠,偶联效率约为130 mg/g;200μL免疫磁珠(5.6 mg/m L)可分离纯化100μL血凝价为28的AIV-H9。制备的免疫磁珠可以为纯化和富集畜禽生活环境中的微量病原提供便利,结合其他病原检测手段将有助于提高环境中病原的监测效率。     

Study on the Characteristics of Two Low Hemagglutinating Activity H9N2 AIV Strains

To study the characteristics of 2 low hemagglutinating activity H9N2 avian influenza virus (AIV) strains.2 strains were identified by HA/HI,electron microscope observation,HA and NA sequencing.The virus characteristics were studied by morphology,chemistry and biology.2 isolates were identified as H9N2 AIV.The observations demonstrated that the virions expressed various shapes of spherical,oval,elongated forms and polymorphism with diameters in a range of 80 to 120 nm.Hemagglutinin(HA) of the 2 strains was medium-stable to heat,and they were heat-resistant under 50 ℃.2 isolates could agglutinate cock and human O type red blood cells.The agglutination did not appear on the original isolates,but recovered with the passage of virus gradually.2 isolates did not agglutinate pig,cattle,sheep,rabbit and horse red blood cells.2 strains were not sensitive to the ether and chloroform,and only one isolate was sensitive to acids.2 strains were not fatal to the chicken embryo,and the EID₅₀ were both 1×10^-7/0.2 mL.The small White mice showed no clinical symptoms and no deaths after being inoculated with the viruses via respiratory route in our experiment.Serum antibody HI titers of the survived mice were measured after inoculated 14 d,and the antibody of H9N2 AIV were positive.Some tolerant H9N2 strains existed in live animal markets of Shanghai area.     

泡核桃良种胜霜的选育

胜霜是从云南核桃(J.sigillata D)实生种群中选育出的核桃新品种。文中介绍了选育技术路线,详细阐述了其选育过程以及植物学特征、物候期、生长结果习性、经济性状、营养成份含量、适应性、抗逆性等生物学性状。并简要叙述了其繁殖和栽培技术要点。