3类生境下脐橙果实细胞壁酶、瓤囊壁超微结构和品质变化的研究

为改进脐橙果实质地和科学生态区划与高品质栽培技术提供理论依据,研究了四川3类不同生境下脐橙果实果胶甲酯酶(PE)、多聚半乳糖醛酸酶(PG)、纤维素酶(CX)、瓤囊壁超微结构及主要品质指标的变化。结果表明:果实生长发育期细胞壁酶活性逐渐升高,但不同生境类型的变化趋势不同。超微结构中,南亚热带攀枝花脐橙的线粒体明显,中胶层清晰,细胞壁形态结构较完整;中亚热带江安和中北亚热带雅安脐橙细胞壁的中胶层明显裂解,线粒体膜分解,细胞器空泡化。不同生境SSC和可溶性糖差异显著。PG酶活性与≥10℃积温、1月份平均气温、年平均气温显著负相关,与年降雨量显著正相关。固酸比与≥10℃积温、年平均气温、1月均气温极显著正相关,与日照时数极显著正相关,与降雨量显著负相关。     

Detection and characterization of avian leukosis virus in Marek's disease vaccines

Avian leukosis virus (ALV) infection in chickens is known to induce increased mortality, tumors, delayed growth, and suboptimal egg production. Countries importing specified pathogen-free eggs, vaccines, and poultry breeding stock require freedom of infection or contamination with ALV in such products among other avian pathogens. Recently, ALV was found as a contaminant in a limited number of commercial poultry vaccines, even after routine quality assurance procedures cleared the vaccines for commercialization. The contaminated vaccines were promptly withdrawn from the market, and no direct detrimental effects were reported in poultry vaccinated with such vaccines. We describe herein the characterization in vitro of the contaminant viruses. All exogenous viruses detected in four vaccine lots belong to subgroup A of ALV based on cell receptor interaction, subgroup-specific polymerase chain reaction (PCR), envelope gene sequencing, and virus neutralization. A combination of thermal treatment and serial dilutions of the contaminated vaccines facilitated detection of contaminating ALVs in cell culture coupled with antigen-capture enzyme-linked immunosorbent assay. Subgroup-specific PCR readily detected ALV-A directly in the contaminated vaccines but not in naive vaccines or cell controls. Our methods are proposed as complementary procedures to the currently required complement fixation for avian leukosis test for detection of ALV in commercial poultry vaccines.     

牛分枝杆菌特异性PCR检测方法的建立及初步应用

根据已发表的牛分枝杆菌的pncA的基因序列，设计和合成了一对可扩增294bp目的片段的引物，建立了特异性检测牛分枝杆菌的PCR方法。对牛分枝杆菌国际参考株和国内分离株成功扩增出294bp的特异性基因片段；对人结核分枝杆菌、副结核分枝杆菌、鸟胞内分枝杆菌和草分枝杆菌DNA的PCR扩增结果均为阴性。本PCR方法检测的敏感度可达到50pg。对10份牛分枝杆菌培养阳性和10份阴性样品的DNA分别进行了PCR检测，结果10份阳性样品中有9份样品为PCR扩增阳性，阳性符合率为90％（9／10）；而10份阴性样品则PCR扩增全部为阴性，阴性符合率为100％（10／10）。本方法可做为牛分枝杆菌的快速检测和流行病学调查的工具。     

鸭源致病性大肠杆菌的血清型鉴定及其相关毒力基因分析

自规模化养鸭场患典型大肠杆菌败血症雏鸭分离的282株致病性大肠杆菌（E.coli）中鉴定出210株（包含37种血清型）,其中O93、O78、O92、O76占43.8%（92/210）为优势血清型,O46、O32＆O93混合型、O60＆O93混合型为首次从鸭群中分离到。应用PCR结合核酸序列测定对210株致病性E.coli（鸭大肠杆菌病分离株）和28株自健康雏鸭泄殖腔拭子分离的E.coli（临床健康鸭大肠杆菌分离株）进行包括强毒力岛（HPI）中的鼠疫菌素受体基因（fyuA）和铁调节蛋白基因（irp2）、Ⅰ型菌毛必需蛋白基因（fimC）、P型菌毛结构基因（papA）和血清耐受基因（iss）检测,结果表明：fyuAi、rp2、fimC、papA和iss基因在鸭大肠杆菌病分离株的携带率分别为41.0%、43.3%、92.9%、97.6%和96.7%,在临床健康鸭大肠杆菌分离株的携带率分别为21.4%、25.0%、92.9%、100%和92.9%,患病鸭和临床健康鸭大肠杆菌分离株iss、fimC和papA携带率差异不显著（P〉0.05）,但papA的携带率均显著高于其他宿主（鸡、猪和人）源E.coli;HPI毒力岛在鸭源E.coli中分布较广,其携带率表现为鸭大肠杆菌病分离株极显著高于临床健康鸭大肠杆菌分离株。HPI毒力岛的携带率与菌株的致病性呈明显的正相关,与O78等特定的血清型有一定的关系。鸭大肠杆菌病分离株有37.6%（79/210）同时携带fyuAi、rp2、fimCi、ss和papA基因,极显著高于健康鸭大肠杆菌分离株的14.3%（4/28）（P〈0.01）。     

烟草气候斑病的发生规律及防治

１９９０－１９９４年研究结果表明，低温是诱发气候斑病的主要因素，不同品种抗性差异显著，氮钾比失调，偏施碳铵地发病严重，当大面积种植感病品种，寄主处于感病阶段，遇气温突然下降和多雨时，最易流行。在防治上，采取以农业防治为主、化学辅的有效措施。     

Adeno-associated virus type 9-mediated p65 silencing inhibits angiotensin II-induced apoptosis of H9c2 cells

AIM: To study the effect of p65 gene silencing by adeno-associated virus type 9 (AAV9)-mediated RNA interference on angiotensin Ⅱ (Ang Ⅱ; 10^-6 mol/L for 24 h)-induced apoptosis of rat ventricular H9c2 myocytes, and to elucidate the possible mechanism. METHODS: The H9c2 cells were transfected with rAAV9-eGFP and rAAV9-eGFP-NF-κB p65-siRNA at multiplicity of infection (MOI)=4×10⁶ vg/cell. eGFP expression in the cells was observed under an inverted fluorescence microscope, and the percentage of eGFP positive cells was determined by flow cytometry. The expression of p65 was determined by Western blot. CCK-8 assay was used to measured the viability of transfected H9c2 cells. The apoptosis of the cells transfected with the virus and with Ang Ⅱ stimulation was analyzed by flow cytometry. RESULTS: The cells began to exhibit eGFP expression on the 2nd day after transfection. The fluorescence intensity was increased over the time of transfection. eGFP expression reached the maximum on the 5th day, and the transfection efficiency was (52.7±1.9)% at this time point. Compared with blank control group, no significant effect of AAV9 on the viability of H9c2 cells was observed. In resting state, p65 in the H9c2 cells had a certain activity. After Ang Ⅱ stimulation, the activity of p65 was obviously increased, while transfection of rAAV9-eGFP-NF-κB p65-siRNA effectively inhibited the expression of p65. The apoptosis of H9c2 cells in Ang Ⅱ stimulation group was significantly higher than that in blank control group, while transfection of rAAV9-eGFP-NF-κB p65-siRNA effectively inhibited apoptosis of H9c2 cells. CONCLUSION: Transfection of rAAV9-eGFP-NF-κB p65-siRNA effectively inhibits the expression of p65 gene of NF-κB pathway in the H9c2 cells without causing cell growth inhibition, and reduces the apoptosis induced by Ang Ⅱ.     

六个八仙花品种气孔特性研究

对6个品种八仙花的叶片气孔特性进行了研究。结果表明:气孔器长轴平均长度在27~40μm之间;气孔器短轴平均长度在18~25μm之间;气孔长轴平均长度在11~24μm之间;气孔短轴平均长度在5~10μm之间。气孔密度最大的是B,为550.87个/mm2,最小的是A,为295.06个/mm2。气孔面积最大的是G,为745.31μm2,最小的是E,为425.92μm2。各个品种气孔器的形状均为椭圆形或近圆形。     

不同处理方法对辣椒采后贮藏特性的影响

分别采用热处理、1-MCP处理、乙烯处理尖椒.结果显示,各处理均引起了采后辣椒膜损伤,同时热处理和1-MCP处理可以抑制乙烯生成和呼吸高峰,延迟叶绿素降解,起到延长贮藏期的目的.     

甘氨酸铁对断奶仔猪生长性能的影响

试验选用72头杜长大断奶仔猪,随机分为3组,每组3个重复,每个重复8头。试验分为对照组Ⅰ(基础日粮含100 mg/kg无机铁)、对照组Ⅱ(基础日粮+50 mg/kg无机铁)、试验组(基础日粮+50 mg/kg甘氨酸铁),试验结果表明:对照组Ⅰ、对照组Ⅱ和试验组3个组之间差异不显著,试验组的日增重比对照组Ⅰ和对照组Ⅱ分别提高2.67%(P>0.05)和2.18%(P>0.05);从料肉比来看,试验组和对照组Ⅰ差异显著,但与对照组Ⅱ相比差异不显著。分别比对照组Ⅰ和对照组Ⅱ降低1.4%(P<0.05)和0.7%(P>0.05);在腹泻率方面,试验组与对照组Ⅰ之间差异显著(P<0.05),但与对照组Ⅱ之间差异不显著(P>0.05)。试验组比对照组Ⅰ和对照组Ⅱ分别降低93.3%和83.3%;育成率3组之间差异不显著;血清微量元素铁增加的趋势试验组均高于对照组Ⅰ和对照组Ⅱ,组间差异均不显著(P<0.05);试验组粪中微量元素铁的含量比对照组Ⅰ和Ⅱ分别降低30.02%和30.47%,且试验组和对照组Ⅰ、对照组Ⅱ之间差异极显著(P<0.01),但对照组Ⅰ和对照组Ⅱ之间差异不显著(P>0.05)。由此可见,在基础日粮中添加50 mg/kg(含二价铁)甘氨酸铁不仅能提高断奶仔猪生产性能,还能减少粪中微量元素铁的排放量。