多营养层次生态养殖模式简析

系统介绍了多营养层次生态养殖模式在淡水养殖及海水养殖中的应用与发展,对比了国内外有关该养殖模式发展方向的异同,简述了该养殖模式通过提高物质和空间利用率、改善养殖环境的原理以及在我国推广应用情况,并汇总了我国沿海省份近年来开展该养殖模式选用的品种搭配及产量产值。指出了多营养层次生态养殖模式还存在的问题,对今后发展提出了建议。     

绿肥翻压后减肥和基施控释肥对烟叶产质量和土壤肥力的影响

为研究绿肥（豌豆）翻压后合理施用肥料问题,采用田间小区试验,在翻压绿肥的基础上通过减少基肥用量和控释肥代替部分基肥,研究其对烟叶产量、产值和土壤肥力的影响。结果表明,绿肥翻压可以提高低有机质土壤（有机质含量<10 g/kg）的有机质含量,对其他土壤化学性质无显著影响;绿肥翻压后将基肥减少15%和30%对烟叶产量、产值无显著影响,对烟叶化学成分无明显影响。在减少15%基肥后,将剩余基肥的50%以控释肥代替,可以显著提高烟叶产量和产值,提高烟叶钾含量和钾/氯比,改善烟叶品质。     

玉米早期籽粒中强表达启动子的筛选

在植物基因表达调控的过程中,启动子作为调控基因表达的顺式元件起着重要作用。为了筛选在玉米早期籽粒中强表达的启动子,选取6个启动子pCaMV35SD、pUbiquitin、pZmActin1、pZmSTK2、pZm66589和pZmbHLH148,分别构建EGFP表达载体并转染玉米原生质体,快速验证载体功能构建的正确性;同时采用花粉磁转染法将6个表达载体导入玉米自交系郑58中,并对不同启动子驱动的EGFP载体在授粉后48h玉米籽粒中的荧光强度和荧光检出率进行观察和统计分析。结果表明,6个启动子驱动EGFP表达载体构建正确;pCaMV35SD启动子驱动EGFP表达载体的荧光最强,6个启动子驱动EGFP表达载体由强到弱依次为pCaMV35SD>pZmSTK2>pZm66589>pZmbHLH148>pUbiquitin>pZmActin1,其荧光检出率分别为27.17%、27.17%、29.83%、23.84%、13.40%和30.57%。     

多措并举保障北京市昌平区设施草莓优质绿色生产

为了保障草莓的安全生产,打造昌平草莓产业的良性健康发展模式,主要从技术支撑、政府扶持及宣传3个方面阐述了其重要举措。具体措施包括通过注重提升田园清理、土壤消毒、田间管理等一系列技术措施,确保草莓安全生产;通过政府政策、资金支持及专业技术指导,打造强有力的后盾保障;建立绿色安全生产宣传模式,扩大品牌影响力,如多渠道、多方面进行宣传;组织培训,增强种植水平;充分利用互联网新媒体等。     

From borders to ecotones – Private-public co-management of urban woodland edges bordering private housing

This paper conceptualises and evaluates so-called co-management zones as an approach for user participation in urban forestry, specifically in the management of public woodland edges bordering residential areas. Co-management zones can metaphorically be viewed as ‘ecotone-like’ spaces, i.e. zones where overlapping interest – in this case residents’ and municipal authorities’ – can be used to create richness and meetings rather than boundaries. Building on the perspectives of ecotone thinking and governance arrangements, co-management zones in the Danish residential area of Sletten in Holstebro were evaluated. The presented case study combined interviews with residents and interviews with three key green space professionals who had led the planning, design, establishment and management of the woodland and the implementation of co-management. The resident participation in the co-management zone was also assessed and photo documented in a field survey, categorising individual households according to type and degree of physical signs of participation. Findings illustrate the potential of co-management zones to initiate collaboration between residents and public woodland managers in creating recreationally valuable and varied meetings between private gardens and urban woodlands. Challenges with establishing co-management zones were also highlighted, especially the need for clear guidelines and continuous communication between residents and the municipality. Perspectives and implications related to residents, managers and green space quality are discussed.     

寨卡病毒SYBR GreenⅠreal-time PCR方法的建立及应用

为建立一种针对寨卡病毒的快速诊断方法,本研究根据寨卡病毒的3’端保守基因序列,设计合成1对引物,建立了检测寨卡病毒的荧光定量PCR方法。结果显示:所建立的检测方法的Ct值与标准品在1.41×10^1~1.41×10^10^ copies/μL具有良好的线性关系,相关性为1,斜率为-3.502;灵敏性结果显示,该方法的检测限度为1.41×10^1 copies/μL,是普通PCR的10000倍;特异性结果显示,对CHIKV、DENV和JEV无特异性扩增,特异性强;重复性试验结果显示,组内和组间变异系数均小于1%,重复性好。本研究建立的SYBR Green I real-time PCR检测方法,可用于寨卡病毒感染的快速诊断。     

非洲猪瘟疫情对生猪产业链上市公司市场价值的影响研究

[目的] 研究旨在应用实证方法分析非洲猪瘟疫情对生猪产业链上市公司市场价值造成的影响,进而得出疫情对生猪产业链上养殖、屠宰、加工、消费等环节利益相关者收益的影响。[方法]采用事件研究法,选取涉及生猪产业链上市公司,按主营业务统计为肉制品加工、养殖、饲料和兽药4种类型的32家相关上市公司,通过设计指标对生猪产业链上市公司股票异常收益率波动进行计算和检验。[结果]研究结果表明：非洲猪瘟疫情事件对生猪养殖行业的影响最大；对兽药行业的影响周期最长；肉制品加工行业的影响程度和周期仅次于兽药行业,对饲料行业的影响最小。[结论] “非洲猪瘟”事件对猪产业链上的饲料、养殖、肉制品加工、兽药类上市公司市场价值存在显著的负面影响。     

不同间作绿肥替代化肥模式对木薯性状和产量的影响

通过探讨秸秆还田与化肥减施下间作绿肥对木薯产量性状的影响,着力解决连作木薯土壤肥力提高与改良相关技术的协调增效。于2019-2020年,以木薯品种“南美1号”为供试材料,设置8个处理,调查每个小区的木薯茎径、叶绿素（SPAD）、块根直径、块根长、单株茎秆鲜重、单株块根鲜重、株高、单片叶重、单株块根数以及小区产量等农艺性状。结果表明,处理5（木薯秆还田+化肥减量12.5%+12.5%营养元素当量黑豆绿肥还田）的木薯产量最高,并得到拟合方程。绿肥秸秆还田以及间作绿肥从整体上改良了土壤肥力,并通过显著影响木薯块根、单片叶重以及单株块根数而影响最终产量。     

Insights into African swine fever virus immunoevasion strategies

African swine fever(ASF) is an acute and highly contagious disease that causes severe economic losses to the swine industry. ASF is caused by infection of African swine fever virus(ASFV) in domestic pigs, leading to almost 100% mortality. However, no effective vaccines and pharmacologic treatment against ASF are available. ASF poses a severe threat to the swine industry and the economy. Here we summarize potential virus-host cell interaction mechanisms involving the suppression of innate and adaptive immune responses to ASFV entry and infection. These mechanisms include modulation of apoptosis, inhibition of inflammatory responses, reduction of IFN production, inhibition of autophagy, and suppression of MHC-I expression. Insights into immunoevasion strategies by ASFV may shed light on the development of vaccines, as well as preventive and therapeutic drugs.     

African Horse Sickness Fever in Vaccinated Horses: Short Communication

Our investigation has shown that multiple vaccinations with inactivated African horse sickness (AHS) vaccines containing all 9 serotypes and produced at the Central Veterinary Research Laboratory in Dubai, UAE, protect horses from AHS. However, the immunization did not prevent African horse sickness fever (AHSF) in approximately 10% of the vaccinated horses despite high enzyme-linked immunosorbent assay and virus neutralizing antibodies. African horse sickness fever is a very mild form of AHS with similar clinical signs. From all 6 horses which had developed AHSF, no virus was isolated from EDTA blood withdrawn during the acute phase of infection. Despite high neutralizing antibodies, serotype 9 was detected by polymerase chain reaction in 4 of them. All 6 horses recovered within 72 hours, after they developed mild clinical signs of AHS.