芝麻新品种中芝12配套栽培技术研究

在湖北鄂州和武汉进行了芝麻新品种中芝12的播期、密度、打顶、化控及高产攻关试验,结果表明,该品种的最适宜播期为5月30日,密度为每公顷15万株,第3对真叶期间隔1周连喷两次150mg·kg-1或200 mg·kg-1缩节胺.中芝12在高肥水条件下不宜打顶,但在一般种植条件下以初花后25 d打顶效果好.鄂州和武汉高产攻关公顷产量分别为2 139.75kg 和2 418.75kg.     

基于高通量测序及分离培养初步研究美国大豆中真菌多样性

中国是全球最大的大豆进口国,进境大豆所携带的病原真菌传入我国的风险极高.基于高通量测序技术对6批美国大豆真菌多样性进行分析,同时采用分离培养获得单一菌株,依据菌落形态、显微结构及分子技术进行鉴定.高通量测序结果显示,大豆中所有真菌共计5门15纲35目63科112属155种,主要为链格孢属(Alternaria)、球腔菌...     

高效液相色谱在手性农药分析分离上的应用研究进展

随着人类社会可持续发展的需要,环境中手性农药的污染日渐受到人们的重视,因此手性农药的拆分也得到越来越多的重视.高效液相色谱是一门适用于手性分离的研究技术.本文综述了近年来高效液相色谱在手性农药拆分中的应用研究,并对该方法的发展前景进行了讨论.     

杀线虫苏云金芽胞杆菌NBIN-863高含量悬浮剂的研制

目前我国微生物农药原药生产技术已达到甚至超过发达国家水平,但制剂技术却存在较大差距,主要体现在剂型结构不合理、制剂质量差、农药助剂种类及品种少、剂型加工工艺总体水平还比较落后等方面。苏云金芽胞杆菌(Bt)等功能微生物产品的市场容量及应用效果与剂型是密切相关的。为了明确新型生物杀线剂NBIN-863的最佳施用剂型,特开展此试验。通过对防腐剂、分散剂、悬浮剂等不同助剂的选择,研制了一种高含量Bt悬浮剂(5.2×10⁹～7.9×10⁹ CFU/mL)。配方优化试验表明,在Bt发酵液中加入0.4%防腐剂山梨酸钾、1.0%分散剂硅酸镁铝、4.0%悬浮剂木质素磺酸钙,用盐酸调节p H至4.5,54℃热储前芽胞数最高为7.9×10⁹ CFU/mL,对秀丽隐杆线虫活性最高,LC₅₀为2.83 mg/L,对黄瓜根结线虫田间防效达68.64%。综合各指标,尤其是对秀丽隐杆线虫的半致死浓度,杀线虫NBIN-863悬浮剂(7.9×10⁹CFU/mL)效果最好,不仅流动性好,而且耐贮藏,是防治作物根结线...     

广东省吴川红火蚁生境类型、空间分布和抽样技术的研究

系统调查和研究了红火蚁在广东省吴川市农田生态系统的生境类型、空间分布规律和抽样技术。结果表明:红火蚁的生境类型较丰富多样,表现出较强的环境适应能力,荒坡、荒地、田埂等受到干扰较少的地点红火蚁发生密度高,而耕作农田如水稻田、菜田、花生地、红薯地等红火蚁发生密度很低;单个指标如丛生指数、聚块性指数、久野指数表明活动蚁巢在平面空间上主要呈现随机分布;经对Iwaom*-m回归模型、Taylor幂模型参数分析认为红火蚁活动蚁巢空间分布基本成分为单个蚁巢,蚁巢间存在相互排斥的作用,在所有密度下都是随机分布,且密度越高,分布越均匀。在空间格局研究基础上给出了最适理论抽样数公式和不同密度下的理论抽样数。提出的抽样方法为:先选取具代表性的小面积地块,对发生密度进行初步估计,如密度较低,零星发生,调查面积要大一些,每点面积应在500 m2以上;如密度较高,发生较普遍,根据理论抽样面积进行相应的调整,每点面积可在100~200 m2。一般每个类型的地点要调查3点以上。     

山东地区夏玉米的高产种植技术

随着我国市场经济的不断发展和农业供给侧的不断改革,玉米价格呈现出大幅度下降趋势, 玉米种植面积也急剧下降。为了提高玉米的产量和效益,科学推广和应用玉米高产种植技术是当务 之急,同时也是玉米产业快速发展的必然趋势。基于以上情况,本文从精细播种、苗期管理、玉米穗期 管理、花粒期管理五个方面入手,研究了夏玉米高产种植技术。希望通过这次研究,为相关种植人员 提供有效的参考。     

我国农作物绿色食品的生产瓶颈和生产前景

生产农作物绿色食品是农业的发展方向,也是可持续发展的必然要求,是世界范围都要引起 重视的普遍课题,我国更需迫切重视。使用一般的无公害杀虫剂是不能生产出绿色食品的,而目前病 虫害绿色防控技术还不成熟,现在可用于绿色食品生产的高效无毒的杀虫剂在我国已首先研究出来 了,当前缺少的仅是农产品市场完备的农药残留检测机制,解决这个瓶颈问题可给绿色食品创造存在 的空间,从而实现农业绿色产业大发展,这一天的到来已为期不远。     

Primary productivity in patches of heterogeneous swards after 12 years of low-intensity cattle grazing

In low-intensity grazing systems, patch grazing leads to a mosaic structure of short (frequently defoliated) and tall (rarely defoliated) patches, with the stocking rate determining the proportion of these patch types on the pasture. Little is known about the long-term effects of patch grazing on the productivity of contrasting sward height patches developed under varying stocking rates. On a 12-year low-intensity cattle pasture we investigated aboveground net primary productivity (ANPP) and its seasonal variation in different patch types (‘short’, ‘medium’ and ‘tall’) under three stocking rates (‘moderate’, ‘lenient’ and ‘very lenient’) over two years. Additionally, we determined stocks of soil phosphorus, potassium and magnesium as well as soil pH. ANPP was affected by an interaction of patch type and stocking rate and ranged from less than 300 g/m² in short patches under very lenient stocking to more than 1,000 g/m² in medium patches under moderate stocking. In contrast with observations at the start of the experiment, ANPP in short patches was similar to or less than that in medium and tall patches. As topsoil phosphorus and potassium stocks were lowest in short patches, this indicates a long-term redistribution of nutrients by grazing animals, which limits short-patch productivity. Productivity of medium patches increased with stocking rate, and soil potassium concentration showed a similar trend, pointing towards enhanced nutrient cycling under more intensive stocking. We conclude that nutrient redistribution may lead to increasing trade-offs between ecological and agronomic aims in long-term low-intensity grazing systems.     

苗期甘蔗氮高效基因型评价指标的筛选

本研究通过低氮压力选择,筛选出甘蔗氮高效种质,分析影响甘蔗氮高效的重要指标,为甘蔗氮高效育种及栽培提供理论依据。以58份甘蔗种质资源为材料,在苗期采用正常供氮（2 mmol/L N）和低氮（0.2 mmol/L N）处理,分析甘蔗植株形态、干重及氮素在各器官中累积分配的特征。通过主成分分析方法筛选影响甘蔗氮高效利用的重要指标,通过聚类分析对58份种质进行聚类。结果表明,低氮（0.2 mmol/L N）处理可以明显从植物形态区分不同种质的氮利用差异,58份种质低氮条件下的干重范围为0.64~14.75 g/株,氮累积量为5.53~63.00 mg/株,氮利用率范围为115.40~279.30 g/g。对低氮压力下甘蔗干重及氮累积等25个指标进行主成分分析后,提取出4个主要成分,总贡献率为92.35%。通过高、低氮条件下与氮利用效率有关的氮转移系数及基因潜力等19个指标分析后提取出5个主成分,总贡献率为82.21%。影响甘蔗氮高效的重要指标有甘蔗的干重（全株、叶、根）、氮累积量（全株、叶、茎）、氮利用率（全株、叶）、叶的相对氮利用率、茎的基因潜力、茎的相对干物质量和茎的相对氮累积量。经聚类分析后初步将58份甘蔗种质分为氮高效基因型、偏氮高效基因型、偏氮低效基因型和氮低效基因型。     

A New Bioassay Platform Design for the Discovery of Small Molecules with Anticancer Immunotherapeutic Activity

Immunotherapy takes advantage of the immune system to prevent, control, and eliminate neoplastic cells. The research in the field has already led to major breakthroughs to treat cancer. In this work, we describe a platform that integrates in vitro bioassays to test the immune response and direct antitumor effects for the preclinical discovery of anticancer candidates. The platform relies on the use of dendritic cells that are professional antigen-presenting cells (APC) able to activate T cells and trigger a primary adaptive immune response. The experimental procedure is based on two phenotypic assays for the selection of chemical leads by both a panel of nine tumor cell lines and growth factor-dependent immature mouse dendritic cells (D1). The positive hits are then validated by a secondary test on human monocyte-derived dendritic cells (MoDCs). The aim of this approach is the selection of potential immunotherapeutic small molecules from natural extracts or chemical libraries.