拮抗草坪蘑菇圈生防菌剂的关键发酵工艺及优化

为获得草坪蘑菇圈病原菌拮抗生防菌剂的优化参数,本研究以拮抗蘑菇圈病原-肉褐麟小伞菌(Lepiota brunneo-incarnata)的黄曲霉(Aspergillus flavus)CP01为目的菌,对其分别进行液、固态发酵条件的优化。通过单因素试验优化发酵时间、培养温度、培养基类型及初始pH等条件,对最佳液态发酵条件进行筛选;并通过单因素试验优化培养物料、外源养分、发酵时间和温度等条件,对最佳固态发酵条件进行筛选。结果表明:液体发酵条件下,马铃薯葡萄糖液体培养基(PDB)中菌丝体干重含量最高,而在青秸秆粉浸提液培养基(CSE)中有效菌数最高,且该发酵液对蘑菇圈病原的抑菌效果最佳,培养基最适初始pH为5、最佳发酵条件为30℃、5d;在固态发酵条件下,最适发酵培养物料为经浸提法去营养化的青秸秆粉,外源添加养分为料水比1∶50的青秸秆粉浸提液,最适发酵条件为33℃、9d。以上优化参数为草坪蘑菇圈生防菌剂的研发奠定了基础。     

广东省广州市活禽批发市场从业人员H7N9流感“知信行”现状调查

为了解广东省广州市活禽批发市场从业人员对H7N9流感的认知、态度和行为,也为制定针对性的健康教育措施提供依据,2017年4—5月对广州市全部6个活禽批发市场的435名从业人员进行了问卷调查。调查结果显示:318名密切接触人员和117名非密切接触人员对H7N9流感相关知识的总知晓率分别为80.59%和69.60%;在"发现对禽高致病性的H7N9流感病毒""病死禽应该进行深埋或焚烧等无害化处理""外省养殖场发生过H7N9流感疫情"方面,密切接触者的知晓率显著高于非密切接触者(P0.03);获取H7N9流感知识的途径主要有培训,以及电视、网络和海报等宣传媒介;绝大多数市场从业人员认为政府有能力防控H7N9流感,对政府采取的H7N9流感防控措施及对目前的"1110"制度感到满意,认为活禽集中屠宰可行(P0.01);从业人员在预防H7N9流感时,接触禽类后用肥皂或洗手液洗手的占比最高(83.45%),其次是戴手套(69.20%)和穿水鞋(63.91%),而戴口罩(39.77%)和用消毒液消毒手(35.86%)的占比较低。调查认为,广州市活禽批发市场从业人员的H7N9流感知识知晓率较高,但个人防护措施实施不全面。调查结果提示,应充分利用培训,以及电视和网络等优势媒介,强化微信和微博等新兴媒介,加强对H7N9流感防控知识的宣传。     

规范执法监管 营造良好市场营商环境

本文阐述了规范执法监管营造公平高效市场营商环境的必要性,从执法体系、执法制度、执法能力和执法形象建设等方面,分析了石家庄市执法规范化建设概况。建议通过加强对生产经营主体源头治理,注重问题导向加大侦办力度,强化行业自律诚信经营等方面的监管,以期进一步优化市场营商环境。     

一起未经执业兽医注册从事诊疗活动案引发的思考

2017年成都市办理的一起未经兽医执业注册而进行犬只声带切除的行政处罚案件,引发了笔者对动物诊疗机构监督执法中"动物诊疗"范畴界定、动物诊疗许可证申请对象探究、"一事不再罚"原则的适用、"责令停业诊疗活动"与"责令停产停业"区别等问题的思考。本文以法学理论和相关法律规定为基础,对成都市动物诊疗机构执法实践的疑点与难点进行分析,提出执法人员应更准确适用法律法规,并呼吁尽快建立全国执业兽医查询系统的建议。     

2018年安徽省部分地区A型禽流感流行率横断面研究

为了解安徽省A型禽流感病毒感染情况,2018年4—5月,在安徽省北部、中部和南部7个市,随机选取各类型场点173个,在每个场点内随机采集35份咽喉/泄殖腔和环境拭子样品,使用荧光RT-PCR进行A型、H5亚型、H7亚型流感病毒核酸检测。结果显示：在4个养殖场、3个活禽批发市场和17个农贸市场检出了A型禽流感病毒,场点阳性率分别为2.9%（4/140）、75.0%（3/4）、80.9%（17/21）,未检出H5和H7亚型流感病毒核酸;A型禽流感群体流行率为11.2%（95%CI：6.5%~15.8%）,个体流行率为1.2%（95%CI：0.9%~1.5%）;活禽交易市场内,禽群感染A型禽流感病毒的风险较高（OR=136,95%CI：32.7~549.4）。结果表明,A型禽流感病毒在养殖和交易环节存在一定的污染,而在活禽交易市场的污染更严重,是今后禽流感防控的重点,需继续加强活禽交易市场的管理和消毒灭源工作。     

贵州省农村信息化服务现状实证分析与发展对策

[目的]为深入了解贵州省农村信息化服务现状,以期更科学地探索与设计贵州省农村信息化服务模式,为广大农民提供优质的信息服务.[方法]对贵州省所有地州市典型县份、典型乡（镇）和行政村的农户以进村入户、现场调查、走访、座谈和发放问卷等方式进行实地调查和数据采集,并利用SPSS 19.0统计分析软件对数据进行分析处理.[结果]贵州省农村信息化服务基础设施建设成效显著、信息传播渠道呈立体化发展、信息服务内容丰富.但也存在基础设施运行效率不高、信息传播渠道不够畅通、信息资源质量不高、信息支付意愿不强等问题.[建议]应加大基础设施建设力度、提高基础设施利用率,整合各种信息传播途径、畅通信息服务渠道,加大信息资源建设力度、提高信息内容质量,加强教育力度、提高信息意识,以推动贵州省农村信息化服务快速发展.     

Improvements of TKC Technology Accelerate Isolation of Transgene-Free CRISPR/Cas9-Edited Rice Plants

Elimination of the CRISPR/Cas9 constructs in edited plants is a prerequisite for assessing genetic stability, conducting phenotypic characterization, and applying for commercialization of the plants. However, removal of the CRISPR/Cas9 transgenes by genetic segregation and by backcross is laborious and time consuming. We previously reported the development of the transgene killer CRISPR (TKC) technology that uses a pair of suicide genes to trigger self-elimination of the transgenes without compromising gene editing efficiency. The TKC technology enables isolation of transgene-free CRISPR-edited plants within a single generation, greatly accelerating crop improvements. Here, we presented two new TKC vectors that show great efficiency in both editing the target gene and in undergoing self-elimination of the transgenes. The new vectors replaced the CaMV35S promoter used in our previous TKC vector with two rice promoters to drive one of the suicide genes, providing advantages over our previous TKC vector under certain conditions. The vectors reported here offered more options and flexibility to conduct gene editing experiments in rice.     

生猪养殖规模成本与收益的比较研究

文章通过对1991~2012年我国生猪散养和规模养殖的有关成本和收益的比较分析后发现,生猪养殖的风险在不断加大,散户养殖的成本高于规模养殖,差距在不断扩大;散户养殖的收益低于规模养殖;虽然规模养殖的物质与服务成本高于散户养殖,但人工成本远低于散户养殖;规模养殖的单位用工量和平均饲养周期低于散户养殖。基于上述比较分析的结论,得出发展规模化养殖的几点启示。     

Copper‐Induced Oxidative Stress and Responses of the Antioxidant System in Roots of Medicago sativa

The effects of various copper (Cu) concentrations on the antioxidative system in the roots of Medicago sativa were explored. The results indicated that the Cu content of the roots reached a value of 854 μg g^?1 DW at 10 μm Cu and a value of 4415 μg g^?1 DW at 100 μm Cu, suggesting that M. sativa has better ability to tolerate and accumulate Cu than other Cu‐bioaccumulators, and is a potential plant for phytoremediation. Treatment with Cu resulted in a significant increment in the levels of H₂O₂, O₂˙^? and OH˙. The reduced form of ascorbate and glutathione reached a peak at 30 μm Cu, and was followed by a sharp depletion to a lower level than that of the control. In contrast, the levels of the oxidised forms of ascorbate and glutathione showed a progressive increment with increasing Cu concentrations, suggesting that the antioxidant system was unable to cope with Cu stress at higher Cu levels. Under the Cu concentrations tested, the activity of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) increased at lower Cu concentrations, and then decreased, reaching a maximum at 30 μm of Cu for APX and GR, at 10 μm for CAT, whereas the activities of guaiacol peroxidase (POD, EC 1.11.1.7) were gradually increased with increasing Cu concentrations. PAGE analysis of superoxide dismutase (SOD, EC 1.1.5.1.1) revealed that one band is a Mn‐SOD and five bands are identified as Cu, Zn‐SOD, whereas Fe‐SOD isoforms were not found in the roots of alfalfa. Cu at 10–100 μm increased the intensity of constitutive isozymes of CAT, APX and POD, whereas it decreased the intensity of isozymes of glucose‐6‐phosphate dehydrogenase (G6PDH, EC 1.1.1.49) significantly. The activities of lipoxygenases (LOX, EC 1.13.11.12) were gradually augmented with increasing Cu concentrations, demonstrating that LOXs are probably involved in production of lipid hydroperoxides and superoxide anion. There was a continuous and pronounced enhancement in the activity of esterase (EST, EC 3.1.1.1) in roots treated with 10–30 Cu μm , whereas EST activity in roots exposed to above 30 μm Cu declined, suggesting that EST plays a protective role under lower Cu concentrations stress.     

赤霉素调控植物块茎形态建成的研究进展

赤霉素对植物的生长发育具有重要的调控作用。综述了赤霉素调控块茎形态建成的研究进展。块茎形态建成是一个复杂的生理过程,受遗传、坏境等因素共同调控,其中,激素调控发挥重要作用。虽然多种激素参与调控块茎的形态建成,但它们的效果最终均依赖于赤霉素含量。一般认为赤霉素抑制或延缓块茎的形成,但对块茎生长膨大的作用有不同的看法。已明确植物体内赤霉素转导的GA-GID1-DELLA路径,但是否在块茎形态建成过程中发挥作用还不清楚。最后提出块茎形态建成可能分为块茎启动和生长膨大两个不同阶段,分属于两个独立的调控系统,同时存在不同于GA-GID1-DELLA信号通路的赤霉素途径,赤霉素在其中发挥的作用不同,机制也不同。