ORYKTA土壤调理剂对油葵生产影响试验

在试验区域内,ORYKTA土壤调理剂对土壤有机质有增加作用,土壤速效养分、pH无明显变化;施用量为50kg/667m^2的处理,其油葵增产最高,增产率为6．93％,有机质增幅也最高,增幅为1．76g·kg^-1。     

浅谈水稻机插氮肥施用技术

通过对机插水稻氮肥应用技术的试验研究,氮肥的施用时期、施肥比例对水稻生长发育关系重大,直接影响后期水稻的产量和质量。     

长白松引种试验初报

长白松是吉林省长白山地区一种集造林绿化观赏于一身的优良针叶树种。把该树种从原产地引入到我省西部地区进行育苗及造林技术试验,旨在增加该区主要造林树种和绿化树种的品种。本文试验结果表明：在常规育苗技术下,长白松在我省西部地区获得成功。采用容器育苗技术用于试验造林,同当地的樟子松相比,4年生幼树长白松略好于樟子松,抗逆性同樟子松相仿。     

水稻病害综合防治试验总结

对寒地水稻常发生的四种病害进行分析,并提出应采取何种防治措施。     

水稻氮磷钾肥料运筹试验研究

水稻是我省主要粮食作物,种植面积大,经济效益高,在生产中,其氮磷钾营养元素对产量影响最大,合理进行肥料运筹对产量高低起决定作用。为研究探索在适宜施肥总量确定的情况下,氮钾肥在底肥、蘖肥、穗肥的不同比例配施,对水稻生育形状及产量影响,旨在有效提高肥料利用率,实现增产和施肥效益最大化。     

几种药剂防治水稻稻飞虱田间药效试验

进行15％阿维·噻嗪酮WP、10％醚菊酯悬浮剂、20％烯啶虫胺可溶性液剂、40％福戈水分散粒剂防治水稻稻飞虱田间药效研究,结果表明：15％阿维·噻嗪酮WP、10％醚菊酯悬浮剂、20％烯啶虫胺可溶性液剂以及40％福戈水分散粒剂对水稻稻飞虱均有较好的防效,最高药效均达到了90％,且对作物安全,可推广应用。农业管理者可以根据稻飞虱的发生情况,选择合适的药剂、合适的处理后进行喷洒,用于防治水稻稻飞虱的发生、发展。     

寒地水稻低产田改造试验技术总结

本试验通过在水整地前向低产田中施入稻壳灰和腐熟有机肥来改善土壤理化性状,结果土壤耕层增加12.5%、水稻产量增加13.12%。     

土壤电导特性及影响因素试验研究

土壤电导的测量是本文的出发点,在分析土壤电导机理的基础上,构成了一个能同时检测土壤电导和土壤含水量的土壤电导试验系统。探索了土壤电导与土壤容积含水率、土壤含盐量之间的关系,得出了随含水量的增加土壤电导的变化趋势和土壤电导随土壤盐分含量的增加而变大的规律。同时还探讨了土壤电导与土壤pH值之间的关系,对pH值不同的土壤进行了分别的试验,通过分析认为土壤pH值对土壤电导的影响较弱,待今后再做深入的探讨。     

一种泡制型酸茶加工方法的研究

针对夏秋季茶树鲜叶资源利用率低、茶产业效益偏低等突出问题,依据少数民族生产和食用酸茶的传统,以夏秋茶树鲜叶为原料,开展新型生物茶产品――泡制型酸茶发酵工艺技术研究,为夏秋茶树鲜叶的开发利用提供新途径,同时丰富了生物茶产品的种类,提高茶产品价值,满足人们的保健消费需求。     

东北白桦在城市园林绿化中的引种驯化试验初报

城市绿化是城市生态环境建设的重要内容,它的质和量的发展水平反映一个城市形象,是衡量城市现代文明积蓄和是否可持续发展的重要标志。民乐县城由于地处高寒,可用于城市绿化的树种较少,尤其是阔叶乔木树种相对匮乏。为了改善我县城市园林景观,丰富园林绿化树种,加快建设“宜居宜游”的高原生态文明县的步伐。通过引种试验,初步掌握了东北白桦的生物学特性,总结出了科学适用的驯化和促活技术,为全面推广提供了科学依据。     

应用型《水产动物疾病学实验》课程教学改革

为了提高学生的综合应用能力,增强本科毕业生就业竞争力,在学校向应用型转型的特殊环境下,《水产动物疾病学实验》课程从教学内容、教学模式和方法、实验室管理、教师培养、考核方式等方面进行改革和实践,并将EEPO有效教育引入实验教学,取得了一定成效。     

Optimization of callus cultures at Echinacea purpurea L. for the amount of caffeic acid derivatives

BackgroundIn order to produce an effective callus in Echinacea purpurea L.; determination of the explant type and growth regulators that best respond to callus induction and the optimization of the culture conditions to increase the amount of caffeic acid derivatives (CADs) in the obtained callus. CADs contents of callus cultures of E. purpurea were evaluated by establishing an effective callus induction system in vitro.ResultsVarious medium containing different growth regulators were tested using leaf, petiole, cotyledon and root as the explants. The best callus development was achieved in MS medium with 1.0 mg l⁻¹ 2,4-D + 2.0 mg l⁻¹ BAP in leaf, 1.0 mg l⁻¹ NAA + 0.5 mg l⁻¹ TDZ in petiole, 2.0 mg l⁻¹ NAA + 1.0 mg l⁻¹ TDZ in cotyledon and 0.5 mg l⁻¹ NAA + 0.5 mg l⁻¹ BAP in roots. Upon optimisation of callus growth, each type of explant was cultured for 4, 6, 8 and 10 weeks in medium for the analyses of caftaric acid, chlorogenic acid, caffeic acid and chicoric acid contents. The highest amounts of caftaric acid (4.11 mg/g) and chicoric acid (57.89 mg/g) were found from petiole explants and chlorogenic acid (8.83 mg/g) from root explants at the end of the 10-week culture time.ConclusionsAs a result of the present study, the production of caffeic acid derivatives was performed by providing the optimization of E. purpurea L. callus cultures. Effective and repeatable protocols established in this study may offer help for further studies investigating the production of caffeic acid derivatives in vitro.How to cite: Tanur Erkoyuncu M, Yorgancilar M. Optimization of callus cultures at Echinacea purpurea L. for the amount of caffeic acid derivatives. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.02.003.     

传播失效与行业格局——试析中国古代金属活字落选的社会原因

从商代至宋,中国已为金属活字做好了全面的技术准备。明代中叶,随着各方面社会条件的具备,江南乡绅开始尝试金属活字,十几年间技术成熟,传播面涵盖三大出版中心,时间持续近百年。然而,最终传播失效,古人仍选择雕板印刷。对这桩中国古代科技传播史上著名悬案的解答,本文从传播学观点出发,认为行业三元格局中的官刻对技术创新的不作为和私刻对精粹文化品位的追求外在地对坊刻起着示范作用;金属活字技术上的"借壳现象"与书坊家族制劳动力结构特性又形成内在的合力,共同导致了书商投资的社会动力不足,是中国古代金属活字技术传播失效、落选的主要社会原因。     

技术认知、风险感知对黄土高原农户水土保持耕作技术采用意愿的影响及代际差异

黄土高原农户对水土保持耕作技术的认知和对水土流失风险的感知是水土保持耕作技术采用意愿的关键影响因素,探究二者对技术采用意愿的作用有利于促进农户技术采用率的提高、控制水土流失、减少入黄泥沙量、改善生态环境。本文利用黄土高原1237户农户的调查数据,基于代际差异的视角,采用逐步回归法和分组回归法,分析了农户技术认知和风险感知对其水土保持耕作技术采用意愿的影响及代际差异。结果表明：①技术认知对水土保持耕作技术的采用意愿有显著的正向影响,技术认知对等高耕作、沟垄种植、少免耕、深松耕、秸秆还田、残茬覆盖和地膜覆盖技术采用意愿的作用强度均是新生代农户大于老一代农户。②风险感知对新生代和老一代农户等高耕作和沟垄种植技术采用意愿均有显著的正向影响,其影响强度存在代际差异;对新生代农户少免耕技术采用意愿有显著的正向影响,对老一代农户深松耕、秸秆还田、残茬覆盖和地膜覆盖技术采用意愿有显著的正向影响。③风险感知在技术认知和采用意愿之间发挥正向调节作用,在等高耕作、沟垄种植、残茬覆盖和地膜覆盖技术采用意愿中,风险感知对于老一代农户的调节作用强于新一代;在少免耕、深松耕和秸秆还田技术采用意愿中,风险感知对于新一代农户的调节作用强于老一代。户主年龄、受教育程度、家庭劳动力数量等控制变量对新生代和老一代农户水土保持耕作技术采用意愿的影响有显著差异。建议农业技术和政策推广视新老农户区别对待,提供有针对性的补贴,并通过鼓励土地流转为技术采用提供便利。     

中药寒热相关药性和抑制脂肪酸合酶能力关系的探索

测定了药典中106味温热性中药和119味寒凉性中药对脂肪酸合酶的抑制水平,发现温热药中对该酶强抑制的频数高于寒凉药约38％.进一步分析发现,温热药中的温里和散内寒药中强抑制药的频数大幅提高,而寒凉药中的清热泻火、明目、清虚热药中强抑制药的频数则进一步降低,差异均具有显著性.综合以上结果提出,直接影响能量代谢系统、造成能量代谢率变化是形成中药的寒热药性的因素之一.     

Using PacBio sequencing to investigate the effects of treatment with lactic acid bacteria or antibiotics on cow endometritis

BackgroundEndometritis is the most common disease of dairy cows and traditionally treated with antibiotics. Lactic acid bacteria can inhibit the growth of pathogens and also have potential for treatment of endometritis. Using PacBio single-molecule real-time sequencing technology, we sequenced the full-length l6S rRNA of the microbiota in uterine mucus samples from 31 cows with endometritis, treated with lactic acid bacteria (experimental [E] group) and antibiotics (control [C] group) separately. Microbiota profiles taken before and after treatment were compared.ResultsAfter both treatments, bacterial species richness was significantly higher than before, but there was no significant difference in bacterial diversity. Abundance of some bacteria increased after both lactic acid bacteria and antibiotic treatment: Lactobacillus helveticus, Lactococcus lactis, Lactococcus raffinolactis, Pseudomonas alcaligenes and Pseudomonas veronii. The bacterial species that significantly decreased in abundance varied depending on whether the cows had been treated with lactic acid bacteria or antibiotics. Abundance of Staphylococcus equorum and Treponema brennaborense increased after lactic acid bacteria treatment but decreased after antibiotic treatment. According to COG-based functional metagenomic predictions, 384 functional proteins were significantly differently expressed after treatment. E and C group protein expression pathways were significantly higher than before treatment (p < 0.05).ConclusionsIn this study, we found that lactic acid bacteria could cure endometritis and restore a normal physiological state, while avoiding the disadvantages of antibiotic treatment, such as the reductions in abundance of beneficial microbiota. This suggests that lactic acid bacteria treatment has potential as an alternative to antibiotics in the treatment of endometritis in cattle.How to cite: Yang L, Huang W, Yang C, et al. Using PacBio sequencing to investigate the effects of treatment with lactic acid bacteria or antibiotics on cow endometritis. Electron J Biotechnol 2021:51. https://doi.org/10.1016/j.ejbt.2021.02.004