首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
选取腈化合物和醛化合物为研究对象,以明亮发光杆菌为模式生物,以15 min发光抑制为测定终点,测定了10种腈醛化合物的单一急性毒性和55组二元非等毒性比腈醛混合体系的联合毒性,分别建立了腈、醛化合物单一急性毒性的QSAR模型,并提出了非等毒性比腈醛混合化合物对发光菌联合毒性的QSAR模型。结果表明,不同的腈醛混合化合物对发光菌的联合毒性不同,主要呈现协同作用和相加作用。采用QSAR模型定量描述了腈醛类化合物对明亮发光杆菌的联合毒性作用,为环境介质中腈醛的联合生态风险评价和修复提供了理论依据。  相似文献   

2.
Identification and Practical Application of Silicate-dissolving Bacteria   总被引:2,自引:0,他引:2  
Slime-forming bacteria were isolated from soils, rock surface and earthworm intestine, and their effects on dissolving silicate minerals and tomato growth were examined. One of the bacteria, Bacillus mucilaginosus RGBc13, had particularly strong ability to form slime and dissolve silicates. RGBc13 could also colonize and develop in both non-rhizosphere and rhizosphere soil. Total number of slime-forming bacteria increased from 2.9 × 103 cfu·g- 1and 8.4 × 103 cfu·g-1 to 9.6 × 106 cfu·g-1 and 6.0 × 107 cfu·g-1 in the non-rhizosphere and rhizosphere soils respectively. Potassium and phosphorus nutritional conditions in the rhizosphere were markedly improved through inoculation of this bacterium. Available K and P respectively increased from 25.86 and 3.63mg· kg-1 in the non-rhizosphere soil to 91.23 and 5.74mg· kg-1 in the rhizosphere soil. Tomato biomass increased by 125%, K and P uptakes were more than 150%, greater than the non- inoculation. Thus, there is a potential in applying RGBc13 for improving plant K and P nutrition.  相似文献   

3.
【目的】通过对小麦重组自交系群体光温生产效率的分析,阐明小麦光温生产效率的遗传特点与生物学性状的关系,为高光温生产效率小麦品种的选育提供理论依据。【方法】利用重组自交系群体(RIL),通过相关分析,检测高光温生产效率及其相关位点,并利用分子标记辅助选育高光温生产效率小麦新品系。【结果】小麦的光温生产效率与单株成穗数、穗粒数、平均灌浆速率、最大灌浆速率呈高度正相关,其中成穗数对小麦的光温生产效率贡献最大。光能生产效率受平均灌浆速率影响较大,而温度生产效率受最大灌浆速率影响较大。11个位点与光温生产效率相关,其中4个位点的贡献率在10%以上,分别为Xwmc167-2D、Xcwm23-2D、Xbarc218-3A和Xwmc326-3B。通过分子标记筛选到5个高光温效率的新品系,并且进行了验证。【结论】高光温效率小麦品种能很好地利用低温阶段的光温资源,形成较多分蘖,提高单株穗数和穗粒数。因而,在小麦新品种培育过程中,注重筛选单株成穗数多、穗粒数多和灌浆速度快的株系有利于提高小麦的光温生产效率和高产、稳产。利用同一群体可以将QTL分析与新品种选育相结合,是分子标记辅助选择的一条有效途径。  相似文献   

4.
套袋对茄果类蔬菜品质和产量的影响   总被引:3,自引:0,他引:3  
采用田间对比试验,研究了套袋措施对早春露地茄子和番茄农药残留及品质的影响。结果表明:套袋能有效防止害虫对露地茄子和番茄果实的直接为害,减少农药使用次数,降低产品农药残留,并改善果实外观色泽,提高产品的商品性能和生产效益。  相似文献   

5.
Although water and energy resources are well-recognized concerns regarding economic and social development sustainability, little specific research has focused on both water and energy problems at the same time. This study analyzed the water and electricity-use patterns in Shenzhen, South China during 2001-2009. A curve regression method was used to examine the relationship between water and electricity use per gross domestic product (GDP) in Shenzhen and its three sectors, i.e., agriculture, industry & construction, and residential life & services. Results showed that agriculture only covered less than 10% of water and electricity use in Shenzhen, while industry & construction and residential life & services accounted for more than 90% of water and electricity use in Shenzhen, which coincided with the city's industrial structure. The water and electricity use per GDP in agriculture was the biggest among three sectors in Shenzhen during 2001-2009, which means inefficiency of water and electricity use in agriculture. Due to transitioning to advanced materials and manufacturing, both water and electricity use per GDP in industry & construction decreased during 2001-2009 and their utilization efficiencies gradually increased over time. The same held true for those in residential life & services transformed toward modern business, creative culture, finance services, etc. Derived from the survival of the fittest in competing for limited water and electricity resources, agriculture in Shenzhen has been gradually substituted by industry & construction and residential life & services, with much higher efficiencies of water and electricity use. And traditional agriculture will not be sustainable in the process of urbanization and industrialization, except high-tech intensive agriculture with low water and energy cost. Furthermore, by means of curve regression, we found that there was a significant quadratic relationship between water use per GDP and electricity use per GDP in the entire city and its three sectors. Suitable industrial transformation and advancement was a very effective way to save water and energy for modern cities. This can provide some reference for systematic planning and design of water and electricity allocation and use in agriculture, industry & construction and residential life & services in a city.  相似文献   

6.
 从10种供试药剂中筛选4种对玉米黑腐病有效的药剂,于2002年在楚雄州元谋县进行田间防治试验。结果表明,在所用的4种药剂中,防治结果以3%多抗霉素WP效果最好,防治效果为55.5%,每公顷能增产玉米870 kg,比对照增产12%.  相似文献   

7.
调查分析了2000-2005年崇明县种植业农用化学品使用情况;并结合崇明岛的气候、农业生产及地域等特点,探讨了农用化学品使用对崇明生态环境建设的影响;为把崇明建设成生态岛,提出了农用化学品控制对策。  相似文献   

8.
星火科技引领海峡西岸新农村建设的实践与探索   总被引:2,自引:1,他引:1       下载免费PDF全文
李朝灿 《农学学报》2013,3(1):71-78
根据泉州市组织实施星火计划25年的实践与探索,论述星火科技支撑引领海峡西岸新农村建设的主要模式及其成效。构建政策支撑引导、科技项目引领、专家智力支撑、星火科技培训、科技信息服务、星火科技示范六大星火科技体系;组织实施国家星火产业带建设、新农村建设科技促进行动、星火科技创新中心、农村信息化示范、科技特派员农村创业等五大星火科技工程,推进海峡西岸新农村建设。提出星火科技工作启示及今后发展思路。  相似文献   

9.
Metabolic interactions among environmental chemicals and drugs   总被引:6,自引:0,他引:6  
It is evident that metabolic interactions can occur among drugs, insecticides, food additives, carcinogenic hydrocarbons, and a variety of environmental chemicals. A common denominator governing these effects is the versatile nature of the liver microsomal enzymes that metabolize chemicals with diverse structures and biological activities, and the fact that these enzymes can be stimulated or inhibited by other chemicals administered simultaneously. The discovery of these particular enzymes in the 1950's laid the groundwork for the current research on metabolic interactions. Such research provides information that is helpful in the evaluation of the safety and efficacy of drugs and environmental chemicals, and suggests new directions for further research. Some examples are as follows.  相似文献   

10.
热力烟雾机在玉米病虫害防治上的应用研究   总被引:3,自引:0,他引:3  
玉米病虫害的药剂防治主要在玉米生长的中后期进行,但由于株高叶茂,田间喷药困难。热力烟雾机采用一些油剂作为农药的载体,经输导管在高温点(350~400℃)时瞬间气化,形成热雾且分布均匀,可沿田埂施药。试验以机动弥雾机喷雾防治为对照,在玉米田进行了热力烟雾机热雾粒田间不同水平距离和垂直高度的药剂雾滴分布规律和对玉米南方锈病、纹枯病、蚜虫的防效试验。结果表明,使用热力烟雾机防治效果高于机动弥雾机喷雾防治效果,热力烟雾机防治有效距离为25 m以上,热雾粒数量在田间不同水平距离(0~25 m)、垂直高度(0~2 m)范围内比较均匀,正面热雾粒附着量为150~300粒.cm-2,背面热雾粒附着量为50~140 cm2粒。  相似文献   

11.
辣椒疫病菌的抗药性和新药剂的筛选研究   总被引:16,自引:1,他引:16  
辣椒疫病是由辣椒疫霉(PhytophthoracapsiciL.)引起的重要植物病害,化学药剂是目前防治该病害最有效的途径之一。为此,对辣椒疫病的发生特点、化学药剂防治的抗性问题和新化学防治药剂的筛选进行了研究。  相似文献   

12.
 合理使用农用化学制品如化肥、农药、食物添加剂等,对农产品的产量和品质有良好的作用.然而,使用不当也会对作物和人体健康造成不良后果.本文就主要农用化学制品对农作物尤其是人体健康产生的负效应以及如何减少这些危害的问题作一简要评述.  相似文献   

13.
The resistance of transgenic tomato plants containing genes of chitin-binding proteins from Amaranthus caudatus (ac) and A. retraflexus (RS-intron-Shir) and hevein-like antimicrobial peptides (amp1 and amp2) from Stellaria media is analyzed. Lines expressing genes ac, amp1, and amp2 are characterized, unlike the untransformed control, by enhanced resistance to a isolate Phytophthora infestans obtained from potato leaves.  相似文献   

14.
This paper explores ways in which experiential learning theories, in particular transformative learning theory, can inform farmer participatory research and extension (PR&E). I identify and discuss three key elements of experiential learning theory – second-order experiences, reflection, and dialogue – that are particularly pertinent to PR&E practice. I then turn to one experiential learning theorist – Mezirow, and examine his theory of transformative learning to assess how it may inform the PR&E process. I outline the basic components and stages of transformative learning and summarize the main criticisms of the theory. Following this, parallels are drawn between transformative learning and what actually takes place in PR&E, and examples are given of the ways in which scientists and rural people may undergo transformative learning through the PR&E process. Ways in which transformative learning can be encouraged within the PR&E context are discussed. I conclude that Mezirows work can provide PR&E practitioners and theorists with additional insights into how adults learn and especially how they – researchers, extensionists and rural people – can transform their ways of thinking to accommodate a shift from conventional research and extension to PR&E.Rachel Percy is a lecturer in the International and Rural Development Department of the University of Reading, UK, teaching gender, participatory learning and action, and participatory research and extension. Her research interests center on how adult learning theories, particularly those related to experiential learning, can inform participatory practice. From 1980 to 1997, before she joined the University of Reading, she worked in the field of agricultural extension, training and sustainable development in Ethiopia, Nigeria, Sudan, and Malawi. She has published on experiential learning and the training of agricultural extensionists (International Journal of Lifelong Education), capacity building for gender-sensitive agricultural extension planning (Journal of Agricultural Education and Extension), and gender analysis and participatory rural appraisal (International Journal of Educational Development).  相似文献   

15.
果树化学疏花疏果研究进展   总被引:1,自引:0,他引:1  
首先综述了世界各国常用的化学疏花疏果剂,如西维因、石硫合剂、萘乙酸等,归纳总结了各自的研究进展、作用机理、使用方法和优缺点等;进而探讨了新型疏花疏果剂的种类和应用情况;最后讨论了化学疏花疏果剂今后的发展趋势。  相似文献   

16.
影响玉米孤雌生殖诱导率的因素研究   总被引:1,自引:0,他引:1  
为加快玉米自交系的选育速度,2009年进行玉米孤雌生殖试验,研究了药物诱导玉米孤雌生殖的方法和效果.试验采用MH(青鲜素)、DMSO(二甲基亚砜)和COL(秋水仙素)3种药剂,5种试验处理,对6份不同遗传背景材料诱导玉米孤雌生殖.结果表明,在已处理的250穗中,平均诱导率为0.022%~0.257%;化学药物配比最佳组...  相似文献   

17.
【目的】蜜蜂幼虫在饥饿状态下会通过释放特定信息素来向外界传递饥饿信号,称为蜜蜂幼虫饥饿信息素(hunger pheromone)。论文旨在研究西方蜜蜂(Apis mellifera)蜂王与雄蜂幼虫饥饿信息素化学成分及在幼虫体内的生物合成通路,明确蜜蜂幼虫与成年蜂之间的化学信息素交流机制。【方法】采集2日龄与4日龄西方蜜蜂蜂王与雄蜂幼虫及其食物,将其分为饥饿组、饲喂组与纯食物组。饲喂组幼虫平躺在预先准备好的食物表面,饥饿处理组则不提供食物。所有样品分别放入20 m L密封采样瓶中并在35℃条件下放置45 min。利用Needle trap技术从样品瓶中采集10 m L气体,富集气体中的挥发性化学物质。在气质联用进样口以250℃高温将富集的化学物质解离,并通过气质联用技术分析鉴定蜂王与雄蜂幼虫饥饿信息素。同时,采用RNA-Seq技术分析饥饿信息素在蜂王与雄蜂幼虫体内的生物合成通路及相关基因表达。【结果】从蜂王与雄蜂幼虫中分别分析鉴定出10种与9种信息素,其中蜂王幼虫含有一种特有的幼虫信息素——2-庚酮,且在蜂王食物中含量最高。E-β-罗勒烯在蜂王与雄蜂幼虫各饥饿组含量均显著高于其饲喂幼虫组与食物组,表明蜂王与雄蜂幼虫均以E-β-罗勒烯为其饥饿信息素。2日龄蜂王与雄蜂幼虫饥饿组E-β-罗勒烯含量均差异不显著,但4日龄蜂王幼虫饥饿组E-β-罗勒烯含量显著低于雄蜂幼虫组。其余8种信息素为肉豆蔻酸、棕榈酸、甲基棕榈酸脂、硬脂酸、棕榈油酸、十五烷酸、乙酸与乙酸乙酯,均未出现饥饿组高于其他两组的规律。其中乙酸乙酯与乙酸在食物组与饲喂组含量高于饥饿组,推测其可能来自于幼虫食物。RNA-Seq结果表明蜂王与雄蜂幼虫通过甲羟戊酸途径由乙酰辅酶A从头合成E-β-罗勒烯。发现Geranylgeranyl pyrophosphate synthase-like与Farnesyl pyrophosphate synthase等9个基因参与该通路,但在饥饿组与其饲喂组幼虫中表达差异均不显著。【结论】蜜蜂蜂王与雄蜂幼虫利用E-β-罗勒烯作为其饥饿信息素乞求食物,并且在体内从头合成E-β-罗勒烯。工蜂利用2-庚酮标记蜂王幼虫,但未对雄蜂幼虫进行标记。  相似文献   

18.
稻纵卷叶螟为害对水稻防御化合物及信号分子含量的影响   总被引:1,自引:0,他引:1  
    测定稻纵卷叶螟Cnaphalocrocis medinalis(Guenee)为害后水稻体内过氧化氢、水杨酸、茉莉酸3种信号分子以及防御相关化合物含量的变化.结果表明,稻纵卷叶螟为害后0.5、24 h能显著提高水稻体内过氧化氢浓度,为害后0.5、1、24 h显著增加水杨酸浓度,但不影响茉莉酸浓度.稻纵卷叶螟为害能导致水稻叶片中胰蛋白酶抑制剂和6种未知防御化合物含量上升,在叶鞘中只引起6种未知物中的3种含量上升,其他的3种未知物与胰蛋白酶抑制剂没有明显变化.外用水杨酸或过氧化氢处理水稻只在叶鞘中增加6种未知物中1种化舍物的含量.说明稻纵卷叶螟为害诱导的防御化合物的变化部分是系统性的,而另一部分则是局部性的;并且稻纵卷叶螟为害诱导的防御反应是多种信号分子相互作用的结果.  相似文献   

19.
不同药剂喷施处理对海南油茶保花保果效果的影响   总被引:1,自引:0,他引:1  
在油茶试验基地设定15个处理,分别在花期喷洒不同类型及浓度的药物进行保花保果处理,并以喷洒清水为对照;采收成熟果实,测定其产量和单果重、横纵径、籽粒重等果实指标,进行生物统计分析,并结合喷洒成本,计算经济效益,筛选出海南油茶最适宜的保花保果药物及浓度。结果表明:0.5%硼砂、20 mg/L GA_3、800倍爱多收和0.1%硼砂+800倍爱多收+800倍高美施处理的株产量显著高于对照组;0.5%硼砂处理的果实横纵径显著高于对照组;20 mg/L GA_3、0.1%硼砂、800倍爱多收处理的单果重显著高于对照组;各处理的籽粒重和出籽率与对照组差异不显著。说明赤霉素、硼砂、爱多收、高美施等药物处理对增加油茶产量和提高单果重有显著性作用。这些药剂价格低廉企且易购买,对提高海南油茶的经济效益具有较高的推广价值。  相似文献   

20.
本文从理论上研究了系统分析法在害虫防治上的应用。全文分4个部分:1.系统分析法在作物产量损失计算上的应用;2.由作物产量损失评价农药效果;3.经济损失意义下药物效果评价;4.经济阈值向量的一种确定方法,防治适期预测等控制问题。文中方法从理论上讲,对种群结构较为复杂,一年多世代发生,世代重叠,不只一个虫态(龄)造成损害的情况具有更加特殊的重要性,对种群结构较为简单的情况亦适用。文中涉及的产量均指作物产量,试验中测出的生物产量损失用模拟方法折算为作物产量损失,或者直接用对照的方法测出模型中作物产量损失参数。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号