甘氨酸法制备草甘膦工艺改进

为了实现甘氨酸法合成草甘膦工艺中溶剂回收的便捷、经济化,并减少氯甲烷等副产物的排放,采用在酯化反应完成后直接从该无水体系中回收溶剂的工艺方法。结果表明,改进后的工艺在不影响草甘膦收率和品质的前提下,不仅可以回收98%以上的溶剂,而且回收后的溶剂可在不进行任何处理的情况下直接循环套用;同时可回收40％ ~63%的三乙胺,并使酸化水解时可以减排50％ ~81%的氯甲烷。相应地,草甘膦吨生产成本可下降10％ ~15%,并可有效降低环境污染。     

替代母液配制30%草甘膦水剂崭露头角

浙江作为我国经济最发达省份之一,省委省政府一直高度重视环境保护工作,强调建设生态浙江。在"浙江植保双交会"上,浙江省植物保护检疫局明确提出,倡导绿色环保,禁止使用母液配置的草甘膦水剂在浙江使用。国内新安集团率     

草甘膦母液残渣对小麦玉米油菜安全性测定

测定草甘膦母液残渣对农作物小麦、玉米、油菜的安全性。10 g/m2以上剂量对小麦、玉米、油菜种子出苗不安全;0.3 g/m2以上剂量对小麦生长不安全;2.5 g/m2以上剂量对油菜生长不安全。如用在道路工程施工上产生飘移,对周边的农作物会造成一定的危害性。     

闽西北柑桔园草甘膦应用技术研究

近年来,使用草甘膦防除柑桔园杂草的方法已被广泛采用。但由于使用技术的差异,防除效果和经济效益相差悬殊。为此,我们于1985～1987年进行了柑桔园草甘膦应用技术的研究。材料与方法 (一)试验地点:沙县畔溪洋柑桔园。树龄2～5年。试验田地势平坦,土壤肥沃,     

美国默赛技术公司先进技术产品——美利达％1％草甘膦异丙胺盐水剂

41％草甘膦异丙胺盐水剂（美利达）为美国默赛技术公司近年来开发的内吸传导型、广谱灭生性除草剂,该产品有效成分为草甘膦异丙胺盐。该产品采用特殊工艺和先进的专利助剂系统加工而成,活性高、易吸收、传导快、除草效果好。     

蛇床子素乳油对谷蠹的防治效果研究

采用粮食拌药法,研究了2%蛇床子素乳油母液对谷蠹的防治效果。结果表明,2%蛇床子素乳油母液对谷蠹具有较好的防治效果,用2%的蛇床子素乳油母液母液处理谷蠹96h后的LC50仅为1.7381mg/kg。     

草甘膦应用技术研究

目前草甘膦应用浪费问题严重 ,本文对国内外草甘膦应用技术方面的研究 ,包括施药最适期的选择 ,施药技术 ,发挥最佳药效的环境条件 ,合理混用技术等进行了论述 ,以其得到更经济、更广泛的应用。     

甲磺隆和草甘膦对空心莲子草乙酰乳酸合酶活性和莽草酸含量的影响

为研究甲磺隆和草甘膦对空心莲子草的作用机理,探索其最佳的使用技术,采用有效成分为30 g/hm2和60 g/hm2 的甲磺隆处理空心莲子草,能明显抑制其茎和根乙酰乳酸合酶的比活性;有效成分为1537.5g/ hm2和3075g/ hm2 的草甘膦处理则能明显抑制空心莲子草莽草酸含量的积累;施用甲磺隆和草甘膦对空心莲子草生长的抑制作用随药剂浓度的提高而增大.二次施用草甘膦(间隔30天)的结果表明,低剂量处理对抑制空心莲子草根组织莽草酸含量的积累更明显.     

提高草甘膦除茅效果的初步研究

本文系1981～1982年的研究结果,目的是为草甘膦高效经济的应用技术提供依据。草甘膦是防除茅草的高效药剂,其效果受剂量、施药期、用水量、土壤湿度和水质等因素影响。施药期是影响草甘膦除茅效果的主要因素。施药适期为3叶中期,此生育期的茅草展着药剂多,药剂下行传导量较大、茅草根茎含糖量低、抗药性弱,因此效果高。土壤湿度对草甘膦的下行传导有一定影响。土壤湿度高,药剂下行传导多、药效好;含土量为2%的浑浊水或相当于二倍草甘膦浓度的三氯化铁、硝酸铝对草甘膦的活性有一定拮抗作用。硫酸铵对草甘膦的除茅效果有增效作用,而且在草甘膦低剂量下增效作用大。     

耐草甘膦菜豆耐性机理的初步研究

采用液谱测定耐性、感性菜豆叶片对草甘膦的吸收及草甘膦传导入根中的量。耐性、感性菜豆吸收、传导草甘膦无差异。耐性、感性菜豆 EPSP合成酶提取物中的蛋白质含量分别为 3.0 0 mg/ m L和 3.0 8mg/ m L ,EPSP合成酶的比活性分别为 2 .13nmol· min-1· mg-1蛋白和 1.97nmol· min-1· mg-1蛋白 ,但耐性、感性菜豆 EPSP合成酶比活性被草甘膦不同浓度抑制的差异大 ,抑制耐性菜豆 EPSP合成酶活性的草甘膦浓度 I50 为 19.2μmol/ L ,而感性的 I50 为 6 .3μmol/ L。两种菜豆对草甘膦的耐性差异在于各自的 EPSP合成酶比活性被草甘膦的抑制程度不同。     

类黄酮在草甘膦诱导的苦荞膜脂过氧化中的作用

研究了草甘膦对苦荞类黄酮次生代谢的影响及类黄酮与草甘膦作用下膜脂过氧化伤害的关系，以探讨植物类黄酮代谢的意义及在草甘膦伤害中的作用机制。结果表明，分别用浓度为0．1、0．3、1mmoL／L的草甘膦处理苦荞幼苗，苦荞类黄酮代谢受到明显抑制，处理3天时类黄酮含量比对照分别下降58．1％、65．8％和76．5％。草甘膦处理导致苦荞膜脂过氧化加剧，0．1mmoL／L草甘膦处理使苦荞相对电导率增加275．4％、丙二醛（MDA）含量增加134．1％、超氧自由基O2^-产生速率增加121．7％，且随草甘膦浓度升高而增加幅度加大，说明草甘膦伤害与膜脂过氧化程度有关。0．3mmoL／L草甘膦处理后再用0．1mmoL／L类黄酮物质芦丁处理，电解质外渗下降34．2％，MDA含量下降51．1％，O2^-产生下降33．9％，明显减轻了草甘膦的伤害，这说明草甘膦作用下类黄酮含量的下降与草甘膦对苦荞组织伤害有一定的关系。     

分子对接阐明草甘膦与水稻醛酮还原酶(OsALR2)的作用及OsALR2的表达纯化

草甘膦是一种广谱高效的有机磷类除草剂, 因其对水稻等禾本科作物缺乏选择性, 导致其在水稻田中的应用受到限制。杂草中醛酮还原酶(aldo-keto reductase, AKR)具有降解小分子农药草甘膦的功能, 但是水稻响应草甘膦的作用机制未知。本文通过生物信息学分析、分子对接研究草甘膦与其在水稻中的靶标AKR蛋白OsALR2的互作机制。采用TMHMM 2.0和DiANNA 1.1 web server 等在线软件对 OsALR2 蛋白的跨膜特性和二硫键含量等生物学特性进行了分析, 结果表明OsALR2分子量为 35 kD, 等电点为 5.89; OsALR2不是膜蛋白, 但是含有3组二硫键。使用AlphaFold 预测OsALR2 蛋白的三级结构, 并利用Auto Dock Vina将草甘膦与OsALR2进行分子对接, 结果显示, 最低结合能为 -13.4 kcal/mol, 草甘膦与OsALR2的结合主要通过氢键作用。通过Ramachandran图, ERRAT和Verify 3D证明对接获得的三维结构是合理的。进一步通过分子克隆技术构建重组表达载体 pET-32a-OsALR2 并进行原核表达, 结果显示OsALR2主要以包涵体的形式表达, 对包涵体进行变复性后, 蛋白表现出酶活性且蛋白结构有较好的均一性。本文的研究结果助于阐明草甘膦与水稻蛋白互作的分子机制, 为研发抗草甘膦水稻新品种和新型小分子农药提供理论指导。     

New multiple-herbicide crop resistance and formulation technology to augment the utility of glyphosate

Glyphosate has performed long and well, but now some weed communities are shifting to populations that survive glyphosate, and growers need new weed management technologies to augment glyphosate performance in glyphosate-resistant crops. Unfortunately, most companies are not developing any new selective herbicides with new modes of action to fill this need. Fortunately, companies are developing new herbicide-resistant crop technologies to combine with glyphosate resistance and expand the utility of existing herbicides. One of the first multiple-herbicide-resistant crops will have a molecular stack of a new metabolically based glyphosate resistance mechanism with an active-site-based resistance to a broad spectrum of ALS-inhibiting herbicides. Additionally, new formulation technology called homogeneous blends will be used in conjunction with glyphosate and ALS-resistant crops. This formulation technology satisfies governmental regulations, so that new herbicide mixture offerings with diverse modes of action can be commercialized more rapidly and less expensively. Together, homogeneous blends and multiple-herbicide-resistant crops can offer growers a wider choice of herbicide mixtures at rates and ratios to augment glyphosate and satisfy changing weed management needs.     

In vitro expression of variation of glyphosate tolerance in Sorghum halepense

The in vitro response of five different Sorghum halepense biotypes against the non-selective, broad-spectrum herbicide glyphosate was assessed. Seeds from donor plants (collected in various sites all over Greece) were aseptically germinated on a hormone-free liquid Murashige and Skoog (MS) medium and emerging plantlets were inoculated on a solid MS medium supplemented with 13.6 μM 2.4-dichlorophenoxyacetic acid and 4.6 μM kinetin for callus induction. Exponentially growing calli were initially subcultured twice on induction medium and then transferred to a selection medium containing 10⁻³ M or 10⁻⁴ M (a.i.) glyphosate. The fresh weight of the cultured calli and the callus viability (expressed as callus dehydrogenase activity) were reduced as glyphosate concentration increased. Significant differences were observed among different biotypes. Regenerated plantlets were submitted to a conventional evaluation for glyphosate tolerance. The observed in vitro response of S. halepense to glyphosate was directly related to the in vivo herbicide tolerance observed both on donor and on regenerant plants.     

Non‐target‐site mechanism of glyphosate resistance in Italian ryegrass (Lolium multiflorum)

In Shizuoka Prefecture, Japan, glyphosate‐resistant Lolium multiflorum is a serious problem on the levees of rice paddies and in wheat fields. The mechanism of resistance of this biotype was analyzed. Based on LD₅₀, the resistant population was 2.8–5.0 times more resistant to glyphosate than the susceptible population. The 5‐enolpyruvyl‐shikimate‐3‐phosphate synthase (EPSPS) gene sequence of the resistant biotype did not show a non‐synonymous substitution at Pro106, and amplification of the gene was not observed in the resistant biotype. The metabolism and translocation of glyphosate were examined 4 days after application through the direct detection of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) using liquid chromatograph‐tandem mass spectrometer (LC‐MS/MS). AMPA was not detected in either biotype in glyphosate‐treated leaves or the other plant parts. The respective absorption rates of the susceptible and resistant biotypes were 37.90 ± 3.63% and 41.09 ± 3.36%, respectively, which were not significantly different. The resistant biotype retained more glyphosate in a glyphosate‐treated leaf (91.36 ± 1.56% of absorbed glyphosate) and less in the untreated parts of shoots (5.90 ± 1.17%) and roots (2.76 ± 0.44%) compared with the susceptible biotype, 79.58 ± 3.73%, 15.77 ± 3.06% and 4.65 ± 0.89%, respectively. The results indicate that the resistance mechanism is neither the acquisition of a metabolic system nor limiting the absorption of glyphosate but limited translocation of the herbicide in the resistant biotype of L. multiflorum in Shizuoka Prefecture.     

Basis for changes in glyphosate phytotoxicity to barley by the non-ionic surfactants Tween 20 and Renex 36*

The non-ionic surfactants, Tween 20 (polyoxy-ethylene 20 sorbitan monolaurate) and Renex 36 (polyoxyethylene 6-tridecyl ether) enhanced the retention of a glyphosate-dye spray solution by barley (Hordeum vulgare L.) leaves. Tween 20 also enhanced absorption of ¹⁴C-glyphosate applied as droplets to barley leaves whereas Renex 36 similarly applied, reduced both absorption and movement of ¹⁴C-glyphosate. Renex 36 alone or mixed with glyphosate increased leakage of electrolytes from barley leaf segments whereas neither Tween 20 nor glyphosate, alone or mixed together, had any effect. No ¹⁴C-glyphosate complexes were detected in mixtures with either surfactant and neither surfactant affected the pH of the glyphosate solution. The results indicate that the reported enhancement of glyphosate phytotoxicity by Tween 20 is due to increased retention and absorption of the herbicide while the reported antagonism caused by Renex 36 is due to reduced glyphosate absorption and movement possibly as a result of alteration of membrane integrity.     

Perspectives on transgenic,herbicide‐resistant crops in the United States almost 20 years after introduction

Herbicide‐resistant crops have had a profound impact on weed management. Most of the impact has been by glyphosate‐resistant maize, cotton, soybean and canola. Significant economic savings, yield increases and more efficacious and simplified weed management have resulted in widespread adoption of the technology. Initially, glyphosate‐resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate‐resistant crops over broad areas facilitated the evolution of glyphosate‐resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate‐resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl‐CoA carboxylase and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive effects (reduced cost, simplified weed management, lowered environmental impact and reduced tillage) that glyphosate‐resistant crops had initially. In the more distant future, other herbicide‐resistant crops (including non‐transgenic ones), herbicides with new modes of action and technologies that are currently in their infancy (e.g. bioherbicides, sprayable herbicidal RNAi and/or robotic weeding) may affect the role of transgenic, herbicide‐resistant crops in weed management. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

Glyphosate resistance in common ragweed ( A mbrosia artemisiifolia L.) from Mississippi,USA

Glyphosate is one of the most commonly used broad‐spectrum herbicides over the last 40 years. Due to the widespread adoption of glyphosate‐resistant (GR) crop technology, especially corn, cotton and soybean, several weed species have evolved resistance to this herbicide. Research was conducted to confirm and characterize the magnitude and mechanism of glyphosate resistance in two GR common ragweed ( A mbrosia artemisiifolia L.) biotypes from Mississippi, USA. A glyphosate‐susceptible (GS) biotype was included for comparison. The effective glyphosate dose to reduce the growth of the treated plants by 50% for the GR1, GR2 and GS biotypes was 0.58, 0.46 and 0.11 kg ae ha^?1, respectively, indicating that the level of resistance was five and fourfold that of the GS biotype for GR1 and GR2, respectively. Studies using ¹⁴ C‐glyphosate have not indicated any difference in its absorption between the biotypes, but the GR1 and GR2 biotypes translocated more ¹⁴ C‐glyphosate, compared to the GS biotype. This difference in translocation within resistant biotypes is unique. There was no amino acid substitution at codon 106 that was detected by the 5‐enolpyruvylshikimate‐3‐phosphate synthase gene sequence analysis of the resistant and susceptible biotypes. Therefore, the mechanism of resistance to glyphosate in common ragweed biotypes from Mississippi is not related to a target site mutation or reduced absorption and/or translocation of glyphosate.