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。     

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。     

草甘膦近期价格上涨

草甘膦价格近期由21000元／吨上涨至28000元／吨。上涨主要来源于两个方面,一是去年的库存已经接近消化完毕;二是由于原材料黄磷和甘氨酸价格上涨。甘氨酸的价格由10000元／吨上涨至12000元／吨。如果按照1吨甘氨酸生产2．25吨草甘膦,对草甘膦成本影响是889元／吨,1吨黄磷生产5．6吨草甘膦,对草甘膦成本影响为178元,总计为1067元／吨,但成本推动远小于受库存减少、需求回暖的影响力度。     

对草甘膦有恶性抗性杂草的铲除方案

<正>1草甘膦抗性现状及面临的其他问题草甘膦为内吸传导型慢性广谱灭生性除草剂,主要抑制植物物体内烯醇丙酮基莽草素磷酸合成酶(EPSP),从而抑制莽草素向苯丙氨酸、酪氨酸及色氨酸的转化,使蛋白质的合成受到干扰,从而导致植物死亡。由于草甘膦优异的杀草活性、广泛的杀草谱、较低的土壤残留、较长的控草时间,加上抗除草剂转基因作物的广泛种植,使其成为全球销量第一的除草剂品种。然而由于长时间大量单一连续使用草甘膦,杂草的抗性问题已经非常突出。到目前已经公布了有31种     

草甘膦防治菟丝子的机理研究

作者以菟丝子幼苗为材料研究了草甘膦防治菟丝子的机理。结果表明:草甘膦处理后,幼苗内色氨酸和花色素的含量均减少了,且其蛋白质合成也受到抑制。外源苯丙氨酸(Phe)、酪氨酸(Tyr)和色氨酸(Trp)的供给既可保证幼苗内蛋白质合成不受草甘膦的影响,又可保证其在这一除草剂存在的介质中能够正常生长。所有结果表明3种芳香族氨基酸的生物合成是草甘膦防治菟丝子的唯一作用点。     

新型除草剂—草甘膦及应用

草甘膦(Glyphosate)是近几年来青海化工研究所、沈阳化工研究院和镇江农药厂研制成功的一种新型化学除草剂。在我国又称为镇草宁或膦甘酸。它的母体化合物是N——膦酸甲基甘氨酸,它可以加工成为一钠、二钠、三钠盐、异丙胺盐、二甲胺盐等剂型。     

草甘膦加入硫酸铵提高防效

草甘膦是内吸型灭生性除草剂,用作杂草生长期茎叶处理,可防除马唐、狗尾草、画眉草、野苋等一年生杂草和多种多年生杂草。本文介绍草甘膦(N-膦羧甲基甘氨酸和氢氧化钠混剂)加入硫酸铵提高对杂草防     

新型N-芳基-2-((5-((4,6-二甲基嘧啶-2-基)硫甲基)-1,3,4-噻二唑-2-基)硫)乙酰胺类化合物的合成及杀菌活性

为寻找新型杂环活性化合物,通过活性亚结构拼接,以硫脲和乙酰丙酮为起始原料合成4,6-二甲基嘧啶-2-硫醇,随后经酯化、肼化、环化和缩合反应,设计并采用微波辅助合成了10个新型N-芳基-2-（（5-（（4,6-二甲基嘧啶-2-基）硫甲基）-1,3,4-噻二唑-2-基）硫）乙酰胺类化合物,其结构通过核磁共振氢谱和碳谱、红外光谱、质谱及元素分析确认。初步生物活性测试结果表明,在50 mg/L下,大部分目标化合物对植物病原真菌具有一定的抑制活性,其中化合物8h对黄瓜炭疽病菌Colletotrichum orbiculare的抑制率达77.3%。     

草甘膦应用技术研究与推广工作总结

一、概况草甘膦为新型的低毒、低残留、内吸传导灭生性除草剂。其活性成份是甘氨酸。国产草甘膦为10%铵盐或钠盐(镇草宁)水剂。由于草甘膦具有较强的内吸传导性能,因此它不仅能有效地杀灭一年生或二年生单、双子叶杂草,而且在解决多年生杂草方面有独特的作用,故得到广泛的应用。     

亚氨基二乙腈生产草甘膦中间体双甘膦降低能耗工艺条件改进

对以亚氨基二乙腈为起始原料,经碱解、缩合制备草甘膦中间体N-膦酰基甲基亚氨基二乙酸(简称双甘膦)工艺条件的优化试验,通过提高原料浓度,提高了亚氨基二乙酸一钠盐浓度,减少了缩合脱水时间,缩短了双甘膦生产周期,降低了能源消耗.     

Influence of glyphosate on uptake and translocation of calcium ion in soybean seedlings

Calcium ion in hydroponic solution with glyphosate [N-phosphonomethyl (glycine)] did not significantly influence the efficacy of the herbicide in reducing growth of soybean (Glycine max) seedlings. Data from atomic absorption spectroscopy studies revealed that glyphosate reduced Ca²⁺ uptake and translocation, whether supplied alone or with other metal ions. Results with radiolabelled ⁴⁵Ca²⁺ indicated that glyphosate severely retards translocation of Ca²⁺ from the roots to the leaves and cotyledons but the effect is not detectable until 24 h after exposure to glyphosate. Influence du glyphosate sur l'absorption el le mourement de I'ion calcium dans des plantules de soja. L'ion calcium présent dans une solution hydroponique contenant du glyphosate (N-phosphono-methyl (glycine) ne modifie pas dc facon significative I'efficacité de I'herbicide dans son action sur la réduction de croissance de plantules de soya. Des données fournies par la spectroscopie d'absorption atomique montrent que le glyphosate reduit l'absorption et le mouvement des ions Ca²⁺ seuls ou en présence d'ionsd'autresmétaux. Les résultats obtenus avec des ions marqués ⁴⁵Ca²⁺ révèlent que le glyphosate retarde notablement le mouvement des ions Ca²⁺ entre les racines et les feuilles ou les cotylédons mais cet effct n'est pas détectable avant une péríode de 24h suivant l'exposition au glyphosate.     

The determination of glyphosate in soils with moderate to high clay content

An improved method for the quantitative analysis of the herbicide glyphosate [N-(phosphonomethyl)glycine] in soils containing moderate to high clay content is described. Critical evaluations of previously published methods have indicated that recoveries of glyphosate from soils with high clay content are often low. Where acceptable recovery estimates have been reported, these methods also report increased interferences and rarely include soils with clay content exceeding 30%. The proposed method was developed and characterized using six soils of different clay content (25–87% clay), with other physical and chemical properties as described. Recoveries of glyphosate from the soils were determined after duplicate extractions with 0.1 M potassium hydroxide. Clean-up of soil extract solutions was by cation-exchange column chromatography. Subsequent quantitation was by HPLC with post-column oxidation, followed by derivatization using OPA-MERC with fluorometric detection. No interferences were detected. Recovery estimates for each fortified sample were determined over a concentration range (0.56–11.25 mg glyphosate kg ?1 ) with all recoveries being greater than 80%. Detection limit for glyphosate in soil was 0.04 mg kg ?1, and instrument response was linear for solutions up to 50.0μg glyphosate ml ?1. Reproducibility relative confidence interval, for a single sample analysis, was determined as.     

[14C]Glyphosate transport in undisturbed topsoil columns

Although glyphosate (N‐(phosphonomethyl)glycine) is one of the most frequently used herbicides, few controlled transport experiments in undisturbed soils have been carried out to date. The aim of this work was to study the influence of the sorption coefficient, soil‐glyphosate contact time, pH, phosphorus concentration and colloid‐facilitated transport on the transport of [¹⁴C]glyphosate in undisturbed top‐soil columns (20 cm height × 20 cm diameter) of a sandy loam soil and a sandy soil. Batch sorption experiments showed strong Freundlich‐type sorption to both soil materials. The mobility of glyphosate in the soil columns was strongly governed by macropore flow. Consequently, amounts of glyphosate leached from the macroporous sandy loam soil were 50–150 times larger than from the sandy soil. Leaching rates from the sandy soil were not affected by soil‐glyphosate contact time, whereas a contact time of 96 h strongly reduced the leaching rates from the sandy loam soil. The role of pH and phosphorus concentration in solution was relatively unimportant with respect to total glyphosate leaching. The contribution of colloid‐facilitated transport was <1 to 27% for the sandy loam and <1 to 52% for the sandy soil, depending on soil treatment. The risk for glyphosate leaching from the top‐soils seems to be limited to conditions where pronounced macropore flow occurs shortly after application. © 2000 Society of Chemical Industry     

Selective complexometric determination of glyphosate and related compounds

A complexometric method has been developed for the selective determination of glyphosate and related compounds. The method is based upon the different pH-dependence of tridentate and tetradentate ligand-metal complex stabilities. Glyphosate, the tridentate ligand forms a stable copper complex at pH ≥ 8 only, whereas N-carboxymethyl-N-phosphonomethylglycine and N,N-bis(phosphonomethyl)glycine, the tetradentate ligands, form sufficiently stable bismuth complexes even at low pH. The method, therefore, consists of aliquot titrations in basic and acidic media, using metal ion titrant solutions. The first aliquot containing N-(phosphonomethyl)glycine plus N-carboxymethyl-N-phosphonomethylglycine or N,N,-bis(phosphonomethyl)glycine is titrated with bismuth volumetric solution at pH 1.8–2–5 in the presence of methylthymol blue indicator. Quantities of the tetradentate ligands can be calculated from the bismuth consumption. The second aliquot is titrated with copper volumetric solution at pH 8–10, in the presence of murexide indicator. The content of glyphosate can be calculated from the difference between the copper and bismuth consumptions. Efficacy of the method is verified by analyses of standard mixtures and industrial samples.     

Characteristics of glyphosate inhibition of growth in soybean and tobacco callus cultures

Callus cultures or tobacco (Nicotiana tabacum L. cv. While Gold and N. glauca-langsdorffii, a tumour-forming amphidiploid hybrid) and soybean Glycine max L., cv. Chippewa) were used lo study the effect of glyphosate [N-(phosphonnmethyl) glycine) un growth and interactions with growth hormones. Glyphosate inhibited growth both in the dark and light but showed a greater toxicity in the dark. This was contrary to its effect on chlorophyll degradation which was accelerated by light. The inhibition of growth was not reversed by simultaneous addition of aromatic amino acids to the medium. Thus the results suggest a multiple glyphosate action. The tobacco callus tissue was more sensitive to glyphosate than the soybean callus tissue, confirming a difference in tolerance between plant species. Despite the inhibitory effect of glyphosate. the treated tissue revived after being transferred to a glyphosate-free medium. The glyphosate-induced growth inhibition in soybean and tumour-forming tobacco callus cultures also was reversible by high levels of indole-3-acetic acid (IAA), which itself was inhibitory Theglyphosate-IAA interaction in the tissues which were sensitive to IAA suggests that the inhibition of growth by glyphosate was related to auxin levels in these tissues.     

Comparison of commercial glyphosate formulations for control of prickly sida, purple nutsedge, morningglory and sicklepod

The efficacy of the commercial glyphosate [( N -phosphonomethyl) glycine] formulations Roundup Ultra, Touchdown and Engame were compared for the control of prickly sida ( Sida spinosa L.), morningglory ( Ipomeae hederacea var. integriuscula Gray), sicklepod ( Senna obtusifolia L.) and purple nutsedge ( Cyperus rotundus L.). Engame is a new formulation of glyphosate that contains glyphosate acid and 1-aminomethanamide dihydrogen tetraoxosulfate (AMADS), a proprietary mixture of sulfuric acid and urea, other than glyphosate salt and surfactants. Injury by Engame differed from Roundup Ultra and Touchdown in that necrotic lesions formed on leaves several hours after treatment. Leaves of very susceptible species, such as prickly sida, were rapidly, although incompletely, desiccated and then became chlorotic and died in a manner typical of other glyphosate formulations. Engame was 2–3 times more active to growth inhibition than either the Roundup Ultra or Touchdown formulations, based on GR₅₀ comparisons expressed on an acid equivalent basis. The GR₅₀ estimates did not change over the 3 week evaluation period for prickly sida and purple nutsedge, and after 2 weeks after treatment for morningglory. The GR₅₀ estimates for sicklepod decreased over the 3 week evaluation period indicating a slower response to glyphosate. The application of AMADS alone caused minute necrotic lesions on sicklepod and purple nutsedge, and lesions up to 3 mm in diameter on prickly sida and morningglory. Further injury from AMADS was not noted and plants resumed growth without apparent delay. At glyphosate rates above 1120 g ha⁻¹, greater than 80% control was achieved at 7 days after treatment. These results demonstrate that glyphosate efficacy can be further enhanced by formulations that apparently improve uptake and translocation.     

Glyphosate: a once-in-a-century herbicide

Since its commercial introduction in 1974, glyphosate [N-(phosphonomethyl)glycine] has become the dominant herbicide worldwide. There are several reasons for its success. Glyphosate is a highly effective broad-spectrum herbicide, yet it is very toxicologically and environmentally safe. Glyphosate translocates well, and its action is slow enough to take advantage of this. Glyphosate is the only herbicide that targets 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPS), so there are no competing herbicide analogs or classes. Since glyphosate became a generic compound, its cost has dropped dramatically. Perhaps the most important aspect of the success of glyphosate has been the introduction of transgenic, glyphosate-resistant crops in 1996. Almost 90% of all transgenic crops grown worldwide are glyphosate resistant, and the adoption of these crops is increasing at a steady pace. Glyphosate/glyphosate-resistant crop weed management offers significant environmental and other benefits over the technologies that it replaces. The use of this virtually ideal herbicide is now being threatened by the evolution of glyphosate-resistant weeds. Adoption of resistance management practices will be required to maintain the benefits of glyphosate technologies for future generations.     

Monitoring glyphosate residues in transgenic glyphosate-resistant soybean

The availability of Roundup Ready (RR) varieties of soybean has increased the use of glyphosate for weed control in Argentina. Glyphosate [(N-phosphonomethyl)glycine] is employed for the eradication of previous crop vegetation and for weed control during the soybean growing cycle. Its action is effective, and low environmental impact has been reported so far. No residues have been observed in soil or water, either of glyphosate or its metabolite, AMPA (aminomethylphosphonic acid). The objective of this work was to monitor glyphosate and AMPA residues in soybean plants and grains in field crops in Santa Fe Province, Argentina. Five sites were monitored in 1997, 1998 and 1999. Individual soybean plants were sampled from emergence to harvest, dried and ground. Analysis consisted in residue extraction with organic solvents and buffers, agitation, centrifugation, clean-up and HPLC with UV detection. In soybean leaves and stems, glyphosate residues ranged from 1.9 to 4.4 mg kg(-1) and from 0.1 to 1.8 mg kg(-1) in grains. Higher concentrations were detected when glyphosate was sprayed several times during the crop cycle, and when treatments approached the flowering stage. AMPA residues were also detected in leaves and in grains, indicating metabolism of the herbicide.     

Absorption, translocation and allocation of glyphosate in resistant and susceptible Chilean biotypes of Lolium multiflorum

Glyphosate [N-(phosphonomethyl) glycine] is currently the most important non-selective, wide-spectrum herbicide used worldwide. Introduced in 1974, glyphosate was initially a non-crop herbicide and plantation crop herbicide, although it is now widely used in no-till crop production and, more recently, for weed control in herbicide-resistant transgenic crops, such as maize, soybean and cotton ( Baylis 2000 ; Caseley & Copping 2000 ). Despite its widespread and long-term use, no case of evolved resistance to glyphosate was documented until 1996 ( Pratley et al . 1996 ). Since then, a few other cases have been reported. To date, evolved resistance to glyphosate has been identified and documented in Lollium rigidum in Australia ( Powles et al . 1998 ; Pratley et al . 1999 ), Eleusine indica in Malaysia ( Lee & Ngim 2000 ), and L. rigidum in South Africa and California (USA), and Conyzia canadensis in Delawere (USA) ( Van Gessel 2001 ). Also, accessions of L. rigidum from South Africa and California have been reported to resist glyphosate ( Heap 2001 ). In Chile, the first case of glyphosate-resistance in Lolium multiflorum was reported in 1999 and documented in 2003 ( Pérez & Kogan 2003 ). This case was the result of an intensive selection pressure caused by the continuous applications of glyphosate in fruit orchards over 8–10 years. The present study is a first approach to elucidating the mechanism involved in the resistance of one biotype of L. multiflorum selected in Chilean orchards.