微生物降解二苯醚类除草剂的研究进展

本文概述了降解二苯醚类除草剂的微生物种类、降解机理及影响微生物降解二苯醚类除草剂的因素,指出利用微生物修复土壤中二苯醚类除草剂残留是一个有效的手段; 同时指出二苯醚类除草剂微生物降解过程中起关键作用的酶及基因有待于进一步研究。     

微生物降解农药的研究进展

在农药的微生物降解研究中,分离构建一种由天然微生物构成的复合系,将其应用于被污染的环境是消除农药污染的一个有效方法。本文综述了环境中降解农药的微生物种类、微生物降解农药的机理、在自然条件下影响微生物降解农药的因素及农药微生物降解研究方面的新技术和新方法。     

磺酰脲类除草剂的微生物降解研究进展

磺酰脲类除草剂是使用最广泛的除草剂之一。微生物降解是磺酰脲类除草剂在土壤中降解的重要方式。本文简要概述了土壤微生物对磺酰脲类除草剂的降解、降解机理及影响微生物降解磺酰脲类除草剂的因素。     

烟嘧磺隆的微生物降解研究进展

烟嘧磺隆属磺酰脲类除草剂,因其对玉米安全,对一年生和多年生禾本科杂草及部分阔叶杂草、莎草科杂草高效而在玉米田广泛应用,但其在土壤中的残留则易对后茬敏感作物产生药害。微生物对烟嘧磺隆的降解有望成为修复污染土壤的有效措施。文章从烟嘧磺隆的使用及危害,可降解烟嘧磺隆的微生物种类及降解特性、降解途径、降解酶及其编码基因等方面进行了综述。目前有关烟嘧磺隆微生物降解的研究多集中于其降解菌的筛选、降解特性及降解途径等方面,对于其微生物降解过程中起关键作用的酶和基因方面的研究仍较少,因此未来的研究趋势将主要体现在降解复合菌系的培养、降解微生物的环境生态学、降解基因以及降解酶制剂等方面。     

微生物降解磺酰脲类除草剂的研究进展

磺酰脲类除草剂具有高效和高选择性等优点,但其微量残留在土壤环境中就会对敏感作物会产生药害。因此,解决其残留问题便成为当今的研究热点。其中微生物降解是磺酰脲类除草剂降解的最有效方法之一。本文综述了降解磺酰脲类除草剂微生物种类、降解机理及研究现状,并展望了微生物降解磺酰脲类除草剂修复污染土壤的前景。     

三唑类杀菌剂对水稻药害机理及解决方案

三唑类杀菌剂(triazole fungicide, TFs)是一类广谱、高效、低残留、长效、内吸传导性好,同时具有保护和治疗作用的新型杀菌剂,对真菌性病害有较好的防控效果,在作物病害防治上被广泛应用。三唑类杀菌剂在防治水稻中、后期真菌性病害上取得了极好的防效,是应用量较大的杀菌剂之一。但由于三唑类杀菌剂使用不当,在生产上造成了大量的药害实例,导致水稻减产或绝收,同时引起了一些社会问题,需要引起高度重视。本文在作者多年的调查和研究基础上结合相关文献资料,阐述了三唑类杀菌剂的分类、使用方法、作用机制,对水稻产生药害的原因、症状表现和机理,使用三唑类杀菌剂时避免发生药害的措施及药害发生后的补救方法。     

微生物降解有机磷农药残留机理及菌种筛选研究进展

农药的使用一方面可以保证农业稳产和增产,另一方面却改变了土壤微环境,污染周边的水体乃至大气环境。在农药使用造成的各种污染中,农药残留对人类影响大,作用时间长,尤其是部分有机磷农药具有高毒、降解慢的特点,污染人类生存环境,危害人体健康。使用微生物降解农药残留是解决该问题的有效方法。本文对微生物降解有机磷农药残留的机理和微生物诱变和筛选的最新进展进行总结,并对农药残留降解微生物的发展方向提出了自己的观点。     

三唑类杀菌剂的研究进展

本文介绍了国内外几种主要的三唑类杀菌荆，简叙了三唑类杀菌剂的作用机理，对目前三唑类杀菌剂的检测方法以及环境行为及降解途径作了一般介绍。     

三唑类杀菌剂作用机理和残留检测技术分析研究

本文对已商品化的三唑类杀菌剂代表性品种进行了信息介绍,阐述了三唑类杀菌剂的作用机理,对三唑类杀菌剂的残留检测技术进行了分析研究并总结出各类检测方法的优点,最后对三唑类杀菌剂的应用前景进行了推测和判断,为今后研究新颖三唑类杀菌剂提供探索依据。     

莠去津微生物降解的研究进展

综述了莠去津降解微生物的筛选方法、降解速度的影响因素、降解机理,并对农药降解微生物的应用前景进行了展望。对降解农药微生物的研究不但可以得到消除莠去津环境污染的菌株和相应的酶制剂,而且对于抗莠去津转基因技术的研究也有促进作用。     

Degradation rates in soil of 1-benzyltriazoies and two triazole fungicides

The degradation rates in soil of 1-benzyltriazole together with six analogues having substituents in the phenyl ring and two commercial triazole fungicides, PP450 and triadimefon, were determined at 15°C and 20 % soil water content. The order of degradation rates of the benzyltriazoles was H > 4-OCH₃ > 4-F>4-Cl.4-≥tert-C₄H_g3,4-diCl>3-CF₃. Thus, in general, persistence was enhanced by electron-withdrawing substituents and by lipophilic groups that increased sorption by soil. Of the commercial fungicides, PP450 was degraded very slowly (half-life 578 days) while triadimefon was quickly converted (half-life 15 days) to the corresponding alcohol, triadimenol, which in turn was degraded very slowly. The effects of temperature and soil water content on rate of degradation were studied for 1-benzyltriazole and 1-(4-fluorobenzyl)triazole. The rate of degradation of 1-benzyltriazole was more sensitive to soil temperature and water content than was that of 1 -(4-fluorobenzyl)triazole. The influence of these results on the input data required by models which simulate persistence in field soil is discussed.     

Mobility of four triazole fungicides in two Indian soils

The sorption and downward mobility of four triazole fungicides, triadimefon, hexaconazole, penconazole and propiconazole, were studied in two Indian soils (New Delhi and Punjab). Punjab soil (organic carbon 0.4%) showed greater sorption capability for triazole fungicides than New Delhi soil (organic carbon 0.5%) and the order of sorption of triazoles in both soils was: penconazole > hexaconazole > propiconazole > triadimefon. Fungicides were more mobile in New Delhi soil columns than Punjab soil columns, and increasing the total water flux from 1 pore volume to 3 pore volumes further increased the transport to lower down in the column. Triadimefon showed maximum mobility while penconazole was the least mobile triazole fungicide. After percolating 3 pore volumes of water, triadimefon leached down to 25-30 cm depth in New Delhi soil and 15-20 cm in Punjab soil columns. Downward mobility of triazole fungicides was in order of their sorption results.     

Sorption, degradation and leaching of the fungicide iprodione in a golf green under Scandinavian conditions: measurements, modelling and risk assessment

In cold climates, fungicides are used on golf greens to prevent snow mould causing serious damage to the turf. However, fungicide residues have been detected in runoff from golf courses, which may lead to restrictions on use. There is therefore an urgent need to improve understanding of the processes affecting leaching of fungicides from turfgrass systems to allow identification of green construction and management practices that minimize environmental impacts. In this study we monitored the leaching of the fungicide iprodione in a putting green. Sorption and degradation of iprodione was measured in batch and incubation experiments, and the simulation model MACRO was used as a risk assessment tool. Degradation of iprodione was bi-phasic, with a rapid initial phase (half-life 17 h) caused by enhanced biodegradation. Degradation rates slowed considerably after 5 days, with half-lives of up to 38 days. Sorption of iprodione was linear, with a K(oc) value of ca 400 cm(3) g(-1). MACRO reasonably accurately matched measured drainflows and concentrations of iprodione in soil and drainflow. However, peak concentrations in drainage were underestimated, which was attributed to preferential finger flow due to water repellency. The results also showed the importance of the organic matter content in the green root zone in reducing leaching. It was concluded that, with 'reasonable worst-case' use, losses of iprodione from greens can occur at concentrations exceeding water quality limits for aquatic ecosystems. Snow mould problems should be tackled by adopting green root zone mixes that minimize leaching and 'best management practices' that would avoid the need for intensive prophylactic use of fungicides.     

含两个手性中心的三唑类杀菌剂色谱分离研究进展

三唑类杀菌剂是目前世界上广泛应用的杀菌剂,而绝大多数三唑类杀菌剂属于手性农药,具有1个或2个手性中心,存在2个或4个对映异构体。本文在近年有关三唑类杀菌剂研究成果的基础上,综述了采用高效液相色谱、超临界流体色谱、毛细管电泳、气相色谱和合相色谱法等方法对含两个手性中心的11种三唑类杀菌剂 (氟环唑、多效唑、三唑醇、联苯三唑醇、丙环唑、苯醚甲环唑、叶菌唑、苄氯三唑醇、环唑醇、糠菌唑和乙环唑) 进行分离测定的研究进展,可为多个手性中心三唑类化合物的分离、分析和深入研究提供参考。     

Availability and biodegradation of metribuzin in alluvial soils as affected by temperature and soil properties

Herbicide degradation in soils is highly temperature‐dependent. Laboratory incubations and field experiments are usually conducted with soils from the temperate climatic zone. Few data are available for cold conditions and the validation of approaches to correct the degradation rate at low temperatures representative of Nordic environments is scarce. Laboratory incubation studies were conducted at 5, 15 and 28°C to compare the influence of temperature on the dissipation of metribuzin in silt/sandy loam soils in southern and northern Norway and in a sandy loam soil under temperate climate in France. Using ¹⁴C‐labelled metribuzin, sorption and biodegradation were studied over an incubation period of 49 days. Metribuzin mineralisation and total soil organic carbon mineralisation rates showed a positive temperature response in all soils. Metribuzin mineralisation was low, but metabolites were formed and their abundance depended on temperature conditions. The rate of dissipation of ¹⁴C‐metribuzin from soil pore water was strongly dependent on temperature. In Nordic soils with low organic content, metribuzin sorption is rather weak and biodegradation is the most important process controlling its mobility and persistence.     

Environmental fungicides and triazole resistance in Aspergillus

Fungal diseases are problematic in both human health and agriculture. Treatment options are limited and resistance may emerge. The relatively recent recognition of triazole resistance in Aspergillus fumigatus has prompted questioning of the origin of resistance. While multiple mechanisms are described in clinical isolates from triazole‐treated patients, some de novo resistance is also recognised, especially attributable to TR₃₄/L98H. Such strains probably arose in the environment, and, indeed, multiple studies have now demonstrated TR₃₄/L98H triazole resistance strains of A. fumigatus from soil. Docking and other in vitro studies are consistent with environmental resistance induction through exposure to certain triazole fungicides, notably difenoconazole, propiconazole, epoxiconazole, bromuconazole and tebuconazole. This article addresses the potential implications of this issue for both human health and food security. © 2013 Society of Chemical Industry     

Degradation and adsorption of terbuthylazine and chlorpyrifos in biobed biomixtures from composted cotton crop residues

BACKGROUND: Biobeds have been well studied in northern Europe, whereas little is known regarding their use in southern Europe. The degradation and adsorption of terbuthylazine (TA) and chlorpyrifos (CP) were studied in three different biomixtures composed of composted cotton crop residues, soil and straw in various proportions, and also in sterilised and non‐sterilised soil. RESULTS: Compost biomixtures degraded the less hydrophobic TA at a faster rate than soil, while the opposite was evident for the more hydrophobic CP. These results were attributed to the rapid abiotic hydrolysis of CP in the alkaline soil (pH 8.5) compared with the lower pH of the compost (6.6), but also to the increasing adsorption (K_d = 746 mL g^?1) and reduced bioavailability of CP in the biomixtures compared with soil (K_d = 17 mL g^?1), as verified by the adsorption studies. CONCLUSIONS: Compost had a dual but contrasting effect on degradation that depended on the chemical nature of the pesticide studied: a positive effect towards TA owing to increasing biodegradation and a negative effect towards CP owing to increasing adsorption. Overall, composted cotton crop residues could be potentially used in local biobed systems in Greece, as they promoted the degradation of hydrophilic pesticides and the adsorption of hydrophobic pesticides. Copyright © 2010 Society of Chemical Industry     

不同生育阶段黄瓜菌核病菌对几种三唑类杀菌剂的敏感性

采用菌丝生长速率法测定了6种三唑类杀菌剂和4种其他杀菌剂抑制黄瓜菌核病菌Sclerotinia sclerotiorum(Lib.)de Bary菌丝生长的毒力,同时测定了其对菌核形成及萌发的抑制作用。结果表明,甲基硫菌灵抑制菌丝生长的毒力最低,EC50值为65.75 μg/mL;己唑醇和戊唑醇的抑制活性较高, EC50值分别为0.09和0.16 μg/mL,毒力分别是甲基硫菌灵的763.7和423.4倍;其次是丙环唑、氟硅唑、腈菌唑,毒力是甲基硫菌灵的137.3~286.6倍;再次为三唑酮,毒力仅为甲 基硫菌灵的20.6倍;腐霉利、菌毒清抑制菌丝生长的毒力较低,EC50值均大于10 μg/mL。在EC50值 浓度下,所有供试药剂对菌核形成及其数量均没有影响,但三唑类杀菌剂对菌核单重影响较大,各处理所形成的菌核单重降低率均在70%以上;而当药剂浓度在10 μg/mL以下时,己唑醇等三唑类杀菌剂对菌核萌发均没有影响。     

4种三唑类杀菌剂对黄瓜生长的影响

本文研究了在黄瓜幼苗期和三叶期施用4种三唑类杀菌剂对黄瓜生长的影响,幼苗期土壤浇灌结果表明:己唑醇和戊唑醇对黄瓜的影响作用相当且较明显,在12.5～200mg/L时,株高抑制率为25%～70%,己唑醇对根长的抑制率在20%～55%。丙环唑和腈菌唑对黄瓜的影响相对较弱,在50～200mg/L时,对株高的抑制率为10%～45%,在100～200mg/L时,对根长的抑制率仅为10%～15%。4种药剂对根鲜重均有明显的增加作用。三叶期茎叶喷雾处理结果显示,己唑醇和戊唑醇在25～100mg/L时,株高抑制率为15%～40%,丙环唑和腈菌唑50～100mg/L的株高抑制程度为5%～15%,4种药剂50～100mg/L对叶片叶绿素含量的增加在5%～30%。     

Sensitivity of Crinipellis perniciosa to two triazole fungicides in vitro and their effect on development of the fungus in cocoa

Two triazole fungicides, hexaconazole and triadimenol, were evaluated for their effects on the growth of Crinipellis perniciosa in vitro, and for their ability to prevent broom formation on cocoa seedlings. Amounts of both fungicides required to reduce fungal growth, germ tube extension and basidiospore germination by 50% were found respectively to be less than 1, 10-150 and more than 200 mg/l. Reductions in germ tube length were associated with slower rates of cell growth, whereas growth of dikaryotic mycelium was reduced due to shorter cell lengths. Isolates of C. perniciosa showed different sensitivities to the fungicides, variation between collections from different localities being greater than between collections from the same locality. Hexaconazole gave good control of the disease applied as a spray to cocoa seedlings both before and after inoculation. Triadimenol showed good activity when used as a preinoculation soil drench and in some treatments where plants became infected no necrosis of host tissue was observed. Activity was greatly reduced by drench treatments applied 10 days after inoculation, and most infected plants formed necrotic cankers.