大豆除草剂对水稻秧苗生长的影响

就施过豆磺隆、普施特、广灭灵的大豆茬,对后作水稻本田秧苗生长的影响进行研究。结果表明:各处理对水稻移栽后的幼苗生长发育都有程度不同的影响。     

浙北稻麦连作区稻田糠稷发生对水稻生长的影响及对除草剂敏感性研究

调研了浙北稻麦连作区稻田糠稷发生及分布状况,并考察了糠稷种子萌发特性和对水稻生长的影响及植株对不同除草剂的敏感性,旨在为有效防治糠稷提供参考.结果 表明,糠稷在浙北稻麦连作区直播田发生的相对优势度在0～2.8％、机插田发生的相对优势度在0～3.6％;糠稷种子在光照条件下才能萌发,光照36℃(12 h)/黑暗28℃(12...     

基于镧系金属有机框架材料检测水体中酰胺类除草剂残留的可视化技术研究

研发水体中酰胺类农药残留简便快捷的检测技术,对评估农药造成的水体污染和提出相应的治理对策具有重要意义。以共掺杂镧系金属离子 (Eu3+ 和Tb3+) 作为配位金属离子,分别利用水热法和微波法制备了镧系金属有机框架材料 (lanthanide metal-organic frameworks, Ln-MOF),对其结构和性质进行了表征,并采用所制备的Ln-MOF对水体中残留的5种常见酰胺类除草剂 (乙草胺、异丙草胺、丙草胺、敌草胺和异丙甲草胺) 进行了定性和定量分析。结果表明:与水热法相比,采用微波法制备的Ln-MOF样品呈蓬松的簇状、结晶度好,且具有更高的发光效率,故选择微波法制备Ln-MOF。农药残留检测试验结果表明,不同除草剂对Tb3+和Eu3+的发光会产生差别性猝灭,并使整体发射光发生变化,进而实现水体中农药的可视化检测。进一步研究发现,荧光强度比值I (Tb3+)/I (Eu3+) 与丙草胺浓度在0.1~1 mmoL/L范围时呈线性相关,线性相关系数R2 = 0.998,检测限 (LOD) 为0.08 mmoL/L。另外,该材料对于用湖水配制的除草剂溶液也具有一定的定性检测能力。本研究结果展现了Ln-MOF用于水体中酰胺类除草剂的定性、定量分析具有良好应用前景。     

Phytotoxic sites of action for molecular design of modern herbicides (Part 1): The photosynthetic electron transport system

A bird's eye review was tried to select the bio‐rational targets from known and novel plant‐specific ones for the molecular design of modern herbicides, which exhibit efficient phytotoxicity at a low‐use rate and preserve a good environment in the 21st century. In phytotoxic sites in the photosynthetic electron transport (PET) system discussed in the present article (Part 1), the generally called bleaching herbicides interfering with the biosynthesis of photosynthetic pigments, chlorophylls and carotenoids, and the biosynthesis of plastoquinone, were considered to be good models for the molecular design of modern herbicides. The PET itself was still considered as an interesting target site for new herbicides, although they need to exert their action in all green leaves of weeds to achieve herbicidal efficacy. Because these herbicides never form a tight binding with D1‐protein, their use‐rate cannot be expected to be as low as the herbicides inhibiting chlorophyll or branched amino‐acid biosynthesis. Other herbicidal targets found in chloroplasts, namely ATP and NADPH formations, have already been omitted from the worldwide biorational molecular design program of herbicides targeting the PET system.     

不同粘度矿物油助剂对除草剂活性的影响

室内及温室内测定了10种不同粘度矿物油助剂对除草剂防除苘麻和稗草药效的影响及对玉米苗期的安全性。结果表明,10种矿物油助剂均不同程度地增加了氰草津和烟嘧磺隆防除两种杂草的活性。其中粘度为46 mm2/s (40℃)的矿物油乳剂(MOC46)对供试除草剂药效的增强作用最为明显,其次为粘度32 mm2/s (40℃)的矿物油乳剂。10种助剂对氰草津药效的增强作用大于对烟嘧磺隆。MOC46对除草剂活性的增加由高到低依次为:莠去津、氰草津＞莠去津+氰草津、莠去津+烟嘧磺隆、氰草津+烟嘧磺隆＞烟嘧磺隆;对玉米苗期安全性依次为:莠去津、烟嘧磺隆、莠去津+烟嘧磺隆＞莠去津+氰草津、氰草津+烟嘧磺隆＞氰草津。氰草津与MOC46混用对玉米苗期药害较重。     

微生物除草剂与生物安全

随着人类环境意识的提高和农业可持续发展的需要,高效、环保微生物除草剂的研究越来越显示其重要的社会意义和经济价值。本文概述了微生物除草剂的种类、剂型及特点,介绍了利用微生物及其天然产物防治杂草的潜在优势和目前国内外的研究进展,尤其是对微生物除草剂的生物安全性进行了评价。     

除草剂安全剂的作用机制研究进展

本文对国内外关于除草剂安全剂的作用机制研究情况进行了介绍,并对几种较为普遍认同的作用机制重点给予解释。     

Glutathione transferase activities toward herbicides used selectively in soybean

Using extracts from suspension-cultured cells of soybean (Glycine max cv. Mandarin) as a source of active enzymes, the activities of glutathione transferases (GSTs) catalysing the conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) and selective herbicides were determined to be in the order CDNB≫ fomesafen>metolachlor=acifluorfen>chlorimuron-ethyl. GST activities showed a thiol dependence in a substrate-specific manner. Thus, GST activities toward acifluorfen and fomesafen were greater when homoglutathione (hGSH), the endogenously occurring thiol in soybean, was used as the co-substrate rather than glutathione (GSH). Compared with GSH, hGSH addition either reduced or had no effect on GST activities toward other substrates. In the absence of enzyme, the rates of hGSH conjugation with acifluorfen, chlorimuron-ethyl and fomesafen were negligible, suggesting that rapid hGSH conjugation in soybean must be catalysed by GSTs. GST activities were subsequently determined in 14-day-old plants of soybean and a number of annual grass and broadleaf weeds. GST activities of the plants were then related to observed sensitivities to post-emergence applications of the four herbicides. When enzyme activity was expressed on a mg^-1 protein basis, all grass weeds and Abutilon theophrasticontained considerably higher GST activity toward CDNB than soybean. With fomesafen as the substrate, GST activities were determined to be in the order soybean≫Echinochloa crus-galli>Digitaria sanguinalis>Sorghum halepense=Setaria faberi with none of the broadleaf weeds showing any activity. This order related well to the observed selectivity of fomesafen, with the exception of A. theophrasti, which was partially tolerant to the herbicide. Using metolachlor as the substrate the order of the GST activities was soybean>A. theophrasti≫S. halepense>Amaranthus retroflexus>Ipomoea hederacea, with the remaining species showing no activity. GST activities toward metolachlor correlated well with the selectivity of the herbicide toward the broadleaf weeds but not toward the grass weeds. Acifluorfen and chlorimuron-ethyl were selectively active on these species, but GST activities toward these herbicides could not be detected in crude extracts from whole plants. © 1997 SCI     

Development of an enzyme-linked immunosorbent assay for quantitative determination of cyhalofop-butyl

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for cyhalofop-butyl was developed with a polyclonal antibody produced against a hapten (cyhalofop acid) conjugated with bovine serum albumin (BSA). The ELISA of cyhalofop-butyl showed an IC₅₀ value of 0.067 ± 0.004 mg/l and the limit of detection (LOD, IC₁₀) of 0.0029 ± 0.0001 mg/l at the optimal conditions. No significant cross-reaction to other structure-related compounds suggested high specificity for cyhalofop-butyl of the method. The average recoveries of cyhalofop-butyl from fortified water and soil were in the range of 83.2-119.7% and 80.1-104.0%, respectively. These data indicate that this method is a convenient analytical technique for monitoring cyhalofop-butyl in water and soil without purification steps.     

微生物农药研究的现状及展望

综述了国内外微生物农药研究的现状，重点评述了微生物杀虫剂、家用抗生素和微生物除草剂等方面的研究应用及进展情况，展望了其应用前景。