除草剂的副效应——除草剂对植物-病原菌相互关系的调节机制

化学除草剂是一种替代人工除草的重要措施,它在作物田尤其是需要采用保护性耕作制度的田块中大规模使用来防除农田杂草.杂草不仅影响作物的产量和质量,还影响作物正常的种植和采收.从全世界农药的销售情况来看,杂草的防除也是耗费金钱最多的.除草剂的副效应是指除草剂除了对靶标——杂草有抑制作用外,对非靶标生物、外在环境和生态系统的影响作用.作为除草剂的副效应,除草剂对植物病害的影响作用越来越受到植物保护界和环境保护者的关心和重视.一般来说,除草剂对植物、病原体、土壤微生物及环境等都有一定的影响,进而间接调节植物-病原体之间的相互关系.20世纪40年代,Smith等人首先报道了除草剂对植物病害的影响作用,此后这方面的研究逐渐增多.目前为止,已有非常多关于多种除草剂对植物病原菌和病害发展的直接影响作用的研究报道.分类号：TQ450 文献标识码：A文章编号：1009-6485（2013）06-0035-06     

植物源除草剂研究进展

植物源除草剂是杂草的生物防除及新型生物源除草剂的研究方向,综述了商品化的植物源除草剂及具有除草活性的植物资源的研究进展,并对植物源除草剂在未来的发展做了展望。     

2-硫基-3-苄氧基吡啶的合成

2-巯基-3-苄氧基吡啶是合成三氟啶磺隆的重要中间体。三氟啶磺隆是由先正达（原诺华公司）开发的新型超效磺酰脲类除草剂，属于内吸传导型除草剂。其作用机理是通过抑制植物（杂草）的乙酰乳酸合成酶（ALS），阻止支链氨基酸的生物合成，干扰DNA的合成以及细胞的分裂与生长，最终导致植物（杂草）死亡。这类除草剂药效高、使用是少、效果稳定、低毒、低残留，对后茬作用安全。     

微生物除草剂与生物安全

杂草是农作物的主要劲敌，自从人类进行农业生产以来，人们就采用各种方式对其进行防除。化学除草剂以其作用迅速、使用方便等特点在20世纪50年代得到迅速发展。但随着化学除草剂的广泛应用，弊端日趋势突出，化学除草剂造成环境污染和农药残留问题引起农药科技工作者的高度关注，渴求开发研制无污染、安全的新型除草剂。生物除草剂具有对目标杂草以外的植物影响小，环境负效应小、安全性高的特点，符合可持续农业的发展要求。因而许多研究机构和农药公司纷纷将研究重点转向生物除草剂的研制，人们开始考虑运用植物病原物或微生物代谢产物防除杂草。     

乙草胺防除花生田杂草

乙草胺防除花生田杂草苗春生，孙玉英，赵花其，高玉芬（河北省沧州地区农科所，０６１００１）花生是重要经济作物，是我国一大出口特产，近年来发展迅速。但花生田杂草的防除始终是一个很难解决的问题，人工锄草既费工，且后期影响座果。为此，我们开展了应用除草剂乙草...     

用真菌防治撒哈拉沙漠的独脚金杂草

一种生物控制剂即用真菌防治给撒哈拉沙漠地区农民提供一种防治独脚金（witchweed）杂草的新方法。此技术被看成是防治杂草技术的新突破,和替代芽后除草剂的新手段。负责此项目研究的病理学家FenBeed博士说：“在杂草防治综合战略中,我们找到了一种极端有效的手段．此法是安全的、实用的,农民承受得起和可持续应用的。”     

硝磺酮的合成与除草效果

硝磺酮（甲基磺草酮，mesotrione）是先正达公司开发的三酮类除草剂剂．是对羟基丙酮酸双加氧酶（HPPD）抑制剂，能将酪氨酸转化为质体醌，吸收了硝磺酮的杂草在3—5d分生组织出现黄化症状，随之引起枯斑，两星期后遍及整株植物。作为内吸性玉米田苗前苗后广谱型除草剂。硝磺酮能有效防除玉米田一年生阔叶杂草和一些禾本科杂草．如苘麻、苍耳、刺苋、藜属杂草、地肤、蓼属杂草、芥菜、稗草、繁缕、马唐等，不仅对玉米安全，而且对环境、后茬作物安全。对磺酰脲类除草剂产生抗性的杂草有效，使用剂量：     

真菌除草剂的剂型及应用研究现状

综述了影响真菌除草剂进一步发展和应用的生物和环境性限制因子，通过研制液体和固体配方，改进真菌除草剂的应用技术，与逆乳液、低剂量化学除草剂、真菌毒素或其它真菌除草剂复配，可以克服这些限制因子，增强真菌除草剂生防潜力。     

狼尾草对嗯草酮、二甲戊乐灵和异丙甲草胺的抗药性

（Pennisetum alopecuroides）是新型的园林观赏植物，在我国具有广阔的发展前景。利用化学除草剂防除狼尾草生产与应用中的杂草问题，对减少生产与管理费用意义很大。采用盆栽方法研究了狼尾草对常用的苗前型除草剂的抗药性，以期找出适宜控制狼尾草杂草的安全除草剂与安全用量。结果表明，狼尾草喷施异丙甲草胺后叶片变为紫红色，产生严重药害，晤草酮在2700mL／hm^2用量下或二甲戊乐灵在3500mL／hm^2用量下狼尾草的生长仍安全。     

先正达公司在阿根廷推出新产品

先正达公司在阿根廷推出了一种非选择性除草剂Cerillo（百草枯＋敌草隆）,可作为在秋季和春季休耕地中除草剂草甘膦的一种补充除草剂。使用Cerillo可以阻止抗草甘膦的残留杂草的再生,如荠菜和宝盖草。2006年CASAFE与Ciafa两个行业协会,证实了在阿根廷首次报道的抗除草剂是从阿拉伯高梁的生物品种获得的。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。