五种杀菌剂在水稻上的吸收与传导性能研究

茎叶喷雾是当前化学农药最常用的施药方式,但是存在着农药蒸发飘移、弹跳碎裂、因过度铺展而脱靶流失等缺陷,导致农药利用率低。通过研究农药在植物体内的吸收及传导性能,选择合适的农药研发根部施药的剂型与技术,能够降低环境因素对农药有效成分的不利影响,并通过农药的缓慢释放与剂量调控维持更长时间的药效,从而有效提高农药利用率。本研究以室内营养土和营养液两种模式培育的水稻为模式作物,研究了三环唑、噻呋酰胺、己唑醇、氟环唑和嘧菌酯5种不同类型的杀菌剂在水稻苗期植株中的吸收与传导行为。结果表明,这5种杀菌剂均可以被水稻幼苗根系吸收并向上传导,但效率存在差异。在营养土和营养液培养条件下,水稻幼苗根部的三环唑含量在4 h~2 d内明显高于茎叶部,施药5 d后三环唑在水稻中的转运因子值均大于1,说明三环唑具有良好的向上传输性能,而其他农药向上传输的能力较差。相比其他4种农药,三环唑更适合加工成根部施用的剂型,更易于通过水稻根部吸收后向上传输与分布,以有效防控茎叶部病害。该结果可为根部施用的药剂研发提供思路,为农药根部施药技术的发展提供指导。     

Some factors affecting the activities of dinitrophenol fungicides

The vapour phase and protectant activities of members of seven homologous series of alkyldinitrophenols against cucumber powdery mildew (Oidium sp.) are discussed. No correlation existed between vapour activities in vitro or in vivo and vapour pressure, but a positive correlation between Vapour' protection in vivo and conventional protectant activity was evident. Although vapour activity occurs with some homologues, results obtained for zone assays in vivo are probably better explained in terms of easy movement of the compound in the leaf surface than in terms of vapour transmission. Alkyldinitrophenyl-crotonates showed no zone activity in vivo but often good protectant activity. The possible existence of two optimum π-values for protectant activity is suggested. No appreciable systemic activity was found with these compounds.     

Some studies on the systemic activity of the thiophanate fungicides in plants

Three closely related fungicides, thiophanate (NF 35), thiophanate methyl (NF 44) and NF 48 have been found to be active against a wide range of diseases including the powdery mildews of apple, cucumber and barley; apple and pear scab and grey mould of soft fruit. This paper deals with the preliminary experiments to compare their relative mobilities and biological persistence in crop plants, using the powdery mildews as indicator infections. NF 44 and NF 48 in particular showed a high degree of systemic activity by root uptake and persistence of action against barley and cucumber mildew but very little systemic activity against apple mildew on potted rootstocks. They have also displayed trans-laminar and localised movement towards the leaf apex in sprayed cucumber and barley leaves but movement was not so marked in sprayed apple leaves. NF 48 was also active as a seed dressing against loose smut of barley.     

植物病原真菌对甾醇生物合成抑制剂类(SBIs)杀菌剂的抗药性研究进展

甾醇生物合成抑制剂类(SBIs)杀菌剂通过抑制植物病原真菌甾醇生物合成途径中不同环节的酶,干扰或阻断病原菌麦角甾醇生物合成而发挥抗真菌作用。综述了植物病原真菌对SBIs杀菌剂的抗药性发生现状、遗传机制、生理生化机制、分子机制及治理策略等方面的最新研究进展。室内及田间有关SBIs杀菌剂抗药性的研究结果表明,植物病原菌对该类杀菌剂的抗药性可能是由1种或多种机制共同作用的结果。ABC和MFS运输蛋白基因及CYP51蛋白基因是植物病原真菌对SBIs杀菌剂产生抗药性的主要分子机制。其中ABC运输蛋白基因能够通过翻转酶将药剂从膜内层转移至外层而排出细胞体外;MFS运输蛋白基因的超表达和本底表达则是导致病原菌产生抗药性的关键因素;而CYP51蛋白基因与药剂作用时易在病原菌体内发生基因点突变或基因超表达,造成编码蛋白与药剂亲和力下降,导致病原菌产生抗药性。随着分子生物学的迅速发展,可从基因水平上寻找出与抗药性直接相关的基因、蛋白及调控途径等信息,同时与其他学科结合,合理设计新的、多作用位点的高效甾醇生物合成抑制剂,从而延长该类杀菌剂的使用寿命。     

Adsorption of systemic fungicides and a herbicide by some components of plant tissues,in relation to some physicochemical properties of the pesticides

Lignin, an important component of plant tissues, adsorbed five systemic fungicides and one herbicide (carbendazim, triadimefon, nuarimol, triarimol, fenarimol and fluometuron) more strongly than bovine serum albumin, cellulose, ethylcellulose or sodium polygalacturonate. Significant correlations were found between the extent of the adsorption of the pesticides on the lignins extracted from three different plant species, and the log Poet (Poet is the octan-1-ol/water partition coefficient) of the compounds. The more lipophilic fungicides triarimol and fenarimol (log Poet about 2.6) were adsorbed to the greatest extent. Fluometuron, triadimefon and nuarimol (log Poet about 2.0) were moderately adsorbed, whereas carbendazim with the lowest log Poet (1.34 at pH 5.0), was adsorbed more than expected from its Poet value. The anomaly of carbendazim is discussed; it is ascribed to it's partial protonation at pH 5.0, whereas the other pesticides were non-ionised.     

辣椒炭疽病病原鉴定及其杀菌剂毒力测定

从贵阳市花溪区磊庄村辣椒基地采集疑似炭疽病的典型的自然发病辣椒果实,采用组织分离、培养、形态学观察、致病性测定以及多基因分子系统学,确定病原菌的种类;采用菌丝生长速率法研究了8种杀菌剂对该病菌菌丝生长的抑制作用。结果表明,引起贵阳市花溪区磊庄村辣椒炭疽病的病原菌为尖孢炭疽菌Capsicum acutatum。室内毒力测定发现8种杀菌剂对尖孢炭疽菌均有一定的抑制作用,其中25%咪鲜胺EC和30%吡唑醚菌酯SC抑制效果最好,EC_(50)分别为0.253 5 mg/L和0.720 3 mg/L;其次为22.5%啶氧菌酯SC和22.7%二氰蒽醌SC,EC_(50)分别为7.249 5 mg/L和21.664 5 mg/L。将30%吡唑醚菌酯SC和22.7%二氰蒽醌SC按照9∶1、6∶4、3∶7、4∶6的比例混配,联合毒力测定和评价结果显示两者混配对该病菌具有协同增效作用,且25%咪鲜胺EC和22.5%啶氧菌酯SC以6∶4、4∶6、8∶2的比例进行混配时也表现出明显的增效作用。引起贵阳市花溪区磊庄村辣椒基地辣椒炭疽病的致病菌为尖孢炭疽菌。咪鲜胺、吡唑醚菌酯、啶氧菌酯和二氰蒽醌对该菌具有较好的抑制作用,可为辣椒炭疽病的田间防治提供参考依据。     

5种链格孢属植物病原真菌对10种杀菌剂的敏感性比较

离体条件下测定并比较了10种杀菌剂对番茄早疫病菌、苹果斑点落叶病菌、梨黑斑病菌、烟草赤星病菌和甘蓝黑斑病菌等5种链格孢属植物病原真菌的抗菌活性。结果表明,不同种的链格孢属病菌对同一药荆的敏感性相近;咪鲜胺、啶菌恶唑、苯醚甲环唑、异菌脲、腐霉利等5种杀菌剂对供试病菌菌丝生长的抑制活性最好,其EC50在0．01～1．28μg／mL之间;百菌清对病菌分生孢子萌发的抑制活性最高,其次是醚菌酯和嘧菌酯。     

植物病原菌对杀菌剂多药抗性的发生现状

近年来, 随着杀菌剂在农作物病害田间防治中的大量使用, 植物病原菌的多药抗性(multidrug resistance, MDR)现象发生越来越普遍。本文综述了在草坪币斑病、灰霉病、小麦叶枯病和苹果青霉病等病害防治中, 病原菌对杀菌剂多药抗性发生的情况。以及在紫外诱导和杀菌剂离体驯化下, 致病疫霉Phytophthora infestans、立枯丝核菌Rhizoctonia solani、指状青霉Penicillium digitatum的多药抗性发生情况。分析了导致植物病原菌多药抗性产生的外排转运蛋白过表达、解毒酶代谢和靶标位点变化等相关机制, 并在此基础上提出了多药抗性预防和治理的策略, 以期为田间杀菌剂的高效利用, 延缓药剂的抗性风险提供科学参考。     

Uptake by roots and translocation to shoots of two morpholine fungicides in barley

Despite being lipophilic, morpholine fungicides are systemic in plants. Such transport may be explicable by their protonation (pKa∽7·5) at the pH of plant compartments to yield the more polar cation. This behaviour might be a useful attribute to be incorporated into other classes of lipophilic pesticides. To understand quantitatively the behaviour of the morpholine fungicides, the uptake by roots and transport to shoots in barley of two such ¹⁴C-labelled compounds, dodemorph and tridemorph, were investigated using bathing solutions of differing pH. At pH 5, uptake and transport were small, but increased by approximately two orders of magnitude at pH 8. Tridemorph, the more lipophilic of the two compounds, was highly accumulated by roots at pH 8 and moderately translocated to shoots. In contrast, dodemorph was translocated to shoots at pH 8 with remarkable efficiency, moving into the xylem across the endodermis at 23 times the efficiency of water, though accumulation in roots was less than that of tridemorph. Behaviour at 24 h was largely similar to that at 48 h for both compounds, indicating that uptake and translocation are equilibrium processes maintained over time. Transport to shoots for each compound was directly proportional to the concentrations accumulated in the roots, except at low pH where partitioning into root solids became proportionately more important with such material not being directly available for transport to the xylem across the endodermis. Uptake and transport of these basic fungicides are explained in terms of their partitioning and of their accumulation in acidic plant compartments by ion trapping as the protonated form; this behaviour is discussed in relation to the pKa and lipophilicity of these compounds. © 1998 Society of Chemical Industry     

Effects of sterol biosynthesis-inhibiting fungicides and plant growth regulators on the sterol composition of barley plants

A number of sterol biosynthesis-inhibiting (SBI) fungicides and plant growth regulator analogs were applied as root drenches to barley seedlings and their effect on the total sterol composition of the roots and shoots was measured by gas-liquid chromatography. Prochloraz was found to be inactive in this system, probably because of poor uptake, while the other compounds could be divided into two groups according to their mode of action as assessed by sterol profiling. The morpholines tridemorph and fenpropimorph inhibited the enzyme cycloeucalenol—obtusifoliol isomerase whereas triadimenol, nuarimol, paclobutrazol, and triapenthenol (RSW 0411) inhibited the enzyme responsible for the removal of the C-14 methyl group. Effects of individual diastereo-isomers and enantiomers of some compounds on sterol profiles were compared with their known fungicidal and anti-gibberellin properties. Shoot growth was reduced by all the compounds tested, paclobutrazol, nuarimol, and triapenthenol being the most effective. As well as inducing accumulation of abnormal sterols, SBI fungicide treatment changed the ratio of campesterol to stigmasterol and sitosterol. It is hypothesized that this may reflect changes in membrane architecture and may offer an explanation for the increased frost hardiness sometimes observed with SBI fungicide-treated plants.     

洋葱茎基盘腐烂病药剂田间筛选试验

为了解决甘肃河西地区洋葱茎基盘腐烂病发病重、药剂防效差的问题,本试验选取7种药剂,在移栽时进行蘸根处理,观测分析不同药剂处理对洋葱植株成活率、生育期、防治效果和产量的影响。结果表明,1%申嗪霉素悬浮剂500倍液蘸根处理对洋葱茎基盘腐烂病防治效果较好,植株成活率达到90%以上,定植后30 d的防治效果为80.89%,57 d的防治效果为64.45%,产量为7029.85 kg/667 m²,增产率达到26.77%。在洋葱定植时可以使用该药剂进行蘸根处理,57 d内对茎基盘腐烂病的防治效果较好,且减少了农药的施用量,为甘肃河西高海拔冷凉区洋葱绿色优质生产提供了技术方法。     

药剂对稻曲病菌的毒力测定及复配研究

为筛选防治稻曲病的有效单剂和复配组合,采用菌丝生长速率法,测定烯唑醇、腈菌唑、丙环唑、咪鲜胺、苯菌灵、多菌灵、戊唑醇、井冈霉素、松脂酸铜9种杀菌剂及互相复配后对稻曲病菌的毒力,并比较了不同复配组合的协同作用.结果表明:稻曲病菌对烯唑醇最敏感,EC5o为0.145 μg/mL;井冈霉素对稻曲病菌的毒力作用最弱,EC50为13.6 μg/mL.从252种不同比例复配的药剂中,筛选出12种增效配方,其中烯唑醇和咪鲜胺复配(1∶10),协同系数高达3.70,增效作用最大;烯唑醇和咪鲜胺(1∶10)对稻曲病菌的毒力作用最强,EC5o为0.06μg/mL,其次是烯唑醇和咪鲜胺(1∶20)与烯唑醇和腈菌唑(10∶1),EC50分别为0.10μ/mL和0.11μg/mL.田间试验结果也表明:烯唑醇与咪鲜胺(1∶10)复配,对稻曲病的平均防效为79.2％,高于其他常用药剂.     

Risk assessment of pesticides and fungicides for acid-base regulation and salt transport in rainbow trout tissues

Carbonic anhydrase enzymes have been shown to play an important role in ion transport and pH regulation in several organisms including fish. Despite this information and the wealth of knowledge regarding the significance of CA enzymes in fish, few studies have reported the hazardous effects of chemicals on fish CA. Using rainbow trout (Oncorhynchus mykiss) as a model, this study aimed to determine the risk of pesticides and fungicides on fish carbonic anhydrase enzymes. For this purpose, screening of rainbow trout carbonic anhydrase activities was carried out in the presence of some pesticides and fungicides. Carbonic anhydrase enzymes were initially purified from rainbow trout liver, muscle, kidney and brain, and exposed to pesticides and fungicides, including mancozeb, cypermethrin, deltamethrin and dinocap. Pesticides and fungicides dose-dependently decreased in vitro CA activity at micromolar concentrations. Since deltamethrin was the most powerful inhibitor for all tissues in in vitro experiments, it was chosen for in vivo analysis as well. rtCAs were significantly inhibited by the three concentrations of deltamethrin (0.25, 1.0 and 2.5 μg/L) at 24th and 48th hours. Our findings indicate that deltamethrin, dinocap, mancozeb and cypermethrin are potent inhibitors for fish CA enzymes, and might cause undesirable results by disrupting acid-base regulation as well as salt transport in freshwater or seawater adapted fish.     

枇杷心腐病病原菌鉴定及其防治药剂室内毒力测定

为明确福建省枇杷心腐病的病原菌种类并筛选有效防治药剂,采用形态学特征与分子生物学技术相结合的方法,对采自漳州漳浦和云霄的枇杷心腐病样品进行病原菌鉴定,同时以菌丝生长速率法测定了17种杀菌剂的室内毒力。结果表明,枇杷心腐病病原菌的ITS序列与Gen Bank中登录的尖孢炭疽菌Colletotrichum acutatum的相似性为99%,结合病原菌的菌落、分生孢子形态等特征,将其鉴定为尖孢炭疽菌C.acutatum,Gen Bank登录号为KU862634,并命名为EJCA-4。室内毒力测定结果显示,17种杀菌剂中对EJCA-4菌株菌丝生长抑制作用最强的为咪鲜胺和氟硅唑,EC_(50)分别为0.1μg/mL和0.2μg/mL;其次为溴菌腈和腈菌唑,EC_(50)均为0.7μg/mL;异菌脲、三唑酮、嘧菌酯、苯醚甲环唑和丙森·醚菌酯对EJCA-4菌株也有较好的抑制作用,EC_(50)均小于10.0μg/mL;苦参·蛇床素和波尔多液对EJCA-4菌株的抑制作用最差,EC_(50)分别为536.0μg/mL和2 526.9μg/mL。     

Cytochrome b gene structure and consequences for resistance to Qo inhibitor fungicides in plant pathogens

The cytochrome b (cyt b) gene structure was characterized for different agronomically important plant pathogens, such as Puccinia recondita f sp tritici (Erikss) CO Johnston, P graminis f sp tritici Erikss and Hennings, P striiformis f sp tritici Erikss, P coronata f sp avenae P Syd & Syd, P hordei GH Otth, P recondita f sp secalis Roberge, P sorghi Schwein, P horiana Henn, Uromyces appendiculatus (Pers) Unger, Phakopsora pachyrhizi Syd & P Syd, Hemileia vastatrix Berk & Broome, Alternaria solani Sorauer, A alternata (Fr) Keissl and Plasmopara viticola (Berk & Curt) Berlese & de Toni. The sequenced fragment included the two hot spot regions in which mutations conferring resistance to QoI fungicides may occur. The cyt b gene structure of these pathogens was compared with that of other species from public databases, including the strobilurin-producing fungus Mycena galopoda (Pers) P Kumm, Saccharomyces cerevisiae Meyer ex Hansen, Venturia inaequalis (Cooke) Winter and Mycosphaerella fijiensis Morelet. In all rust species, as well as in A solani, resistance to QoI fungicides caused by the mutation G143A has never been reported. A type I intron was observed directly after the codon for glycine at position 143 in these species. This intron was absent in pathogens such as A alternata, Blumeria graminis (DC) Speer, Pyricularia grisea Sacc, Mycosphaerella graminicola (Fuckel) J Schr?t, M fijiensis, V inaequalis and P viticola, in which resistance to QoI fungicides has occurred and the glycine is replaced by alanine at position 143 in the resistant genotype. The present authors predict that a nucleotide substitution in codon 143 would prevent splicing of the intron, leading to a deficient cytochrome b, which is lethal. As a consequence, the evolution of resistance to QoI fungicides based on G143A is not likely to evolve in pathogens carrying an intron directly after this codon.     

加强植物检疫源头管理的几点做法

基层植物检疫机构如何抓好检疫性有害生物源头农产品生产地和加工、经营点的管理，是当前农业植物检疫的核心工作。２０００年以来的３a中，我们在农产品生产环节通过实施产地检疫，建立无检疫性有害生物的种子、种苗和大宗农产品生产基地；设立检疫签证点，方便调运报检，巩固产地检疫成果；在加工、经营环节通过对管理相对人实施植物检疫登记证管理制度，规范管理相对人检疫行为。从而强化了植物检疫行政执法，维护产地检疫、调运检疫和市场检疫的正常秩序，有效地控制了检疫性有害生物的传播蔓延。同时，促进了种植业结构调整和农产品流…     

几种杀菌剂对梨黑斑病菌抑制作用研究

经室内研究表明,噻菌灵、咪鲜胺、克菌丹、抑霉唑4种杀菌剂对:梨黑斑病菌(Alternaria alternata)均有很好的抑菌效果,其中有效浓度为5×10-8的抑霉唑和6×10-8的咪鲜胺浸泡处理10min能完全杀灭梨黑斑病菌,是极具潜力的浸果处理杀菌药剂。