新型吡唑双酰肼类化合物的合成及除草活性

为了寻找具有较高除草活性的农药先导化合物,将吡唑环与双酰肼结构进行拼接,设计合成了13个未见报道的含吡唑环的双酰肼类目标化合物6a~6m,其结构均通过核磁共振氢谱及高分辨质谱确认。培养皿法测定结果表明:在200 mg/L下,化合物N'-(2-(2,4-二氯苯氧基)乙酰基)-3-(二氟甲基)-1-甲基-1H-吡唑-4-甲酰肼(6i)对小麦Triticum aestivum、油菜Brassicacampestris、高粱Sorghum bicolor、萝卜Raphanus sativus和黄瓜Cucumis sativus根、茎的抑制率均达80%以上。盆栽试验表明:在有效成分150 g/hm2剂量下,采用苗后茎叶喷雾处理,化合物6i对反枝苋Amaranthus retroflexus和鳢肠Eclipta prostrata的抑制率均达80%;相同剂量下采用苗前土壤喷雾处理,6i对反枝苋A. retroflexus的抑制率也达80%。     

Uptake and metabolism as mechanisms of selective herbicidal activity of the 1,2,4-triazolo[1,5-a] pyrimidines

In order to identify the factors providing the triazolopyrimidines with a wide range of selectivity amongst agriculturally important plant species, studies were made on the uptake and metabolism of a representative compound, N-(2,6-dichlorophenyl)-5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine- 2-sulfonamide. This compound is much more phytotoxic to dicots than to monocots. Experiments showed that variations in leaf morphologies and geometries relative to spray applications resulted in different herbicide dosages applied to plant species used in selectivity evaluations. However, this parameter did not have a statistically significant correlation to herbicide selectivity measurements. Characterization of the metabolic pathways showed that the major herbicide metabolites involved methyl hydroxylation or hydroxylation of the aniline ring followed by glucose conjugation. Since these metabolites were not exclusive to either monocots or dicots, herbicide selectivity does not appear dependent on the pathway of metabolism. Studies on the kinetics of metabolism suggest instead that metabolic rate was important. Monocots metabolized the herbicide rapidly and generally were tolerant while the opposite was true of dicots.     

N-[2-(4,6-二甲氧基嘧啶-2-氧基)苯亚甲基]取代胺类衍生物的合成及除草活性

以水杨醛为原料,经取代、加成和消除反应合成了6个标题化合物(3a~3f),其中4个(3a~3d)为新化合物,其结构经核磁共振氢谱、质谱和元素分析确认。初步的除草活性测试结果表明,在有效成分150 g/hm2的剂量下,除化合物3f对稗草Echinochloa crus-galli的抑制率为55%外,其余5个化合物对供试杂草的抑制率均在80%以上,部分化合物对稗草、早熟禾Poa annua、反枝苋Amaranthus retroflexus或小藜Chenopodium album的抑制率达100%。     

An evaluation of a virobacterial agglutination test for the detection of plant viruses

Agglutination of Staphylococcus aureus bacteria particles, conjugated with specific virus antibodies, has been used to identify a wide range of plant viruses in crude sap extracts. The test distinguishes between seven different potyviruses in homologous and heterologous reactions, but does not distinguish different strains of bean yellow mosaic virus. The sensitivity of the virobacterial agglutination (VBA) test compares favourably with virus detection in ISEM particle trapping and local lesion assay and is only slightly less sensitive than direct ELISA tests. The test is more sensitive and simpler to user than latex particle agglutination tests.     

Effects and possible mode of action of some nonionic surfactants on the diffusion of [14C]glyphosate and [14C]Chlorotoluron acorss isoltated plant cuticles

The following are extended summaries based on posters presented at the 8th International Congress of Pesticide Chemistry (IUPAC), held in Washington, DC, USA, 4–9 July 1994. They are entirely the responsibility of the authors, and do not necessarily reflect the views of the Editorial Board of Pesticide Science.     

Binding of [14C]DDT and [14C]dicyclohexylcarbodi-imide to a lipoprotein of the membrane sector of mitochondrial ATpase

Intact mitochondria, isolated from red coxal muscle of the American cockroach (Periplaneta americana L.), were incubated in the presence of 1,1,1-trichloro-2,2-bis(4-chloro[¹⁴C]phenyl)ethane ([¹⁴C]DDT) to isolate a suspected binding site for DDT in the membrane sector of the mitochondrial ATPase. The requirements for the binding of DDT were compared with those for the binding of dicyclohexyl[¹⁴C]carbodi-imide([¹⁴C]DCCD), a potent inhibitory probe of mitochondrial ATPase activity. [¹⁴C]DDT appeared to bind to a proteolipid of the membrane sector, which also binds [¹⁴C]DCCD. Exchange experiments, with [¹⁴C]DCCD, [¹⁴C]DDT and unlabelled DDT at different concentrations, indicated that DDT and DCCD may be acting on a similar protein. This protein may act as the energy transducing protonophore required for the synthesis and hydrolysis of ATP in coupled mitochondria. Inhibition of mitochondrial ATPase activity may be a consequence of DDT and DCCD binding to this proteolipid protonophore, resulting in the disruption of energy transduction in muscle and nerve.     

Evaluation of regulatory influence of four plant growth regulators on the reproductive potential and longevity of melon fruit fly (Bactrocera cucurbitae)

The topical treatment given to freshly emerged (0–1-day-old) male and female adults ofBactrocera cucurbitae (Coquillett), a serious pest of cucurbit crops in tropical countries, with 25, 125, 625 and 3125 ppm concentrations of gibberellic acid (GA₃), indole-3-acetic acid (IAA), kinetin and coumarin showed a significant adverse influence on the reproductive potential of this fruit fly. The assessment for reproductive potential was made on the basis of reduction in fecundity and fertility of laid eggs and measured as sterility in females and shortening of the longevity,i.e. ovipositional phase. The strongest influence was with kinetin, followed closely by coumarin, then GA₃ and lastly with IAA treatments. It was concluded that although these compounds demonstrate their activities differently in plants and might be following a different mode of action in insects, they ultimately influence the reproductive potential of this insect.     

短密木霉新菌株BF06对黄瓜土传病害的防治效果与促生作用

连作导致枯萎病等土传病害发生日益严重,已成为我国黄瓜生产的重要限制因素。采用化学防治和农业措施防治土传根部病害,操作都较为困难,迫切需要开发环境友好的生物防治技术。本研究从森林土壤分离鉴定一株短密木霉菌株BF06,通过对峙培养发现该菌株可以附着和缠绕病原菌的菌丝,对引起黄瓜枯萎病、茎基腐病、菌核病、根腐病和疫病的病原菌Fusarium oxysporum f. sp. cucumerinum,Rhizoctonia solani,Sclerotinia sclerotiorum,F. solani f. sp. cucurbitae,and Phytophthora cryptogea具有较强的拮抗作用。温室盆栽试验发现短密木霉菌株BF06可以迅速附着定殖于黄瓜根部表面,对上述5种黄瓜根部病害的防效达60%以上,对黄瓜枯萎病和茎基腐病的防效分别为90.4和88.8%。此外,利用植物组织培养基培养观察发现BF06显著地促进幼苗黄瓜侧根的形成和生长。本研究的结果表明短密木霉菌株BF06是一种可以有效防治黄瓜根部病害的新生防资源。     

An assessment of the value of plant growth regulators and herbicides for crops grown for the processed food industries

The use of growth regulators to induce specific modifications in the growth of crops produced for processing is discussed. Increases in yield may be obtained by some treatments but more important effects on uniformity, quality, ease of harvesting and short-term storage may also be achieved. The results of experiments on stem extension of calabrese, chemical stopping and defoliation of Brussels sprouts, root/shoot ratio modification of root crops and short-term storage of green vegetables are presented. It is concluded that although so far, few commercial applications have been discovered, the requirements for growth regulation justify the search for new, more reliable synthetic growth regulators by improving screening tests and more efficient field trials. The use of herbicides on crops grown for processing is also discussed briefly and it is concluded that the prime requirement is for more efficient post-emergence herbicides.     

植物激活蛋白对甜菜夜蛾幼虫生长和发育的影响

来源于真菌交链孢菌Alternaria的新型植物激活蛋白,具有激发植物自身的抗病防虫基因表达、促进植物生长和促进农作物增产的作用.作者以甜菜夜蛾Spodoptera exigua Hübner幼虫为供试虫,测定了植物激活蛋白对甜菜夜蛾幼虫生长、发育的影响.     

喷施组合型生长调节剂对不同品种小麦冬前分蘖和生长及抗寒性的影响

采用大田随机区组试验,比较研究了一种已获得国家发明专利的组合型生长调节剂对不同冬小麦品种（西农979、西农889、郑州831和小偃22）冬前分蘖和生长以及抗寒性的影响。结果表明：在播种后一个半月喷施该生长调节剂能显著提高西农979、西农889及郑州831的冬前分蘖数和地上生物量,但对小偃22的分蘖数和生物量没有显著影响; 与未喷施生长调节剂的对照植株相比,在一年中最寒冷的时间,喷施生长调节剂的西农979叶片中叶绿素、类胡萝卜素、可溶性糖和淀粉、可溶性蛋白质和脯氨酸含量以及SOD和POD活性均显著提高,而丙二醛含量显著降低,但谷胱甘肽和抗坏血酸含量没有显著变化,表明喷施该组合型生长调节剂有助于提高西农979的抗寒性能;而对其余三个小麦品种而言,这些与植物抗寒性相关的生理生化指标未受到显著影响。对产量性状分析结果表明,喷施生长调节剂后,西农979、西农889和郑州831的单株成穗数分别提高了19.0％、17.8％和5.3％,单位面积产量分别提高了16.9％、16.2％和5.9％,但是小偃22的产量基本没有受到影响。说明该生长调节剂对不同品种冬小麦的冬前分蘖和生长、抗寒性及产量的效应不同,其中对西农979冬前分蘖和生长以及抗寒能力的提高、还有增产效果最明显,但对小偃22的效应不明显。     

Metabolism of 2-[methoxy(methylthio)phosphinylimino]-3-ethyl-5-methyl-1,3-oxazolidine in the cotton plant and houseflies

The metabolism of 2-[methoxy(methylthio)phosphinylimino]-3-ethyl-5-methyl-1,3-oxazolidine (Stauffer R-16,661), a new experimental insecticide, was investigated in the cotton plant, houseflies, and in in vitro enzymatic and model oxidation systems. The principal metabolite isolated both in vivo and in vitro proved to be the 4-keto derivative of R-16,661. The structure of this metabolite was confirmed by PMR and mass spectral analysis. Toxicological examination showed that the 4-keto metabolite was approximately equal to R-16,661 in toxicity to the white mouse but was substantially less toxic to the housefly.     

N-[4-叔丁基-6-芳基-5-(1,2,4-三唑-1-基)-1,3-噻嗪-2-基]酰胺类化合物的合成及抑菌活性

以α-三唑基频那酮为起始原料,经缩合、环化和酰胺化反应合成了15个未见文献报道的化合物,其结构均经核磁共振氢谱、红外光谱和质谱确认。初步抑菌活性测试结果表明,在50 mg/L下,目标化合物对供试植物病原菌均有不同程度的抑制作用,其中化合物3a-3、3a-4、3a-5、3b-2和3b-3对番茄灰霉病菌Botrytis cinerea的抑制率达80%以上,3a-4和3a-5对棉花枯萎病菌Fusarium oxysporum vasinfectum的抑制率分别达78.6%和82.4%。     

Distribution and excretion of [14CH3S]methamidophos after intravenous administration of a toxic dose and the relationship with anticholinesterase activity

The tissue distribution and excretion of [¹⁴CH₃S]methamidophos was followed in female Sprague-Dawley rats after intravenous injection at a toxic, but nonlethal, dose (8 mg/kg). Radiolabel was rapidly distributed to all tissues at approximately equal concentrations. Peak tissue levels were achieved within 1–10 min except in the central and peripheral nervous system where peak levels (40 nmol/g) were found between 20 and 60 min, corresponding to peak signs of toxicity. Within 24 hr of dosing, 47% of the radioactivity was recovered in the urine and 34% as ¹⁴CO₂ with <5% in the feces over 7 days. Cholinesterase (ChE) inhibition was measured in erythrocytes, plasma, and various regions of the central nervous system (CNS) at selected times after administration of methamidophos at 8 mg/kg. The degree of acetylcholinesterase (AChE) inhibition in the three CNS regions was similar, reaching a minimum of 15–20% of control values at 30–60 min, when toxicity was most severe. The degree of erythrocyte AChE inhibition was less than that of the CNS although the time course was similar. Plasma ChE inhibition was more rapid than that of the CNS or erythrocytes and reactivation was slower. When similar concentrations of methamidophos to those found in vivo were incubated with CNS homogenates, plasma, or erythrocytes in vitro (5 × 10^?5M) a similar degree of inhibition occurred over the same time course. It is, therefore, concluded that the cholinergic toxicity produced by methamidophos is a result of the in vivo stability of this compound combined with its entry into the nervous system in sufficiently high concentrations to inhibit AChE.     

Effects of lodging of Echinochloa crus-galli L. on the herbicidal efficacy of MTB-951, a mycoherbicide using Drechslera monoceras (Drechsler) Subram. et Jain (= Exserohilum monoceras [Drechsler] Leonard et Suggs)

MTB-951 is a plant pathogen ( Drechslera monoceras ), which was isolated from native Echinochloa spp. in Japan. The conidia of this pathogen were used as the herbicidal active ingredient to control Echinochloa crus-galli L. The herbicidal efficacy of MTB-951 on E. crus-galli was drastically increased with an increasing water depth of between 1 and 10 cm. The efficacy also was increased when shoots were lodged by pushing down on them with a stainless steel net so that all parts of the weed were submerged. These results suggest that the contact area of the leaf surface of E. crus-galli with water is important for infection and that lodging the shoots of E. crus-galli might be effective in increasing the herbicidal efficacy. In order to find other methods to lodge the weed, we investigated several materials, of which diisononyl phthalate (DINP) was found to be the most effective. Using this material as a model, the effect of lodging on the herbicidal efficacy of MTB-951 was examined. The lodging ratio (ratio of the number of the plants lodged on the water surface to that of the total plants) was increased with an increased amount of DINP, between 0.5 and 8 kg ha⁻¹. The herbicidal efficacy of MTB-951 also was increased by DINP and a positive correlation was observed between the lodging ratio and herbicidal efficacy. These results indicate that lodging, which can increase the contact area between the leaf surface and water, enhances the herbicidal efficacy of MTB-951.     

Effect of some ethoxylated alkylphenols and ethoxylated alcohols on the transfer of [14C] chlorotoluron across isolated plant cuticles

The effect of several ethoxylated octylphenols (OP), nonylphenols (NP) and alcohols (AA) on the penetration of [¹⁴C]chlorotoluron through isolated box-tree (Buxus sempervirens L.) leaf cuticles was investigated. The herbicide solution was deposited as droplets onto cuticle discs maintained on agar blocks acting as receivers. The effects on chlorotoluron transfer across the cuticles depended on the degree of ethoxylation of the surfactant. For each series, the chlorotoluron transfer was considerably increased by surfactants with low ethylene oxide (EO) content (3 to 6 EO). This effect appeared 24 h after droplet application, then increased with time. It decreased with further increase in the ethoxylation number, and surfactants with a long ethylene oxide chain (OP16, NP20, NP40 and AA20) had no effect. Surfactant concentration (OP5) had a large influence on chlorotoluron transfer; penetration increased sevenfold when OP5 concentration was raised from 0.01 to 10 g l^?1. Diffusion of the two tritiated octylphenols, [3H]OP5 and [3H]OP16, was measured simultaneously during chlorotoluron transfer. The diffusion rate of the two surfactants across the cuticles was similar, but a higher amount of OP5 was retained within the cuticle during transfer. Study of the effect of surfactants on the cuticular waxes using differential scanning calorimetry showed that wax begins to melt at a lower temperature in the presence of the nonylphenols NP9 and NP4. Fusion enthalpy was close to -30 J g^?1. Effet de quelques alkylphénols et alcools éthoxylés sur la pénétration du [¹⁴C]chlortoluron à travers des cuticules végétales isolées Nous avons testé l'effet de plusieurs octylphénols (OP), nonylphénols (NP) et alcools éthoxylés (AA) sur la pénétration du [¹⁴C]chlortoluron à travers des cuticules isolées de feuilles de buis. L'herbicide en solution était déposé sous forme de gouttelettes sur des disques de cuticules plaées sur agar. Les effets observés dépendaient du degré d'ethoxylation du surfactant. Pour chaque série, le transfert du chlortoluron à travers les cuticules était considérablement accru avec les surfactants faiblement éthoxylés (3 à 6 oxydes d'éthylène). Cet effet apparaissait 24 h après l'application des gouttelettes puis augmentait avec le temps. Il diminuait avec l'accroissement du nombre d'éthoxylation et aucun effet n'était observé avec les surfactants à longue chaine d'oxydes d'éthylène (OP16, NP20, NP40 et AA20). La concentration en surfactant (OP5) avait une grande influence sur le transfert du chlortoluron dans l'agar, il augmentait sept fois entre 0.01 et 10 g l^?1. La diffusion des deux octylphénols (³H-OP5 et ³H-OP16) a été mesurée simultanément durant le transfert du chlortoluron. La vitesse de diffusion des deux surfactants à travers les cuticules était comparable, mais une quantité plus élevée d'OP5 était retenue dans les cuticules durant le transfert. L'étude par analyse calorimètrique à balayage de l'effet des surfactants sur les cires cuticulaires a montré que la fusion des cires commence à plus faible température en présence des nonylphénols NP9 et NP4. L'enthalpie de fusion était en général voisine de -30 J g^?1. Wirkung einiger ethoxylierter Alkylphenole und Alkohole auf den Transfer von [¹⁴C]Chlortoluron durch die Pflanzen-Cuticula Die Wirkung verschiedener ethoxylierter Octylphenole (OP), Nonylphenole (NP) und Alkohole (AA) auf die Penetration von [¹⁴C]Chlortoluron durch die isolierte Blatt-Cuticula von Buxbaum (Buxus sempervirens L.) wurde untersucht. Die Herbizidlösung wurde als Tröpfchen auf Cuticula-Scheiben, die auf Agarblöcken als Empfänger ausgelegt worden waren, ausgebracht. Die Wirkung auf den Chlortoluron-Transfer durch die Cuticula hing von der Ethoxylierung des Zusatzstoffes ab. In allen Serien wurde der Transfer durch Zusatzstoffe mit niedrigem Gehalt an Ethyloxiden (EO) erheblich gesteigert (3 bis 6 EO). Diese Wirkung trat 24 h nach der Applikation der Tröpfchen ein und nahm dann mit der Zeit zu. Mit dem Anstieg der Ethoxylierungszahl nahm die Wirkung ab, und Zusatzstoffe mit einer langen Ethylenoxidkette (OP16, NP20, NP40 und AA20) waren wirkungslos. Die Konzentration des OP5-Zusatzstoffes hatte großen Einfluß auf den Chlortolurontransfer; die Penetration war versiebenfacht, wenn die OP5-Konzentration von 0,01 auf 10 g l^?1 angehoben wurde. Die Diffusion der Octylphenole [³H]OP5 und [³H]OP16 wurde während des Chlortolurontransfers gemessen; die Diffusionsrate war ähnlich, aber von OP5 wurde ein größerer Anteil in der Cuticula zuückgehalten. Die Wirkung der Zusatzstoffe auf das Cuticularwachs wurde calorimetrisch untersucht, und es zeigte sich, daß das Wachs in Gegenwart der Nonylphenole NP9 und NP4 bei niedriger Temperatur zu schmelzen beginnt. Die Fusionsenthalpie lag bei -30 J g^?1     

Cold plasma as a novel treatment to reduce the in vitro growth and germination of Colletotrichum species

This study investigated the use of cold plasma to reduce the in vitro growth of two postharvest fungal plant pathogens, Colletotrichum alienum and C. fioriniae, isolated from avocados. Cold plasma (CP) was used to treat pure cultures and conidial suspensions of both pathogens, for 180 or 360 s, in either open or sealed environments from varying distances. In an open environment, the 360 s treatment at a distance of 5 cm reduced the colony growth of freshly inoculated cultures to less than 2 mm/day compared to the control of more than 8 mm/day, and treatment of conidial suspensions resulted in almost 100% reduction of conidial germination. In the same environment, the 180 s CP treatment did not significantly reduce the colony growth of fresh or actively growing cultures, but did suppress the germination of conidia by up to 80%. In a sealed environment, the 360 s CP treatment also effectively reduced the growth of freshly inoculated cultures, with no growth for some isolates. Production of reactive oxygen and nitrogen species was observed during treatment, and these may have contributed to the reduction in growth and germination. These results demonstrate the potential of CP for the control of two Colletotrichum species.