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1.
T. Enyinnia 《国际虫害防治杂志》2013,59(2):77-80
Abstract Two systemic fungicides, benomyl (methyl 1‐((butylamino)‐carbonyl)‐1H‐benzimidazol‐2‐yl carbamate) (Benlate 50WP, E.I. du Pont de Nemours & Co.) and tricyclazole (5‐methyl‐1,2,4‐triazole (3,4‐b) benzothiazole) (Beam 75 WP, Eli Lilly & Co.), were sprayed on Faro 29, a popular shallow swamp rice, at full tillering stage for the control of natural infection of rice blast caused by Pyricularia oryzae Cav. in the rainforest zone of eastern Nigeria. The rates evaluated for each fungicide were a split application of 150 + 150, 300, and 400ga.i./ha of each fungicide. Both fungicides suppressed foliar and neck blast development, but tricyclazole was superior to benomyl. One application of tricyclazole at 400g a.i./ha at full tillering stage of rice successfully suppressed blast development and resulted in a significantly (P = 005) higher grain yield than the untreated control plants by an average of 42.17% during the 2 years of this study. Similarly, benomyl at 400g a.i./ha produced 18.94% more rice grain than the control. A fungicide such as tricyclazole may therefore be recommended for control of blast in areas where resistant varieties are not available or where popular resistant varieties become susceptible to one or the other phases of the disease. 相似文献
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BACKGROUND: Cercospora leaf spot (CLS), caused by the fungus Cercospora beticola, is the most serious foliar disease of sugar beet (Beta vulgaris L.) worldwide. Disease control is mainly achieved by timely fungicide applications. In 2011, CLS control failures were reported in spite of application of quinone outside inhibitor (QoI) fungicide in several counties in Michigan, United States. The purpose of this study was to confirm the resistant phenotype and identify the molecular basis for QoI resistance of Michigan C. beticola isolates. RESULTS: Isolates collected in Michigan in 1998 and 1999 that had no previous exposure to the QoI fungicides trifloxystrobin or pyraclostrobin exhibited QoI EC50 values of ?0.006 µg mL?1. In contrast, all isolates obtained in 2011 exhibited EC50 values of > 0.92 µg mL?1 to both fungicides and harbored a mutation in cytochrome b (cytb) that led to an amino acid exchange from glycine to alanine at position 143 (G143A) compared with baseline QoI‐sensitive isolates. Microsatellite analysis of the isolates suggested that QoI resistance emerged independently in multiple genotypic backgrounds at multiple locations. A real‐time PCR assay utilizing dual‐labeled fluorogenic probes was developed to detect and differentiate QoI‐resistant isolates harboring the G143A mutation from sensitive isolates. CONCLUSION: The G143A mutation in cytb is associated with QoI resistance in C. beticola. Accurate monitoring of this mutation will be essential for fungicide resistance management in this pathosystem. Copyright © 2012 Society of Chemical Industry 相似文献
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BACKGROUND: Rice blast, caused by Magnaporthe oryzae B. Couch sp. nov., is one of the most destructive rice diseases worldwide, causing substantial yield losses every year. In Italy, its management is based mainly on the use of two fungicides, azoxystrobin and tricyclazole, that restrain the disease progress. The aim of this study was to investigate and compare the inhibitory effects of the two fungicides on the growth, sporulation and secondary infection of M. oryzae. RESULTS: Magnaporthe oryzae mycelium growth was inhibited at low concentrations of azoxystrobin and relatively high concentrations of tricyclazole, while sporulation was more sensitive to both fungicides and was affected at similarly low doses. Furthermore, infection efficiency of conidia obtained from mycelia exposed to tricyclazole was affected to a higher extent than for conidia produced on azoxystrobin‐amended media, even though germination of such conidia was reduced after azoxystrobin treatment. CONCLUSIONS: This study presents for the first time detailed azoxystrobin and tricyclazole growth–response curves for M. oryzae mycelium growth and sporulation. Furthermore, high efficacy of tricyclazole towards inhibition of sporulation and secondary infection indicates an additional possible mode of action of this fungicide that is different from inhibition of melanin biosynthesis. Copyright © 2012 Society of Chemical Industry 相似文献
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Irvin J. Belasco Jerry C-Y. Han Robert L. Chrzanowski Frederic J. Baude 《Pest management science》1981,12(4):355-364
Foliar-applied [14]cymoxanil, 1-(2-cyano-2-methoxyimino-[2-14C]acetyl)-3-ethylurea was rapidly metabolised in grapes, tomatoes and potatoes, Furthermore, the metabolism of this fungicide was unusual in that the metabolites were found to be naturally occurring compounds, with glycine as the major metabolite. Significant levels of radioactivity were found in other amino-acids, sugars, starch, fatty acids and lignin, indicating incorporation of carbon-14 via the various metabolic pathways. 相似文献
5.
Li XH Ji MS Qi ZQ Li XW Shen YX Gu ZM Zhang Y Wei SH Wang YZ Wang DQ 《Pest management science》2011,67(8):986-992
BACKGROUND: With the objective of exploring the fungicidal activity of 2‐oxocyclohexylsulfonamides (2), a series of novel 2‐amino‐6‐oxocyclohexenylsulfonamides (6 to 23) were synthesised, and their fungicidal activities against Botrytis cinerea Pers. were evaluated in vitro and in vivo. RESULTS: The compounds were characterised by IR, 1H NMR and elemental analysis. Bioassay results of mycelial growth showed that compounds 6 to 23 had a moderate antifungal activity against B. cinerea. N‐(2‐methylphenyl)‐2‐(2‐methylphenylamino)‐4,4‐dimethyl‐6‐oxocyclohexenylsulfonamide (13) and N‐(2‐chlorophenyl)‐2‐(2‐chlorophenylamino)‐6‐oxocyclohexenylsulfonamide (21) showed best antifungal activities, with EC50 values of 8.05 and 10.56 µg mL?1 respectively. Commercial fungicide procymidone provided an EC50 value of 0.63 µg mL?1. The conidial germination assay showed that most of compounds 6 to 23 possessed excellent inhibition of spore germination and germ‐tube elongation of conidia of B. cinerea. For in vivo control of B. cinerea colonising cucumber leaves, the compound N‐cyclohexyl‐2‐(cyclohexylamino)‐4,4‐dimethyl‐6‐oxocyclohexenylsulfonamide (19) showed a better control effect than the commercial fungicide procymidone. CONCLUSION: The present work demonstrated that 2‐amino‐6‐oxocyclohexenylsulfonamides can be used as possible new lead compounds for further developing novel fungicides against B. cinerea. Copyright © 2011 Society of Chemical Industry 相似文献
6.
为探索新的农药先导化合物,经取代苯基呋喃甲酰氯与5-肼基-3(2H)哒嗪酮反应,得到15个未见文献报道的含呋喃环3(2H)哒嗪酮类化合物,其结构均通过了红外光谱、核磁共振氢谱和元素分析确认。初步生物活性测定结果表明,目标化合物具有良好的杀菌活性,但杀虫活性较弱。其中化合物3k在50 mg/L时对灰霉病菌的抑制率为86.29%±1.51%,与对照药剂腐霉利相当。初步的构效关系研究结果显示,苯环上取代基的种类和位置对杀菌活性有重要影响。 相似文献
7.
A new pigment, 3,3′-biflaviolin (3,3′-bi-2,2′,5,5′,7,7′-hexahydroxy-1,1′,4,4′-naphthoquinone), was identified from agar cultures of the fungus Thielaviopsis basicola treated with the fungal melanin inhibitor, tricyclazole. An albino mutant of T. basicola that does not form melanin or colored melanin shunt products, synthesized 3,3′-biflaviolin when treated with flaviolin. The dimerization reaction appeared to be enzymatic. 相似文献
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Robert Fowles Baldwin Mootoo Russel Ramsewak Ayub Khan Adesh Ramsubhag William Reynolds Muraleedharan Nair 《Pest management science》2010,66(12):1298-1303
BACKGROUND: Natural limonoids are one group of compounds being studied for their insecticidal properties. To discover new limonoids with better activities, analogs were prepared via acylation and hydrolysis, and bioassayed. RESULTS: Analogs were identified using one‐ and two‐dimensional (COSY, HMQC and HMBC) 1H and 13C NMR, IR and MS. 3‐O‐Isovalerylswietenolide (13) and 3‐O‐isobutyrylswietenolide (14) showed excellent antifeedant activity, with DC50 values of 0.19 and 0.009 mg L?1 respectively, compared with the natural limonoid swietenolide (80.6 mg L?1) against fourth‐instar Spodoptera frugiperda (JE Smith) larvae. CONCLUSION: This work shows that limonoid analogs prepared through semi‐synthesis can be used as lead compounds for the development of new insecticides. Copyright © 2010 Society of Chemical Industry 相似文献
10.
BACKGROUND: The occurrence of carboxylic acid amide (CAA)‐fungicide‐resistant Plasmopara viticola populations is becoming a serious problem in the control of grapevine downy mildew worldwide. RESULTS: The authors have developed a method, which utilises PCR‐RFLP, for the rapid detection of resistance to the CAA fungicide mandipropamid in P. viticola populations. With this method, a glycine‐to‐serine substitution at codon 1105 of the cellulose synthase gene PvCesA3 of CAA‐fungicide‐resistant P. viticola was easily detected, although no resistant P. viticola was detected from 398 isolates in Japan. CONCLUSION: It is proposed that the PCR‐RFLP method is a reliable tool for the rapid detection of CAA‐fungicide‐resistant P. viticola isolates. Only 4 h was required from the sampling of symptoms to the phenotyping of fungicide resistance. Copyright © 2011 Society of Chemical Industry 相似文献
11.
BACKGROUND: Sclerotinia sclerotiorum (Lib.) de Bary is a major pathogen of witloof chicory. For lack of authorised field treatment, post‐harvest sprays with dicarboximide fungicides have been standard practice since the 1970s to prevent root rot and chicory heart decay during the forcing phase. However, the registration of procymidone and vinclozolin has been withdrawn in Europe. The development of organic agriculture and the necessity to reduce fungicide applications in conventional agriculture prompted an assessment of the efficacy of new fungicides and the use of the mycoparasite Coniothyrium minitans (Campbell). RESULTS: A mixture of the fungicides fludioxonil and cyprodinil (Switch®) applied on chicory roots achieved a very good control of S. sclerotiorum (up to 95%). The use of C. minitans limited root infection, both when applied in the field (50–65% efficacy) and before the forcing period (post‐harvest treatment up to 80%). CONCLUSION: In organic agriculture, two treatments with C. minitans (in field and later at the forcing period) could improve protection against S. sclerotiorum. In conventional agriculture, after the field biological treatment, a post‐harvest chemical treatment could be applied. The addition of other prophylactic methods could lead to a high level of performance in practice against decay caused by S. sclerotiorum. Copyright © 2010 Society of Chemical Industry 相似文献
12.
Thomas Müller Peter Thanei Wolfgang Mücke Hans-Peter Kriemler Tammo Winkler 《Pest management science》1999,55(5):594-596
The metabolism of cyprodinil, a novel broad-spectrum fungicide, was investigated in rats. After single oral administration of 0.5 or 100 mg kg−1 body weight, [phenyl-U-14C]cyprodinil was rapidly eliminated, principally in the urine. The metabolite pattern in urine exhibited a significant sex-related difference with respect to the major metabolite. Males and females both produced a dihydroxy metabolite, N-4-(hydroxyphenyl)-4-cyclopropyl-5-hydroxy-6-methylpyrimidin-2-ylamine. Female rats conjugated this metabolite with sulfate exclusively at the 5-hydroxypyrimidinyl moiety, while males formed equal amounts of the monosulfate and a disulfate conjugate. The sex dimorphism in the conjugation reaction indicates the involvement of a sex-specific sulfotransferase that catalyzed the transfer of the second sulfate group. 相似文献
13.
BACKGROUND: DNA‐based diagnosis has become a common tool for the evaluation of fungicide resistance in obligate phytopathogenic fungus Plasmopara viticola. RESULTS: A multiplex allele‐specific primer PCR assay has been developed for the rapid detection of fungicide resistance in P. viticola populations. With this assay, a glycine‐to‐alanine substitution at codon 143 of the P. viticola cytochrome b gene, which conferred QoI fungicide resistance, and a glycine‐to‐serine substitution at codon 1105 of the P. viticola cellulose synthase gene PvCesA3, which conferred CAA fungicide resistance, were detected simultaneously. CONCLUSION: It is suggested that the present assay is a reliable tool for the rapid and simultaneous detection of QoI and CAA fungicide resistance alleles in P. viticola populations. The assay required only 2 h from the sampling of symptoms to the detection of resistance alleles to both fungicides. Copyright © 2012 Society of Chemical Industry 相似文献
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BACKGROUND: In a screening programme for new agrochemicals from Chinese medicinal herbs, Chenopodium ambrosioides L. was found to possess strong fumigant activity against the maize weevil Sitophilus zeamais (Motsch.). Essential oil of C. ambrosioides was obtained by hydrodistillation, and the constituents were determined by GC‐MS analysis. The active compounds were isolated and identified by bioassay‐directed fractionation. RESULTS: Five active compounds [(Z)‐ascaridole, 2‐carene, ρ‐cymene, isoascaridole and α‐terpinene] were isolated and identified from the essential oil from Chinese C. ambrosioides. The LC50 values (fumigation) of the crude essential oils and the active compound (Z)‐ascaridole against S. zeamais adults were 3.08 and 0.84 mg L?1 air respectively. The LD50 values (contact toxicity) of the crude essential oil and (Z)‐ascaridole against S. zeamais adults were 2.12 and 0.86 µg g?1 body weight respectively. CONCLUSION: The findings suggested that the essential oil of Chenopodium ambrosioides and its main active constituent, (Z)‐ascaridole, may be explored as a natural potential fumigant. Copyright © 2011 Society of Chemical Industry 相似文献
16.
George A Bardas Thomas Veloukas Olga Koutita George S Karaoglanidis 《Pest management science》2010,66(9):967-973
BACKGROUND: Botrytis cinerea Pers.: Fr. is a high‐risk pathogen for fungicide resistance development that has caused resistance problems on many crops throughout the world. This study investigated the fungicide sensitivity profile of isolates from kiwifruits originating from three Greek locations with different fungicide use histories. Sensitivity was measured by in vitro fungitoxicity tests on artificial nutrient media. RESULTS: Seventy‐six single‐spore isolates were tested for sensitivity to the SDHI fungicide boscalid, the QoI pyraclostrobin, the anilinopyrimidine cyprodinil, the hydroxyanilide fenhexamid, the phenylpyrrole fludioxonil, the dicarboxamide iprodione and the benzimidazole carbendazim. All isolates from Thessaloniki showed resistance to both boscalid and pyraclostrobin, while in the other two locations the fungal population was sensitive to these two fungicides. Sensitive isolates showed EC50 values to boscalid and pyraclostrobin ranging from 0.9 to 5.2 and from 0.04 to 0.14 mg L?1 respectively, while the resistant isolates showed EC50 values higher than 50 mg L?1 for boscalid and from 16 to > 50 mg L?1 for pyraclostrobin. All QoI‐resistant isolates carried the G143A mutation in cytb. Sensitivity determinations to the remaining fungicides revealed in total eight resistance phenotypes. No isolates were resistant to the fungicides fenhexamid and fludioxonil. CONCLUSION: This is the first report of B. cinerea field isolates with resistance to both boscalid and pyraclostrobin, and it strongly suggests that there may be a major problem in controlling this important pathogen on kiwifruit. Copyright © 2010 Society of Chemical Industry 相似文献
17.
BACKGROUND: The lead coumarin derivative (E)‐methyl 3‐methoxy‐2‐[2‐(4‐methylcoumarin‐7‐yloxymethyl)phenyl]acrylate was discovered by using an intermediate derivatisation method. To discover new coumarin derivatives with improved activity, a series of substituted coumarins were synthesised and bioassayed. RESULTS: The compounds were identified by 1H NMR, IR, MS and elemental analysis. Bioassays demonstrated that some of the title compounds exhibited excellent fungicidal activity against cucumber downy mildew at 25 mg L?1. The relationship between structure and fungicidal activity is reported. CONCLUSION: The present work demonstrates that coumarin derivatives containing methoxyacrylate moieties can be used as possible lead compounds for developing novel fungicides. Copyright © 2011 Society of Chemical Industry 相似文献
18.
Characterization of the mechanism of action of the fungicide fenpicoxamid and its metabolite UK‐2A 
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下载免费PDF全文 David H Young Nick X Wang Stacy T Meyer Cruz Avila‐Adame 《Pest management science》2018,74(2):489-498
BACKGROUND
Fenpicoxamid is a new fungicide for control of Zymoseptoria tritici, and is a derivative of the natural product UK‐2A. Its mode of action and target site interactions have been investigated.RESULTS
UK‐2A strongly inhibited cytochrome c reductase, whereas fenpicoxamid was much less active, consistent with UK‐2A being the fungicidally active species generated from fenpicoxamid by metabolism. Both compounds caused rapid loss of mitochondrial membrane potential in Z. tritici spores. In Saccharomyces cerevisiae, amino acid substitutions N31K, G37C and L198F at the Qi quinone binding site of cytochrome b reduced sensitivity to fenpicoxamid, UK‐2A and antimycin A. Activity of fenpicoxamid was not reduced by the G143A exchange responsible for strobilurin resistance. A docking pose for UK‐2A at the Qi site overlaid that of antimycin A. Activity towards Botrytis cinerea was potentiated by salicylhydroxamic acid, showing an ability of alternative respiration to mitigate activity. Fungitoxicity assays against Z. tritici field isolates showed no cross‐resistance to strobilurin, azole or benzimidazole fungicides.CONCLUSION
Fenpicoxamid is a Qi inhibitor fungicide that provides a new mode of action for Z. tritici control. Mutational and modeling studies suggest that the active species UK‐2A binds at the Qi site in a similar, but not identical, fashion to antimycin A. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献19.
为探索新的农药先导化合物,经取代苯基呋喃甲酰氯与5-羟基-3(2H)哒嗪酮反应,得到15个未见文献报道的含呋喃环3(2H)哒嗪酮类化合物,其结构均通过了红外光谱、核磁共振氢谱和元素分析确认。初步生物活性测定结果表明,目标化合物表现出良好的杀菌活性,其中化合物3i在50 mg/L时对灰霉病菌和纹枯病菌的抑制率分别为89.16%±1.73%和81.27%±1.38%,与对照药剂腐霉利(88.58%±1.64%和79.62%±1.15%)相当。初步的构效关系结果显示,苯环上取代基的种类和位置对杀菌活性有重要影响。 相似文献
20.
以第一个扁桃酰胺类杀菌剂双炔酰菌胺为模板,在炔丙氧基的邻位引入第二个甲氧基,设计合成了15个未见文献报道的 N-(3,5-二甲氧基-4-烷氧基苯乙基)扁桃酰胺类化合物(8a～8o),其结构通过核磁共振氢谱和高分辨质谱确认。初步的离体和活体杀菌试验结果表明,化合物 8e、8h和8o 对辣椒疫霉 Phytophthora capsici 具有较好的杀菌活性,其中 8h和8o 在62.5 mg/L下对辣椒疫霉活体抑制率达100%。 相似文献