| design, synthesis, and fungicidal activities of new strobilurin derivatives. | strobilurins are one of the most important classes of agricultural fungicides. to discover new strobilurin analogues with high activity against resistant pathogens, a series of new strobilurin derivatives bearing structurally diverse heterocycle side chains 3a-m and 4a-g were designed and synthesized via a microwave-assisted procedure. the advantages, such as good to excellent yields, shorter reaction times, mild reaction conditions, and simple purification procedures, distinguish the present sy ... | 2007 | 17371044 |
| efficacy of osthol, a potent coumarin compound, in controlling powdery mildew caused by sphaerotheca fuliginea. | the efficacy of osthol, a natural coumarin compound, in controlling powdery mildew was evaluated in 2004-2005 in anhui and hebei provinces of china. in both years, the treatments (osthol 15.0 and 18.0 g ai ha(- 1)) showed a stable control efficiency of 75.42, 81.24% and 76.36, 84.84%, respectively, at the institutes of plant protection of hebei academy of agricultural sciences. in field experiments, osthol was as effective as difenoconazole in controlling powdery mildew and was more effective th ... | 2009 | 20183325 |
| synergistic interaction of physcion and chrysophanol on plant powdery mildew. | the extract of the plant rheum officinale baill, mainly containing the anthraquinones physcion and chrysophanol, is highly active against plant powdery mildew. experiments were conducted in the laboratory and greenhouse to determine the interaction of the two compounds on cucumber powdery mildew [sphaerotheca fuliginea (schlecht.) poll] and on wheat powdery mildew [blumeria graminis (dc.) speer f. sp. tritici marchal]. physcion was much more bioactive than chrysophanol against these powdery mild ... | 2007 | 17397111 |
| flavone c-glycosides from leaves of oxalis triangularis. | the flavone c-glycosides luteolin 6-c-(2''-o-beta-xylopyranosyl-beta-glucopyranoside) (1), apigenin 6-c-(2''-o-alpha-rhamnopyranosyl-beta-glucopyranoside) (2), apigenin 6-c-(2''-o-beta-xylopyranosyl-beta-glucopyranoside) (3), apigenin 6-c-(2''-o-(6'''-(e)-caffeoylglucoside)-beta-glucopyranoside) (4), and apigenin 6-c-(2''-o-(6'''-(e)-p-coumaroylglucoside)-beta-glucopyranoside) (5) have been isolated from the purple leaves of oxalis triangularis. compound 4 is new, while 5 has previously been iso ... | 2005 | 16366694 |
| fungal pathogens of euphorbia heterophylla and e. hirta in brazil and their potential as weed biocontrol agents. | a two-year survey of the fungi associated with two important congeneric pantropical weeds, euphorbia heterophylla and e. hirta, was conducted in part of their native range in southern brazil. sampling was concentrated mainly in rio de janeiro state and ten species were identified as pathogens of these weeds. two taxa, botrytis ricini and uromyces euphorbiae, were common to both weed hosts. alternaria euphorbiicola, bipolaris euphorbiae, melampsora sp., oidium sp. and sphaceloma poinsettiae were ... | 1998 | 16284862 |
| changes in specific activities of peroxidase, chitinase and phenylalanine ammonia-lyase and phenolic content in cucumber leaves inoculated with podosphaera fusca, the causal agent of powdery mildew. | in this investigation, the effects of powdery mildew disease [caused by podosphaera fusca (syn. sphaerotheca fuliginea)] on specific activities of several defense-related enzymes and phenolic content were studied in cucumber leaves. spore suspension of the fungus was sprayed on cucumber (cv. super dominus) plants in greenhouse and leaves from both inoculated and non-inoculated control plants were sampled at 0, 24, 48, 72 and 144 hours after inoculation (hai). spore germination and tissue coloniz ... | 2004 | 15756838 |
| paecilomyces fumosoroseus (deuteromycotina: hyphomycetes) as a potential mycoparasite on sphaerotheca fuliginea (ascomycotina: erysiphales). | hyphomycete paecilomyces fumosoroseus that is well known as saprophytic and entomopatogenic fungus was investigated for its mycoparasitism on the cucumber powdery mildew pathogen. mycoparasitism was documented by using standard bioassay and sem. effects of mycoparasitism were evaluated in three types of experiments. paecilomyces fumosoroseus was applied in the form of graded suspensions into a colony of powdery mildew on a leaf segment. interaction between both fungi was observed as the percenta ... | 2005 | 15750732 |
| [effects of silicon supply and sphaerotheca fuliginea inoculation on resistance of cucumber seedlings against powdery mildew]. | by the method of hydroponic culture, this paper studied the effects of soluble silicon (si) supply and sphaerotheca fuliginea inoculation on the active oxygen metabolism, sio2 content and disease resistance of a susceptible cultivar. the results showed that the o2*- producing rate and h2o2 and mda contents of cucumber leaf were increased by sphaerotheca fuliginea inoculation, but reduced by the inoculation plus si supply. the inoculation enhanced the catalase (cat) and peroxidase (pod) activitie ... | 2004 | 15707331 |
| bacterial ghost technology for pesticide delivery. | bacterial ghosts are nondenaturated empty cell envelopes of gram-negative bacteria produced by e-mediated lysis. such envelopes from the plant-adhering bacterium pectobacterium cypripedii were tested for their ability to adhere to plant material and to be used as carriers for pesticide delivery. we show, using fluorescence-labeled p. cypripedii ghosts, that depending on the target plants 55 or 10% (rice or soya, respectively) of the applied bacterial ghosts was retained on the leaves after heavy ... | 2004 | 15373403 |
| screening extracts of achyranthes japonica and rumex crispus for activity against various plant pathogenic fungi and control of powdery mildew. | methanol extracts of fresh materials of 183 plants were screened for in vivo antifungal activity against magnaporthe grisea, corticium sasaki, botrytis cinerea, phytophthora infestans, puccinia recondita and erysiphe graminis f sp hordei. among them, 33 plant extracts showed disease-control efficacy of more than 90% against at least one of six plant diseases. the methanol extracts of achyranthes japonica (whole plant) and rumex crispus (roots) at concentrations greater than 11 g fresh weight of ... | 2004 | 15307672 |
| modeling the qo site of crop pathogens in saccharomyces cerevisiae cytochrome b. | saccharomyces cerevisiae has been used as a model system to characterize the effect of cytochrome b mutations found in fungal and oomycete plant pathogens resistant to q(o) inhibitors (qois), including the strobilurins, now widely employed in agriculture to control such diseases. specific residues in the q(o) site of yeast cytochrome b were modified to obtain four new forms mimicking the q(o) binding site of erysiphe graminis, venturia inaequalis, sphaerotheca fuliginea and phytophthora megasper ... | 2004 | 15153117 |
| powdery mildew (sphaerotheca fuliginea) resistance in melon is selectable at the haploid level. | the major cause of powdery mildew in melons (cucumis melo l.) is the fungus sphaerotheca fuliginea. there are several cultivar- and season-specific races of this fungus. in order to control powdery mildew, it is important to introduce resistance to fungal infection into new cultivars during melon breeding. haploid breeding is a powerful tool for the production of pure lines. in this study, it was investigated whether powdery mildew resistance could be manifested at the haploid level from two dis ... | 2003 | 12598576 |
| mechanisms influencing the evolution of resistance to qo inhibitor fungicides. | fungicides inhibiting the mitochondrial respiration of plant pathogens by binding to the cytochrome bc1 enzyme complex (complex iii) at the qo site (qo inhibitors, qois) were first introduced to the market in 1996. after a short time period, isolates resistant to qois were detected in field populations of a range of important plant pathogens including blumeria graminis speer f sp tritici, sphaerotheca fuliginea (schlecht ex fr) poll, plasmopara viticola (berk & ma curtis ex de bary) berl & de to ... | 2002 | 12233175 |
| evidence of phytoalexins in cucumber leaves infected with powdery mildew following treatment with leaf extracts of reynoutria sachalinensis. | phenolic compounds extracted from cucumber (cucumis sativus l.) leaves were separated and analyzed for their differential presence and fungitoxicity in relation to a prophylactic treatment with milsana (compo, munster, germany) against powdery mildew (sphaerotheca fuliginea). based on our extraction and purification procedures, at least eight separate phenolic compounds with antifungal activity were identified as intrinsic components of cucumber plants. of these compounds, six displayed a signif ... | 1997 | 12223638 |
| salicylic acid and ethylene pathways are differentially activated in melon cotyledons by active or heat-denatured cellulase from trichoderma longibrachiatum. | infiltration of cellulase (ec 3.2.1.4) from trichoderma longibrachiatum into melon (cucumis melo) cotyledons induced several key defense mechanisms and hypersensitive reaction-like symptoms. an oxidative burst was observed 3 hours after treatment and was followed by activation of ethylene and salicylic acid (sa) signaling pathways leading to marked induction of peroxidase and chitinase activities. the treatment of cotyledons by heat-denatured cellulase also led to some induction of peroxidase an ... | 2001 | 11553761 |
| acylated flavone c-glycosides from cucumis sativus. | leaves of cucumis sativus plants treated with silicon and infected with sphaerotheca fuliginea yielded five new acylated flavone c-glycosides identified as isovitexin 2"-o-(6"'-(e)-p-coumaroyl)glucoside (6), isovitexin 2"-o-(6"'-(e)-p-coumaroyl)glucoside-4'-o-glucoside (7), isovitexin 2"-o-(6"'-(e)-feruloyl)glucoside-4'-o-glucoside (11), isoscoparin 2"-o-(6"'-(e)-p-coumaroyl)glucoside (9), and isoscoparin 2"-o-(6"'-(e)-feruloyl)glucoside-4'-o-glucoside (12). the known flavone-glycosides isovitex ... | 2001 | 11524127 |
| [identification of cucumber disease using hyperspectral imaging and discriminate analysis]. | hyperspectral imaging (400-720 nm) and discriminate analysis were investigated for the detection of normal and diseased cucumber leaf samples with powdery mildew (sphaerotheca fuliginea), angular leaf spot (pseudomopnas syringae), downy mildew (pseudoperonospora cubensis), and brown spot (corynespora cassiicola). a hyperspectral imaging system was es tablished to acquire and pre-process leaf images, as well as to extract leaf spectral properties. owing to the complexity of the original spectral ... | 2010 | 20672633 |
| [horticultural plant diseases multispectral classification using combined classified methods]. | the research on multispectral data disposal is getting more and more attention with the development of multispectral technique, capturing data ability and application of multispectral technique in agriculture practice. in the present paper, a cultivated plant cucumber' familiar disease (trichothecium roseum, sphaerotheca fuliginea, cladosporium cucumerinum, corynespora cassiicola, pseudoperonospora cubensis) is the research objects. the cucumber leaves multispectral images of 14 visible light ch ... | 2010 | 20384138 |
| [cucumber diseases diagnosis using multispectral imaging technique]. | for a reliable diagnosis of plant diseases and insect pests, spectroscopy analysis technique and mutispectral imaging technique are proposed to diagnose five cucumber diseases, namely trichothecium roseum, sphaerotheca fuliginea, cladosporium cucumerinum, corynespora cassiicola and pseudoperonospora cubensis. in the experiment, the cucumbers' multispectral images of 14 visible lights channels, near infrared channel and panchromatic channel were captured using narrow-band multispectral imaging sy ... | 2009 | 19445229 |
| inorganic salts for suppressing powdery mildew in cucurbits--a worldwide survey. | the present review provides an update of recent progress in the use of inorganic salts to manage powdery mildew (sphaerotheca fuliginea and erysiphe cichoracearum) in cucurbits (cucurbitaceae). a literature survey identified 16 salts, mainly bicarbonates (e.g. khco3), phosphates (e.g. k2hpo4) and silicates (e.g. na2sio3), as having potential to suppress powdery mildew in cucurbits. the percentage suppression compared with untreated controls was calculated from the best treatment of each of 20 pe ... | 2008 | 19226741 |
| synthesis, fungicidal, and insecticidal activities of beta-methoxyacrylate-containing n-acetyl pyrazoline derivatives. | 1-acetyl-3,-5-diarylpyrazolines have received considerable interests from the fields of medicinal and agricultural chemistry due to their broad spectrum of biological activities. to discover new lead compounds exhibiting both fungicidal and insecticidal activities, a series of pyrazoline derivatives were designed and synthesized by introducing the beta-methoxyacrylate pharmacophore into the scaffold of 1-acetyl-3,5-diarylpyrazoline. the fungicidal activities against pseudoperoniospora cubensis, ... | 2008 | 18973342 |
| ultrastructural and cytochemical investigations of the antagonistic effect of verticillium lecanii on cucumber powdery mildew. | abstract chronological events of the intercellular interaction between verticillium lecanii and cucumber powdery mildew, caused by sphaerotheca fuliginea, were investigated at different times after inoculation by transmission electron microscopy. v. lecanii hyphae colonized host structures by tight binding, apparently mediated by a thin mucilaginous matrix. as early as 24 h after application of the antagonist, increased vacuolation and disorganization of the cytoplasm of the pathogen hyphae were ... | 1997 | 18945181 |
| potential of lecanicillium spp. for management of insects, nematodes and plant diseases. | fungi in the genus lecanicillium (formerly classified as the single species verticillium lecanii) are important pathogens of insects and some have been developed as commercial biopesticides. some isolates are also active against phytoparasitic nematodes or fungi. lecanicillium spp. use both mechanical forces and hydrolytic enzymes to directly penetrate the insect integument and the cell wall of the fungal plant pathogen. in addition to mycoparasitism of the plant pathogen, the mode of action is ... | 2008 | 18423483 |
| spectral quality affects disease development of three pathogens on hydroponically grown plants. | plants were grown under light-emitting diode (led) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (tomv) on pepper (capsicum annuum l.), powdery mildew [sphaerotheca fuliginea (schlectend:fr.) pollaci] on cucumber (cucumis sativus l.), and bacterial wilt (pseudomonas solanacearum smith) on tomato (lycopersicon esculentum mill.). one led (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak he ... | 1997 | 11540250 |
| synthesis and fungicidal evaluation of novel chalcone-based strobilurin analogues. | strobilurin derivatives have become one of the most important classes of agricultural fungicide due to a novel action mode, wide fungicidal spectrum, lower toxicity toward mammalian cells, and environmentally benign characteristics. to discover new strobilurin analogues with high activity against resistant pathogens, a series of new chalcone-based strobilurin derivatives are designed and synthesized by integrating a chalcone scaffold with a strobilurin pharmacophore. the preliminary bioassay sho ... | 2007 | 17579441 |
| expression of a ribosome-inactivating protein gene in bitter melon is induced by sphaerotheca fuliginea and abiotic stimuli. | the gene encoding a single-chain, ribosome-inactivating protein (scrip) was cloned from bitter melon (momordica charantia l.) leaves infected with the fungus, sphaerotheca fuliginea, by rt-pcr. the orf was 861 bp. the ribosome-inactivating protein was expressed in e. coli and, when purified, it inhibited the growth of fusarium solani [corrected] northern blot analysis revealed that rip transcripts rapidly accumulated in leaves 1-day post inoculation with sphaerotheca fuliginea and reached a peak ... | 2007 | 17579811 |