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Sample records for control alternaria padwickii

  1. In vitro control of Alternaria citri using antifungal potentials of ...

    African Journals Online (AJOL)

    In vitro control of Alternaria citri using antifungal potentials of Trichoderma species. Asma Murtaza, Shazia Shafique, Tehmina Anjum, Sobiya Shafique. Abstract. The antifungal potential of five species of Trichoderma viz., Trichoderma viride, Trichoderma aureoviride, Trichoderma reesei, Trichoderma koningii and ...

  2. Induced resistance in tomato fruit by γ-aminobutyric acid for the control of alternaria rot caused by Alternaria alternata.

    Science.gov (United States)

    Yang, Jiali; Sun, Cui; Zhang, Yangyang; Fu, Da; Zheng, Xiaodong; Yu, Ting

    2017-04-15

    The study investigated the effect of γ-aminobutyric acid (GABA) on the control of alternaria rot in tomato fruit and the possible mechanism involved. Our results showed exogenous GABA could stimulate remarkable resistance to the alternaria rot, while it had no direct antifungal activity against Alternaria alternata. Moreover, the activities of antioxidant enzymes, including peroxidase, superoxide dismutase and catalase, along with the expression of these corresponding genes, were significantly induced in the GABA treatment. The obtained data suggested GABA induced resistance against the necrotrophic pathogen A. alternata, at least in part by activating antioxidant enzymes, restricting the levels of cell death caused by reactive oxygen species. Meanwhile, the key enzyme genes of GABA shunt, GABA transaminase and succinic-semialdehyde dehydrogenase, were found up-regulated in the GABA treatment. The activation of the GABA shunt might play a vital role in the resistance mechanism underpinning GABA-induced plant immunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Potencial de pseudomonas spp. fluorescentes para biocontrole de alternaria ricini em mamoneira Potential of fluorescent pseudomonas spp. For biological control of alternaria ricini on castorbean

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    Francisco de A.G. da Silva

    1998-06-01

    Full Text Available The potential of fluorescent Pseudomonas spp. to control Alternaria leaf spot on castorbean, caused by Alternaria ricini, was studied under greenhouse conditions. Two periods for antagonist applications were tested: 48h before and simultaneously to the pathogen inoculation. Among the antagonists tested JA4 and BJ22 were the most effectives showing disease severity reduction of 20.9% and 17.8% respectively, when applied simultaneously. The effect of Pseudomonas spp. on the micelial growth and sporulation was also studied throughout three different methods (funel, streak and celophane. Inhibition of micelial growth and sporulation was observed. There was no correlation between in vitro and in vivo data. Antibiosis was showed as a mode of action for Pseudomonas spp. in relation to Alternaria ricini. Ultrastructural studies confirmed the inhibition of spore germination by the bacteria.

  4. Eficiência e custo do controle químico da mancha de alternaria em tangor murcote Efficiency and cost of chemical control of alternaria brown spot

    Directory of Open Access Journals (Sweden)

    Adimara Bentivoglio Colturato

    2009-09-01

    Full Text Available A mancha de alternaria, causada por Alternaria alternata f. sp. citri, afeta tangelos Minneola, tangerinas Dancy, tangores Murcote e, menos freqüentemente, tangelos Orlando, tangerinas Novas, Lees e Sunburst. Esta doença causa desfolha grave, queda de frutos e manchas nas frutas. O objetivo deste trabalho foi estabelecer o melhor fungicida e a melhor dose para o controle da mancha marrom de alternaria. O delineamento experimental foi de parcelas subdivididas em blocos, com 10 tratamentos principais e 3 doses (subparcelas, com 5 repetições. Foram feitas 5 aplicações, com intervalo de 15 dias. Os tratamentos foram: azoxystrobin, pyraclostrobin, trifloxystrobin, trifloxystrobin + tebuconazole (2 aplicações seguido de 3 aplicações de mancozeb, difenoconazole, trifloxystrobin + propiconazole, iprodione, trifloxystrobin + propineb (2 aplicações seguido de 3 aplicações de oxicloreto de cobre, oxicloreto de cobre + óleo e testemunha. Simultaneamente foram feitas avaliações de incidência e número de lesões por folha. Ao surgimento dos frutos foram avaliadas a incidência em frutos e a produtividade em Kg/ha. Todos os tratamentos foram superiores à testemunha quanto a produtividade. Entre os produtos utilizados o tratamento com trifloxystrobin + propiconazole foi rentável comparando-se custo e produtividade.Alternaria brown spot, caused by Alternaria alternata sp. citri, attacks with more intensity the Tangelos Minneola, tangerine Dancy, and Murcotts, and with less intensity the tangelos Orlando and the tangerinas Novas, Lees and Sunburst. This disease causes severe defoliation and drop or necrotic spots in the fruits. The aim of this work was to evaluated the chemical control of brown spot, and to define the most appropriate dosage of fungicide to control it. The experimental design was split-spot, with ten treatments and 3 doses of fungicides, with five replicates, the fungicides were: azoxystrobin, pyraclostrobin, trifloxystrobin

  5. Biological control of Alternaria radicina in seed production of carrots with Ulocladium atrum

    NARCIS (Netherlands)

    Köhl, J.; Langerak, C.J.; Meekes, E.T.M.; Molhoek, W.M.L.

    2004-01-01

    Black rot of carrots is caused by seed-borne Alternaria radicina. Biological control of seed infestation by treatments applied to plants in flower during seed production with the fungal antagonist Ulocladium atrum was investigated in laboratory and field experiments resulting in a reduction of seed

  6. Alternaria redefined

    NARCIS (Netherlands)

    Woudenberg, J.H.C.; Groenewald, J.Z.; Binder, M.; Crous, P.W.

    2013-01-01

    Alternaria is a ubiquitous fungal genus that includes saprobic, endophytic and pathogenic species associated with a wide variety of substrates. In recent years, DNA-based studies revealed multiple non-monophyletic genera within the Alternaria complex, and Alternaria species clades that do not always

  7. In vitro control of Alternaria citri using antifungal potentials of ...

    African Journals Online (AJOL)

    msc06-08

    2012-05-24

    May 24, 2012 ... black-pod disease (Phytophthora palmivora) of cacao. Biol. Control,. 50:143-149. Hanhong B (2011). Trichoderma species as abiotic and biotic stress · quenchers in plants. Res. J. Biotechnol., 6(3): 73-79. Harman GE (2000). Myths and dogmas of biocontrol: Changes in perceptions derived from research ...

  8. Restyling Alternaria

    NARCIS (Netherlands)

    Woudenberg, J.H.C.

    2015-01-01

    The omnipresent dematiaceous hyphomycete genus Alternaria is associated with a wide variety of substrates including seeds, plants, agricultural products, humans, soil and even the atmosphere. It includes saprophytic, endophytic and pathogenic species, among which multiple plant

  9. Exploring polyamine metabolism of Alternaria alternata to target new substances to control the fungal infection.

    Science.gov (United States)

    Estiarte, N; Crespo-Sempere, A; Marín, S; Sanchis, V; Ramos, A J

    2017-08-01

    Polyamines are essential for all living organisms as they are involved in several vital cell functions. The biosynthetic pathway of polyamines and its regulation is well established and, in this sense, the ornithine descarboxylase (ODC) enzyme acts as one of the controlling factors of the entire pathway. In this work we assessed the inhibition of the ODC with D, l-α-difluoromethylornithine (DFMO) on Alternaria alternata and we observed that fungal growth and mycotoxin production were reduced. This inhibition was not completely restored by the addition of exogenous putrescine. Actually, increasing concentrations of putrescine on the growth media negatively affected mycotoxin production, which was corroborated by the downregulation of pksJ and altR, both genes involved in mycotoxin biosynthesis. We also studied the polyamine metabolism of A. alternata with the goal of finding new targets that compromise its growth and its mycotoxin production capacity. In this sense, we tested two different polyamine analogs, AMXT-2455 and AMXT-3016, and we observed that they partially controlled A. alternata's viability in vitro and in vivo using tomato plants. Finding strategies to design new fungicide substances is becoming a matter of interest as resistance problems are emerging. Copyright © 2017. Published by Elsevier Ltd.

  10. Combination of UV-C treatment and Metschnikowia pulcherrimas for controlling Alternaria rot in postharvest winter jujube fruit.

    Science.gov (United States)

    Guo, Dongqi; Zhu, Lixia; Hou, Xujie

    2015-01-01

    The potential of using antagonistic yeast Metschnikowia pulcherrimas alone or in combination with ultraviolet-C (UV-C) treatment for controlling Alternaria rot of winter jujube, and its effects on postharvest quality of fruit was investigated. The results showed that spore germination of Alternaria alternata was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m(-2) ) in vitro. In vivo, UV-C treatment (5 kJ m(-2) ) or antagonist yeast was capable of reducing the percentage of infected wounds and lesion diameter in artificially inoculated jujube fruits, however, in fruit treated with combination of UV-C treatment and M. pulcherrima, the percentage of infected wounds and lesion diameter was only 16.0% and 0.60 cm, respectively. The decay incidence on winter jujube fruits treated with the combination of UV-C treatment and M. pulcherrima was 23% after storage at 0 ± 1 °C for 45 d followed by 22 °C for 7 d. None of the treatments impaired quality parameters of jujube fruit. Thus, the combination of UV-C radiation and M. pulcherrima could be an alternative to synthetic fungicides for controlling postharvest Alternaria rot of winter jujube. © 2014 Institute of Food Technologists®

  11. Evaluation of non-chemical seed treatment methods for control of Alternaria brassicicola on cabbage seeds

    NARCIS (Netherlands)

    Amein, T.; Wright, Al S.; Wikstrom, M.; Koch, E.; Schmitt, A.; Stephan, D.; Jahn, M.; Tinivella, F.; Gullino, M.L.; Forsberg, G.; Werner, S.; Wolf, van der J.M.; Groot, S.P.C.

    2011-01-01

    Due to the lack of foliar fungicide use, the organic production of Brassica seeds free of Alternaria spp. is difficult. Therefore, effective seed treatments certified for use in organic farming are needed to eradicate or at least effec­tively reduce the seed-borne inoculum. We here report results of

  12. Alternaria section Alternaria: Species, formae speciales or pathotypes'

    NARCIS (Netherlands)

    Woudenberg, J.H.C.; Seidl, M.F.; Groenewald, J.Z.; de Vries, M .; Stielow, B.; Thomma, B.P.H.J.; Crous, P.W.

    2015-01-01

    The cosmopolitan fungal genus Alternaria consists of multiple saprophytic and pathogenic species. Based on phylogenetic and morphological studies, the genus is currently divided into 26 sections. Alternaria sect. Alternaria contains most of the small-spored Alternaria species with concatenated

  13. Alternaria section Alternaria: Species, formae speciales or pathotypes?

    NARCIS (Netherlands)

    Woudenberg, J.H.C.; Seidl, M.F.; Groenewald, J.Z.; Vries, de M.; Stielow, J.B.; Thomma, B.; Crous, P.W.

    2015-01-01

    The cosmopolitan fungal genus Alternaria consists of multiple saprophytic and pathogenic species. Based on phylogenetic and morphological studies, the genus is currently divided into 26 sections. Alternaria sect. Alternaria contains most of the small-spored Alternaria species with concatenated

  14. EFEITO DE EXTRATOS DE Allamanda blanchetti NO CONTROLE DE Alternaria brassicicola EM MUDAS DE COUVE-MANTEIGA

    Directory of Open Access Journals (Sweden)

    JULIANA DE SOUZA GRANJA BARROS

    2015-01-01

    Full Text Available The objective of this study was to evaluate the effect of the extract from a native plant from caatinga (Allamanda blanchetti in the control of the fungus Alternaria brassicicola, concerning to induction of resistance mechanisms in seedlings of kale and direct fungitoxic action. Under greenhouse conditions, the seedlings of kale were sprayed with extracts from A. blanchetti extracted at hot and at cold at concentrations of 0; 100; 500 to 1000 ppm. Analysis of disease severity were performed at 5; 6; 7; 8; 9:10 days after inoculation. Peroxidases were analyzed five times 0; 24; 72; 120, and 168 hours after spraying the seedlings with the extracts. Furthermore, the capacity of the hot and cold extracts was also evaluated at 0; 100; 500, and 1000 ppm to inhibit the germination of spores of A. brassicicola. The concentrations of 1000 ppm of the hot and cold extracts were more effective in controlling the disease. The extract of A. blanchetti induced an increase in the peroxidase activity at 24 hours after treatment application and promote inhibition of germination of spores of A. brassicicola. These results indicate the potential from A. blanchetti to control A. brassicicola, both by direct action and the activation of defense mechanisms.

  15. Ex Vivo Application of Secreted Metabolites Produced by Soil-Inhabiting Bacillus spp. Efficiently Controls Foliar Diseases Caused by Alternaria spp.

    Science.gov (United States)

    Ali, Gul Shad; El-Sayed, Ashraf S A; Patel, Jaimin S; Green, Kari B; Ali, Mohammad; Brennan, Mary; Norman, David

    2016-01-15

    Bacterial biological control agents (BCAs) are largely used as live products to control plant pathogens. However, due to variable environmental and ecological factors, live BCAs usually fail to produce desirable results against foliar pathogens. In this study, we investigated the potential of cell-free culture filtrates of 12 different bacterial BCAs isolated from flower beds for controlling foliar diseases caused by Alternaria spp. In vitro studies showed that culture filtrates from two isolates belonging to Bacillus subtilis and Bacillus amyloliquefaciens displayed strong efficacy and potencies against Alternaria spp. The antimicrobial activity of the culture filtrate of these two biological control agents was effective over a wider range of pH (3.0 to 9.0) and was not affected by autoclaving or proteolysis. Comparative liquid chromatography-mass spectrometry (LC-MS) analyses showed that a complex mixture of cyclic lipopeptides, primarily of the fengycin A and fengycin B families, was significantly higher in these two BCAs than inactive Bacillus spp. Interaction studies with mixtures of culture filtrates of these two species revealed additive activity, suggesting that they produce similar products, which was confirmed by LC-tandem MS analyses. In in planta pre- and postinoculation trials, foliar application of culture filtrates of B. subtilis reduced lesion sizes and lesion frequencies caused by Alternaria alternata by 68 to 81%. Taken together, our studies suggest that instead of live bacteria, culture filtrates of B. subtilis and B. amyloliquefaciens can be applied either individually or in combination for controlling foliar diseases caused by Alternaria species. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  16. [In vitro susceptibility of Trichoconiella padwickii to various active ingredients used as fungicides in the cultivation of rice].

    Science.gov (United States)

    Lovato Echeverria, Alfonso D; Gutiérrez, Susana A; Carmona, Marcelo A

    The aim of this study was to evaluate in vitro the mycelial susceptibility of Trichoconiella padwickii to different active ingredients through average median concentration IC 50 calculation. Inoculum disks were seeded on bean agar at different concentrations (0.1; 1; 10; 30, 50; 100 and 1000mg/l) of various fungicides. After seven days the colony diameter was measured. The data obtained were fitted to nonlinear regression models. Susceptibility was classified using the scale proposed by Edgington. The results show that the pathogen is very sensitive to products that act on the respiratory chain (quinone outside inhibitors [QoI] and succinate dehydrogenase inhibitors [SDHI]) and cell membrane (multi-site contact activity), and moderately sensitive to those products interfering with cell division (methyl benzimidazole carbamates [MBC]), synthesis of nucleic acids (phenylamides [PA]) and osmotic signal transduction (multi-site contact activity). This work is the first record on the sensitivity of T. padwickii. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. CONTROL OF Alternaria porri (E11) CIF. AND TOXIC EFFECT OF CAPTAFOL SPRAYING IN GARLIC (Allium sativum L.) CONTROLE DE Alternaria porri (E11) Cif. E EFEITO FITOTÓXICO DE CAPTAFOL EM PULVERIZAÇÃO NA CULTURA DO ALHO (Allium sativum L.)

    OpenAIRE

    Iraídes Fernandes Carneiro; Wilson Ferreira de Oliveira

    2007-01-01

    The objective of the present work was to verify the effect of the different concentrations of the captafol fungicide (0, 50, 100, 200 and 400 g.i.a./100 l of water), in the control of Alternaria porri (E11) Cif. and their toxic effects on plants, in two cultivars of garlic (Lavinia and Centenário). The results show that, for the cultivars tested, the fungicide, in the concentrations utilized, didn’t control the pat...

  18. Visual, instrumental, mycological and mycotoxicological characterization of wheat inoculated with and protected against Alternaria spp.

    OpenAIRE

    Janić-Hajnal Elizabet P.; Belović Miona M.; Plavšić Dragana V.; Mastilović Jasna S.; Bagi Ferenc F.; Budakov Dragana B.; Kos Jovana J.

    2016-01-01

    The aim of this work was to characterize visual properties, instrumentally measured colour properties, field fungi presence and Alternaria toxins levels in wheat samples grown under conditions aimed at inhibition and stimulation of wheat infection with fungi from the Alternaria genus. Experiment was carried out on the wheat treated by fungicide and wheat inoculated by Alternaria spp., while non treated wheat was used as a control. Statistically significant ...

  19. Combination of Trichoderma harzianum endochitinase and a membrane-affecting fungicide on control of Alternaria leaf spot in transgenic broccoli plants.

    Science.gov (United States)

    Mora, A; Earle, E D

    2001-04-01

    Progeny from transgenic broccoli (cv. Green Comet) expressing a Trichoderma harzianum endochitinase gene were used to assess the interaction between endochitinase and the fungicide Bayleton in the control of Alternaria brassicicola. In vitro assays have shown synergistic effects of endochitinase and fungicides on fungal pathogens. Our study examined the in planta effects of endochitinase and Bayleton, individually and in combination. Two month old transgenic and non-transgenic plants were sprayed with ED50 levels of Bayleton and/or inoculated with an A. brassicicola spore suspension. Disease levels in non-sprayed transgenic plants were not statistically different from sprayed transgenic plants nor from sprayed non-transgenic controls. Thus endochitinase-transgenic plants alone provided a significant reduction of disease severity, comparable to the protection by fungicide on non-transgenic plants. Comparison of the expected additive and observed effects revealed no synergism between endochitinase and Bayleton (at ED50 level), and usually less than an additive effect. Some transgenic lines sprayed with fungicide at doses higher than ED50 showed resistance similar to the non-sprayed transgenic lines, again suggesting no synergistic effect. Lack of synergism may be due to incomplete digestion of the cell wall by endochitinase, so that the effect of Bayleton at the cell membrane is not enhanced.

  20. CONTROL OF Alternaria porri (E11 CIF. AND TOXIC EFFECT OF CAPTAFOL SPRAYING IN GARLIC (Allium sativum L. CONTROLE DE Alternaria porri (E11 Cif. E EFEITO FITOTÓXICO DE CAPTAFOL EM PULVERIZAÇÃO NA CULTURA DO ALHO (Allium sativum L.

    Directory of Open Access Journals (Sweden)

    Iraídes Fernandes Carneiro

    2007-09-01

    Full Text Available

    The objective of the present work was to verify the effect of the different concentrations of the captafol fungicide (0, 50, 100, 200 and 400 g.i.a./100 l of water, in the control of Alternaria porri (E11 Cif. and their toxic effects on plants, in two cultivars of garlic (Lavinia and Centenário. The results show that, for the cultivars tested, the fungicide, in the concentrations utilized, didn’t control the pathogen, and it didn’t show fitotoxicity.

    Com o objetivo de verificar o efeito do Captafol no controle de Alternaria porri (E11 Cif. na cultura do alho, e seus efeitos fitotóxicos nesta A1iácea, foi instalado um experimento nas dependências da Escola de Agronomia da Universidade Federal de Goiás, em Goiânia. O delineamento experimental foi de blocos ao acaso com parcelas subdivididas utilizando-se as cultivares Lavinia e Centenário, submetidas a pulverizações com o fungicida nas seguintes concentrações: 0, 50, 100, 200 e 400 gramas do princípio ativo por 100 litros de água. Os resultados indicam que, para as duas cultivares utilizadas, o Captafol não controlou o patógeno, nem se mostrou fitotóxico.

  1. Biocontrol Potential of Streptomyces hydrogenans strain DH16 Towards Alternaria brassicicola to Control Damping Off and Black Leaf Spot of Raphanus sativus

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    Rajesh Kumari Manhas

    2016-12-01

    Full Text Available Biocontrol agents and their bioactive metabolites provide one of the best alternatives to decrease the use of chemical pesticides. In light of this, the present investigation reports the biocontrol potential of Streptomyces hydrogenans DH16 and its metabolites towards Alternaria brassicicola, causal agent of black leaf spot and damping off of seedlings of crucifers. In vitro antibiosis of strain against pathogen revealed complete suppression of mycelial growth of pathogen, grown in potato dextrose broth supplemented with culture supernatant (20% v/v of Streptomyces hydrogenans DH16. Microscopic examination of the fungal growth showed severe morphological abnormalities in the mycelium caused by antifungal metabolites. In vivo studies showed the efficacy of streptomycete cells and culture supernatant as seed dressings to control damping off of Raphanus sativus seedlings. Treatment of pathogen infested seeds with culture supernatant (10% and streptomycete cells significantly improved seed germination (75-80% and vigour index (1167-1538. Furthermore, potential of cells and culture supernatant as foliar treatment to control black leaf spot was also evaluated. Clearly visible symptoms of disease were observed in the control plants with 66.81% disease incidence and retarded growth of root system. However, disease incidence reduced to 6.78 and 1.47% in plants treated with antagonist and its metabolites, respectively. Additionally, treatment of seeds and plants with streptomycete stimulated various growth traits of plants over uninoculated control plants in the absence of pathogen challenge. These results indicate that S. hydrogenans and its culture metabolites can be developed as biofungicides as seed dressings to control seed borne pathogens, and as sprays to control black leaf spot of crucifers.

  2. Eco-friendly PEG-based controlled release nano-formulations of Mancozeb: Synthesis and bioefficacy evaluation against phytopathogenic fungi Alternaria solani and Sclerotium rolfsii.

    Science.gov (United States)

    Majumder, Sujan; Shakil, Najam A; Kumar, Jitendra; Banerjee, Tirthankar; Sinha, Parimal; Singh, Braj B; Garg, Parul

    2016-12-01

    Controlled release (CR) nano-formulations of Mancozeb (manganese-zinc double salt of N,N-bisdithiocarbamic acid), a protective fungicide, have been prepared using laboratory-synthesized poly(ethylene glycols) (PEGs)-based functionalized amphiphilic copolymers without using any surfactants or external additives. The release kinetics of the developed Mancozeb CR formulations were studied and compared with that of commercially available 42% suspension concentrate and 75% wettable powder. Maximum amount of Mancozeb was released on 42nd day for PEG-600 and octyl chain, PEG-1000 and octyl chain, and PEG-600 and hexadecyl chain, on 35th day for PEG-1000 and hexadecyl chain, on 28th day for PEG-1500 and octyl chain, PEG-2000 and octyl chain, PEG-1500 and hexadecyl chain, and PEG-2000 and hexadecyl chain in comparison to both commercial formulations (15th day). The diffusion exponent (n value) of Mancozeb in water ranged from 0.42 to 0.62 in tested formulations. The half-release (t 1/2 ) values ranged from 17.35 to 35.14 days, and the period of optimum availability of Mancozeb ranged from 18.54 to 35.42 days. Further, the in vitro bioefficacy evaluation of developed formulations was done against plant pathogenic fungi Alternaria solani and Sclerotium rolfsii by poison food technique. Effective dose for 50% inhibition in mgL -1 (ED 50 ) values of developed formulations varied from 1.31 to 2.79 mg L -1 for A. solani, and 1.60 to 3.14 mg L -1 for S. rolfsii. The present methodology is simple, economical, and eco-friendly for the development of environment-friendly CR formulations of Mancozeb. These formulations can be used to optimize the release of Mancozeb to achieve disease control for the desired period depending upon the matrix of the polymer used. Importantly, the maximum amount of active ingredient remains available for a reasonable period after application. In addition, the developed CR formulations were found to be suitable for fungicidal applications, allowing

  3. Visual, instrumental, mycological and mycotoxicological characterization of wheat inoculated with and protected against Alternaria spp.

    Directory of Open Access Journals (Sweden)

    Janić-Hajnal Elizabet P.

    2016-01-01

    Full Text Available The aim of this work was to characterize visual properties, instrumentally measured colour properties, field fungi presence and Alternaria toxins levels in wheat samples grown under conditions aimed at inhibition and stimulation of wheat infection with fungi from the Alternaria genus. Experiment was carried out on the wheat treated by fungicide and wheat inoculated by Alternaria spp., while non treated wheat was used as a control. Statistically significant difference was observed between all three treatments using visual scale. Protected wheat samples were significantly different from other samples in terms of all measured colour parameters while inoculated and control wheat samples were significantly different in terms of lightness and dominant wavelength. Identification of field fungi in the all examined wheat samples showed that the dominant mycotoxigenic fungus was Alternaria spp., followed by Fusarium spp. The content of Alternaria toxins in samples of wheat hulls and dehulled kernels point out at higher concentrations of Alternaria toxins in hulls than in dehulled kernels. [Projekat Ministarstvo nauke Republike Srbije, br. III 46001 i br. III 46005

  4. Toxigenic Alternaria species from Argentinean blueberries.

    Science.gov (United States)

    Greco, M; Patriarca, A; Terminiello, L; Fernández Pinto, V; Pose, G

    2012-03-15

    Blueberries are traditionally consumed in North America, some European countries and Japan. In Argentina, the blueberry crop is profitable because production starts in November, when the northern hemisphere lacks fresh fruit. Fungal contaminants can grow and produce mycotoxins in fresh fruit. The aims of this work were to identify the main genera of the mycobiota of blueberries grown in Argentina and to determine the toxicogenic potential, pathogenicity and host specificity of the species isolated. The genus Alternaria was the main component of the blueberry mycobiota (95%); minor proportions of Phoma spp. (4%) and Penicillium spp. (1%) were also isolated. According to their sporulation patterns, 127 Alternaria isolates belonged to the Alternaria tenuissima species-group, 5 to the Alternaria alternata species-group and 2 to the Alternaria arborescens species-group. The last mentioned species-group was not isolated at 5°C. Of the 134 isolates, 61% were toxicogenic in autoclaved rice; 97% of these produced alternariol (AOH) in a range from 0.14 to 119.18 mg/kg, 95% produced alternariol methylether (AME) in a range from 1.23 to 901.74 mg/kg and 65% produced tenuazonic acid (TA) in a range from 0.13 to 2778 mg/kg. Fifty two isolates co-produced the three mycotoxins. According to the size of the lesion that they caused on blueberries, the isolates were classified as slightly pathogenic, moderately pathogenic and very pathogenic. No significant differences in pathogenicity were found on different blueberry varieties. In this work, high incidence and toxicogenic potential of the Alternaria isolates from blueberries were demonstrated. Thus, more studies should be done to evaluate the health risk posed by the presence of the Alternaria toxins in blueberries and in the manufactured by-products. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Fungi of genus Alternaria occurring on tomato

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    Joanna Marcinkowska

    2013-12-01

    Full Text Available Tomato early blight in central Poland was caused by Alternaria solani (A. porri f. sp., solani and A. alernata (A. tenuis. A. alternata was isolated more often than A. solani. All isolates of A. solani in controlled conditions killed tomato seedlings, while pathogenic isolates of A. alternata caused only slight seedling blight. In greenhouse tests A. solani proved to be strongly pathogenic for leaves and stems of tomato but A. alternata was weakly pathogenic. The latter species attacked only injured fruits while, A. solanicould penetrate through undamaged peel of fruits. Both of these species caused the same type of symptoms; the differences consisted only in intensification of disease symptoms. During 1974 and 1975 field tomatoes were moderately attacked by early blight. Thebest development of this disease occurred by the turn of August and September. Determinate variety 'New Yorker' was distinguished by more severe infection of stem parts of tomato whereas the fruits of a stock variety 'Apollo' were more strongly attacked.

  6. Large-spored Alternaria pathogens in section Porri disentangled

    NARCIS (Netherlands)

    Woudenberg, J H C; Truter, M; Groenewald, J Z; Crous, P W

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens

  7. Large-spored Alternaria pathogens in section Porri disentangled

    NARCIS (Netherlands)

    Woudenberg, J.H.C.; Truter, M.; Groenewald, J.Z.; Crous, P.W.

    2014-01-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens

  8. Infectopyrone, a potential mycotoxin from Alternaria infectoria

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Perry, N.B.; Andersen, Birgitte

    2003-01-01

    A new metabolite, infectopyrone (1), has been isolated from the filamentous fungus Alternaria infectoria. The structure of 1 was elucidated by analysis of 2D NMR spectroscopic data. Compound 1 is an alpha-pyrone resembling known toxins, and is a useful phenotaxonomic marker for the A. infectoria ...

  9. New antitumour fungal metabolites from Alternaria porri.

    Science.gov (United States)

    Phuwapraisirisan, Preecha; Rangsan, Jakaphan; Siripong, Pongpan; Tip-Pyang, Santi

    2009-01-01

    Chemical investigation of the onion pathogenic fungus Alternaria porri resulted in the isolation of two new phthalides named zinnimide (2) and deprenylzinnimide (8), along with a new bianthraquinone, alterporriol F (10). The structures of the new metabolites were characterised by spectroscopic analysis and chemical degradation. Of the new compounds isolated, alterporriol F was highly cytotoxic towards HeLa and KB cells, with IC(50) values of 6.5 and 7.0 microg mL(-1).

  10. Large-spored Alternaria pathogens in section Porri disentangled

    OpenAIRE

    Woudenberg, J.H.C.; Truter, M.; Groenewald, J.Z.; Crous, P.W.

    2014-01-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological an...

  11. Differentiation of Alternaria infectoria and Alternaria alternata based on morphology, metabolite profiles, and cultural characteristics

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Thrane, Ulf

    1996-01-01

    Some small-spored species belonging to the genus Alternaria Nees have been studied according to their chemical, morphological, and cultural characteristics. A data matrix was constructed based on a combination of characters. Cluster analysis of the combined data set showed good resolution of two...

  12. Comparative Genomics of Pathogens Causing Brown Spot Disease of Tobacco: Alternaria longipes and Alternaria alternata.

    Directory of Open Access Journals (Sweden)

    Yujie Hou

    Full Text Available The genus Alternaria is a group of infectious/contagious pathogenic fungi that not only invade a wide range of crops but also induce severe allergic reactions in a part of the human population. In this study, two strains Alternaria longipes cx1 and Alternaria alternata cx2 were isolated from different brown spot lesions on infected tobacco leaves. Their complete genomes were sequenced, de novo assembled, and comparatively analyzed. Phylogenetic analysis revealed that A. longipes cx1 and A. alternata cx2 diverged 3.3 million years ago, indicating a recent event of speciation. Seventeen non-ribosomal peptide synthetase (NRPS genes and 13 polyketide synthase (PKS genes in A. longipes cx1 and 13 NRPS genes and 12 PKS genes in A. alternata cx2 were identified in these two strains. Some of these genes were predicted to participate in the synthesis of non-host specific toxins (non-HSTs, such as tenuazonic acid (TeA, alternariol (AOH and alternariol monomethyl ether (AME. By comparative genome analysis, we uncovered that A. longipes cx1 had more genes putatively involved in pathogen-plant interaction, more carbohydrate-degrading enzymes and more secreted proteins than A. alternata cx2. In summary, our results demonstrate the genomic distinction between A. longipes cx1 and A. altenata cx2. They will not only improve the understanding of the phylogenetic relationship among genus Alternaria, but more importantly provide valuable genomic resources for the investigation of plant-pathogen interaction.

  13. Discovering Novel Alternaria solani Succinate Dehydrogenase Inhibitors by in Silico Modeling and Virtual Screening Strategies to Combat Early Blight

    Directory of Open Access Journals (Sweden)

    Sehrish Iftikhar

    2017-11-01

    Full Text Available Alternaria blight is an important foliage disease caused by Alternaria solani. The enzyme Succinate dehydrogenase (SDH is a potential drug target because of its role in tricarboxylic acid cycle. Hence targeting Alternaria solani SDH enzyme could be efficient tool to design novel fungicides against A. solani. We employed computational methodologies to design new SDH inhibitors using homology modeling; pharmacophore modeling and structure based virtual screening. The three dimensional SDH model showed good stereo-chemical and structural properties. Based on virtual screening results twelve commercially available compounds were purchased and tested in vitro and in vivo. The compounds were found to inhibit mycelial growth of A. solani. Moreover in vitro trials showed that inhibitory effects were enhanced with increase in concentrations. Similarly increased disease control was observed in pre-treated potato tubers. Hence the applied in silico strategy led us to identify novel fungicides.

  14. Marginal scorch caused by Alternaria alternata on Purple-Caitai ...

    African Journals Online (AJOL)

    Marginal scorch caused by Alternaria alternata on Purple-Caitai (Brassia campestris L. ssp. chinensis L.var. utilis Tsen et Lee) in China. Qijun Nie, Zhongjiu Jiao, Fengjuan Zhu, Zhenbiao Jiao, Xiaohui Deng, Zhengming Qiu, Jinping Wu ...

  15. Alternaria spp.: from general saprophyte to specific parasite

    NARCIS (Netherlands)

    Thomma, B.P.H.J.

    2003-01-01

    Alternaria species are mainly saprophytic fungi. However, some species have acquired pathogenic capacities collectively causing disease over a broad host range. This review summarizes the knowledge on pathogenic strategies employed by the fungus to plunder the host. Furthermore, strategies employed

  16. Large-spored Alternaria pathogens in section Porri disentangled.

    Science.gov (United States)

    Woudenberg, J H C; Truter, M; Groenewald, J Z; Crous, P W

    2014-09-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological and cultural studies, forms the basis for species recognition in sect. Porri. Our data reveal 63 species, of which 10 are newly described in sect. Porri, and 27 species names are synonymised. The three known Alternaria pathogens causing early blight on tomato all cluster in one clade, and are synonymised under the older name, A. linariae. Alternaria protenta, a species formerly only known as pathogen on Helianthus annuus, is also reported to cause early blight of potato, together with A. solani and A. grandis. Two clades with isolates causing purple blotch of onion are confirmed as A. allii and A. porri, but the two species cannot adequately be distinguished based on the number of beaks and branches as suggested previously. This is also found among the pathogens of Passifloraceae, which are reduced from four to three species. In addition to the known pathogen of sweet potato, A. bataticola, three more species are delineated of which two are newly described. A new Alternaria section is also described, comprising two large-spored Alternaria species with concatenate conidia.

  17. Alternaria Leaf Spot on Mealycup Sage (Salvia farinacea Benth.) Caused by Alternaria alternata (Fr.) Keissler

    OpenAIRE

    Hiromitsu, NEGISHI; Kazuo, SUYAMA; Faculty of Agriculture,Tokyo University of Agriculture; Faculty of Agriculture,Tokyo University of Agriculture

    2002-01-01

    In June 1995, a disease causing round to irregular-shaped, water-soaked, brown to blackish brown spots on mealycup sage (Salvia farinacea Benth.) was found in Atsugi-shi, Kanagawa Prefecture, Japan. The symptoms were seen only on leaves, not on neither flower petals or stems. The disease was also found in Setagaya-ku, Tokyo, Memambetsu-cho, Hokkaido and Shimoda-shi and Matsuzaki-cho, Shizuoka. An Alternaria sp. was frequently isolated from these diseased plants. The isolates were severely pat...

  18. Sensivity of Jordanian Isolates of Alternaria solani to Manchotane

    Directory of Open Access Journals (Sweden)

    K.I. Al-Mughrabi

    2004-04-01

    Full Text Available Early blight of potato, caused by Alternaria solani, poses a significant risk to potato crops worldwide. Fifty A. solani isolates representing a population were collected from the Jordan Valley, purified, and tested for their sensitivity to the fungicide mancothane. The isolates were tested against a series of concentrations of 0, 0.1, 1, 10, 100, and 1000 mg mancothane ml-1 in 5% sodium dodecyl sulfate (SDS. Some A. solani isolates tolerated up to 1000 mg mancothane ml-1. Isolates treated with the various concentrations were divided into 5 groups based on the percentage of A. solani growth achieved despite treatment: group 1 comprised isolates with mycelial growth of 0.1– 20.9%; group 2, 21–40.9%; group 3, 41–60.9%; group 4, 61–80.9%; and group 5, 81–100%. Ninety-seven percent of all isolates grew at 0.1 mg mancothane ml-1, 94% at 1 mg ml-1, 86% at 10 mg ml-1, 66% at 100 mg ml-1, and 16% at 1000 mg ml-1. Isolates appeared to be distributed normally at 10 mg mancothane ml-1. Eight isolates were highly resistant to mancothane and grew even at the highest test concentration. An A. solani population collected from potato fields in the Jordan Valley exhibited a moderate level of resistance to mancothane. Growers should be careful and vigilant when using this fungicide to control early blight.

  19. Toxigenic profile and AFLP variability of Alternaria alternata and Alternaria infectoria occurring on wheat

    Directory of Open Access Journals (Sweden)

    María Silvina Oviedo

    2013-01-01

    Full Text Available The objectives of this study were to evaluate the ability to produce alternariol (AOH, alternariol monomethyl ether (AME and tenuazonic acid (TA by A. alternata and A. infectoria strains recovered from wheat kernels obtained from one of the main production area in Argentina; to confirm using AFLPs molecular markers the identify of the isolates up to species level, and to evaluate the intra and inter-specific genetic diversity of these two Alternaria species. Among all the Alternaria strains tested (254, 84% of them were able to produce mycotoxins. The most frequent profile of toxin production found was the co-production of AOH and AME in both species tested. TA was only produced by strains of A. alternata. Amplified fragment polymorphism (AFLPs analysis was applied to a set of 89 isolates of Alternaria spp (40 were A. infectoria and 49 were A. alternata in order to confirm the morphological identification. The results showed that AFLPs are powerful diagnostic tool for differentiating between A. alternata and A. infectoria. Indeed, in the current study the outgroup strains, A. tenuissima was consistently classified. Characteristic polymorphic bands separated these two species regardless of the primer combination used. Related to intraspecific variability, A. alternata and A. infectoria isolates evaluated seemed to form and homogeneous group with a high degree of similarity among the isolates within each species. However, there was more scoreable polymorphism within A. alternata than within A. infectoria isolates. There was a concordance between morphological identification and separation up to species level using molecular markers. Clear polymorphism both within and between species showed that AFLP can be used to asses genetic variation in A. alternata and A. infectoria. The most important finding of the present study was the report on AOH and AME production by A. infectoria strains isolated from wheat kernels in Argentina on a semisynthetic

  20. Alternaria leaf spot in Michigan and fungicide sensitivity issues

    Science.gov (United States)

    Since 2010 there has been an increase in identification of Alternaria leaf spot on sugar beet in Michigan and other growing regions in the US and Canada. In 2016, the disease was severe enough to cause economic losses in the Michigan growing region. Michigan isolates from sugar beet were examined ...

  1. Alternaria infectoria phaeohyphomycosis in a renal transplant patient.

    NARCIS (Netherlands)

    Nulens, E.; Laere, E. De; Vandevelde, H.; Hilbrands, L.B.; Rijs, A.J.M.M.; Melchers, W.J.G.; Verweij, P.E.

    2006-01-01

    A male renal transplant patient developed a tumor on the dorsum of his right hand. After excision, histological examination of the tumor showed hyphal structures, but growth developed very slowly. Therapy consisted of surgery alone. A definitive identification of Alternaria infectoria was only

  2. Alternaria Toxins: Potential Virulence Factors and Genes Related to Pathogenesis

    Directory of Open Access Journals (Sweden)

    Mukesh Meena

    2017-08-01

    Full Text Available Alternaria is an important fungus to study due to their different life style from saprophytes to endophytes and a very successful fungal pathogen that causes diseases to a number of economically important crops. Alternaria species have been well-characterized for the production of different host-specific toxins (HSTs and non-host specific toxins (nHSTs which depend upon their physiological and morphological stages. The pathogenicity of Alternaria species depends on host susceptibility or resistance as well as quantitative production of HSTs and nHSTs. These toxins are chemically low molecular weight secondary metabolites (SMs. The effects of toxins are mainly on different parts of cells like mitochondria, chloroplast, plasma membrane, Golgi complex, nucleus, etc. Alternaria species produce several nHSTs such as brefeldin A, tenuazonic acid, tentoxin, and zinniol. HSTs that act in very low concentrations affect only certain plant varieties or genotype and play a role in determining the host range of specificity of plant pathogens. The commonly known HSTs are AAL-, AK-, AM-, AF-, ACR-, and ACT-toxins which are named by their host specificity and these toxins are classified into different family groups. The HSTs are differentiated on the basis of bio-statistical and other molecular analyses. All these toxins have different mode of action, biochemical reactions and signaling mechanisms to cause diseases. Different species of Alternaria produced toxins which reveal its biochemical and genetic effects on itself as well as on its host cells tissues. The genes responsible for the production of HSTs are found on the conditionally dispensable chromosomes (CDCs which have been well characterized. Different bio-statistical methods like basic local alignment search tool (BLAST data analysis used for the annotation of gene prediction, pathogenicity-related genes may provide surprising knowledge in present and future.

  3. Epidemiology of dark leaf spot caused by Alternaria brassicicola and Alternaria brassicae in organic seed production of cauliflower

    NARCIS (Netherlands)

    Köhl, J.; Tongeren, van C.A.M.; Groenenboom-de Haas, B.H.; Hoof, van R.A.; Driessen, R.; Heijden, van der L.

    2010-01-01

    In organic seed production of Brassica vegetables, infections by Alternaria brassicicola and A. brassicae can cause severe losses of yield and seed quality. Four field experiments with or without artificial inoculation with A. brassicicola were conducted in organically managed seed-production crops

  4. Emerging Fusarium and Alternaria Mycotoxins: Occurrence, Toxicity and Toxicokinetics

    Directory of Open Access Journals (Sweden)

    Sophie Fraeyman

    2017-07-01

    Full Text Available Emerging Fusarium and Alternaria mycotoxins gain more and more interest due to their frequent contamination of food and feed, although in vivo toxicity and toxicokinetic data are limited. Whereas the Fusarium mycotoxins beauvericin, moniliformin and enniatins particularly contaminate grain and grain-based products, Alternaria mycotoxins are also detected in fruits, vegetables and wines. Although contamination levels are usually low (µg/kg range, higher contamination levels of enniatins and tenuazonic acid may occasionally occur. In vitro studies suggest genotoxic effects of enniatins A, A1 and B1, beauvericin, moniliformin, alternariol, alternariol monomethyl ether, altertoxins and stemphyltoxin-III. Furthermore, in vitro studies suggest immunomodulating effects of most emerging toxins and a reproductive health hazard of alternariol, beauvericin and enniatin B. More in vivo toxicity data on the individual and combined effects of these contaminants on reproductive and immune system in both humans and animals is needed to update the risk evaluation by the European Food Safety Authority. Taking into account new occurrence data for tenuazonic acid, the complete oral bioavailability, the low total body clearance in pigs and broiler chickens and the limited toxicity data, a health risk cannot be completely excluded. Besides, some less known Alternaria toxins, especially the genotoxic altertoxins and stemphyltoxin III, should be incorporated in risk evaluation as well.

  5. Alternaria Mycotoxins in Food and Feed: An Overview

    Directory of Open Access Journals (Sweden)

    Laura Escrivá

    2017-01-01

    Full Text Available Alternaria is one of the major mycotoxigenic fungal genera with more than 70 reported metabolites. Alternaria mycotoxins showed notably toxicity, such as mutagenicity, carcinogenicity, induction of DNA strand break, sphingolipid metabolism disruption, or inhibition of enzymes activity and photophosphorylation. This review reports on the toxicity, stability, metabolism, current analytical methods, and prevalence of Alternaria mycotoxins in food and feed through the most recent published research. Half of the publications were focused on fruits, vegetables, and derived products—mainly tomato and apples—while cereals and cereal by-products represented 38%. The most studied compounds were alternariol, alternariol methyl ether, tentoxin, and tenuazonic acid, but altenuene, altertoxins (I, II, and III, and macrosporin have been gaining importance in recent years. Solid-liquid extraction (50% with acetonitrile or ethyl acetate was the most common extraction methodology, followed by QuEChERS and dilution-direct injection (both 14%. High- and ultraperformance liquid chromatography coupled with tandem mass spectrometry was the predominant determination technique (80%. The highest levels of alternariol and alternariol methyl ether were found in lentils, oilseeds, tomatoes, carrots, juices, wines, and cereals. Tenuazonic acid highest levels were detected in cereals followed by beer, while alternariol, alternariol methyl ether, tenuazonic acid, and tentoxin were found in legumes, nuts, and oilseeds.

  6. Pathogenic, morphological and molecular characteristics of Alternaria Tenuissima from soybean

    Directory of Open Access Journals (Sweden)

    Jasnić Stevan M.

    2011-01-01

    Full Text Available During 2008 and 2009 phytopathological isolations were done from soybean plants and seed samples from several localities in Serbia. A total of 19 isolates of Alternaria spp. were isolated, 13 from the seed and 3 from both leaf and stem. In order to determine and characterize isolates, cultural, morphological, molecular and pathogenic characteristics were thoroughly investigated. The slowest growth of the examined isolates was noted on Malt agar (MA with average colony diameter of 42.9 mm after 7 days of incubation. On other two media (V8 and PCA, colony growth was uniform and faster, with average diameter of 66.8 mm and 66.1 mm, respectively. Isolates of fungi form unbranched or poorly branched conidial chains on short unbranched conidiophores. Conidia are dark in colour, multicellular with transverse and longitudinal septae. They are of different size regarding the place of formation in the chain. Based on these characteristics, the tested isolates were determined as Alternaria tenuissima. Molecular identification with sequencing of ITS1-5.8S-ITS2 rDNA verified that investigated isolates belong to Alternaria tenuissima group. Pathogenicity test proved that all isolates were more or less virulent to soybean seed (12.5% to 40% of rotten seeds, while pathogenicity on plants was poorly expressed.

  7. THE USE OF AZADIRACHTA INDICA EXTRACT TO DECREASE OF ALTERNARIA PORRI DISEASE ON ONION

    Directory of Open Access Journals (Sweden)

    Loso Winarto

    2013-01-01

    Full Text Available Purple spot caused by Alternaria porri a major disease in the onion crop in the world. The disease is also widespread in the onion crop in Indonesia. This research aim was to know the effect of mimba leaf (Azadirachta indica extract concentration to decrease of Alternaria porri on onion (Allium ascalonicum L.This research conducted at Research Garden of the Center of Agricultural Technology Assessment of North Sumatra Province, from October 2010 until January 2011.The research used non factorial Block Randomized Design (BRD and four replications.The treatment consisted of six levels of Azadirachta indica which is dissolved in one litre of water each treatment. The number of replication are four each treatment. Treatment applied were 0 g plot-1 (control; 100 g plot-1; ; 150 g plot-1 ; 200 g plot-1 ; 250 g plot-1 ; 300 g plot-1 . The results showed that mimba leaf extract significantly affect the intensity of the purple spot disease and onion production.

  8. Characterisation of Alternaria species-groups associated with core rot of apples in South Africa

    DEFF Research Database (Denmark)

    Serdani, M.; Kang, J.C.; Andersen, Birgitte

    2002-01-01

    Alternaria core rot of red apple cultivars is a serious post-harvest disease in South Africa. Thirty isolates of Alternaria spp. previously isolated from apple, together with reference isolates of A. alternata and A. infectoria, were characterised and grouped according to their sporulation patter...

  9. Alternaria and Fusarium in Norwegian grains of reduced quality - a matched pair sample study

    DEFF Research Database (Denmark)

    Kosiak, B.; Torp, M.; Skjerve, E.

    2004-01-01

    The occurrence and geographic distribution of species belonging to the genera Alternaria and Fusarium in grains of reduced and of acceptable quality were studied post-harvest in 1997 and 1998. A total of 260 grain samples of wheat, barley and oats was analysed. The distribution of Alternaria and ...

  10. Reinvestigation of structure of porritoxin, a phytotoxin of Alternaria porri.

    Science.gov (United States)

    Horiuchi, Masayuki; Maoka, Takashi; Iwase, Noriyasu; Ohnishi, Keiichiro

    2002-08-01

    The structure of porritoxin, a phytotoxin of Alternaria porri, was reinvestigated by detailed 2D NMR analysis including (1)H-(13)C and (1)H-(15)N HMBC experiments. The structure of porritoxin was determined to be 2-(2'-hydroxyethyl)-4-methoxy-5-methyl-6-(3' '-methyl-2' '-butenyloxy)-2,3-dihydro-1H-isoindol-1-one (1). Thus our previous proposed structure, 8-(3',3'-dimethylallyloxy)-10-methoxy-9-methyl-1H-3,4-dihydro-2,5-benzoxazocin-6(5H)-one (2), is incorrect.

  11. Alternaria resistance of Brassicae campestris L. improved by induced mutations

    International Nuclear Information System (INIS)

    Das, M.L.; Rahman, A.

    1989-01-01

    Full text: Seeds of 'YS 52', a cultivar susceptible to Alternaria brassicae (Berk.) Sacc., were exposed to gamma rays (30-90 kR). Eight more resistant mutants were selected in M3 and subjected to further field evaluation. The best mutant '17-5-83' appeared resistant and gave 44% higher yield than the parent, mutant '70-7-82' was found to be moderately resistant and gave a yield 21% higher than the parent. The yield increases seem to be connected with plant architecture changes. (author)

  12. Discovering novel Alternaria solani succinate dehydrogenase inhibitors by in silico modeling and virtual screening strategies to combat early blight

    NARCIS (Netherlands)

    Iftikhar, Sehrish; Shahid, Ahmad A.; Halim, Sobia A.; Wolters, Pieter J.; Vleeshouwers, Vivianne G.A.A.; Khan, Ajmal; Al-Harrasi, Ahmed; Ahmad, Shahbaz

    2017-01-01

    Alternaria blight is an important foliage disease caused by Alternaria solani. The enzyme Succinate dehydrogenase (SDH) is a potential drug target because of its role in tricarboxylic acid cycle. Hence targeting Alternaria solani SDH enzyme could be efficient tool to design novel fungicides against

  13. Inhibition of spore germination of Alternaria tenuis by sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Couey, H.M.

    1962-08-01

    As a part of a continuing study of SO/sub 2/ fumigation of table grapes, the effect of SO/sub 2/ on spores of an isolate of A. tenuis Auct. causing decay of table grapes was determined. The amount of SO/sub 2/ required to inhibit completely spore germination depended on availability of moisture and the temperature. At 20/sup 0/C, wet spores required 20-min exposure to 100 ppm SO/sub 2/ to prevent germination, but spores equilibrated at 90% relative humidity (RH) required 10-min exposure to 1000 ppm SO/sub 2/. Dry spores at 60% RH were unaffected by a 20-min exposure to 4000 ppm SO/sub 2/. Increasing the temperature in the range 5-20/sup 0/C increased effectiveness of the SO/sub 2/ treatment. A comparison of Alternaria with Botrytis cinerea Fr. (studied earlier) showed that wet spores of these organisms were about equally sensitive to SO/sub 2/, but that dry Alternaria spores were more resistant to SO/sub 2/ than dry Botrytis spores under comparable conditions.

  14. Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs.

    Science.gov (United States)

    Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M A; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E; Casadevall, Arturo; Gonçalves, Teresa

    2015-12-28

    The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  15. Yield loss assessment due to Alternaria blight and its management in linseed.

    Science.gov (United States)

    Singh, R B; Singh, H K; Parmar, Arpita

    2014-04-01

    Field experiments were conducted during 2010-11 and 2011-12 to assess the yield losses due to Alternaria blight disease caused by Alternaria lini and A. linicola in recently released cultivars and their management with the integration of Trichoderma viride, fungicides and plant extract. Disease severity on leaves varied from 41.07% (Parvati) to 65.01% (Chambal) while bud damage per cent ranged between 23.56% (Shekhar) to 46.12% (T-397), respectively in different cultivars. Maximum yield loss of 58.44% was recorded in cultivar Neelum followed by Parvati (55.56%), Meera (55.56%) and Chambal (51.72%), respectively while minimum loss was recorded in Kiran (19.99%) and Jeevan (22.22%). Minimum mean disease severity (19.47%) with maximum disease control (69.74%) was recorded with the treatment: seed treatment (ST) with vitavax power (2 g kg(-1) seed) + 2 foliar sprays (FS) of Saaf (a mixture of carbendazim+mancozeb) 0.2% followed by ST with Trichoderma viride (4g kg(-1) seed) + 2 FS of Saaf (0.2%). Minimum bud damage (13.75%) with maximum control (60.94%) was recorded with treatment of ST with vitavax power+2 FS of propiconazole (0.2%). Maximum mean seed yield (1440 kg ha(-1)) with maximum net return (Rs. 15352/ha) and benefit cost ratio (1:11.04) was obtained with treatment ST with vitavax power + 2 FS of Neem leaf extract followed by treatment ST with vitavax power+2 FS of Saaf (1378 kg ha(-1)).

  16. [Determination of the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato].

    Science.gov (United States)

    Benavidez Rozo, Martha Elizabeth; Patriarca, Andrea; Cabrera, Gabriela; Fernández Pinto, Virginia E

    2014-01-01

    Many Alternaria species have been studied for their ability to produce bioactive secondary metabolites, such as tentoxin (TEN), some of which have toxic properties. The main food contaminant toxins are tenuazonic acid, alternariol (AOH), alternariol monomethyl ether (AME), altenuene, and altertoxins i, ii and iii. To determine the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato for their chemotaxonomic classification. The profiles of secondary metabolites were determined by HPLC MS. The Alternaria isolates obtained from spoiled tomatoes belong, according to their morphological characteristics, to the species groups Alternaria alternata, Alternaria tenuissima and Alternaria arborescens, with A. tenuissima being the most frequent. The most frequent profiles of secondary metabolites belonging to the species groups A. alternata (AOH, AME, TEN), A. tenuissima (AOH, AME, TEN, tenuazonic acid) and A. arborescens (AOH, AME, TEN, tenuazonic acid) were determined, with some isolates of the latter being able to synthesize AAL toxins. Secondary metabolite profiles are a useful tool for the differentiation of small spored Alternaria isolates not easily identifiable by their morphological characteristics. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  17. Phylogenetic, Morphological, and Pathogenic Characterization of Alternaria Species Associated with Fruit Rot of Blueberry in California.

    Science.gov (United States)

    Zhu, X Q; Xiao, C L

    2015-12-01

    Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were to characterize Alternaria isolates using morphological and molecular approaches and test their pathogenicity to blueberry fruit. Alternaria spp. isolates were collected from decayed blueberry fruit in the Central Valley of California during 2012 and 2013. In total, 283 isolates were obtained and five species of Alternaria, including Alternaria alternata, A. tenuissima, A. arborescens, A. infectoria, and A. rosae, were identified based on DNA sequences of the plasma membrane ATPase, Alt a1 and Calmodulin gene regions in combination with morphological characters of the culture and sporulation. Of the 283 isolates, 61.5% were identified as A. alternata, 32.9% were A. arborescens, 5.0% were A. tenuissima, and only one isolate of A. infectoria and one isolate of A. rosae were found. These fungi were able to grow at temperatures from 0 to 35°C, and mycelial growth was arrested at 40°C. Optimal radial growth occurred between 20 to 30°C. Pathogenicity tests showed that all five Alternaria spp. were pathogenic on blueberry fruit at 0, 4, and 20°C, with A. alternata, A. arborescens, and A. tenuissima being the most virulent species, followed by A. infectoria and A. rosae. Previously A. tenuissima has been reported to be the primary cause of Alternaria fruit rot of blueberry worldwide. Our results indicated that the species composition of Alternaria responsible for Alternaria fruit rot in blueberry can be dependent on geographical region. A. alternata, A. arborescens, A. infectoria, and A. rosae are reported for the first time on blueberry in California. This is also the first report of A. infectoria and A. rosae infecting blueberry fruit.

  18. Characterization of Alternaria strains from Argentinean blueberry, tomato, walnut and wheat

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Nielsen, Kristian Fog; Fernández Pinto, Virginia

    2015-01-01

    of the chemical potential. Four strains belonged to the Alternaria infectoria sp.-grp., 6 to the Alternaria arborescens sp.-grp., 6 showed a sporulation pattern similar to that of “M” according to Simmons, 1 to that of Alternaria vaccinii, and the remaining 70 constituted a diverse group belonging...... sporulation pattern “M” were only isolated from tomatoes. Otherwise, no clear association between substrate and identity could be found. The analyses in the study show that at least 75% of the Argentinean strains are able to produce potential mycotoxins....

  19. The major Alternaria alternata allergen, Alt a 1: A reliable and specific marker of fungal contamination in citrus fruits.

    Science.gov (United States)

    Gabriel, M F; Uriel, N; Teifoori, F; Postigo, I; Suñén, E; Martínez, J

    2017-09-18

    The ubiquitously present spores of Alternaria alternata can spoil a wide variety of foodstuffs, including a variety of fruits belonging to the Citrus genus. The major allergenic protein of A. alternata, Alt a 1, is a species-specific molecular marker that has been strongly associated with allergenicity and phytopathogenicity of this fungal species. This study aimed to evaluate the potential of the detection of Alt a 1 as a reliable indicator of A. alternata contamination in citrus fruits. To accomplish this aim, sixty oranges were artificially infected with a spore suspension of A. alternata. Internal fruit material was collected at different incubation times (one, two and three weeks after the fungal inoculation) and used for both total RNA extraction and protein extraction. Alt a 1 detection was then performed by polymerase chain reaction (PCR) amplification using Alt a 1 specific primers and by enzyme-linked immunosorbent assay (ELISA). The experimental model presented in this work was effective to simulate the typical Alternaria black rot phenotype and its progression. Although both PCR and ELISA techniques have been successfully carried out for detecting Alt a 1 allergen in A. alternata infected oranges, the PCR method was found to be more sensitive than ELISA. Nevertheless, ELISA results were highly valuable to demonstrate that considerable amounts of Alt a 1 are produced during A. alternata fruit infection process, corroborating the recently proposed hypothesis that this protein plays a role in the pathogenicity and virulence of Alternaria species. Such evidence suggests that the detection of Alt a 1 by PCR-based assay may be used as a specific indicator of the presence of pathogenic and allergenic fungal species, A. alternata, in fruits. This knowledge can be employed to control the fungal infection and mitigate agricultural losses as well as human exposure to A. alternata allergens and toxins. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea

    Directory of Open Access Journals (Sweden)

    Jian Xin Deng

    2015-03-01

    Full Text Available In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea.

  1. Monograph on alternaria diseases of crucifers. Technical bulletin No. 1994-6E

    Energy Technology Data Exchange (ETDEWEB)

    Verma, P R

    1994-12-31

    The brassicas include an important group of oilseed crops such as canola and commercial vegetables such as cabbage and broccoli. Infection by species of the fungus Alternaria causes severe yield losses to those crops. This document compiles the most recent information on fundamental and applied knowledge of Alternaria species infecting Brassicaceae crops and weeds. It includes a review of the symptoms, geographical distribution, yield losses, and disease assessment methods of infections from the four most widely distributed species of Alternaria; information on the characteristics of the pathogen, its host range, disease cycle, process of infection, epidemiology, fine structures and electron microscopy, resistance, and phytotoxins; and techniques for disease infection and management. The document concludes with an evaluation of future strategies and priorities in the management of Alternaria diseases.

  2. [Expression of plant antimicrobial peptide pro-SmAMP2 gene increases resistance of transgenic potato plants to Alternaria and Fusarium pathogens].

    Science.gov (United States)

    Vetchinkina, E M; Komakhina, V V; Vysotskii, D A; Zaitsev, D V; Smirnov, A N; Babakov, A V; Komakhin, R A

    2016-09-01

    The chickweed (Stellaria media L.) pro-SmAMP2 gene encodes the hevein-like peptides that have in vitro antimicrobial activity against certain harmful microorganisms. These peptides play an important role in protecting the chickweed plants from infection, and the pro-SmAMP2 gene was previously used to protect transgenic tobacco and Arabidopsis plants from phytopathogens. In this study, the pro-SmAMP2 gene under control of viral CaMV35S promoter or under control of its own pro-SmAMP2 promoter was transformed into cultivated potato plants of two cultivars, differing in the resistance to Alternaria: Yubiley Zhukova (resistant) and Skoroplodny (susceptible). With the help of quantitative real-time PCR, it was demonstrated that transgenic potato plants expressed the pro-SmAMP2 gene under control of both promoters at the level comparable to or exceeding the level of the potato actin gene. Assessment of the immune status of the transformants demonstrated that expression of antimicrobial peptide pro-SmAMP2 gene was able to increase the resistance to a complex of Alternaria sp. and Fusarium sp. phytopathogens only in potato plants of the Yubiley Zhukova cultivar. The possible role of the pro-SmAMP2 products in protecting potatoes from Alternaria sp. and Fusarium sp. is discussed.

  3. THE USE OF AZADIRACHTA INDICA EXTRACT TO DECREASE OF ALTERNARIA PORRI DISEASE ON ONION

    OpenAIRE

    Loso Winarto; Novia Chairuman

    2013-01-01

    Purple spot caused by Alternaria porri a major disease in the onion crop in the world. The disease is also widespread in the onion crop in Indonesia. This research aim was to know the effect of mimba leaf (Azadirachta indica) extract concentration to decrease of Alternaria porri on onion (Allium ascalonicum L).This research conducted at Research Garden of the Center of Agricultural Technology Assessment of North Sumatra Province, from October 2010 until January 2011.The researc...

  4. Effects of postharvest salicylic acid dipping on Alternaria rot and disease resistance of jujube fruit during storage.

    Science.gov (United States)

    Cao, Jiankang; Yan, Jiaqi; Zhao, Yumei; Jiang, Weibo

    2013-10-01

    Considerable postharvest losses caused by Alternaria alternata often occur in Chinese jujube fruit, and synthetic fungicides have been widely used to protect the fruit from Alternaria rot. However, the potential harmfulness of fungicide residues to human health and the environment cannot be ignored. This study was conducted to develop an alternative approach for controlling postharvest disease by inducing fruit resistance with salicylic acid (SA) dipping. Disease incidence and lesion area in the jujube fruit inoculated with A. alternata were significantly inhibited by 2 and 2.5 mmol L(-1) SA dipping. Naturally infected decay rate and index in jujubes were also significantly reduced by SA dipping during long-term storage at 0°C. SA enhanced activities of the main defense-related enzymes including phenylalanine ammonia-lyase, peroxidase, chitinase and β-1,3-glucanase in the fruit during storage. SA strongly decreased catalase activity but increased superoxide dismutase activity and ascorbic acid content in jujubes. The beneficial effects of SA on fruit protection may be due to its ability to activate several highly coordinated defence-related systems in jujubes, instead of its fungicidal activity. The findings indicated that application of SA would offer an alternative approach that helps to control postharvest disease and maintain storage quality in fruits. © 2013 Society of Chemical Industry.

  5. Induction of mutant resistant to alternaria blotch of apple by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Yoshioka, Toji; Ito, Yuji; Masuda, Tetsuo

    2000-01-01

    Apple cultivars resistant to Alternaria blotch disease have been produced by cross-breeding, but it is difficult to produce resistance by crossing without changing the properties of cultivar because the gene composition of the cultivar tree is almost heterozygous. This study aimed to investigate the resistant mutation in Alternaria blotch susceptible and semiresistant cultivars. The resistance to Alternaria blotch pathogen or AM toxin is classified into the following three groups: 1) highly sensitive group including Indo, Redgold and Starking delicious, 2) semi-resistant group including Fuji, Orin and Golden delicious and 3) resistant group including Gala and Tsugaru. After gamma ray exposure of 80 Gy (at 5 Gy/hour), AM-toxin insensitive clones were selected in the VM 6 generation. These selected mutants could be rooted and habituated under field conditions. The degree of disease resistance was assessed by AM toxin treatment and Alternaria blotch fungi spore inoculation test. The leaves of these mutants were changed to variegated at high temperature, suggesting that some mutation related to chloroplast might have occurred. Alternaria blotch resistant strains could be produced by exposing to γray and selecting with AM toxin in shoot-tip culture system, but the functional effects of the AM toxin in Alternaria blotch and also the mechanism in the mutant lines were still unclear. (M.N.)

  6. Effect of eosinophils activated with Alternaria on the production of extracellular matrix from nasal fibroblasts.

    Science.gov (United States)

    Shin, Seung-Heon; Ye, Mi-Kyung; Choi, Sung-Yong; Kim, Yee-Hyuk

    2016-06-01

    Eosinophils and fibroblasts are known to play major roles in the pathogenesis of nasal polyps. Fungi are commonly found in nasal secretion and are associated with airway inflammation. To investigate whether activated eosinophils by airborne fungi can influence the production of extracellular matrix (ECM) from nasal fibroblasts. Inferior turbinate and nasal polyp fibroblasts were stimulated with Alternaria or Aspergillus, respectively, for 24 hours and ECM messenger RNA (mRNA) and protein expressions were measured. Eosinophils isolated from healthy volunteers were stimulated with Alternaria or Aspergillus for 4 hours then superoxide, eosinophil peroxidase, and transforming growth factor β1 were measured. Then activated eosinophils were cocultured with nasal fibroblasts for 24 hours, and ECM mRNA expressions were measured. Alternaria strongly enhanced ECM mRNA expression and protein production from nasal fibroblasts. Alternaria also induced the production of superoxide, eosinophil peroxidase, and transforming growth factor β1 from eosinophils, and activated eosinophils enhanced ECM mRNA expression when they were cocultured without the Transwell insert system. Eosinophils activated with Alternaria enhanced ECM mRNA expression from nasal polyp fibroblasts. Alternaria plays an important role in tissue fibrosis in the pathogenesis of nasal polyps by directly or indirectly influencing the production of ECM from nasal fibroblasts. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  7. Comparative study on the effect of chemicals on Alternaria blight in Indian mustard--a multi-location study in India.

    Science.gov (United States)

    Meena, P D; Chattopadhyay, C; Kumar, A; Awasthi, R P; Singh, R; Kaur, S; Thomas, L; Goyal, P; Chand, P

    2011-05-01

    High severity of Altemaria blight disease is a major constraint in production of rapeseed-mustard in India. The aim of this study was to investigate the suppressive potential of chemicals viz., zinc sulphate, borax, sulphur, potash and calcium sulphate, aqueous extracts viz., Eucalyptus globosus (50 g l-1) leaf extract and garlic (Allium sativum) bulb (20 g l-1) extract, cow urine and bio-agents Trichoderma harzianum, Pseudomonas fluorescence in comparison with the recommended chemical fungicide (mancozeb), against foliar disease Alternaria blight of Indian mustard [Brassica juncea (L.) Czern. and Coss] under five different geographical locations of India. Mancozeb recorded the lowest mean severity (leaf: 33.1%; pod: 26.3%) of Alternaria blight with efficacy of garlic bulb extract alone (leaf = 34.4%; pod = 27.3%) or in combination with cow urine (leaf = 34.2%; pod = 28.6%) being statistically at par with the recommended chemical fungicide. Chemicals also proved effective in reducing Alternaria blight severity on leaves and pods of Indian mustard (leaf = 36.3-37.9%; pod = 27.5-30.1%). The effective treatments besides providing significant reduction in disease severity also enabled increase in dry seed yield of the crop (mancozeb = 2052 kg ha-1; garlic = 2006 kg ha-1; control = 1561 kg ha-1).

  8. Hyperspectral and thermal imaging of oilseed rape (Brassica napus response to fungal species of the genus Alternaria.

    Directory of Open Access Journals (Sweden)

    Piotr Baranowski

    Full Text Available In this paper, thermal (8-13 µm and hyperspectral imaging in visible and near infrared (VNIR and short wavelength infrared (SWIR ranges were used to elaborate a method of early detection of biotic stresses caused by fungal species belonging to the genus Alternaria that were host (Alternaria alternata, Alternaria brassicae, and Alternaria brassicicola and non-host (Alternaria dauci pathogens to oilseed rape (Brassica napus L.. The measurements of disease severity for chosen dates after inoculation were compared to temperature distributions on infected leaves and to averaged reflectance characteristics. Statistical analysis revealed that leaf temperature distributions on particular days after inoculation and respective spectral characteristics, especially in the SWIR range (1000-2500 nm, significantly differed for the leaves inoculated with A. dauci from the other species of Alternaria as well as from leaves of non-treated plants. The significant differences in leaf temperature of the studied Alternaria species were observed in various stages of infection development. The classification experiments were performed on the hyperspectral data of the leaf surfaces to distinguish days after inoculation and Alternaria species. The second-derivative transformation of the spectral data together with back-propagation neural networks (BNNs appeared to be the best combination for classification of days after inoculation (prediction accuracy 90.5% and Alternaria species (prediction accuracy 80.5%.

  9. Radicinols and radicinin phytotoxins produced by Alternaria radicina on carrots.

    Science.gov (United States)

    Solfrizzo, Michele; Vitti, Carolina; De Girolamo, Annalisa; Visconti, Angelo; Logrieco, Antonio; Fanizzi, Francesco P

    2004-06-02

    The phytotoxin epi-radicinol, a diastereomer of radicinol, was isolated from large cultures of Alternaria radicina grown on carrot slices and identified by GC-MS, LC-MS, (1)H NMR, and (13)C NMR. Four strains of A. radicina isolated from rotted carrot produced epi-radicinol as the major metabolite (up to 39414 microg/g) together with radicinol (up to 2423 microg/g), and, to a lesser extent, radicinin when cultured on carrot slices, whereas on rice they mainly produced radicinin (2486-53800 microg/g). Radicinin and epi-radicinol reduced root elongation of germinating carrot seeds at concentrations of 10-20 microg/mL. Carrot samples naturally infected by A. radicina contained detectable quantities of epi-radicinol also in combination with lower levels of radicinin or radicinol. Accumulation of radicinols and radicinin in stored carrots, either naturally contaminated or artificially inoculated with A. radicina, was stimulated by successive temperature rises from 1 to 10 degrees C and from 10 to 20 degrees C, reaching maximum levels of 60 microg/g epi-radicinol and 26 microg/g radicinin. This is the first report on the production of radicinols by A. radicina and its natural occurrence in carrots in association with radicinin.

  10. Multilocus phylogeny and MALDI-TOF analysis of the plant pathogenic species Alternaria dauci and relatives.

    Science.gov (United States)

    Brun, Sophie; Madrid, Hugo; Gerrits Van Den Ende, Bert; Andersen, Birgitte; Marinach-Patrice, Carine; Mazier, Dominique; De Hoog, G Sybren

    2013-01-01

    The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of morphologically similar taxa. This study aimed to assess if strains of four closely-related plant pathogens, i.e., accurately Alternaria dauci (ten strains), Alternaria porri (six), Alternaria solani (ten), and Alternaria tomatophila (ten) could be identified using multilocus phylogenetic analysis and Matrix-Assisted Laser Desorption Ionisation Time of Flight (MALDI-TOF) profiling of proteins. Phylogenetic analyses were performed on three loci, i.e., the internal transcribed spacer (ITS) region of rRNA, and the glyceraldehyde-3-phosphate dehydrogenase (gpd) and Alternaria major antigen (Alt a 1) genes. Phylogenetic trees based on ITS sequences did not differentiate strains of A. solani, A. tomatophila, and A. porri, but these three species formed a clade separate from strains of A. dauci. The resolution improved in trees based on gpd and Alt a 1, which distinguished strains of the four species as separate clades. However, none provided significant bootstrap support for all four species, which could only be achieved when results for the three loci were combined. MALDI-TOF-based dendrograms showed three major clusters. The first comprised all A. dauci strains, the second included five strains of A. porri and one of A. solani, and the third included all strains of A. tomatophila, as well as all but one strain of A. solani, and one strain of A. porri. Thus, this study shows the usefulness of MALDI-TOF mass spectrometry as a promising tool for identification of these four species of Alternaria which are closely-related plant pathogens. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  11. Identification, characterization and mycotoxigenic ability of Alternaria spp. causing core rot of apple fruit in Greece.

    Science.gov (United States)

    Ntasiou, Panagiota; Myresiotis, Charalampos; Konstantinou, Sotiris; Papadopoulou-Mourkidou, Euphemia; Karaoglanidis, George S

    2015-03-16

    Alternaria core rot is a major postharvest disease of apple fruit in several countries of the world, including Greece. The study was conducted aiming to identify the disease causal agents at species level, investigate the aggressiveness of Alternaria spp. isolates and the susceptibility of different apple varieties and determine the mycotoxigenic potential of Alternaria spp. isolates from apple fruit. Seventy-five Alternaria spp. isolates obtained from apple fruit showing core rot symptoms were identified as either Alternaria tenuissima or Alternaria arborescens at frequencies of 89.3 and 11.7%, respectively, based on the sequence of endopolygalacturonase (EndoPG) gene. Artificial inoculations of fruit of 4 different varieties (Fuji, Golden Delicious, Granny Smith and Red Delicious) and incubation at two different temperatures (2 and 25°C) showed that fruit of Fuji variety were the most susceptible and fruit of Golden Delicious the most resistant to both pathogens. In addition, the production of 3 mycotoxins, alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) was investigated in 30 isolates of both species. Mycotoxin determination was conducted both in vitro, on artificial nutrient medium and in vivo on artificially inoculated apple fruit, using a high performance liquid chromatography with diode array detector (HPLC-DAD). The results showed that most of the isolates of both species were able to produce all the 3 metabolites both in vivo and in vitro. On apple fruit A. tenuissima isolates produced more AOH than A. arborescens isolates, whereas the latter produced more TEN than the former. Such results indicate that Alternaria core rot represents a major threat of apple fruit production not only due to quantitative yield losses but also for qualitative deterioration of apple by-products. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Production of transgenic brassica juncea with the synthetic chitinase gene (nic) conferring resistance to alternaria brassicicola

    International Nuclear Information System (INIS)

    Munir, I.; Hussan, W.; Kazi, M.; Mian, A.

    2016-01-01

    Brassica juncea is an important oil seed crop throughout the world. The demand and cultivation of oil seed crops has gained importance due to rapid increase in world population and industrialization. Fungal diseases pose a great threat to Brassica productivity worldwide. Absence of resistance genes against fungal infection within crossable germplasms of this crop necessitates deployment of genetic engineering approaches to produce transgenic plants with resistance against fungal infections. In the current study, hypocotyls and cotyledons of Brassica juncea, used as explants, were transformed with Agrobacterium tumefacien strain EHA101 harboring binary vector pEKB/NIC containing synthetic chitinase gene (NIC), an antifungal gene under the control of cauliflower mosaic virus promoter (CaMV35S). Bar genes and nptII gene were used as selectable markers. Presence of chitinase gene in trangenic lines was confirmed by PCR and southern blotting analysis. Effect of the extracted proteins from non-transgenic and transgenic lines was observed on the growth of Alternaria brassicicola, a common disease causing pathogen in brassica crop. In comparison to non-transgenic control lines, the leaf tissue extracts of the transgenic lines showed considerable resistance and antifungal activity against A. brassicicola. The antifungal activity in transgenic lines was observed as corresponding to the transgene copy number. (author)

  13. Rapid Molecular detection of citrus brown spot disease using ACT gene in Alternaria alternata

    Directory of Open Access Journals (Sweden)

    Hamid Moghimi

    2017-06-01

    Full Text Available Introduction:Using rapid detection methods is important for detection of plant pathogens and also prevention through spreading pests in agriculture. Citrus brown spot disease caused by pathogenic isolates of Alternaria alternata is a common disease in Iran. Materials and methods: In this study, for the first time a PCR based molecular method was used for rapid diagnosis of brown spot disease. Nine isolates of A. Alternata were isolated in PDA medium from different citrus gardens. The plant pathogenic activity was examined in tangerine leaves for isolates. Results showed that these isolates are the agents of brown spot disease. PCR amplification of specific ACT-toxin gene was performed for DNA extracted from A. alternata isolates, with 11 different fungal isolates as negative controls and 5 DNA samples extracted from soil. Results: Results showed that A. alternata, the causal agent of brown spot disease, can be carefully distinguished from other pathogenic agents by performing PCR amplification with specific primers for ACT toxin gene. Also, the results from Nested-PCR method confirmed the primary reaction and the specificity of A. alternata for brown spot disease. PCR results to control samples of the other standard fungal isolates, showed no amplification band. In addition, PCR with the DNA extracted from contaminated soils confirmed the presence of ACT toxin gene. Discussion and conclusion: Molecular procedure presented here can be used in rapid identification and prevention of brown spot infection in citrus gardens all over the country.

  14. Antigenic characteristics as taxonomic criterion of differentiation of Alternaria spp., pathogenic for carrot and parsley

    Directory of Open Access Journals (Sweden)

    Bulajić Aleksandra R.

    2007-01-01

    Full Text Available Identification of Alternaria genus species is a very complicated process which demands broadly designed investigations and studying of great number of properties which together can be considered as satisfying taxonomic criteria. The main objective of these investigations was examining the possibilities of applying the antigenic characteristics of Alternaria spp. phytopathogenic fungi as a taxonomic criterion, as well as introducing the serological methods for their identification. Conducting the examination of Alternaria spp., pathogenic for Apiaceae plants in Serbia, several isolates were obtained and identified as Alternaria radicina, A. petroselini, A. dauci and A. alternata, based on the conventional mycological methods and host range, as well as on molecular detection and partial characterization. The investigation included 12 isolates from plant leaves, seeds and soil which were pathogenic mainly to carrot and parsley and were identified as A. radicina, A. petroselini, A. dauci and A. alternate. Investigated isolates were compared with each other, as well as with standard isolates for the mentioned species (a total of 5 isolates, originating from USA and EU. During the investigation of serological characteristics of Alternaria spp. firstly a polyclonal antiserum was prepared against one isolate from Serbia identified as A. dauci. This antiserum was specific to Alternaria genus while there was no reaction with antigens from other phytopathogenic fungi genera (Fusarium, Rhizoctonia and Agaricus. Antiserum titer, determined by slide agglutination test, was 1/32. Antigenic characteristics of Alternaria genus fungi were examined by Electro-Blot-Immunoassay serological method (EBIA, Western blot, i.e. their protein profiles were compared. Investigated Alternaria spp. isolates showed different protein band profiles in gel and on nitrocellulose paper, and the observed differences were in complete correlation with the results of the previous

  15. Fungitoxic potential of tagetes erectus for the management of alternaria alternata strains of tomato

    International Nuclear Information System (INIS)

    Mehmood, T.; Shafique, S.; Shafique, S.; Zaheer, Z.

    2014-01-01

    Tomato (Lycopersicum esculentum Mill.) is economically the most vital vegetable crops of this world but diseases reduce tomato production to a greater extent worldwide. Plants exudates contribute a lot in fight against pathogens. The current study indicates the pathogenic potential of Alternaria alternata FCBP-573 against tomato. RAPD analysis confirmed that A. alternata FCBP-573 had variability in its genetic constitution with other two isolates; this disparity in genetic constitution might be a cause to stir up more pathogenicity in this isolate. Therefore, it was selected as the most pathogenic isolate and subjected to biological control through Tagetes erectus L. In antifungal bioassays different plant parts of T. erectus with 1-4% concentrations of aqueous, and organic extracts of each part were evaluated against A. alternata FCBP- 573. Results revealed that the growth of A. alternata FCBP-573 was greatly inhibited at 4% concentration of methanol extract followed by aqueous and n-hexane extract. Among different plant parts tested, root extract exhibited more promising results by causing 81-92% reduction in biomass. The research concludes that aqueous and organic extracts of ornamentals have potential to obstruct dreadful effect of pathogenic fungi by suppressing their growth. T. erectus conferred vital and surprisingly stable compounds having inhibitory potential against A. alternata FCBP-573. (author)

  16. Effects of {gamma}-radiation on the fungus Alternaria alternata in artificially inoculated cereal samples

    Energy Technology Data Exchange (ETDEWEB)

    Braghini, R. [Departamento de Microbiologia, Instituto de Ciencias Biomedicas II, Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 1374, CEP 05508-900 Sao Paulo (Brazil)], E-mail: raquelbraghini@yahoo.com.br; Pozzi, C.R. [Instituto de Zootecnia, Rua Heitor Penteado 56, CEP 13460-000, Nova Odessa, Sao Paulo (Brazil); Aquino, S. [Instituto Adolfo Lutz, Av. Dr. Arnaldo, 355 , CEP 01246-902, Sao Paulo (Brazil); Rocha, L.O.; Correa, B. [Departamento de Microbiologia, Instituto de Ciencias Biomedicas II, Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 1374, CEP 05508-900 Sao Paulo (Brazil)

    2009-09-15

    The objective of this study was to evaluate the effects of different {gamma}-radiation doses on the growth of Alternaria alternata in artificially inoculated cereal samples. Seeds and grains were divided into four groups: Control Group (not irradiated), and Groups 1, 2 and 3, inoculated with an A. alternata spore suspension (1x10{sup 6} spores/mL) and exposed to 2, 5 and 10 kGy, respectively. Serial dilutions of the samples were prepared and seeded on DRBC (dichloran rose bengal chloramphenicol agar) and DCMA (dichloran chloramphenicol malt extract agar) media, after which the number of colony-forming units per gram was determined in each group. In addition, fungal morphology after irradiation was analyzed by scanning electron microscopy (SEM). The results showed that ionizing radiation at a dose of 5 kGy was effective in reducing the growth of A. alternata. However, a dose of 10 kGy was necessary to inhibit fungal growth completely. SEM made it possible to visualize structural alterations induced by the different {gamma}-radiation doses used.

  17. Effects of γ-radiation on the fungus Alternaria alternata in artificially inoculated cereal samples

    International Nuclear Information System (INIS)

    Braghini, R.; Pozzi, C.R.; Aquino, S.; Rocha, L.O.; Correa, B.

    2009-01-01

    The objective of this study was to evaluate the effects of different γ-radiation doses on the growth of Alternaria alternata in artificially inoculated cereal samples. Seeds and grains were divided into four groups: Control Group (not irradiated), and Groups 1, 2 and 3, inoculated with an A. alternata spore suspension (1x10 6 spores/mL) and exposed to 2, 5 and 10 kGy, respectively. Serial dilutions of the samples were prepared and seeded on DRBC (dichloran rose bengal chloramphenicol agar) and DCMA (dichloran chloramphenicol malt extract agar) media, after which the number of colony-forming units per gram was determined in each group. In addition, fungal morphology after irradiation was analyzed by scanning electron microscopy (SEM). The results showed that ionizing radiation at a dose of 5 kGy was effective in reducing the growth of A. alternata. However, a dose of 10 kGy was necessary to inhibit fungal growth completely. SEM made it possible to visualize structural alterations induced by the different γ-radiation doses used.

  18. Natural occurrence of mycotoxins and toxigenic capacity of Alternaria strains from mouldy peppers

    DEFF Research Database (Denmark)

    da Cruz Cabral, Lucía; Terminiello, Laura; Fernández Pinto, Virginia

    2016-01-01

    Sweet pepper (Capsicum annuum) is an important crop cultivated worldwide, with Argentina being one of the major producers in South America. The fruit is susceptible to several fungal diseases, leading to severe economic losses for producers. In this study, Alternaria was found as the prevalent...... genus in mouldy peppers (50% fruits infected). Morphological identification revealed that all 64 Alternaria isolates belonged to small-spored species, most of them corresponding to A. tenuissima, A. arborescens and A. alternata species-groups. Their secondary metabolite profile was evaluated in vitro......; alternariols were synthesized by most of the isolates (91% for alternariol and 92% for alternariol monomethyl ether). A high number of Alternaria spp. also produced tenuazonic acid (64%), altenuene (84%) and tentoxin (72%). In addition, damaged pepper fruits were analysed for the presence of tenuazonic acid...

  19. Determination of mycotoxin profiles characteristic of Alternaria strains isolated from Malbec grapes

    Directory of Open Access Journals (Sweden)

    Vargas Trinidad Andrea

    2015-01-01

    Full Text Available The world grape production has increased, reaching 751 million quintals (Mql in 2013. Many Alternaria species have been studied for their ability to produce secondary metabolites in foods, some of which have toxic properties with tenu- azonic acid (TA, alternariol (AOH, alternariol methyl ether (AME being the most important ones. The aim was to determine the characteristic mycotoxin production profiles of Alternaria strains isolated from Malbec grapes in the Patagonian region of Argentina. Fifty Alternaria isolates (5 A. alternata, 5 A. arborescens and 40 A. tenuissima were analyzed for the produc- tion of mycotoxins (TA, AOH and AME in autoclaved rice media by High Performance Liquid Chromatography (HPLC. All isolates were found to be producers of mycotoxins; the 100% was producer of TA (0.016–21.031 mg/kg, 98% produced AOH (0.003–0.057 mg/kg and 36% produced AME (0.001–0.133 mg/kg. Thirty-three isolates co-produced the three mycotoxins. In this study, it was demonstrated a high toxigenic potential of Alternaria isolates. Although Alternaria growth on grapes has been amply demonstrated, there are few studies about the incidence their more characteristic mycotoxin sand their toxicogenic capac- ity determination in grapes, wines and derivatives. In addition, mycotoxins studied in this work are not regulated in oenology. Therefore, further studies should be conducted to assess the health risk due to the presence of Alternaria toxins in grapes, wine, grape juice and raisins.

  20. The presence of Alternaria spp. on the seed of Apiaceae plants and their influence on seed emergence

    Directory of Open Access Journals (Sweden)

    Bulajić Aleksandra

    2009-01-01

    Full Text Available Considerable damping-off of the seedlings of several commercial Apiaceae plant species was observed in Serbia. The infection of a total of 48 seed samples of nine vegetable and spice plants with phytopathogenic Alternaria spp. was established using the deep-freeze-blotter method. Identification of Alternaria species was performed using both conventional methods and PCR. Four different plant-pathogenic Alternaria species were detected in Serbia: A. dauci, A. radicina, A. petroselini, and A. alternata, all of which caused reduction of carrot, parsley, parsnip, and celery seed emergence. Alternaria dauci, A. radicina, and A. petroselini were relatively more aggressive compared to A. alternata. Substantial seed infection levels and strong influence of Alternaria spp. on seed emergence indicated that production of Apiaceae seed needs to be improved in order to obtain pathogen-free seed.

  1. Characterization and Pathogenicity of Alternaria vanuatuensis, a New Record from Allium Plants in Korea and China.

    Science.gov (United States)

    Li, Mei Jia; Deng, Jian Xin; Paul, Narayan Chandra; Lee, Hyang Burm; Yu, Seung Hun

    2014-12-01

    Alternaria from different Allium plants was characterized by multilocus sequence analysis. Based on sequences of the β-tubulin (BT2b), the Alternaria allergen a1 (Alt a1), and the RNA polymerase II second largest subunit (RPB2) genes and phylogenetic data analysis, isolates were divided into two groups. The two groups were identical to representative isolates of A. porri (EGS48-147) and A. vanuatuensis (EGS45-018). The conidial characteristics and pathogenicity of A. vanuatuensis also well supported the molecular characteristics. This is the first record of A. vanuatuensis E. G. Simmons & C. F. Hill from Korea and China.

  2. Alternaria cerasidanica sp nov., isolated in Denmark from drupes of Prunus avium

    DEFF Research Database (Denmark)

    Roberts, R. G.; Reymond, S. T.; Andersen, Birgitte

    2010-01-01

    The ex-type strain of Alternaria cerasidanica was isolated in 2001 from an immature, asymptomatic drupe of Prunus avium collected at a commercial cherry orchard near Skaelskor, Denmark. Cultural morphology, sporulation pattern and cluster analyses of combined RAPD, RAMS (microsatellite), and AFLP...

  3. A rare case of allergic bronchopulmonary mycosis caused by Alternaria alternata.

    NARCIS (Netherlands)

    Chowdhary, A.; Agarwal, K.; Randhawa, H.S.; Kathuria, S.; Gaur, S.N.; Najafzadeh, M.J.; Roy, P.; Arora, N.; Khanna, G.; Meis, J.F.G.M.

    2012-01-01

    A rare case of allergic bronchopulmonary mycosis (ABPM), caused by Alternaria alternata, is reported in an immunocompetent resident of Delhi. Her complaints included a generalized, urticarial skin rash and occasional pain in the right lower chest. Her differential count showed eosinophils, 22%;

  4. Multilocus phylogeny and MALDI-TOF analysis of the plant pathogenic species Alternaria dauci and relatives

    NARCIS (Netherlands)

    Brun, S.; Madrid, H.; Gerritis van den Ende, B.; Andersen, B.; Marinach-Patrice, C.; Mazier, D.; de Hoog, G.S.

    2013-01-01

    The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of

  5. A polyphasic approach to the taxonomy of the Alternaria infectoria species-group

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Sørensen, Jens Laurids; Nielsen, Kristian Fog

    2009-01-01

    Different taxa in the species-group of Alternaria infectoria (teleomorph Lewia spp.) are often isolated from various cereals including barley, maize and wheat grain, ornamental plants and skin lesions from animals and humans. In the present study we made a polyphasic characterization of 39 strains...

  6. Characterization of small-spored Alternaria from Argentinean crops through a polyphasic approach

    DEFF Research Database (Denmark)

    da Cruz Cabral, Lucía; Rodriguero, Marcela; Stenglein, Sebastián

    2017-01-01

    exporter of agricultural products, so it is essential to thoroughly understand the physiological behaviour of this pathogen in a food safety context. Thus, the objective of this work was to characterize small-spored Alternaria spp. obtained from tomato fruits, pepper fruits, wheat grains and blueberries...

  7. Potato carrot agar with manganese as an isolation medium for Alternaria, Epicoccum and Phoma

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Mogensen, Jesper Mølgaard; Thrane, Ulf

    2009-01-01

    A semi-selective medium for isolation of Alternaria spp., Epicoccum sp. and Phoma spp. from soil and plant samples was developed. The basal medium was a modified potato carrot agar (PCA), containing 10 g/L of potato and carrot. It is known that the target genera sporulate well on standard PCA when...

  8. QTL identification for early blight resistance (Alternaria solani) in a Solanum lycopersicum x S. arcanum cross.

    NARCIS (Netherlands)

    Chaerani, R.; Smulders, M.J.M.; Linden, van der C.G.; Vosman, B.; Stam, P.; Voorrips, R.E.

    2007-01-01

    Alternaria solani (Ellis and Martin) Sorauer, the causal agent of early blight (EB) disease, infects aerial parts of tomato at both seedling and adult plant stages. Resistant cultivars would facilitate a sustainable EB management. EB resistance is a quantitatively expressed character, a fact that

  9. Effects of Alternaria alternata f.sp. lycopersici toxins on pollen

    NARCIS (Netherlands)

    Bino, R.J.; Franken, J.; Witsenboer, H.M.A.; Hille, J.; Dons, J.J.M.

    1988-01-01

    Effects of the phytotoxic compounds (AAL-toxins) isolated from cell-free culture filtrates of Alternaria alternata f.sp. lycopersici on in vitro pollen development were studied. AAL-toxins inhibited both germination and tube growth of pollen from several Lycopersicon genotypes. Pollen from

  10. Alternaria alternata peritonitis in a patient undergoing continuous ambulatory peritoneal dialysis

    Directory of Open Access Journals (Sweden)

    Yosra Guedri

    2017-01-01

    Full Text Available Fungal peritonitis is a serious complication of peritoneal dialysis (PD leading to loss of ultrafiltration and discontinuation of PD treatment. The most frequently isolated fungi are Candida albicans and, filamentous fungi such Alternaria alternata species are found only rarely. We report the case of a 75-year-old woman who developed peritonitis due to this black fungus.

  11. A polyphasic approach for the characterization of endophytic Alternaria strains isolated from grapevines

    DEFF Research Database (Denmark)

    Polizzotto, Rachele; Andersen, Birgitte; Martini, Marta

    2012-01-01

    A polyphasic approach was set up and applied to characterize 20 fungal endophytes belonging to the genus Alternaria, recovered from grapevine in different Italian regions.Morphological, microscopical, molecular and chemical investigations were performed and the obtained results were combined in a...

  12. Seed isolates of Alternaria and Aspergillus fungi increase germination of Astragalus utahensis

    Science.gov (United States)

    Sean D. Eldredge; Brad Geary; Scott L. Jensen

    2016-01-01

    Astragalus utahensis (Torr.) Torr. & A. Gray (Fabaceae) (Utah milkvetch) is native lo the arid Great Basin and has desirable attributes that make it a good candidate for restoration in arid, noncompetitive situations. Seed dormancy is a significant barrier to consistent establishment for this species. Species of Alternaria and Aspergillus fungi have...

  13. The effect of cytosolic extract of Alternaria aternata fungus on Monocyte-derived dendritic cell maturation and T-lymphocyte polarization in the presence of myelin basic protein

    Directory of Open Access Journals (Sweden)

    Loghmanni A

    2013-03-01

    Full Text Available Background: Multiple Sclerosis (MS is an autoimmune disease with impairment in function of central nervous system. Macrophages and dendritic cells play important roles in alleviating or progression of the disease. These cells can cause inflammation and damage to the myelin of nerve cells by realizing of harmful substances when these cells get matured. We studied the effect of Alternaria alternata extract on maturation of monocyte- derived dendritic cell (modc and T-cell responses in the presence of Myelin Basic Protein (MBP as a laboratory model of multiple sclerosis (MS. The purpose of this study is suitable dendritic cells production for usage in MS immunotherapy.Methods: For this study plastic adherent monocytes were cultured with granulocyte/ macrophage- colony stimulating factor (GM-CSF and interleukin -4 for converting these cells to modc and pulsed with MBP and matured in the presence of monocyte-conditioned medium (MCM in control group and MCM + Alternaria alternata extract in treatment groups. Anti-CD14, anti-CD83, anti-human leukocyte antigen-DR (anti HLA-DR monoclonal antibody were carried out for phenotyping. Autologos T cell responses and cytokine production were evaluated.Results: The results showed that the expression of CD14 decreased and CD83, HLA-DR increased in treatment groups in comparison with control groups. The production amount of IL-10 overcame IL-12 and in T cell the production of cytokines, IL-17 and Interferon-γ (IFN-γ decreased and IL-4 was increased (P<0.05. These effects escalated with increasing of dosage from 50 to 100 (mg/ml (P<0.001.Conclusion: Alternaria alternata extract can cause maturation of MBP-pulsed modc and skewing of T- lymphocyte toward Th2 and thereby can evolve into a new strategy in immunotherapy of MS.

  14. EPIDEMIOLOGICAL ASPECTS OF LEAF BLIGHT OF CARROT (Daucus carota L. CAUSED BY Alternaria dauci (KÜHN GROVES & SKOLKO: SURVIVAL OF Alternaria dauci IN VEGETAL RESIDUES OF CARROT (Daucus carota L. CROP ASPECTOS EPIDEMIOLÓGICOS DA QUEIMA DAS FOLHAS DA CENOURA (Daucus carota L. CAUSADA POR Alternaria dauci (Kühn GROVES & SKOLKO: Sobrevivência de Alternaria dauci (Kühn Groves & SKOLKO em restos culturais da cenoura (Daucus carota L.

    Directory of Open Access Journals (Sweden)

    Geraldo Martins Chaves

    2007-09-01

    Full Text Available

    The spore viability of Alternaria dauci (Kühn Groves & Skolko in carrot (Daucus carota L. debris which were kept at different levels of temperature and relative humidity, without light, was studied. The temperature levels tested were 8, 16, 24 and 32°C, and the relative humidity levels 3, 18, 51, 73 and 100%. The treatments were different combinations of these levels. Humidity was the more important factor in preserving the fungus spore ability to germinate and its infectivity. Under conditions of high relative humidity and temperatures of 24 and 32°C, the spores rapidly lost their viability. This did not happen when the relative humidity was equal to, or below, 51%. The survival of fungus mycelium on carrot petioles was studied in non-treated organic soil, at different humidity levels, at three different depths, during a period of 120 days. Soil humidity was the factor of major significance in the persistence of the mycelium, followed by depths and time factors. In petioles kept at depths of 10 and 20 cm in humid soil, the survival was greatly reduced, while survival was markedly higher in those kept at the surface of dry soil. The effect of humidity on the viability of mycelium was studied also under soiless condition. Petioles were maintained in relative humidity controlled chamber, at 24°C. In saturated atmosphere (100% humidity, the mycelium viability was lost in less than 20 days. It was concluded that both, the conidial and mycelial form of Alternaria dauci are quite sensitive to high humidity levels.

    Estudou-se a sobrevivência das formas conidial e miceliana de Alternaria dauci, respectivamente, sobre folhas necrosadas e pecíolos de cenoura, sob diferentes condições mesológicas. Os esporos do fungo sobre conidióforos em folhas necrosadas de cenoura foram mantidos por 120 dias sob condi

  15. Csn5 Is Required for the Conidiogenesis and Pathogenesis of the Alternaria alternata Tangerine Pathotype

    Directory of Open Access Journals (Sweden)

    Mingshuang Wang

    2018-03-01

    Full Text Available The COP9 signalosome (CSN is a highly conserved protein complex involved in the ubiquitin-proteasome system. Its metalloisopeptidase activity resides in subunit 5 (CSN5. Functions of csn5 in phytopathogenic fungi are poorly understood. Here, we knocked out the csn5 ortholog (Aacsn5 in the tangerine pathotype of Alternaria alternata. The ΔAacsn5 mutant showed a moderately reduced growth rate compared to the wildtype strain and was unable to produce conidia. The growth of ΔAacsn5 mutant was not affected in response to oxidative and osmotic stresses. Virulence assays revealed that ΔAacsn5 induced no or significantly reduced necrotic lesions on detached citrus leaves. The defects in hyphal growth, conidial sporulation, and pathogenicity of ΔAacsn5 were restored by genetic complementation of the mutant with wildtype Aacsn5. To explore the molecular mechanisms of conidiation and pathogenesis underlying Aacsn5 regulation, we systematically examined the transcriptomes of both ΔAacsn5 and the wildtype. Generally, 881 genes were overexpressed and 777 were underexpressed in the ΔAacsn5 mutant during conidiation while 694 overexpressed and 993 underexpressed during infection. During asexual development, genes related to the transport processes and nitrogen metabolism were significantly downregulated; the expression of csn1–4 and csn7 in ΔAacsn5 was significantly elevated; secondary metabolism gene clusters were broadly affected; especially, the transcript level of the whole of cluster 28 and 30 was strongly induced. During infection, the expression of the host-specific ACT toxin gene cluster which controls the biosynthesis of the citrus specific toxin was significantly repressed; many other SM clusters with unknown products were also regulated; 86 out of 373 carbohydrate-active enzymes responsible for breaking down the plant dead tissues showed uniquely decreased expression. Taken together, our results expand our understanding of the roles of csn5

  16. IN VITRO BIOACTIVITY OF CREOSOTE BUSH EXTRACTS (LARREA TRIDENTATA ON THE INHIBITION OF POSTHARVEST FUNGI: PENICILLIUM POLONICUM, ASPERGILLUS NIGER, RHIZOPUS ORYZAE Y ALTERNARIA TENUISSIMA

    Directory of Open Access Journals (Sweden)

    O. Peñuelas-Rubio

    2015-11-01

    Full Text Available En el presente estudio se evaluó la eficiencia de extractos vegetales deLarrea tridentataobtenidos con diclorometano, etanol, metanol y agua, sobre el crecimiento radial in vitro de cuatro hongos fitopatógenos, los cuales primeramente fueron identificados en género y especie empleando claves taxonómicas y técnicas moleculares. Para los bioensayosin vitrose aplicaron diseños completamente al azar con cuatro tratamientos y tres repeticiones en cada hongo, utilizando las concentraciones: 0, 250, 500 y 750 ppm paraAlternaria sp.; 0, 2000, 2500 y 3000 paraAspergillus sp.; 0, 1500, 1750 y 2000 paraPenicillium sp. y 0, 150, 200 y 250 ppm paraRhizopus sp. Cada tratamiento tuvo tres repeticiones. El análisis molecular determinó la especie tenuissima paraAlternaria,nigerparaApergillus,polonicumparaPenicilliumyoryzaeparaRhizopus. En cuanto a las pruebasin vitro, se determinaron inhibiciones del 100% para tres de los hongos en estudio:Alternaria tenuissimacon extracto EtOH a 750 ppm;Aspergillus nigercon extracto DCM a 3000 ppm yRhizopus oryzaea partir de 150 ppm y 250 ppm de los extractos DCM y EtOH respectivamente. Se presentó una inhibición del 82% a 2000 ppm paraPenicillium polonicum. Se concluye que a pesar de las diferencias en susceptibilidad entre las especies fúngicas, los extractos deLarrea tridentataobtenidos con etanol y dicloromentano son efectivos para el control de los hongos fitopatógenos bajo estudioin vitro.

  17. Sensitivities of baseline isolates and boscalid-resistant mutants of Alternaria alternata from pistachio to fluopyram, penthiopyrad, and fluxapyroxad

    NARCIS (Netherlands)

    Avenot, H.F.; Biggelaar, van den H.; Morgan, D.P.; Moral, J.; Joosten, M.H.A.J.; Michailides, T.J.

    2014-01-01

    Resistance of Alternaria alternata to boscalid, the first succinate dehydrogenase inhibitor (SDHI) fungicide labeled on pistachio, has become a common occurrence in California pistachio orchards and affects the performance of this fungicide. In this study, we established the baseline sensitivities

  18. Identificação de híbridos de citros resistentes à mancha-marrom-de-alternária por meio de fAFLP e testes de patogenicidade Alternaria brown spot resistant citrus hybrid identification by means of fAFLP and pathogenicity tests

    Directory of Open Access Journals (Sweden)

    Edvan Alves Chagas

    2007-07-01

    Full Text Available O objetivo deste trabalho foi identificar híbridos, oriundos de hibridações controladas entre 'Folha Murcha' x 'Ponkan' e testá-los quanto à resistência a Alternaria alternata f. sp. citri. As plântulas foram obtidas via cultura in vitro de embriões. Utilizou-se o marcador molecular fAFLP para identificação dos híbridos e, em seguida, realizou-se o teste de patogenicidade nos híbridos com isolados de Alternaria alternata f. sp. citri, em condições de laboratório. Os pares de primers EcoRI AAG - MseI CAG e EcoRI ACC - MseI CAA foram os mais eficientes na identificação dos híbridos, os quais identificaram 48,5% de híbridos. Os híbridos F64, F108, F111, F113, F131 e F139 são potencialmente resistentes a Alternaria alternata f. sp. citri.The objective of this work was to identify hybrids obtained from controlled crossings between 'Folha Murcha' x 'Ponkan', and to check their resistance to Alternaria alternata f. sp. citri. The seedlings were obtained by in vitro embryo culture. The fAFLP marker technique was used to identify the hybrids, then laboratory pathogenicity test of the hybrids was accomplished with Alternaria alternata f. sp. citri isolates. The pairs of primers EcoRI AAG - Msel CAG and EcoRI ACC - Msel CAA were the most efficient for hybrids identification, and distinguished 48.5% of hybrids. Hybrids F64, F108, F111, F113, F131 and F139 showed potential resistance to the Alternaria alternata f. sp. citri.

  19. Degradation of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking.

    Science.gov (United States)

    Siegel, David; Feist, Michael; Proske, Matthias; Koch, Matthias; Nehls, Irene

    2010-09-08

    The stability of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking was investigated by model experiments using a spiked wholemeal wheat flour matrix. For alternariol and alternariol monomethyl ether, but not for altenuene, degradation products, formed through a sequence of hydrolysis and decarboxylation, could be identified in pilot studies. The simultaneous quantification of alternariol, alternariol monomethyl ether, altenuene, and the degradation products was achieved by a newly developed high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) multimethod. The obtained quantitative data indicate that the Alternaria mycotoxins are barely degraded during wet baking, while significant degradation occurs upon dry baking, with the stability decreasing in the order alternariol monomethyl ether>alternariol>altenuene. The novel degradation products could be detected after the wet baking of flour spiked with alternariol and in a sample survey of 24 commercial cereal based baking products.

  20. Sensivity of Jordanian Isolates of Alternaria solani to Manchotane

    OpenAIRE

    K.I. Al-Mughrabi

    2004-01-01

    Early blight of potato, caused by Alternaria solani, poses a significant risk to potato crops worldwide. Fifty A. solani isolates representing a population were collected from the Jordan Valley, purified, and tested for their sensitivity to the fungicide mancothane. The isolates were tested against a series of concentrations of 0, 0.1, 1, 10, 100, and 1000 mg mancothane ml-1 in 5% sodium dodecyl sulfate (SDS). Some A. solani isolates tolerated up to 1000 mg mancothane ml-1. Isolat...

  1. Genome Sequence of the Necrotrophic Plant Pathogen Alternaria brassicicola Abra43

    Science.gov (United States)

    Belmas, Elodie; Briand, Martial; Kwasiborski, Anthony; Colou, Justine; N’Guyen, Guillaume; Iacomi, Béatrice; Grappin, Philippe; Campion, Claire; Simoneau, Philippe; Barret, Matthieu

    2018-01-01

    ABSTRACT Alternaria brassicicola causes dark spot (or black spot) disease, which is one of the most common and destructive fungal diseases of Brassicaceae spp. worldwide. Here, we report the draft genome sequence of strain Abra43. The assembly comprises 29 scaffolds, with an N50 value of 2.1 Mb. The assembled genome was 31,036,461 bp in length, with a G+C content of 50.85%. PMID:29439047

  2. Bostrycin and 4-deoxybostrycin: two nonspecific phytotoxins produced by Alternaria eichhorniae.

    OpenAIRE

    Charudattan, R; Rao, K V

    1982-01-01

    Two crystalline red pigments with phytotoxic activity were isolated from culture filtrates of Alternaria eichhorniae, a pathogen of the water hyacinth Eichhornia crassipes. The pigments were present in the ratio of 4:1 and were identified as bostrycin and 4-deoxybostrycin, respectively. This is the first isolation of 4-deoxybostrycin from a natural source. Bostrycin, 4-deoxybostrycin, and their isopropylidene derivatives induced necrosis on tested plant leaves comparable to the A. eichhorniae...

  3. Multilocus phylogeny and MALDI-TOF analysis of the plant pathogenic species Alternaria dauci and relatives

    DEFF Research Database (Denmark)

    Brun, Sophie; Madrid, Hugo; Gerrits Van Den Ende, Bert

    2013-01-01

    The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of morp......The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species...... trees based on ITS sequences did not differentiate strains of A. solani, A. tomatophila, and A. porri, but these three species formed a clade separate from strains of A. dauci. The resolution improved in trees based on gpd and Alt a 1, which distinguished strains of the four species as separate clades...... of A. solani, and the third included all strains of A. tomatophila, as well as all but one strain of A. solani, and one strain of A. porri. Thus, this study shows the usefulness of MALDI-TOF mass spectrometry as a promising tool for identification of these four species of Alternaria which are closely...

  4. Characterization and Pathogenicity of Alternaria burnsii from Seeds of Cucurbita maxima (Cucurbitaceae) in Bangladesh.

    Science.gov (United States)

    Paul, Narayan Chandra; Deng, Jian Xin; Lee, Hyang Burm; Yu, Seung-Hun

    2015-12-01

    In the course of survey of endophytic fungi from Bangladesh pumpkin seeds in 2011~2012, two strains (CNU111042 and CNU111043) with similar colony characteristics were isolated and characterized by their morphology and by molecular phylogenetic analysis of the internal transcribed spacer, glyceraldehydes-3-phosphate dehydrogenase (gpd), and Alternaria allergen a1 (Alt a1) sequences. Phylogenetic analysis of all three sequences and their combined dataset revealed that the fungus formed a subclade within the A. alternata clade, matching A. burnsi and showing differences with its other closely related Alternaria species, such as A. longipes, A. tomato, and A. tomaticola. Long ellipsoid, obclavate or ovoid beakless conidia, shorter and thinner conidial size (16~60 [90] × 6.5~14 [~16] µm) distinguish this fungus from other related species. These isolates showed more transverse septation (2~11) and less longitudinal septation (0~3) than did other related species. Moreover, the isolate did not produce any diffusible pigment on media. Therefore, our results reveal that the newly recorded fungus from a new host, Cucurbita maxima, is Alternaria burnsii Uppal, Patel & Kamat.

  5. Production of the Allergenic Protein Alt a 1 by Alternaria Isolates from Working Environments

    Directory of Open Access Journals (Sweden)

    Justyna Skóra

    2015-02-01

    Full Text Available The aim of the study was to evaluate the ability of Alternaria isolates from workplaces to produce Alt a 1 allergenic protein, and to analyze whether technical materials (cellulose, compost, leather present within the working environment stimulate or inhibit Alt a 1 production (ELISA test. Studies included identification of the isolated molds by nucleotide sequences analyzing of the ITS1/ITS2 regions, actin, calmodulin and Alt a 1 genes. It has been shown that Alternaria molds are significant part of microbiocenosis in the archive, museum, library, composting plant and tannery (14%–16% frequency in the air. The presence of the gene encoding the Alt a 1 protein has been detected for the strains: Alternaria alternata, A. lini, A. limoniasperae A. nobilis and A. tenuissima. Environmental strains produced Alt a 1 at higher concentrations (1.103–6.528 ng/mL than a ATCC strain (0.551–0.975 ng/mL. It has been shown that the homogenization of the mycelium and the use of ultrafiltration allow a considerable increase of Alt a 1 concentration. Variations in the production of Alt a 1 protein, depend on the strain and extraction methods. These studies revealed no impact of the technical material from the workplaces on the production of Alt a 1 protein.

  6. Regulation of gene expression for defensins and lipid transfer protein in Scots pine seedlings by necrotrophic pathogen Alternaria alternata (Fr.

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    Hrunyk Nataliya

    2017-06-01

    Full Text Available Damping-off disease in pine seedling, caused by fungi and oomycetes (Fusarium, Alternaria, Botrytis, Phytophthora and other species, is one of the most dangerous diseases in conifer nurseries and greenhouses worldwide. Alternaria alternata is a necrotrophic pathogen, which causes early blight in higher plants and results in massive economic losses in agro-industry as well as in forestry. Pine seedlings that lack strong lignificated and suberized cell walls at early stages of their growth are vulnerable to damping-off disease. So, triggering the synthesis of antimicrobial compounds, such as phytoalexins, anticipins and pathogenesis-related (PR proteins, is the main defense strategy to confine pathogens at early stages of pine ontogenesis. Defensins and lipid transfer proteins are members of two PR-protein families (PR-12 and PR-14 respectively and possess antimicrobial activities in vitro through contact toxicity, and the involvement in defense signalling. In this work, we describe the changes in the expression levels of four defensin genes and lipid transfer protein in Scots pine seedlings infected with A. alternata. The expression levels of PsDef1 and PsDef2 increased at 48 h.p.i. (hours post inoculation. The levels of PsDef4 transcripts have increased after 6 and 24 hours. Notably, at 48 h.p.i., the level of PsDef4 transcripts was decreased by 1.2 times compared to control. The level of PsDef3 transcripts was reduced at all three time points. On the other hand, the level of PsLTP1 transcripts increased at 6 h and 48 h.p.i.; while at 24 h.p.i., it decreased by 20% when compared to the control sample. Our results suggest that defensins and lipid transfer protein are involved in the defense response of young Scots pine to necrotrophic pathogen. Thus, those genes can be used as the molecular markers in forestry selection and development of the ecologically friendly remedies for coniferous seedlings cultivation in greenhouses and nurseries.

  7. [Antifungal effect of phenolic and carotenoids extracts from chiltepin (Capsicum annum var. glabriusculum) on Alternaria alternata and Fusarium oxysporum].

    Science.gov (United States)

    Rodriguez-Maturino, Alfonso; Troncoso-Rojas, Rosalba; Sánchez-Estrada, Alberto; González-Mendoza, Daniel; Ruiz-Sanchez, Esau; Zamora-Bustillos, Roberto; Ceceña-Duran, Carlos; Grimaldo-Juarez, Onecimo; Aviles-Marin, Mónica

    2015-01-01

    The effect of phenolic and carotenoid extracts from chiltepin fruits on mycelial growth and the inhibition of conidial germination of Alternaria alternata and Fusarium oxysporum were investigated in the present work. Phenolic extracts inhibited mycelial growth of A.alternata by 38.46%, and significantly reduced conidial germination on the fifth day after treatment to 92% in relation to control. No significant changes were observed in the inhibition of mycelial growth in Fusarium oxysporum; however, the number of germinated conidia was reduced, showing 85% inhibition five days after treatment in relation to control. Moreover, carotenoid extracts showed 38.5% inhibition of mycelial growth and 85.3% inhibition of conidial germination of A.alternata, five days after treatment. Carotenoid extracts showed less inhibition of mycelial growth (20.3%) in F.oxysporum, with respect to A.alternata; while there was greater inhibition of conidial germination (96%) on the fifth day after treatment. Phenolic and carotenoid extracts from chiltepin may be a promising alternative as a natural fungicide against fungi of agricultural importance. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Biocontrol of Alternaria alternata on cherry tomato fruit by use of marine yeast Rhodosporidium paludigenum Fell & Tallman.

    Science.gov (United States)

    Wang, Yifei; Bao, Yihong; Shen, Danhong; Feng, Wu; Yu, Ting; Zhang, Jia; Zheng, Xiao Dong

    2008-04-30

    The basidiomycetous yeast Rhodosporidium paludigenum Fell & Tallman isolated from the south of East China Sea was evaluated for its activity in reducing postharvest decay of cherry tomatoes caused by Alternaria alternata in vitro and in vivo tests. The results showed that washed cell suspension of R. paludigenum provided better control of A. alternata than any other treatment, while the autoclaved cell culture failed to provide protection against the pathogen. The concentration of antagonist had significant effect on biocontrol effectiveness in vivo: when the concentration of the washed yeast cell suspension was used at 1 x 10(9)cells/ml, the percentage rate of black rot of cherry tomato fruit was only 37%, which was remarkably lower than that treated with water (the control) after 5days of incubation at 25 degrees C. Furthermore, a great biocontrol efficacy of R. paludigenum was observed when it was applied prior to inoculation with A. alternata: the longer the incubation time of R. paludigenum, the lower disease incidence would be. However, there was little efficacy when R. paludigenum was applied after A. alternata inoculation. In addition, on the wounds of cherry tomato, it was observed that R. paludigenum grew rapidly increasing 50-fold during the first 12h at 25 degrees C. To the best of our knowledge, this is a first report concerning that the marine yeast R. paludigenum could be used as a biocontrol agent of postharvest fungal disease.

  9. RESISTÊNCIA DE TOMATEIRO (Lycopersicon esculentum AO PATÓGENO Alternaria solani RESISTANCE OF TOMATO (Lycopersicon esculentum TO Alternaria solani PATHOGEN

    Directory of Open Access Journals (Sweden)

    Wilson Ferreira de Oliveira

    2007-09-01

    Full Text Available

    O objetivo deste trabalho foi avaliar níveis de resistência de variedades comerciais de tomateiro ao patógeno Alternaria solani. Os genótipos são pertencentes ao banco de germoplasma do CNPH-Embrapa, compreendendo híbridos F1, que foram avaliados em condições de campo. Os ensaios foram conduzidos nos campos experimentais da Escola de Agronomia e Engenharia de Alimentos da Universidade Federal de Goiás, em Goiânia-GO, a uma altitude de 730 m, latitude de 16° 41'S e longitude de 49° 17'W. As avaliações foram realizadas aos 36, 43, 50, 57, 64, 71, 78 e 85 dias após o transplantio, combinando-se escala diagramática e de notas. As variedades Ohio 4013 e CNPH 738 foram as mais resistentes entre os materiais tutorados. Entre os materiais rasteiros os mais resistentes foram o híbrido F1 Hawaii 7998 x Monense e Rotam 4. O genótipo Ohio 4013 e híbrido F1 Hawaii 7998 x Monense foram os que mais se destacaram para resistência a este patógeno, podendo ser indicados para futuros programas de melhoramento.

    PALAVRAS-CHAVE: Tomateiro; resistência; Alternaria solani.

    The main objective of this study was to test levels of resistance of commercial varieties, genotypes belonging to the germoplasm bank of CNPH-Embrapa and hibrids F1 of tomat to Alternaria solani, in field condition. The trials were conduced at the experimental fields of the Federal University of Goiás, Goiânia-GO, Brasil. It is located at an altitude of 730 m, latitude of 16° 41'S and longitude of 49° 17'W. The evaluations were accomplished at the 36, 43, 50, 57, 64, 71, 78 and 85 days after the seedlings planting, combining diagramatic scale and grades. Among indeterminate cultivars Ohio 4013 and CNPH 738 were the most resistants. Among determined ones the most

  10. ANTIFUNGAL AND ANTIBACTERIAL POTENTIALITY OF SIX ESSENTIAL OILS EXTRACTED FROM PLANT SOURCE

    OpenAIRE

    DR.LALITHA.V,; DR.KIRAN.B,; DR.RAVEESHA

    2011-01-01

    In vitro evaluation of six essential oils viz., Allium sativum, Capsicum annum Cassia fistula, Coriandrum sativum, Cuminum cyminum and Curcuma longa were tested against ten seed borne fungiof paddy viz., Pyricularia oryzae, Bipolaris oryzae, Alternaria alternata, Tricoconis padwickii, Drechslera tetramera, Drechslera halodes, Curvularia lunata, Fusarium moniliforme, F. oxysprorum andF. solani and five human pathogenic bacteria viz., Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi ,...

  11. The phytoalexin camalexin induces fundamental changes in the proteome of Alternaria brassicicola different from those caused by brassinin.

    Science.gov (United States)

    Pedras, M Soledade C; Minic, Zoran; Abdoli, Abbas

    2014-01-01

    Camalexin is the major phytoalexin produced by Alternaria thaliana, but is absent in Brassica species that usually produce phytoalexin blends containing brassinin and derivatives. The protein profiles of A. brassicicola treated with camalexin were evaluated using proteomics and metabolic analyses and compared with those treated with brassinin. Conidial germination and mycelial growth of A. brassicicola in liquid media amended with camalexin and brassinin showed that fungal growth was substantially slower in presence of camalexin than brassinin; chemical analyses revealed that A. brassicicola detoxified camalexin at much slower rate than brassinin. Two-dimensional gel electrophoresis (2-DE) followed by tryptic digestion and capillary liquid chromatography-mass spectrometric analyses identified 158 different proteins, of which 45 were up-regulated and 113 were down-regulated relative to controls. Venn diagram analyses of differentially expressed proteins in cultures of A. brassicicola incubated with camalexin and brassinin indicated clear differences in the effect of each phytoalexin, with camalexin causing down-regulation of a larger number of proteins than brassinin. Overall, results of this work suggest that each phytoalexin has several different targets in the cells of A. brassicicola, and that camalexin appears to have greater potential to protect cultivated Brassica species against A. brassicicola than brassinin. Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  12. In vitro antifungal activity of four chemotypes of Lippia alba (Verbenaceae essential oils against Alternaria solani (Pleosporeaceae isolates

    Directory of Open Access Journals (Sweden)

    ELISA Z. TOMAZONI

    2016-06-01

    Full Text Available Several volatile natural compounds produced by plant secondary metabolism have been proven to present antimicrobial action, enabling their use in phytopathogen control. They also present low environmental impact when compared to conventional pesticides. Essential oils contain these compounds and can be found in several plant species, such as Lippia alba (Mill. N.E. Brown (Verbenaceae. Essential oils of four chemotypes of L. alba, characterized by their major compounds, namely camphor, citral, linalool and camphor/1,8-cineole, were tested against the phytopathogen Alternaria solani Sorauer (Pleosporaceae, which causes early blight on tomatoes and is responsible for great economic losses regarding production. Essential oils antifungal action was tested in vitro using potato dextrose agar medium with essential oil concentrations at 0.1, 0.5, 1.0, 1.5 and 2.0 µL mL-1. The chemotype that had the best performance was citral, showing significant inhibition compared to the others, starting at the 0.5 µL mL-1 concentration. The essential oil belonging to the linalool chemotype was efficient starting at the 1.5 µL mL-1 concentration. Conversely, the camphor chemotype did not show any action against the phytopathogen. Moreover, the essential oils had no remarkable effect on tomato germination and growth. In conclusion, these essential oils presented fungicidal action against A. solani.

  13. Selection and differentiation of Bacillus spp. Antagonistic to Fusarium oxysporum f.sp. lycopersici and Alternaria solani infecting Tomato.

    Science.gov (United States)

    Shanmugam, Veerubommu; Atri, Kamini; Gupta, Samriti; Kanoujia, Nandina; Naruka, Digvijay Singh

    2011-03-01

    Antagonistic Bacillus spp. displaying in vitro production of siderophore, chitinase, and β-1,3-glucanase were identified from dual culture assays. In independent greenhouse studies, seed bacterization and soil application of Bacillus atrophaeus S2BC-2 challenge inoculated with Fusarium oxysporum f.sp. lycopersici (FOL) and Alternaria solani (AS) recorded low percent disease index of 25.3 and 28.7, respectively, over nonbacterised pathogen control (44.3 and 56.4). The low disease incidence corroborated with tomato growth promotion with high vigor index (8,041.2) and fresh plant weight (82.5 g) on challenge inoculation with FOL. Analysis of root and leaf samples in rhizobacterial treatment challenged with FOL and AS revealed maximum induction of chitinase (1.9 and 1.7 U/mg of protein, respectively) and β-1,3-glucanase (23.5 and 19.2 U/mg of protein, respectively). In native gel activity assays, the rhizobacterial treatment on challenge inoculation strongly expressed three high intensity PO isoforms along with one low intensity isoform. In studies on genetic diversity of the Bacillus strains by repetitive extragenomic palindromic-polymerase chain reaction (REP-PCR) and amplified rDNA restriction analysis (ARDRA) patterns, ARDRA was more highly discriminant than REP-PCR and allowed grouping of the strains and differentiation of the antagonistic strains from other isolates.

  14. In vitro antifungal activity of four chemotypes of Lippia alba (Verbenaceae) essential oils against Alternaria solani (Pleosporeaceae) isolates.

    Science.gov (United States)

    Tomazoni, Elisa Z; Pansera, Márcia R; Pauletti, Gabriel F; Moura, Sidnei; Ribeiro, Rute T S; Schwambach, Joséli

    2016-05-31

    Several volatile natural compounds produced by plant secondary metabolism have been proven to present antimicrobial action, enabling their use in phytopathogen control. They also present low environmental impact when compared to conventional pesticides. Essential oils contain these compounds and can be found in several plant species, such as Lippia alba (Mill.) N.E. Brown (Verbenaceae). Essential oils of four chemotypes of L. alba, characterized by their major compounds, namely camphor, citral, linalool and camphor/1,8-cineole, were tested against the phytopathogen Alternaria solani Sorauer (Pleosporaceae), which causes early blight on tomatoes and is responsible for great economic losses regarding production. Essential oils antifungal action was tested in vitro using potato dextrose agar medium with essential oil concentrations at 0.1, 0.5, 1.0, 1.5 and 2.0 µL mL-1. The chemotype that had the best performance was citral, showing significant inhibition compared to the others, starting at the 0.5 µL mL-1 concentration. The essential oil belonging to the linalool chemotype was efficient starting at the 1.5 µL mL-1 concentration. Conversely, the camphor chemotype did not show any action against the phytopathogen. Moreover, the essential oils had no remarkable effect on tomato germination and growth. In conclusion, these essential oils presented fungicidal action against A. solani.

  15. Mycoherbicidal potential of Alternaria alternata for management of ...

    African Journals Online (AJOL)

    hope&shola

    2010-12-06

    Dec 6, 2010 ... ramosaDevelopment of a PCR-based assay for the detection of. Fusarium oxysporum strain FT2, a potential mycoherbicide of. Orobanche ramosa. Biol. Control, 50: 78-84. Ellison CA, Barreto RW (2004). Prospects for the Management of. Invasive Alien Weeds Using Co-Evolved Fungal Pathogens: A Latin.

  16. Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Dongo, Anita; Pryor, Barry M.

    2008-01-01

    Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species....... The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each...

  17. Specific PCR-based detection of Alternaria helianthi

    DEFF Research Database (Denmark)

    Udayashankar, A.C.; Nayaka, S. Chandra; Archana, B.

    2012-01-01

    Alternaria helianthi is an important seed-borne pathogenic fungus responsible for blight disease in sunflower. The current detection methods, which are based on culture and morphological identification, are time-consuming, laborious and are not always reliable. A PCR-based diagnostic method...... tested. The detection limit of the PCR method was of 10 pg from template DNA. The primers could also detect the pathogen in infected sunflower seed. This species-specific PCR method provides a quick, simple, powerful and reliable alternative to conventional methods in the detection and identification...

  18. Chemical composition and fungicidal activity of the essential oil of Thymus vulgaris against Alternaria citri

    Directory of Open Access Journals (Sweden)

    Erica A. Soto Mendívil

    2006-01-01

    Full Text Available Se analizó químicamente el aceite esencial de tomillo (Thymus vulgaris L. por Cromatografía de Gases/Espectroscopia de Masas y se evaluó su actividad fungicida. Los principales constituyentes fueron borneol (28.4%, timol (16.6%, carvacrol metil eter (9.6%, camfeno (6.9%, α-humulene (6.4% y carvacrol (5.0%. Las pruebas de actividad fungicida (in vitro indicaron que la concentración de 1000ppm del aceite esencial de tomillo fue efectivo para inhibir a Alternaria citri, cuando se adicionó al medio de cultivo agar papa dextrosa

  19. A new perylenequinone from a halotolerant fungus, Alternaria sp. M6.

    Science.gov (United States)

    Zhang, Song-Ya; Li, Zhan-Lin; Bai, Jiao; Wang, Yu; Zhang, Li-Min; Wu, Xin; Hua, Hui-Ming

    2012-01-01

    To study the metabolites of a halotolerant fungus Alternaria sp. M6. The metabolites were isolated and purified by various chromatographic techniques. Their structures were determined on the basis of physical properties and spectroscopic data. Nine compounds were isolated and identified as 8β-chloro-3, 6aα, 7β, 9β, 10-pentahydroxy-9, 8, 7, 6a-tetrahydroperylen-4(6aH)-one (1), alterperylenol (2), dihydroalterperylenol (3), adenine (4), adenosine (5), deoxyadenosine (6), guanosine (7), tryptophan (8), and hexadecanoic acid (9). Compound 1 is a new perylenequinone. Copyright © 2012 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  20. An association of Alternaria alternata and Scopulariopsis brevicaulis in cutaneous phaeohyphomycosis

    Directory of Open Access Journals (Sweden)

    Anandan V

    2008-01-01

    Full Text Available Rare molds are increasingly emerging as a cause of deep and invasive fungal infections. We report here a rare case of cutaneous phaeohyphomycosis of the lower limbs due to Alternaria alternata associated with extra-ungual localization of Scopulariopsis brevicaulis. Diagnosis was made based on repeated, direct, microscopic mycological and histological examinations. The study revealed hyphae and fungal cells in a granulomatous dermal infiltrate. Identification of the molds was based on macroscopic appearance on culture of samples from the lesions on Sabouraud′s dextrose agar and microscopic appearance on Lactophenol cotton blue following slide culture.

  1. Maculosin, a host-specific phytotoxin for spotted knapweed from Alternaria alternata

    Science.gov (United States)

    Stierle, Andrea C.; Cardellina, John H.; Strobel, Gary A.

    1988-01-01

    Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10-5 M; synthetic maculosin possessed chemical and biological activities identical to those of the natural product. Other diketopiperazines isolated from the fungus possessed either less activity or none at all. In tests against 19 plant species, maculosin was phytotoxic only to spotted knapweed. Thus maculosin is a host-specific phytotoxin from a weed pathogen. PMID:16593989

  2. Natural zinniol derivatives from Alternaria tagetica. Isolation, synthesis, and structure-activity correlation.

    Science.gov (United States)

    Gamboa-Angulo, M Marcela; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Alejos-González, Fátima; Delgado-Lamas, Guillermo; Peña-Rodríguez, Luis M

    2002-02-27

    Two novel phytotoxins, 8-zinniol methyl ether (5) and 8-zinniol acetate (6), in addition to 6-(3',3'-dimethylallyloxy)-4-methoxy-5-methylphthalide (2), 5-(3',3'-dimethylallyloxy)-7-methoxy-6-methylphthalide (3), and the novel metabolites 8-zinniol 2-(phenyl)ethyl ether (4) and 7-zinniol acetate (7) have been identified as natural zinniol derivatives from the organic crude extract of Alternaria tagetica culture filtrates. Using zinniol as the starting material, phytotoxin 5 was synthesized, together with a number of synthetic intermediates (8-13). Both natural and synthetic zinniol derivatives were evaluated in the leaf-spot bioassay against marigold leaves (Tagetes erecta).

  3. [Peculiarities of linear growth of the melanin-containing fungi Cladosporium sphaerospermum Penz. and Alternaria alternata (Fr.) Keissler].

    Science.gov (United States)

    Vember, V V; Zhdanova, N N

    2001-01-01

    Results on determination of radial (linear) growth rate of melanin-containing fungi Cladosporium sphaerospermum Penz. and Alternaria alternata (Fr.) Keissler concerning place of their isolation and ecologic peculiarities are presented in the paper. Essential differences, as to all studied indices of the strains of C. sphaerospermum strains, isolated from premices of the ChNPP 4th unit from the control strains of this species have been established. Only strain 34 of C. sphaerospermum, isolated from the cable driving region of the "Shelter" object, which did not differ from the control strains as to all the studied indices, made the exception. The radial growth rate was 2-4 times as low and variability amplitude 10-30 times as high in strains 60 and 5-1 of C. sphaerospermum, (which suffered high radiation load), as in the control strains of this species. The radial growth rate of C. sphaerospermum studied strains was an order lower as a whole than that of A. alternata strains. All the above said evidence for implementation of K-type vital strategy by C. sphaerospermum species and in this connection one can suppose its active growth on the surface of walls and ferroconcrete structures of the ChNPP 4th unit. Absence of differences, as to the studied radial growth indices, between A. alternata strains isolated from the ChNPP 4th unit premices and control strains of the species can evidence for the existence of A. alternata species under the conditions of high radioactivity in the surviving state.

  4. Cholinesterase inhibitor (Altenuene) from an endophytic fungus Alternaria alternata: optimization, purification and characterization.

    Science.gov (United States)

    Bhagat, J; Kaur, A; Kaur, R; Yadav, A K; Sharma, V; Chadha, B S

    2016-10-01

    The aim of this study was to screen endophytic fungi isolated from Vinca rosea for their potential to produce acetylcholinesterase (AChE) inhibitors. Endophytic fungi isolated from V. rosea (Catharanthus roseus), were screened for AChE inhibitor production using Ellman's method. Maximum inhibition against AChE (78%) was observed in an isolate VS-10, identified to be Alternaria alternata on morphological and molecular basis. The isolate also inhibited butyrylcholinesterase (73%). Significant increase (1·3 fold) was achieved after optimization of process parameters using one variable at time approach. The inhibitor was purified using chromatographic techniques. The structure elucidation of the inhibitor was carried out using spectroscopic techniques and was identified to be 'altenuene'. The purified inhibitor possessed antioxidant potential as revealed by dot blot assay. The insecticidal potential of purified inhibitor was evaluated by feeding Spodoptora litura on diet amended with inhibitor. It evinced significant larval mortality. Endophytic A. alternata can serve as a source of dual cholinesterase inhibitor 'altenuene' with significant antioxidant and insecticidal activity. This is the first report on acetylcholinestearse inhibitory activity of altenuene. Alternaria alternata has the potential to produce a dual ChE inhibitor with antioxidant activity useful in the treatment of neurodegenerative disorders and in agriculture as biocontrol agent. © 2016 The Society for Applied Microbiology.

  5. Furfural from Pine Needle Extract Inhibits the Growth of a Plant Pathogenic Fungus, Alternaria mali

    Science.gov (United States)

    Yoo, Sun Kyun; Moon, Sung-Kwon; Lee, Ung-Soo

    2007-01-01

    The antifungal effect of pine needle extract prepared by a distinguishable extraction method and the dry distillation method, was examined. The effect of this extract itself was insignificant. The chemical components of pine needle extract were then investigated by gas chromatographic analysis, and four chemical components, acetol, furfural, 5-methyl furfural, and terpine-4-ol, were identified. The antifungal effects of those four chemical components against Alternaria mali (A. mali), an agent of Alternaria blotch of apple, were then examined. It was observed that the minimum inhibitory concentrations (MICs) were 6.25, 0.78, 0.78, and 12.5 (mg/ml) of acetol, furfural, 5-methyl furfural, and terpine-4-ol, respectively. MICs of furfural and 5-methyl furfural had the same order of magnitude as that of an antifungal agrochemical, chlorothalonil. Although furfural itself can not be completely substituted for an antifungal agrochemical, a partial mixture of furfural and antifungal agrochemical may be used as a substitute. The use of agrochemicals for the prevention of plant disease caused by pathogenic fungus such as A. mali could be partially reduced by the application of this mixture. PMID:24015067

  6. Studies on the cost-effective management of Alternaria blight of rapeseed-mustard (Brassica spp.

    Directory of Open Access Journals (Sweden)

    M.M. Khan

    2007-08-01

    Full Text Available Three systemic fungicides: Topsin-M (Thiophanate methyl, 70%WP, Ridomil MZ (Mancozeb, 64% + Metalaxyl, 8%WP, and Bavistin (Carbendazim, 50%WP alone and in combination with four non-systemic fungicides Captaf (Captan, 50%WP, Indofil M-45 (Mancozeb, 75%WP, Indofil Z-78 (Zineb, 75%WP, and Thiram (Thiram, 75%WP were evaluated both in vitro and in vivo for their effectiveness to manage Alternaria blight of rapeseedmustard caused by Alternaria brassicae. A pure culture of the pathogenic fungus was applied in the field at 2 g colonized sorghum seeds kg-1 soil. All the fungicides were evaluated for their efficacy at various concentrations, 50, 100, 150, 200 and 500 ppm, and were sprayed in the field at 0.2% a.i. l-1. All fungicides significantly reduced the severity of the disease but Ridomil MZ was most effective. Topsin-M at a concentration of 500 ppm was the most effective in reducing radial growth of the pathogenic fungi (74.2%. Ridomil MZ reduced disease severity by 32% and was followed in effectiveness by the combination Bavistin+Captaf (26.5%. Maximum yield was obtained in plots sprayed with Bavistin+Captaf (1198 kg ha-1 followed by Bavistin+Indofil Z-78 (1172 kg ha-1. It was worth noting that the highest net profit as well as the highest cost-benefit ratio was obtained with Bavistin+Indofil Z-78 (1:3.2, followed by Bavistin+Captaf (1:1.3.

  7. Participation of the phosphoinositide metabolism in the hypersensitive response of Citrus limon against Alternaria alternata

    Directory of Open Access Journals (Sweden)

    XIMENA ORTEGA

    2001-01-01

    Full Text Available Lemon seedlings inoculated with Alternaria alternata develop a hypersensitive response (HR that includes the induction of Phenylalanine ammonia-lyase (PAL, E. C. 4.3.1.5 and the synthesis of scoparone. The signal transduction pathway involved in the development of this response is unknown. We used several inhibitors of the Phosphoinositide (PI animal system to study a possible role of Inositol-1,4,5-triphosphate (IP3 in the transduction of the fungal conidia signal in Citrus limon. The HR was only partially inhibited by EGTA, suggesting that not only external but internal calcium as well are necessary for a complete development of the HR. In this plant system, Alternaria alternata induced an early accumulation of the second messenger IP3. When lemon seedlings were watered long term with LiCl, an inhibitor of the phosphoinositide cycle, the IP3 production was reduced, and the LiCl-watered plants could neither induce PAL nor synthesize scoparone in response to fungal conidia. Furthermore, neomycin, a Phospholipase C (PLC, E. C. 3.1.4.3 inhibitor, also inhibited PAL induction and scoparone synthesis in response to A. alternata. These results suggest that IP3 could be involved in the signal transduction pathway for the development of the HR of Citrus limon against A. alternata

  8. Multilocus phylogeny and MALDI-TOF analysis of the plant-pathogenic species Alternaria dauci and relatives

    NARCIS (Netherlands)

    Brun, S.; Madrid, H.; Gerrits van den Ende, A.H.G.; Andersen, B.; Marinach-Patrice, C.; Mazier, D.; de Hoog, G.S.

    2013-01-01

    The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of

  9. Overexpression of a tea flavanone 3-hydroxylase gene confers tolerance to salt stress and Alternaria solani in transgenic tobacco.

    Science.gov (United States)

    Mahajan, Monika; Yadav, Sudesh Kumar

    2014-08-01

    Flavan-3-ols are the major flavonoids present in tea (Camellia sinensis) leaves. These are known to have antioxidant and free radical scavenging properties in vitro. Flavanone 3-hydroxylase is considered to be an important enzyme of flavonoid pathway leading to accumulation of flavan-3-ols in tea. Expression analysis revealed the upregulation in transcript levels of C. sinensis flavanone 3-hydroxylase (CsF3H) encoding gene under salt stress. In this study, the biotechnological potential of CsF3H was evaluated by gene overexpression in tobacco (Nicotiana tabacum cv. Xanthi). Overexpression of CsF3H cDNA increased the content of flavan-3-ols in tobacco and conferred tolerance to salt stress and fungus Alternaria solani infection. Transgenic tobaccos were observed for increase in primary root length, number of lateral roots, chlorophyll content, antioxidant enzyme expression and their activities. Also, they showed lesser malondialdehyde content and electrolyte leakage compared to control tobacco plants. Further, transgenic plants produced higher degree of pectin methyl esterification via decreasing pectin methyl esterase (PME) activity in roots and leaves under unstressed and salt stressed conditions. The effect of flavan-3-ols on pectin methyl esterification under salt stressed conditions was further validated through in vitro experiments in which non-transgenic (wild) tobacco seedlings were exposed to salt stress in presence of flavan-3-ols, epicatechin and epigallocatechin. The in vitro exposed seedlings showed similar trend of increase in pectin methyl esterification through decreasing PME activity as observed in CsF3H transgenic lines. Taken together, overexpression of CsF3H provided tolerance to salt stress and fungus A. solani infection to transgenic tobacco through improved antioxidant system and enhanced pectin methyl esterification.

  10. Porritoxins, metabolites of Alternaria porri, as anti-tumor-promoting active compounds.

    Science.gov (United States)

    Horiuchi, Masayuki; Tokuda, Harukuni; Ohnishi, Keiichiro; Yamashita, Masakazu; Nishino, Hoyoku; Maoka, Takashi

    2006-02-01

    To search for possible cancer chemopreventive agents from natural sources, we performed primary screening of metabolites of Alternaria porri by examining their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. The ethyl acetate extract of A. porri showed the inhibitory effect on EBV-EA activation. Three porritoxins (1-3) were obtained as inhibitory active compounds for EBV-EA from ethyl acetate extract. 6-(3',3'-Dimethylallyloxy)-4-methoxy-5-methylphthalide (2) showed the strongest activity among them. Inhibitory effect of porritoxin (1) and (2) was superior to that of beta-carotene, a well-known anti-tumor promoter. Furthermore, the structure-activity correlation of porritoxins and their related compounds were discussed.

  11. Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila.

    Science.gov (United States)

    Andersen, Birgitte; Dongo, Anita; Pryor, Barry M

    2008-02-01

    Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species. The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each with their own specific metabolite profiles, and that A. solani and A. tomatophila both produce altersolanol A, altertoxin I, and macrosporin. By using automated chemical image analysis and other multivariate statistic analyses, three sets of species-specific metabolites could be selected, one each for A. dauci, A. solani, and A. tomatophila.

  12. Bostrycin and 4-deoxybostrycin: two nonspecific phytotoxins produced by Alternaria eichhorniae.

    Science.gov (United States)

    Charudattan, R; Rao, K V

    1982-04-01

    Two crystalline red pigments with phytotoxic activity were isolated from culture filtrates of Alternaria eichhorniae, a pathogen of the water hyacinth Eichhornia crassipes. The pigments were present in the ratio of 4:1 and were identified as bostrycin and 4-deoxybostrycin, respectively. This is the first isolation of 4-deoxybostrycin from a natural source. Bostrycin, 4-deoxybostrycin, and their isopropylidene derivatives induced necrosis on tested plant leaves comparable to the A. eichhorniae-induced necrosis on water hyacinth. The lowest phytotoxic concentrations of crystalline bostrycin and 4-deoxybostrycin on water hyacinth leaves were about 7 and 30 microgram/ml, respectively. Both substances were inhibitory to Bacillus subtilis but were inactive against the fungus Geotrichum candidum.

  13. Three New Resveratrol Derivatives from the Mangrove Endophytic Fungus Alternaria sp.

    Directory of Open Access Journals (Sweden)

    Jinhua Wang

    2014-05-01

    Full Text Available Three new resveratrol derivatives, namely, resveratrodehydes A–C (1–3, were isolated from the mangrove endophytic fungus Alternaria sp. R6. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. All compounds showed broad-spectrum inhibitory activities against three human cancer cell lines including human breast MDA-MB-435, human liver HepG2, and human colon HCT-116 by MTT assay (IC50 < 50 μM. Among them, compounds 1 and 2 both exhibited marked cytotoxic activities against MDA-MB-435 and HCT-116 cell lines (IC50 < 10 μM. Additionally, compounds 1 and 3 showed moderate antioxidant activity by DPPH radical scavenging assay.

  14. Effects of gamma irradiation on the fungus Alternaria alternata and on mycotoxins Alternariol and Alternariol monomethyl ether in artificially contaminated cereal samples;Efeitos da radiacao gama no fungo Alternaria alternata e nas micotoxinas Alternariol e Alternariol monometil eter em amostras de cereais artificialmente contaminadas

    Energy Technology Data Exchange (ETDEWEB)

    Braghini, Raquel

    2009-07-01

    The present study aimed to evaluate the effects of different gamma irradiation doses on the growth of Alternaria alternata and on production of mycotoxins Alternariol (AOH) and Alternariol Monomethyl Ether (AME) in cereal samples. The results showed a significant reduction in the number of CFU/g in rice grains and sunflower seeds, which were proportional to radiation dose used. However, in corn and wheat grains was observed an increase in the number of CFU/g with the increase of gamma irradiation. The radiation doses used resulted in a reduction of AOH levels. In rice and corn grains, the production of AOH was highest in the group irradiated with 5 kGy. Similar result was obtained with relation to AME. Scanning electron microscopy made it possible to visualize structural alterations on A. alternata induced by the different g-radiation doses used. Analysis of irradiated AOH and AME toxins standards did not show any alteration comparing to the control group. (author)

  15. Alternaria sp. MG1, a resveratrol-producing fungus: isolation, identification, and optimal cultivation conditions for resveratrol production.

    Science.gov (United States)

    Shi, Junling; Zeng, Qin; Liu, Yanlin; Pan, Zhongli

    2012-07-01

    Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4'-trihydroxystilbene) has attracted great research interest. The objective of this study was to identify microorganisms from selected plants that produce resveratrol and to optimize the conditions for resveratrol production. Endophytes from Merlot wine grapes (Vitis vinifera L. cv. Merlot), wild Vitis (Vitis quinquangularis Rehd.), and Japanese knotweed (Polygonum cuspidatum Siebold & Zucc.) were isolated, and their abilities to produce resveratrol were evaluated. A total of 65 isolates were obtained and 21 produced resveratrol (6-123 μg/L) in liquid culture. The resveratrol-producing isolates belonged to seven genera, Botryosphaeria, Penicillium, Cephalosporium, Aspergillus, Geotrichum, Mucor, and Alternaria. The resveratrol-producing capability decreased or was completely lost in most isolates after three rounds of subculture. It was found that only the strain Alternaria sp. MG1 (isolated from cob of Merlot using GA1 medium) had stable and high resveratrol-producing capability in all subcultures. During liquid cultivation of Alternaria sp. MG1 in potato dextrose medium, the synthesis of resveratrol began on the first day, increased to peak levels on day 7, and then decreased sharply thereafter. Cell growth increased during cultivation and reached a stable and high level of biomass after 5 days. The best fermentation conditions for resveratrol production in liquid cultures of Alternaria sp. MG1 were an inoculum size of 6 %, a medium volume of 125 mL in a 250-mL flask, a rotation speed of 101 rpm, and a temperature of 27 °C.

  16. Pengaruh Kepekatan Esktrak Daun Nimba Terhadap Penekanan Serangan (Alternaria porri (EII.CIF) Pada Tanaman Bawang Merah (Allium ascalonicum L)

    OpenAIRE

    Enni Sahrani Nst

    2009-01-01

    Penelitian bertujuan untuk mengetahui pengaruh kepekatan ekstrak daun mimba terhadap penekanan Alternaria porri (EII. Cif.) pada tanaman bawang merah. Penelitian ini dilaksanakan di BPTP (Balai Pengkajian Teknologi Pertanian) Sumatera Utara, pada ketinggian tempat lebih kurang 25 m dpl. Penelitian dimulai bulan Nopember 2007 sampai Januari 2008. Penelitian ini menggunakan metode Rancangan Acak Kelompok Non factorial yang terdiri dari P0 (Kontrol tanpa perlakuan), P1 (100 gr daun mimba d...

  17. A novel isoindoline, porritoxin sulfonic acid, from Alternaria porri and the structure-phytotoxicity correlation of its related compounds.

    Science.gov (United States)

    Horiuchi, Masayuki; Ohnishi, Keiichiro; Iwase, Noriyasu; Nakajima, Yoshikazu; Tounai, Kenji; Yamashita, Masakazu; Yamada, Yasumasa

    2003-07-01

    Novel zinniol-related compound 3, named porritoxin sulfonic acid, with an isoindoline skeleton was isolated from the culture liquid of Alternaria porri. The structure was determined to be 2-(2"-sulfoethyl)-4-methoxy-5-methyl-6-(3'-methyl-2'-butenyloxy)-2,3-dihydro-1H-isoindol-1-one. The phytotoxic activities of three isoindolines (1-3) were evaluated in a seedling-growth assay against stone leek and lettuce.

  18. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis) Ciferri

    OpenAIRE

    Satyabrata Nanda; Subodh Kumar Chand; Purander Mandal; Pradyumna Tripathy; Raj Kumar Joshi

    2016-01-01

    Purple blotch, caused by Alternaria porri (Ellis) Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession ?CBT-Ac77? and cultivar ?Arka Kalyan? were observed to be highly resistant. In vitro inoculation...

  19. Alt a 1 allergen homologs from Alternaria and related taxa: analysis of phylogenetic content and secondary structure.

    Science.gov (United States)

    Hong, Soon Gyu; Cramer, Robert A; Lawrence, Christopher B; Pryor, Barry M

    2005-02-01

    A gene for the Alternaria major allergen, Alt a 1, was amplified from 52 species of Alternaria and related genera, and sequence information was used for phylogenetic study. Alt a 1 gene sequences evolved 3.8 times faster and contained 3.5 times more parsimony-informative sites than glyceraldehyde-3-phosphate dehydrogenase (gpd) sequences. Analyses of Alt a 1 gene and gpd exon sequences strongly supported grouping of Alternaria spp. and related taxa into several species-groups described in previous studies, especially the infectoria, alternata, porri, brassicicola, and radicina species-groups and the Embellisia group. The sonchi species-group was newly suggested in this study. Monophyly of the Nimbya group was moderately supported, and monophyly of the Ulocladium group was weakly supported. Relationships among species-groups and among closely related species of the same species-group were not fully resolved. However, higher resolution could be obtained using Alt a 1 sequences or a combined dataset than using gpd sequences alone. Despite high levels of variation in amino acid sequences, results of in silico prediction of protein secondary structure for Alt a 1 demonstrated a high degree of structural similarity for most of the species suggesting a conservation of function.

  20. Role of the pathotype-specific ACRTS1 gene encoding a hydroxylase involved in the biosynthesis of host-selective ACR-toxin in the rough lemon pathotype of Alternaria alternata.

    Science.gov (United States)

    Izumi, Yuriko; Kamei, Eri; Miyamoto, Yoko; Ohtani, Kouhei; Masunaka, Akira; Fukumoto, Takeshi; Gomi, Kenji; Tada, Yasuomi; Ichimura, Kazuya; Peever, Tobin L; Akimitsu, Kazuya

    2012-08-01

    The rough lemon pathotype of Alternaria alternata produces host-selective ACR-toxin and causes Alternaria leaf spot disease of the rootstock species rough lemon (Citrus jambhiri) and Rangpur lime (C. limonia). Genes controlling toxin production were localized to a 1.5-Mb chromosome carrying the ACR-toxin biosynthesis gene cluster (ACRT) in the genome of the rough lemon pathotype. A genomic BAC clone containing a portion of the ACRT cluster was sequenced which allowed identification of three open reading frames present only in the genomes of ACR-toxin producing isolates. We studied the functional role of one of these open reading frames, ACRTS1 encoding a putative hydroxylase, in ACR-toxin production by homologous recombination-mediated gene disruption. There are at least three copies of ACRTS1 gene in the genome and disruption of two copies of this gene significantly reduced ACR-toxin production as well as pathogenicity; however, transcription of ACRTS1 and production of ACR-toxin were not completely eliminated due to remaining functional copies of the gene. RNA-silencing was used to knock down the remaining ACRTS1 transcripts to levels undetectable by reverse transcription-polymerase chain reaction. The silenced transformants did not produce detectable ACR-toxin and were not pathogenic. These results indicate that ACRTS1 is an essential gene in ACR-toxin biosynthesis in the rough lemon pathotype of A. alternata and is required for full virulence of this fungus.

  1. Genetically based location from triploid populations and gene ontology of a 3.3-mb genome region linked to Alternaria brown spot resistance in citrus reveal clusters of resistance genes.

    Directory of Open Access Journals (Sweden)

    José Cuenca

    Full Text Available Genetic analysis of phenotypical traits and marker-trait association in polyploid species is generally considered as a challenge. In the present work, different approaches were combined taking advantage of the particular genetic structures of 2n gametes resulting from second division restitution (SDR to map a genome region linked to Alternaria brown spot (ABS resistance in triploid citrus progeny. ABS in citrus is a serious disease caused by the tangerine pathotype of the fungus Alternaria alternata. This pathogen produces ACT-toxin, which induces necrotic lesions on fruit and young leaves, defoliation and fruit drop in susceptible genotypes. It is a strong concern for triploid breeding programs aiming to produce seedless mandarin cultivars. The monolocus dominant inheritance of susceptibility, proposed on the basis of diploid population studies, was corroborated in triploid progeny. Bulk segregant analysis coupled with genome scan using a large set of genetically mapped SNP markers and targeted genetic mapping by half tetrad analysis, using SSR and SNP markers, allowed locating a 3.3 Mb genomic region linked to ABS resistance near the centromere of chromosome III. Clusters of resistance genes were identified by gene ontology analysis of this genomic region. Some of these genes are good candidates to control the dominant susceptibility to the ACT-toxin. SSR and SNP markers were developed for efficient early marker-assisted selection of ABS resistant hybrids.

  2. Genetically based location from triploid populations and gene ontology of a 3.3-mb genome region linked to Alternaria brown spot resistance in citrus reveal clusters of resistance genes.

    Science.gov (United States)

    Cuenca, José; Aleza, Pablo; Vicent, Antonio; Brunel, Dominique; Ollitrault, Patrick; Navarro, Luis

    2013-01-01

    Genetic analysis of phenotypical traits and marker-trait association in polyploid species is generally considered as a challenge. In the present work, different approaches were combined taking advantage of the particular genetic structures of 2n gametes resulting from second division restitution (SDR) to map a genome region linked to Alternaria brown spot (ABS) resistance in triploid citrus progeny. ABS in citrus is a serious disease caused by the tangerine pathotype of the fungus Alternaria alternata. This pathogen produces ACT-toxin, which induces necrotic lesions on fruit and young leaves, defoliation and fruit drop in susceptible genotypes. It is a strong concern for triploid breeding programs aiming to produce seedless mandarin cultivars. The monolocus dominant inheritance of susceptibility, proposed on the basis of diploid population studies, was corroborated in triploid progeny. Bulk segregant analysis coupled with genome scan using a large set of genetically mapped SNP markers and targeted genetic mapping by half tetrad analysis, using SSR and SNP markers, allowed locating a 3.3 Mb genomic region linked to ABS resistance near the centromere of chromosome III. Clusters of resistance genes were identified by gene ontology analysis of this genomic region. Some of these genes are good candidates to control the dominant susceptibility to the ACT-toxin. SSR and SNP markers were developed for efficient early marker-assisted selection of ABS resistant hybrids.

  3. Identification and antifungal activity of an actinomycete strain against Alternaria spp.

    Directory of Open Access Journals (Sweden)

    Fen Gao

    2014-10-01

    Full Text Available Alternaria alternata (Fries Keissler is a phytopathogenic fungus responsible for tobacco brown spot disease. This study aims to evaluate the antifungal activity of strain 163 against A. alternata and clarify its taxonomic status. The evaluation of the antifungal activity of strain 163 and its bacteria-free filtrate of fermentation broth was done through measuring the diameters of inhibition zones, and testing the antimicrobial spectrum and the inhibition effect on mycelial growth in vitro. The biocontrol activity of the bacteria-free filtrate in vivo was evaluated by using detached tobacco leaves method and assaying the inhibition rate to disease incidence in growth chamber. A polyphasic approach was taken in the identification of strain 163. The bacterial strain 163 showed inhibitory effect in vitro against A. alternata. The bacteria-free filtrate of the strain 163 fermentation broth showed a 56.7% inhibition rate in a detached leaf assay. In growth chamber conditions, it showed greater biocontrol activity when applied before plants being inoculated with A. alternata than after, the inhibition rate being 46.05%. Investigations into the morphological, cultural, physiological and biochemical properties of strain 163 found it to be most similar to Streptomyces microflavus. Its classification into cell wall type I and sugar type C further confirmed its Streptomyces characteristics. Construction of a phylogenetic tree based on 16S rDNA verified that strain 163 was most closely related to Streptomyces microflavus. From polyphasic taxonomical analysis, strain 163 was found to be identical to S. microflavus.

  4. Role of mannitol metabolism in the pathogenicity of the necrotrophic fungus Alternaria brassicicola

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    Benoit eCalmes

    2013-05-01

    Full Text Available In this study, the physiological functions of fungal mannitol metabolism in the pathogenicity and protection against environmental stresses were investigated in the necrotrophic fungus Alternaria brassicicola. Mannitol metabolism was examined during infection of Brassica oleracea leaves by sequential HPLC quantification of the major soluble carbohydrates and expression analysis of genes encoding two proteins of mannitol metabolism, i.e. a mannitol dehydrogenase (AbMdh, and a mannitol-1-phosphate dehydrogenase (AbMpd. Knockout mutants deficient for AbMdh or AbMpd and a double mutant lacking both enzyme activities were constructed. Their capacity to cope with various oxidative and drought stresses and their pathogenic behaviour were evaluated. Metabolic and gene expression profiling indicated an increase in mannitol production during plant infection. Depending on the mutants, distinct pathogenic processes, such as leaf and silique colonization, sporulation, survival on seeds, were impaired by comparison to the wild-type. This pathogenic alteration could be partly explained by the differential susceptibilities of mutants to oxidative and drought stresses. These results highlight the importance of mannitol metabolism with respect to the ability of A. brassicicola to efficiently accomplish key steps of its pathogenic life cycle.

  5. PRODUCTIVE POTENTIAL OF THE CHERRY TOMATO GENOTYPE GROUP BEFORE INFECTION BY Alternaria tomatophila

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    HUGO CESAR RODRIGUES MOREIRA CATÃO

    2017-01-01

    Full Text Available Early blight (caused by Alternaria tomatophila is a major disease of tomato with no resistant cultivars. Thus, it is necessary to identify sources of resistance and productive genotypes for the development of new cultivars. Therefore, this study aimed to evaluate the productive potential of cherry tomato genotypes grown in the summer / fall, the severity of early blight on leaves and the incidence of disease in fruits. The treatments consisted of Carolina tomato genotypes, Cereja Vermelho, CH 152 and CLN1561A. The experimental design consisted of randomized blocks with six replications, and the experimental plot had 16 plants. The following characteristics were evaluated: area under the disease progress curve (AUDPC, average number of microinjuries on the fruits (MF, average number of fruits per bunch (NFC, average number of bunches per plant (NCP, average number of fruits per plant (NFP, average yield, number of fruits with incidence of early blight per plant (NFI and the severity of early blight in leaves (%. The cherry tomato genotype CH152 showed tolerance to early blight with a smaller area under the disease progress curve, lower severity and fruits with incidence of A. tomatophila were not observed in this genotype. The CH152 had the highest number of fruits per bunch, greater number of bunches per plant, higher number of fruits per plant and higher productivity. This line has great potential of being integrated into breeding programs.

  6. Plasma-Based Degradation of Mycotoxins Produced by Fusarium, Aspergillus and Alternaria Species

    Directory of Open Access Journals (Sweden)

    Lars ten Bosch

    2017-03-01

    Full Text Available The efficacy of cold atmospheric pressure plasma (CAPP with ambient air as working gas for the degradation of selected mycotoxins was studied. Deoxynivalenol, zearalenone, enniatins, fumonisin B1, and T2 toxin produced by Fusarium spp., sterigmatocystin produced by Aspergillus spp. and AAL toxin produced by Alternaria alternata were used. The kinetics of the decay of mycotoxins exposed to plasma discharge was monitored. All pure mycotoxins exposed to CAPP were degraded almost completely within 60 s. Degradation rates varied with mycotoxin structure: fumonisin B1 and structurally related AAL toxin were degraded most rapidly while sterigmatocystin exhibited the highest resistance to degradation. As compared to pure compounds, the degradation rates of mycotoxins embedded in extracts of fungal cultures on rice were reduced to a varying extent. Our results show that CAPP efficiently degrades pure mycotoxins, the degradation rates vary with mycotoxin structure, and the presence of matrix slows down yet does not prevent the degradation. CAPP appears promising for the decontamination of food commodities with mycotoxins confined to or enriched on surfaces such as cereal grains.

  7. Chemical constituents of marine mangrove-derived endophytic fungus Alternaria tenuissima EN-192

    Science.gov (United States)

    Sun, Hong; Gao, Shushan; Li, Xiaoming; Li, Chunshun; Wang, Bingui

    2013-03-01

    A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN-192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted in the isolation of nine known secondary metabolites, including four indole-diterpenoids: penijanthine A ( 1), paspaline ( 2), paspalinine ( 3), and penitrem A ( 4); three tricycloalternarene derivatives: tricycloalternarene 3a ( 5), tricycloalternarene 1b ( 6), and tricycloalternarene 2b ( 7); and two alternariol congeners: djalonensone ( 8) and alternariol ( 9). The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature. The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum, with inhibition zone diameters of 8 and 9 mm, respectively, at 100 μg/disk. To the best of our knowledge, this is the first report on the secondary metabolites of mangrove-derived A lternaria tenuissima and also the first report of the isolation of indole-diterpenoids from fungal genus A lternaria.

  8. BIOUTILIZATION OF GRAPE WASTE FOR EXOPOLYSACCHARIDE PRODUCTION USING ALTERNARIA ALTERNATA NON-PIGMENT STRAIN

    International Nuclear Information System (INIS)

    MELEIGY, S.A.

    2009-01-01

    In the present investigation, five mutant strains from A. alternate were isolated after exposure to gamma irradiation at dose level 8 kGy. The mutant isolated strains (MIS) were non-producing dark pigment and producing polysaccharide. The mutant isolated strain (MIS) belong to the Alternaria alternata MIS (1-5). In shake flask experiments, the exopolysaccharide (EPS) production was 2.90-5.24 g/l and biomass 5.8-8.31g/l. The effect of some fermentation conditions on grape wastes by A. alternata were investigated to produce EPS using gamma irradiation and non-pigment strain. The economical optimum fermentation condition for the highest EPS production by MIS4 when grown on grape waste containing 150 g/l sugar, incubation temperature 28 o C, pH 7 with addition of both 2 % yeast extract and 1.5 % surfactant triton x-100 achieved 14.68 g/l EPS and 6.22 g/l biomass

  9. Identification and Bioactivity of Compounds from the Mangrove Endophytic Fungus Alternaria sp.

    Directory of Open Access Journals (Sweden)

    Jinhua Wang

    2015-07-01

    Full Text Available Racemic new cyclohexenone and cyclopentenone derivatives, (±-(4R*,5S*,6S*-3-amino-4,5,6-trihydroxy-2-methoxy-5-methyl-2-cyclohexen-1-one (1 and (±-(4S*,5S*-2,4,5-trihydroxy-3-methoxy-4-methoxycarbonyl-5-methyl-2-cyclopenten-1-one (2, and two new xanthone derivatives 4-chloro-1,5-dihydroxy-3-hydroxymethyl-6-methoxycarbonyl-xanthen-9-one (3 and 2,8-dimethoxy-1,6-dimethoxycarbonyl-xanthen-9-one (4, along with one known compound, fischexanthone (5, were isolated from the culture of the mangrove endophytic fungus Alternaria sp. R6. The structures of these compounds were elucidated by analysis of their MS (Mass, one and two dimensional NMR (nuclear magnetic resonance spectroscopic data. Compounds 1 and 2 exhibited potent ABTS [2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid] scavenging activities with EC50 values of 8.19 ± 0.15 and 16.09 ± 0.01 μM, respectively. In comparison to Triadimefon, compounds 2 and 3 exhibited inhibitory activities against Fusarium graminearum with minimal inhibitory concentration (MIC values of 215.52 and 107.14 μM, respectively, and compound 3 exhibited antifungal activity against Calletotrichum musae with MIC value of 214.29 μM.

  10. Green Chemistry Approach for the Synthesis of Gold Nanoparticles Using the Fungus Alternaria sp.

    Science.gov (United States)

    Dhanasekar, Naresh Niranjan; Rahul, Ganga Ravindran; Narayanan, Kannan Badri; Raman, Gurusamy; Sakthivel, Natarajan

    2015-07-01

    The synthesis of gold nanoparticles has gained tremendous attention owing to their immense applications in the field of biomedical sciences. Although several chemical procedures are used for the synthesis of nanoparticles, the release of toxic and hazardous by-products restricts their use in biomedical applications. In the present investigation, gold nanoparticles were synthesized biologically using the culture filtrate of the filamentous fungus Alternaria sp. The culture filtrate of the fungus was exposed to three different concentrations of chloroaurate ions. In all cases, the gold ions were reduced to Au(0), leading to the formation of stable gold nanoparticles of variable sizes and shapes. UV-Vis spectroscopy analysis confirmed the formation of nanoparticles by reduction of Au(3+) to Au(0). TEM analysis revealed the presence of spherical, rod, square, pentagonal, and hexagonal morphologies for 1 mM chloroaurate solution. However, quasi-spherical and spherical nanoparticles/heart-like morphologies with size range of about 7-13 and 15-18 nm were observed for lower molar concentrations of 0.3 and 0.5 mM gold chloride solution, respectively. The XRD spectrum revealed the face-centered cubic crystals of synthesized gold nanoparticles. FT-IR spectroscopy analysis confirmed the presence of aromatic primary amines, and the additional SPR bands at 290 and 230 nm further suggested that the presence of amino acids such as tryptophan/tyrosine or phenylalanine acts as the capping agent on the synthesized mycogenic gold nanoparticles.

  11. Ethyl p-coumarate exerts antifungal activity in vitro and in vivo against fruit Alternaria alternata via membrane-targeted mechanism.

    Science.gov (United States)

    Li, Wusun; Yuan, Shuzhi; Sun, Jing; Li, Qianqian; Jiang, Weibo; Cao, Jiankang

    2018-08-02

    The fungus Alternaria alternata can cause food contamination by black spot rot and food safety issues due to the production of mycotoxins. In particular, A. alternata can infect many fresh fruits and vegetables and lead to considerable postharvest decay during storage and processing. The use of plant-derived products in postharvest disease management may be an acceptable alternative to traditional chemical fungicides. The aim of this study was to assess the antifungal activity of ethyl p-coumarate (EpCA) against Alternaria alternata in vitro and in vivo, and to determine the underlying mechanism. Results indicated that EpCA exhibited pronounced antifungal activity against in vitro mycelial growth of A. alternata, with half-inhibition concentration of 176.8 μg/mL. Spore germination of the pathogen was inhibited by EpCA in a dose-dependent manner. Moreover, in vivo test confirmed that both 100 and 800 μg/mL EpCA significantly reduced disease development of black spot rot in jujube fruit caused by A. alternata. The EpCA treatments increased plasma membrane permeability as great leakage of intercellular electrolytes, soluble proteins and sugars of A. alternata occurred during incubation. The EpCA treatments also caused increase of the influx of propidium iodide, a fluorescence dye binding nucleus DNA, into the affected spores, indicating the disrupted plasma membrane integrity. Observations of ultrastructure further evidenced the damage to plasma membrane and morphology of A. alternata caused by EpCA, which resulted in distortion, sunken and shrivelled of spores and mycelia of the pathogen. In addition, fluorometric assay by confocal laser scanning microscopy confirmed that the EpCA treatments induced endogenous reactive oxygen species (ROS) formation in the spores of A. alternata, with stronger and more stable accumulation of ROS at higher concentration of EpCA. Therefore, heavy oxidative damage to cellular membranes and organelles might happen as demonstrated

  12. Comparative study of airborne Alternaria conidia levels in two cities in Castilla-La Mancha (central Spain), and correlations with weather-related variables.

    Science.gov (United States)

    Sabariego, Silvia; Bouso, Veronica; Pérez-Badia, Rosa

    2012-01-01

    Alternaria conidia are among the airborne biological particles known to trigger allergic respiratory diseases. The presented paper reports on a study of seasonal variations in airborne Alternaria conidia concentrations in 2 cities in the central Spanish region of Castilla-La Mancha, Albacete and Toledo. The influence of weather-related variables on airborne conidia levels and distribution was also analysed. Sampling was carried out from 2008-2010 using a Hirst sampler, following the methodology established by the Spanish Aerobiology Network. Annual airborne Alternaria conidia counts were higher in Toledo (annual mean 3,936 conidia) than in Albacete (annual mean 2,268 conidia). Conidia were detected in the air throughout the year, but levels peaked between May-September. Considerable year-on-year variations were recorded both in total annual counts and in seasonal distribution. A significant positive correlation was generally found between mean daily Alternaria counts and both temperature and hours of sunlight, while a significant negative correlation was recorded for relative humidity, daily and cumulative rainfall, and wind speed. Regression models indicated that between 31%-52% of the variation in airborne Alternaria conidia concentrations could be explained by weather-related variables.

  13. Antifungal activity of food additives in vitro and as ingredients of hydroxypropyl methylcellulose-lipid edible coatings against Botrytis cinerea and Alternaria alternata on cherry tomato fruit.

    Science.gov (United States)

    Fagundes, Cristiane; Pérez-Gago, María B; Monteiro, Alcilene R; Palou, Lluís

    2013-09-16

    The antifungal activity of food additives or 'generally recognized as safe' (GRAS) compounds was tested in vitro against Botrytis cinerea and Alternaria alternata. Radial mycelial growth of each pathogen was measured in PDA Petri dishes amended with food preservatives at 0.2, 1.0, or 2.0% (v/v) after 3, 5, and 7 days of incubation at 25 °C. Selected additives and concentrations were tested as antifungal ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings. The curative activity of stable coatings was tested in in vivo experiments. Cherry tomatoes were artificially inoculated with the pathogens, coated by immersion about 24 h later, and incubated at 20 °C and 90% RH. Disease incidence and severity (lesion diameter) were determined after 6, 10, and 15 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. In general, HPMC-lipid antifungal coatings controlled black spot caused by A. alternata more effectively than gray mold caused by B. cinerea. Overall, the best results for reduction of gray mold on cherry tomato fruit were obtained with coatings containing 2.0% of potassium carbonate, ammonium phosphate, potassium bicarbonate, or ammonium carbonate, while 2.0% sodium methylparaben, sodium ethylparaben, and sodium propylparaben were the best ingredients for coatings against black rot. © 2013 Elsevier B.V. All rights reserved.

  14. Transcription factor Amr1 induces melanin biosynthesis and suppresses virulence in Alternaria brassicicola.

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    Yangrae Cho

    Full Text Available Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC were nonpathogenic and another gene (AbVf8 caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of Δamr1 and characterized their phenotypes. The Δamr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite.

  15. HOG MAP kinase regulation of alternariol biosynthesis in Alternaria alternata is important for substrate colonization.

    Science.gov (United States)

    Graf, Eva; Schmidt-Heydt, Markus; Geisen, Rolf

    2012-07-16

    Strains of the genus Alternaria are ubiquitously present and frequently found on fruits, vegetables and cereals. One of the most commonly found species from this genus is A. alternata which is able to produce the mycotoxin alternariol among others. To date only limited knowledge is available about the regulation of the biosynthesis of alternariol, especially under conditions relevant to food. Tomatoes are a typical substrate of A. alternata and have a high water activity. On the other hand cereals with moderate water activity are also frequently colonized by A. alternata. In the current analysis it was demonstrated that even minor changes in the osmotic status of the substrate affect the alternariol biosynthesis of strains from vegetables resulting in nearly complete inhibition. High osmolarity in the environment is usually transmitted to the transcriptional level of downstream regulated genes by the HOG signal cascade (high osmolarity glycerol cascade) which is a MAP kinase transduction pathway. The phosphorylation status of the A. alternata HOG (AaHOG) was determined. Various concentrations of NaCl induce the phosphorylation of AaHOG in a concentration, time and strain dependent manner. A strain with a genetically inactivated aahog gene was no longer able to produce alternariol indicating that the activity of the aahog gene is required for alternariol biosynthesis. Further experiments revealed that the biosynthesis of alternariol is important for the fungus to colonize tomato tissue. The tight water activity dependent regulation of alternariol biosynthesis ensures alternariol biosynthesis at conditions which indicate an optimal colonization substrate for the fungus. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Expression analysis of chitinase upon challenge inoculation to Alternaria wounding and defense inducers in Brassica juncea

    Directory of Open Access Journals (Sweden)

    Sandhya Rawat

    2017-03-01

    Full Text Available Chitinases are the hydrolytic enzymes which belong to the pathogenesis-related (PR protein family and play an important role not only in plant defense but also in various abiotic stresses. However, only a limited number of chitinase genes have been characterised in B. juncea. In this study, we have characterised B. juncea class IV chitinase gene (accession no EF586206 in response to fungal infection, salicylic acid (SA, jasmonic acid (JA treatments and wounding. Gene expression studies revealed that the transcript levels of Bjchitinase (BjChp gene increases significantly both in local and distal tissues after Alternaria infection. Bjchitinase gene was also induced by jasmonic acid and wounding but moderately by salicylic acid. A 2.5 kb class IV chitinase promoter of this gene was isolated from B. juncea by Genome walking (accession no KF055403.1. In-silico analysis of this promoter revealed a number of conserved cis-regulatory elements related to defense, wounding and signalling molecules like SA, and JA. For validation, chitinase promoter was fused to the GUS gene, and the resultant construct was then introduced into Arabidopsis plants. Histochemical analysis of T2 transgenic Arabidopsis plants showed that higher GUS activity in leaves after fungal infection, wounding and JA treatment but weakly by SA. GUS activity was seen in meristematic tissues, young leaves, seeds and siliques. Finally investigation has led to the identification of a pathogen-inducible, developmentally regulated and organ-specific promoter. Present study revealed that Bjchitinase (BjChp promoter is induced during biotic and environmental stress and it can be used in developing finely tuned transgenics.

  17. Transcription Factor Amr1 Induces Melanin Biosynthesis and Suppresses Virulence in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yangrae; Srivastava, Akhil; Ohm, Robin A.; Lawrence, Christopher B.; Wang, Koon-Hui; Grigoriev, Igor V.; Marahatta, Sharadchandra P.

    2012-05-01

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC) were nonpathogenic and another gene (AbVf8) caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of ?amr1 and characterized their phenotypes. The ?amr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite.

  18. Characterization of glutathione transferases involved in the pathogenicity of Alternaria brassicicola.

    Science.gov (United States)

    Calmes, Benoit; Morel-Rouhier, Mélanie; Bataillé-Simoneau, Nelly; Gelhaye, Eric; Guillemette, Thomas; Simoneau, Philippe

    2015-06-18

    Glutathione transferases (GSTs) represent an extended family of multifunctional proteins involved in detoxification processes and tolerance to oxidative stress. We thus anticipated that some GSTs could play an essential role in the protection of fungal necrotrophs against plant-derived toxic metabolites and reactive oxygen species that accumulate at the host-pathogen interface during infection. Mining the genome of the necrotrophic Brassica pathogen Alternaria brassicicola for glutathione transferase revealed 23 sequences, 17 of which could be clustered into the main classes previously defined for fungal GSTs and six were 'orphans'. Five isothiocyanate-inducible GSTs from five different classes were more thoroughly investigated. Analysis of their catalytic properties revealed that two GSTs, belonging to the GSTFuA and GTT1 classes, exhibited GSH transferase activity with isothiocyanates (ITC) and peroxidase activity with cumene hydroperoxide, respectively. Mutant deficient for these two GSTs were however neither more susceptible to ITC nor less aggressive than the wild-type parental strain. By contrast mutants deficient for two other GSTs, belonging to the Ure2pB and GSTO classes, were distinguished by their hyper-susceptibility to ITC and low aggressiveness against Brassica oleracea. In particular AbGSTO1 could participate in cell tolerance to ITC due to its glutathione-dependent thioltransferase activity. The fifth ITC-inducible GST belonged to the MAPEG class and although it was not possible to produce the soluble active form of this protein in a bacterial expression system, the corresponding deficient mutant failed to develop normal symptoms on host plant tissues. Among the five ITC-inducible GSTs analyzed in this study, three were found essential for full aggressiveness of A. brassicicola on host plant. This, to our knowledge is the first evidence that GSTs might be essential virulence factors for fungal necrotrophs.

  19. The influence of different nitrogen and carbon sources on mycotoxin production in Alternaria alternata.

    Science.gov (United States)

    Brzonkalik, Katrin; Herrling, Tanja; Syldatk, Christoph; Neumann, Anke

    2011-05-27

    The aim of this study was to determine the influence of different carbon and nitrogen sources on the production of the mycotoxins alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) by Alternaria alternata at 28°C using a semi-synthetic medium (modified Czapek-Dox broth) supplemented with nitrogen and carbon sources. Additionally the effect of shaken and static cultivation on mycotoxin production was tested. Initial experiments showed a clear dependency between nitrogen depletion and mycotoxin production. To assess whether nitrogen limitation in general or the type of nitrogen source triggers the production, various nitrogen sources including several ammonium/nitrate salts and amino acids were tested. In static culture the production of AOH/AME can be enhanced greatly with phenylalanine whereas some nitrogen sources seem to inhibit the AOH/AME production completely. TA was not significantly affected by the choice of nitrogen source. In shaken culture the overall production of all mycotoxins was lower compared to static cultivation. Furthermore tests with a wide variety of carbon sources including monosaccharides, disaccharides, complex saccharides such as starch as well as glycerol and acetate were performed. In shaken culture AOH was produced when glucose, fructose, sucrose, acetate or mixtures of glucose/sucrose and glucose/acetate were used as carbon sources. AME production was not detected. The use of sodium acetate resulted in the highest AOH production. In static culture AOH production was also stimulated by acetate and the amount is comparable to shaken conditions. Under static conditions production of AOH was lower except when cultivated with acetate. In static cultivation 9 of 14 tested carbon sources induced mycotoxin production compared to 4 in shaken culture. This is the first study which analyses the influence of carbon and nitrogen sources in a semi-synthetic medium and assesses the effects of culture conditions on

  20. Intensidade de ataque de tripes, de alternaria e da queima-das-pontas em cultivares de cebola

    OpenAIRE

    Leite,Germano L.D.; Santos,Marília Cristina dos; Rocha,Silma L.; Costa,Cândido A. da; Almeida,Chrystian I. Maia e

    2004-01-01

    Avaliou-se a intensidade de ataque de Thrips tabaci Lind., a incidência de Alternaria porri (Ellis) e Botrytis squamosa J.C. Walker em nove cultivares de cebola [Aurora, Primavera, CNPH 6400, Crioula Alto-Vale, Vale-Ouro (IPA 11), Franciscana (IPA-16), Piraouro, Conquista e Serrana], num experimento no delineamento em blocos casualizados com cinco repetições. Foram feitas avaliações semanais, do transplantio até a colheita, em dez plantas/parcela do número de T. tabaci presente na bainha das ...

  1. Altertoxins with potent anti-HIV activity from Alternaria tenuissima QUE1Se, a fungal endophyte of Quercus emoryi

    OpenAIRE

    Bashyal, Bharat P.; Wellensiek, Brian P.; Ramakrishnan, Rajesh; Faeth, Stanley H.; Ahmad, Nafees; Leslie Gunatilaka, A. A.

    2014-01-01

    Screening of a small library of natural product extracts derived from endophytic fungi of the Sonoran desert plants in a cell-based anti-HIV assay involving T-cells infected with the HIV-1 virus identified the EtOAc extract of a fermentation broth of Alternaria tenuissima QUE1Se inhabiting the stem tissue of Quercus emoryi as a promising candidate for further investigation. Bioactivity-guided fractionation of this extract led to the isolation and identification of two new metabolites, alterto...

  2. In Silico Identification of Mimicking Molecules as Defense Inducers Triggering Jasmonic Acid Mediated Immunity against Alternaria Blight Disease in Brassica Species

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    Dinesh Pandey

    2017-04-01

    Full Text Available Alternaria brassicae and Alternaria brassicicola are two major phytopathogenic fungi which cause Alternaria blight, a recalcitrant disease on Brassica crops throughout the world, which is highly destructive and responsible for significant yield losses. Since no resistant source is available against Alternaria blight, therefore, efforts have been made in the present study to identify defense inducer molecules which can induce jasmonic acid (JA mediated defense against the disease. It is believed that JA triggered defense response will prevent necrotrophic mode of colonization of Alternaria brassicae fungus. The JA receptor, COI1 is one of the potential targets for triggering JA mediated immunity through interaction with JA signal. In the present study, few mimicking compounds more efficient than naturally occurring JA in terms of interaction with COI1 were identified through virtual screening and molecular dynamics simulation studies. A high quality structural model of COI1 was developed using the protein sequence of Brassica rapa. This was followed by virtual screening of 767 analogs of JA from ZINC database for interaction with COI1. Two analogs viz. ZINC27640214 and ZINC43772052 showed more binding affinity with COI1 as compared to naturally occurring JA. Molecular dynamics simulation of COI1 and COI1-JA complex, as well as best screened interacting structural analogs of JA with COI1 was done for 50 ns to validate the stability of system. It was found that ZINC27640214 possesses efficient, stable, and good cell permeability properties. Based on the obtained results and its physicochemical properties, it is capable of mimicking JA signaling and may be used as defense inducers for triggering JA mediated resistance against Alternaria blight, only after further validation through field trials.

  3. Antifungal activity of medicinal plant extracts against phytopathogenic fungus Alternaria spp Actividad antifúngica de extractos de plantas medicinales contra el hongo fitopatógeno Alternaria spp

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    Paola Díaz Dellavalle

    2011-06-01

    Full Text Available The aim of the study was to evaluate the antifungal activity of extracts of 10 plant species used in traditional Uruguayan medicine against the phytopathogenic fungus Alternaria spp. The plants were selected on the basis of their reported ethnobotanical uses. Aqueous, saline buffer and acid extracts of different plant species were screened in vitro for their antifungal activity against Alternaria spp. For the antifungal evaluation we used a microspectrophotometric assay. Minimal inhibitory concentration (MIC and minimum fungicidal concentration (MFC of the extracts were determined. Three solvents were assayed on different tissues of the plants and among the 29 evaluated extracts, 31% of the extracts inhibited growth, similar to the effects of a chemical fungicide. Acid extracts of the plants were more effective than the aqueous or buffer extracts against Alternaria spp. The MIC values of the extracts were determined ranging between 1.25 and 25 µg mL-1. The MFC values of the extracts ranged between 1.25 µg mL-1 (Rosmarinus officinalis L. and 10 µg mL-1 (Cynara scolymus L.. MICs and MFCs values obtained from leaves (Salvia officinalis L. and R. officinalis and seeds extracts (Salvia sclarea L. were quite comparable to values obtained with the conventional fungicide captan (2.5 µg mL-1. The extracts of Salvia sclarea, S. officinalis and R. officinalis could be considered as potential sources of antifungal compounds for treating diseases in plants. These extracts showed maximum activity, even at very low concentrations, and the same fungicide effects as chemical fungicide. We conclude from this that these extracts exhibit amazing fungicidal properties that support their traditional use as antiseptics.El objetivo de este trabajo fue evaluar la actividad antifúngica de extractos vegetales de 10 especies utilizadas en la medicina tradicional uruguaya contra el hongo fitopatógeno Alternaria spp. Las plantas fueron seleccionadas en base a usos

  4. An integrated in silico/in vitro approach to assess the xenoestrogenic potential of Alternaria mycotoxins and metabolites.

    Science.gov (United States)

    Dellafiora, Luca; Warth, Benedikt; Schmidt, Verena; Del Favero, Giorgia; Mikula, Hannes; Fröhlich, Johannes; Marko, Doris

    2018-05-15

    Xenoestrogenic mycotoxins may contaminate food and feed posing a public health issue. Besides the zearalenone group, the Alternaria toxin alternariol (AOH) has been described as a potential mycoestrogen. However, the estrogenicity of Alternaria toxins is still largely overlooked and further data are needed to better describe the group toxicity. In the frame of risk assessment, mixed in silico/in vitro approaches already proved to be effective first-line analytical tools. An integrated in silico/in vitro approach was used to investigate the effects of metabolic and chemical modifications on the estrogenicity of AOH. Among the considered modifications, methylation was found critical for enhancing estrogenicity (as seen for alternariol monomethyl ether (AME)) while hydroxylation and glucuronidation had the opposite effect (as seen for 4-hydroxy AOH and 4-hydroxy AME). The structure-activity relationship analysis provided the structural rationale. Our results provide insights to design more efficient risk assessment studies expanding knowledge over the group toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Efecto antifúngico de extractos fenólicos y de carotenoides de chiltepín (Capsicum annum var. glabriusculum en Alternaria alternata y Fusarium oxysporum

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    Alfonso Rodriguez-Maturino

    2015-03-01

    Full Text Available En el presente estudio se evaluó el efecto de extractos fenólicos y de carotenoides procedentes de frutos de chiltepín sobre el crecimiento micelial y la germinación de conidios de Alternaria alternata y Fusarium oxysporum, 2 importantes hongos causantes de podredumbres en frutas y hortalizas. Los extractos fenólicos presentaron una inhibición en el crecimiento micelial de A. alternata del 38,46 %, y redujeron significativamente la germinación de conidios al quinto día después del tratamiento al 92 % en relación al control. No se observaron cambios significativos en el crecimiento micelial de F. oxysporum, pero sí se redujo significativamente al 85 % en relación al control, el número de conidios germinados a los 5 días de tratamiento. Los extractos de carotenoides mostraron una inhibición del 38,5 % en el crecimiento micelial y del 85,3 % en la germinación de conidios de A. alternata, 5 días después del tratamiento. Frente a F. oxysporum, dichos extractos presentaron menor inhibición del crecimiento micelial (20,3 %, mientras que hubo una mayor inhibición en la germinación de conidios (96 %. Los extractos fenólicos y de carotenoides de chiltepín pueden ser una alternativa promisoria de importancia agrícola como fungicidas naturales.

  6. Comparative transcriptomic analysis reveals that Ethylene/H2O2-mediated hypersensitive response and program cell death determine the compatible interaction of Sand pear and Alternaria Alternata

    Science.gov (United States)

    A major production restriction on sand pear (Pyrus pyrifolia) is black spot disease caused by the necrotrophic fungus Alternaria alternata. However, pear response mechanism to A. alternata is unknown at molecular level. Here, host responses of a resistant cultivar Cuiguan (CG) and a susceptible cult...

  7. Occurrence of Cladosporium spp. and Alternaria spp. spores in Western, Northern and Central-Eastern Poland in 2004-2006 and relation to some meteorological factors

    Science.gov (United States)

    Grinn-Gofroń, Agnieszka; Rapiejko, Piotr

    2009-08-01

    The concentration of airborne spores of Cladosporium spp. and Alternaria spp. has been investigated at three monitoring stations situated along the west-north and central-east transect in Poland (Szczecin, Olsztyn, Warszawa,) i.e. from a height of 100 m to 149 m above sea level. The aerobiological monitoring of fungal spores was performed by means of three Lanzoni volumetric spore traps. Cladosporium spp. spores were dominant at all the stations. The highest Cladosporium spp. and Alternaria spp. numbers of spores were observed at all the cities in July and August. Statistically significant correlations have been found between the Cladosporium spp. and Alternaria spp. concentration in the air and the mean air temperature, amount of precipitation, air pressure and relative air humidity. The spore count of Cladosporium spp. and Alternaria spp. is determined by the diversity of local flora and weather conditions, especially by the air temperature. The identification of factors, which influence and shape spore concentrations, may significantly improve the current methods of allergy prevention.

  8. The dynamics of the fungal aerospores Alternaria sp. and Cladosporium sp. in Parisian atmospheric air, in France

    Science.gov (United States)

    Brezoczki, V. M.

    2016-08-01

    The bioallergens occurring naturally in the atmospheric air are microorganisms, pollen grains, plant seeds, leaf and stem scrap, or their protein molecules. The presence of various airborne fungal spores determines a high allergenic potential for public health. This effect is due to the high number of produced spores, which under favourable meteorological conditions (dry weather and wind) reach the surrounding air. This paper traces the dynamics of two types of fungi, Alternaria sp and Cladosporium sp, fungi which can be found outdoors, in the surrounding air, as well as indoors, inside houses (especially the conidia of Cladosporium sp). The effects of these fungal spores on human health are varies, ranging from seasonal allergies (hay fever, rhinitis, sinusitis etc.) to sever afflictions of the respiratory system, onset of asthma, disfunctionalities of the nervous systems, of the immune system, zymoses etc. The monitoring of the dynamics of the aerospores Alternaria sp and Cladosporium sp was carried out between 2010 and 2013, over a period of 42 weeks during one calendar year, from February to the end of September, in the surrounding air in the French capital, Paris. The regional and global climate and meteorological conditions are directly involved in the occurrence and development of fungi colonies, the transportation and dispersion of fungal spores in the atmospheric air, as well as in the creation of the environment required for the interaction of chemical and biological components in the air. Knowledge of the dynamics of the studied fungal aerospores, coupled with climate and meteorological changes, offers a series of information on the magnitude of the allergenic potential these airborne spores can determine. Legal regulations in this domain set the allergen risk threshold for the Alternaria sp aerospores at 3500 ÷ 7000 spores/m3 air/week, and for the Cladosporium sp aerospores at 56,000 spores/m3 air/week. Besides these regulations there exist a series of

  9. Hyperspectral remote sensing for advanced detection of early blight (Alternaria solani) disease in potato (Solanum tuberosum) plants

    Science.gov (United States)

    Atherton, Daniel

    Early detection of disease and insect infestation within crops and precise application of pesticides can help reduce potential production losses, reduce environmental risk, and reduce the cost of farming. The goal of this study was the advanced detection of early blight (Alternaria solani) in potato (Solanum tuberosum) plants using hyperspectral remote sensing data captured with a handheld spectroradiometer. Hyperspectral reflectance spectra were captured 10 times over five weeks from plants grown to the vegetative and tuber bulking growth stages. The spectra were analyzed using principal component analysis (PCA), spectral change (ratio) analysis, partial least squares (PLS), cluster analysis, and vegetative indices. PCA successfully distinguished more heavily diseased plants from healthy and minimally diseased plants using two principal components. Spectral change (ratio) analysis provided wavelengths (490-510, 640, 665-670, 690, 740-750, and 935 nm) most sensitive to early blight infection followed by ANOVA results indicating a highly significant difference (p potato plants.

  10. In vitro sensitivity of Alternaria solani to conventional fungicides and a biofungicide based on tea tree essential oil

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    Miloš Stepanović

    2015-01-01

    Full Text Available A study of in vitro sensitivity of five Alternaria solani isolates to cooper-oxychloride, chlorothalonil, difenoconazole, pyraclostrobin and a biofungicide based on tea tree essential oil was carried out. The isolates were obtained from infected tomato leaves collected from five different locations in Serbia. The tested isolates showed the highest sensitivity to pyraclostrobin with EC50 values ranging from 0.0014 to 0.0041 μg ml-1. The EC50 values of difenoconazole were 0.018-0.037 μg ml-1, chlorothalonil 2.99-4.54 μg ml-1, and cooper-oxychloride 13.27-15.63 μg ml-1. All tested A. solani isolates were the least sensitive to tea tree oil (1323.97-3307.08 μg l-1.

  11. Partial resistance of carrot to Alternaria dauci correlates with in vitro cultured carrot cell resistance to fungal exudates.

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    Mickaël Lecomte

    Full Text Available Although different mechanisms have been proposed in the recent years, plant pathogen partial resistance is still poorly understood. Components of the chemical warfare, including the production of plant defense compounds and plant resistance to pathogen-produced toxins, are likely to play a role. Toxins are indeed recognized as important determinants of pathogenicity in necrotrophic fungi. Partial resistance based on quantitative resistance loci and linked to a pathogen-produced toxin has never been fully described. We tested this hypothesis using the Alternaria dauci-carrot pathosystem. Alternaria dauci, causing carrot leaf blight, is a necrotrophic fungus known to produce zinniol, a compound described as a non-host selective toxin. Embryogenic cellular cultures from carrot genotypes varying in resistance against A. dauci were confronted with zinniol at different concentrations or to fungal exudates (raw, organic or aqueous extracts. The plant response was analyzed through the measurement of cytoplasmic esterase activity, as a marker of cell viability, and the differentiation of somatic embryos in cellular cultures. A differential response to toxicity was demonstrated between susceptible and partially resistant genotypes, with a good correlation noted between the resistance to the fungus at the whole plant level and resistance at the cellular level to fungal exudates from raw and organic extracts. No toxic reaction of embryogenic cultures was observed after treatment with the aqueous extract or zinniol used at physiological concentration. Moreover, we did not detect zinniol in toxic fungal extracts by UHPLC analysis. These results suggest that strong phytotoxic compounds are present in the organic extract and remain to be characterized. Our results clearly show that carrot tolerance to A. dauci toxins is one component of its partial resistance.

  12. Sobrevivência saprofítica de Alternaria brassicicola e manejo de restos foliares de brócolos Saprophytic survival of Alternaria brassicicola and management of broccoli leaf debris

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    Luiz Augusto Martins Peruch

    2007-02-01

    Full Text Available A sobrevivência saprofítica do fungo Alternaria brassicicola foi investigada em restos foliares de brócolos (Brassica oleracea var. italica, em diferentes profundidades de incorporação no solo, períodos do ano e sistemas de manejo do solo. Os restos foliares infectados pelo patógeno foram distribuídos em parcelas no campo, na superfície do solo e nas profundidades de 5 e 10cm. Periodicamente, os restos foliares foram coletados e a concentração de conídios quantificada, sendo obtida a longevidade da esporulação e a taxa de extinção da esporulação. Foi verificada maior longevidade da esporulação nos restos foliares no período com temperaturas amenas, maior umidade relativa do ar e menor precipitação pluvial. Menor esporulação ocorreu quando os restos culturais foram incorporados a 10cm de profundidade. Quando comparados os sistemas de manejo convencional e orgânico, houve diferença na taxa de extinção da esporulação do patógeno quando a fonte de inóculo foi depositada nas profundidades de 5 e 10cm, sendo superior no solo sob manejo convencional, enquanto na superfície do solo não houve diferença. O manejo da alternariose em brócolos na região do estudo pode ser realizado pela incorporação dos restos foliares infectados no solo, à profundidade mínima de 10cm, visando a um intervalo mínimo de 60 dias entre cultivos de brássicas.The saprophytic survival of the fungus Alternaria brassicicola was investigated in leaf debris of broccoli (Brassica oleracea var. italica, at different depths of soil incorporation, periods of the year, and systems of soil management. Infected leaf debris were distributed in field plots, at the soil surface and at depths of 5 and 10cm. Periodically, the debris in the bags were collected and conidia concentrations were quantified for longevity of spore production and extinction rate. Higher spore production longevity was observed on leaf debris in the period with lower temperatures

  13. Phylogeny of Alternaria fungi known to produce host-specific toxins on the basis of variation in internal transcribed spacers of ribosomal DNA.

    Science.gov (United States)

    Kusaba, M; Tsuge, T

    1995-10-01

    The internal transcribed spacer regions (ITS1 and ITS2) of ribosomal DNA from Alternaria species, including seven fungi known to produce host-specific toxins, were analyzed by polymerase chain reaction-amplification and direct sequencing. Phylogenetic analysis of the sequence data by the Neighbor-joining method showed that the seven toxin-producing fungi belong to a monophyletic group together with A. alternata. In contract, A. dianthi, A. panax, A. dauci, A. bataticola, A. porri, A. sesami and A. solani, species that can be morphologically distinguished from A. alternata, could be clearly separated from A. alternata by phylogenetic of the ITS variation. These results suggest that Alternaria pathogens which produce host-specific toxins are pathogenic variants within a single variable species, A. alternata.

  14. Genetic Diversity of Alternaria alternata Causal Agent of Early Blight of Tomato in Khuzestan Province Using SSRs Marker

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    Khoshnood Nourollahi

    2017-03-01

    Full Text Available Introduction: The early blight of tomato caused by Alternaria alternata is one of the most important and destructive diseases in Khuzestan province. Study genetic structure of A. alternata populations provides different levels of information in the management of early blight disease in tomato farms. Short sequence repeat (SSR markers were used to determine the genetic structure and estimate genetic diversity in A. alternata isolates in Khuzestan province. Materials and Methods: In this study to evaluate the genetic diversity and genetic populations of A. alternata pathogen, sampling was randomly carried out on aerial parts of tomato plants with leaf brown lesions in farms and glasshouses from five different regions in Khuzestan province such as: Shoshtar, Omidiyeh, Dashte azadagan, Ahvaz, and Dezful. Each sample was cut into 2–5-mm long pieces, were surface-sterilized with 1% sodium hypochlorite for 3 min and rinsed three times with sterile distilled water and air-dried with sterile filter paper. The sterilized samples were placed onto a general medium potato dextrose agar (PDA. A total of 64 A. alternata isolates were obtained from infected samples. Pathogenicity test was carried out on local susceptible cultivar under an artificial condition in the greenhouse. For obtaining the mycelia mass, liquid cultures were initiated by adding 2–4 mm 2 pieces of filter paper to 250-mL Erlenmeyer flasks containing 100 mL PDB medium (potato dextrose broth. Mycelium was collected by filtration through sterile filter paper with a vacuum funnel. Mycelia were harvested, frozen and stored at -20°C. DNA was extracted using a modified hexadecyl trimethyl-ammonium bromide (CTAB procedure. A set of five paired sequence repeat primers (SSR were used to determine the genetic diversity of A. alternata isolates. PCR amplification was performed in a 25 μl reaction volume. The bands generated by SSR primers that were repeatable and clearly visible with a high

  15. Determination of Alternaria mycotoxins in wine and juice using ionic liquid modified countercurrent chromatography as a pretreatment method followed by high-performance liquid chromatography.

    Science.gov (United States)

    Fan, Chen; Cao, Xueli; Liu, Man; Wang, Wei

    2016-03-04

    Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants in food materials. The objective of this study was to develop a pretreatment method with countercurrent chromatography (CCC) for enrichment and cleanup of trace Alternaria mycotoxins in food samples prior to high-performance liquid chromatography (HPLC) analysis. An Analytical CCC instrument with a column volume 22.5mL was used, and a two-phase solvent system composed of ethyl acetate and water modified with 6% [HOOMIM][Cl] in mass to volume ratio was selected. Under the optimized CCC operation conditions, trace amounts of AOH, AME, and TeA in large volume of liquid sample were efficiently extracted and enriched in the stationary phase, and then eluted out just by reversing the stationary phase as mobile phase in the opposite flowing direction tail-to-head. The enrichment and elution strategies are unique and can be fulfilled online with high enrichment factors (87-114) and high recoveries (81.14-110.94%). The method has been successively applied to the determination of Alternaria mycotoxins in real apple juice and wine samples with the limits of detection (LOD) in the range of 0.03-0.14μgL(-1). Totally 12 wine samples and 15 apple juice samples from the local market were analyzed. The detection rate of AOH and AME in both kinds of the samples were more than 50%, while TeA was found in relatively high level of 1.75-49.61μgL(-1) in some of the apple juice samples. The proposed method is simple, rapid, and sensitive and could also be used for the analysis and monitoring of Alternaria mycotoxin in other food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Evaluation of a triplex real-time PCR system to detect the plant-pathogenic molds Alternaria spp., Fusarium spp. and C. purpurea.

    Science.gov (United States)

    Grube, Sabrina; Schönling, Jutta; Prange, Alexander

    2015-12-01

    This article describes the development of a triplex real-time PCR system for the simultaneous detection of three major plant-pathogenic mold genera (Alternaria spp., Fusarium spp. and the species Claviceps purpurea). The designed genus-specific primer-probe systems were validated for sensitivity, specificity and amplification in the presence of background DNA. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  18. Efeito do óleo essencial de pimenta longa (Piper hispidinervum C. DC e do emulsificante Tween® 80 sobre o crescimento micelial de Alternaria alternata (Fungi: Hyphomycetes The effect of Long-pepper essential oil (Piper hispidinervum C. DC. and of Tween®; 80 emulsifier on the mycelial growth of Alternaria alternate (Fungi: Hyphomycetes

    Directory of Open Access Journals (Sweden)

    Fabiane Reis Nascimento

    2008-01-01

    Full Text Available Este trabalho objetivou avaliar o efeito do óleo essencial de folhas de pimenta longa (Piper hispidinervum C. DC, sobre o crescimento micelial de Alternaria alternata e a análise da influência da concentração do emulsificante Tween® 80 no controle deste fitopatógeno. O óleo essencial foi obtido pela técnica "arraste a vapor d'água", utilizando-se aparelho de Clevenger modificado, e posteriormente submetido, à análise por cromatografia em fase gasosa acoplada a espectrômetro de massas CG-EM a CG. Para os ensaios biológicos, o método foi o bioanalítico in vitro observando-se o crescimento ou inibição do micélio de A. alternata no meio de cultura BDA na presença de diferentes concentrações do óleo essencial (0, 100, 250, 500 e 1000 mgL-1 sob diferentes concentrações de Tween® 80. Adotou-se esquema fatorial com quatro repetições, em delineamento inteiramente casualizado (DIC. Observou-se que o óleo essencial de pimenta longa apresentou inibição sobre o crescimento micelial do fungo A. alternataem todas as concentrações analisadas, sendo que na concentração de 1000 mgL-1 esta inibição foi de 100% , e a porcentagem de emulsificante (Tween® 80, influenciou na atividade fungitóxica das concentrações de 250 mgL -1 e 500 mgL -1 do óleo essencial.The object of this work was to evaluate the effectof essential oils from Long-pepper leaves Piper hispidinervum on the mycelial growth of Alternaria alternata and to analyze the influence of emulsifier Tween® 80 concentration in the control of this phytopathogen. The essential oil was obtained by steam stream distillation, using a modified Clevenger apparatus, and the chemical composition was analyzed by gas chromatography coupled to mass spectroscopy GC-MS and GC. For biological tests, the bioanalytical in vitro method was used, observing the growth or inhibition of such phytopathogen in BDA culture media, in the presence of different essential oil concentrations (0, 100

  19. The Arabidopsis thaliana-Alternaria brassicicola pathosystem: A model interaction for investigating seed transmission of necrotrophic fungi

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    Pochon Stephanie

    2012-05-01

    Full Text Available Abstract Background Seed transmission constitutes a major component of the parasitic cycle for several fungal pathogens. However, very little is known concerning fungal or plant genetic factors that impact seed transmission and mechanisms underlying this key biological trait have yet to be clarified. Such lack of available data could be probably explained by the absence of suitable model pathosystem to study plant-fungus interactions during the plant reproductive phase. Results Here we report on setting up a new pathosystem that could facilitate the study of fungal seed transmission. Reproductive organs of Arabidopsis thaliana were inoculated with Alternaria brassicicola conidia. Parameters (floral vs fruit route, seed collection date, plant and silique developmental stages that could influence the seed transmission efficiency were tested to define optimal seed infection conditions. Microscopic observations revealed that the fungus penetrates siliques through cellular junctions, replum and stomata, and into seed coats either directly or through cracks. The ability of the osmosensitive fungal mutant nik1Δ3 to transmit to A. thaliana seeds was analyzed. A significant decrease in seed transmission rate was observed compared to the wild-type parental strain, confirming that a functional osmoregulation pathway is required for efficient seed transmission of the fungus. Similarly, to test the role of flavonoids in seed coat protection against pathogens, a transparent testa Arabidopsis mutant (tt4-1 not producing any flavonoid was used as host plant. Unexpectedly, tt4-1 seeds were infected to a significantly lower extent than wild-type seeds, possibly due to over-accumulation of other antimicrobial metabolites. Conclusions The Arabidopsis thaliana-Alternaria brassicicola pathosystem, that have been widely used to study plant-pathogen interactions during the vegetative phase, also proved to constitute a suitable model pathosystem for detailed analysis

  20. Comparative Evaluation of Biochemical Changes in Tomato (Lycopersicon esculentum Mill.) Infected by Alternaria alternata and Its Toxic Metabolites (TeA, AOH, and AME).

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    Meena, Mukesh; Zehra, Andleeb; Dubey, Manish K; Aamir, Mohd; Gupta, Vijai K; Upadhyay, Ram S

    2016-01-01

    In the present study, we have evaluated the comparative biochemical defense response generated against Alternaria alternata and its purified toxins viz. alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA). The necrotic lesions developed due to treatment with toxins were almost similar as those produced by the pathogen, indicating the crucial role of these toxins in plant pathogenesis. An oxidative burst reaction characterized by the rapid and transient production of a large amount of reactive oxygen species (ROS) occurs following the pathogen infection/toxin exposure. The maximum concentration of hydrogen peroxide (H 2 O 2 ) produced was reported in the pathogen infected samples (22.2-fold) at 24 h post inoculation followed by TeA (18.2-fold), AOH (15.9-fold), and AME (14.1-fold) in treated tissues. 3,3'- Diaminobenzidine staining predicted the possible sites of H 2 O 2 accumulation while the extent of cell death was measured by Evans blue dye. The extent of lipid peroxidation and malondialdehyde (MDA) content was higher (15.8-fold) at 48 h in the sample of inoculated leaves of the pathogen when compared to control. The cellular damages were observed as increased MDA content and reduced chlorophyll. The activities of antioxidative defense enzymes increased in both the pathogen infected as well as toxin treated samples. Superoxide dismutase (SOD) activity was 5.9-fold higher at 24 h post inoculation in leaves followed by TeA (5.0-fold), AOH (4.1-fold) and AME (2.3-fold) treated leaves than control. Catalase (CAT) activity was found to be increased upto 48 h post inoculation and maximum in the pathogen challenged samples followed by other toxins. The native PAGE results showed the variations in the intensities of isozyme (SOD and CAT) bands in the pathogen infected and toxin treated samples. Ascorbate peroxidase (APx) and glutathione reductase (GR) activities followed the similar trend to scavenge the excess H 2 O 2 . The reduction in CAT

  1. Comportamento de cultivares de arroz irrigado em relação a fungos manchadores de sementes Performance of lowland rice cultivam to seed discoloration fungi

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    Jaciro Soave

    1985-01-01

    Full Text Available Em ensaios regionais instalados no ano agrícola de 1980/81, em Tremembé e Pindamonhangaba (SP, determinaram-se, em 37 cultivares de arroz irrigado, os fungos responsáveis por manchas em sementes de arroz e o comportamento desses cultivares em relação a cada fungo detectado. Amostras de sementes foram coletadas da produção total de cada parcela experimental, procedendo-se à separação visual das sementes manchadas e sem manchas e, posteriormente, aos cálculos da porcentagem de sementes manchadas e da porcentagem de perda de peso devida às manchas. Testes de patologia de sementes detectaram a presença das seguintes espécies de fungos: Alternaria sp. Cephalosporium sp., Cladosposium spp., Corynespora sp., Curvularia spp., Epicoccum spp., Fusarium moniliforme, Helminthosporium oryzae, Phoma spp., Pyricularia oryzae, Rhizoctonia solani, Rhynchosporium oryzae, Trichoconiella padwickii, Trichoderma sp. e Trichothecium sp. Diferenças altamente significativas entre o número de sementes manchadas e sem manchas foram observadas para os fungos H. oryzae, Phoma spp., R. oryzae e T. padwickii nos dois locais, patógenos então considerados os principais responsáveis pela manchas de sementes observadas. A análise conjunta das duas localidades para cada parâmetro revelou 32 cultivares com menor porcentagem de sementes manchadas do que o controle comercial, quatro cultivares com menor porcentagem de perda de peso devida às manchas, 24 com menor porcentagem de sementes com H. oryzae, seis com menor porcentagem de sementes com Phoma spp,, todos os cultivares com menor porcentagem de sementes com R. oryzae e onze com menor porcentagem de sementes com T. padwickii do que o controle comercial. Considerando todos os parâmetros avaliados na análise conjunta e obtidos para as duas localidades, concluiu-se que os cultivares PI-1291, PI-1356, PI-1377, IR 1544, P2-48, P2-S2, P2-S1-78, L-17-72 e GI-6904-6 apresentaram melhor comportamento que os demais

  2. Characterization of the programmed cell death induced by metabolic products of Alternaria alternata in tobacco BY-2 cells.

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    Cheng, Dan-Dan; Jia, Yu-Jiao; Gao, Hui-Yuan; Zhang, Li-Tao; Zhang, Zi-Shan; Xue, Zhong-Cai; Meng, Qing-Wei

    2011-02-01

    Alternaria alternata has received considerable attention in current literature and most of the studies are focused on its pathogenic effects on plant chloroplasts, but little is known about the characteristics of programmed cell death (PCD) induced by metabolic products (MP) of A. alternata, the effects of the MP on mitochondrial respiration and its relation to PCD. The purpose of this study was to explore the mechanism of MP-induced PCD in non-green tobacco BY-2 cells and to explore the role of mitochondrial inhibitory processes in the PCD of tobacco BY-2 cells. MP treatment led to significant cell death that was proven to be PCD by the concurrent cytoplasm shrinkage, chromatin condensation and DNA laddering observed in the cells. Moreover, MP treatment resulted in the overproduction of reactive oxygen species (ROS), rapid ATP depletion and a respiratory decline in the tobacco BY-2 cells. It was concluded that the direct inhibition of the mitochondrial electron transport chain (ETC), alternative pathway (AOX) capacity and catalase (CAT) activity by the MP might be the main contributors to the MP-induced ROS burst observed in tobacco BY-2 cells. The addition of adenosine together with the MP significantly inhibited ATP depletion without preventing PCD; however, when the cells were treated with the MP plus CAT, ROS overproduction was blocked and PCD did not occur. The data presented here demonstrate that the ROS burst played an important role in MP-induced PCD in the tobacco BY-2 cells.

  3. Transcriptional Responses of the Bdtf1-Deletion Mutant to the Phytoalexin Brassinin in the Necrotrophic Fungus Alternaria brassicicola

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    Yangrae Cho

    2014-07-01

    Full Text Available Brassica species produce the antifungal indolyl compounds brassinin and its derivatives, during microbial infection. The fungal pathogen Alternaria brassicicola detoxifies brassinin and possibly its derivatives. This ability is an important property for the successful infection of brassicaceous plants. Previously, we identified a transcription factor, Bdtf1, essential for the detoxification of brassinin and full virulence. To discover genes that encode putative brassinin-digesting enzymes, we compared gene expression profiles between a mutant strain of the transcription factor and wild-type A. brassicicola under two different experimental conditions. A total of 170 and 388 genes were expressed at higher levels in the mutants than the wild type during the infection of host plants and saprophytic growth in the presence of brassinin, respectively. In contrast, 93 and 560 genes were expressed, respectively, at lower levels in the mutant than the wild type under the two conditions. Fifteen of these genes were expressed at lower levels in the mutant than in the wild type under both conditions. These genes were assumed to be important for the detoxification of brassinin and included Bdtf1 and 10 putative enzymes. This list of genes provides a resource for the discovery of enzyme-coding genes important in the chemical modification of brassinin.

  4. Dehydrin-like proteins in the necrotrophic fungus Alternaria brassicicola have a role in plant pathogenesis and stress response.

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    Stéphanie Pochon

    Full Text Available In this study, the roles of fungal dehydrin-like proteins in pathogenicity and protection against environmental stresses were investigated in the necrotrophic seed-borne fungus Alternaria brassicicola. Three proteins (called AbDhn1, AbDhn2 and AbDhn3, harbouring the asparagine-proline-arginine (DPR signature pattern and sharing the characteristic features of fungal dehydrin-like proteins, were identified in the A. brassicicola genome. The expression of these genes was induced in response to various stresses and found to be regulated by the AbHog1 mitogen-activated protein kinase (MAPK pathway. A knock-out approach showed that dehydrin-like proteins have an impact mainly on oxidative stress tolerance and on conidial survival upon exposure to high and freezing temperatures. The subcellular localization revealed that AbDhn1 and AbDhn2 were associated with peroxisomes, which is consistent with a possible perturbation of protective mechanisms to counteract oxidative stress and maintain the redox balance in AbDhn mutants. Finally, we show that the double deletion mutant ΔΔabdhn1-abdhn2 was highly compromised in its pathogenicity. By comparison to the wild-type, this mutant exhibited lower aggressiveness on B. oleracea leaves and a reduced capacity to be transmitted to Arabidopsis seeds via siliques. The double mutant was also affected with respect to conidiation, another crucial step in the epidemiology of the disease.

  5. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis) Ciferri.

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    Nanda, Satyabrata; Chand, Subodh Kumar; Mandal, Purander; Tripathy, Pradyumna; Joshi, Raj Kumar

    2016-12-01

    Purple blotch, caused by Alternaria porri (Ellis) Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession 'CBT-Ac77' and cultivar 'Arka Kalyan' were observed to be highly resistant. In vitro inoculation of a selected set of genotypes with A. porri , revealed that 7 days after inoculation was suitable to observe the disease severity. In vitro screening of 43 genotypes for resistance to A. porri revealed two resistant lines. An additional 14 genotypes showed consistent moderate resistance in the field as well as in vitro evaluations. Among the related Allium species, A. schoenoprasum and A. roylei showed the least disease index and can be used for interspecific hybridization with cultivated onion. Differential reaction analysis of three A. porri isolates ( Apo-Chiplima, Apn-Nasik, Apg-Guntur ) in 43 genotypes revealed significant variation among the evaluated Allium species ( P = 0.001). All together, the present study suggest that, the newly identified resistance sources can be used as potential donors for ongoing purple blotch resistance breeding program in India.

  6. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis Ciferri

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    Satyabrata Nanda

    2016-12-01

    Full Text Available Purple blotch, caused by Alternaria porri (Ellis Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession ‘CBT-Ac77’ and cultivar ‘Arka Kalyan’ were observed to be highly resistant. In vitro inoculation of a selected set of genotypes with A. porri, revealed that 7 days after inoculation was suitable to observe the disease severity. In vitro screening of 43 genotypes for resistance to A. porri revealed two resistant lines. An additional 14 genotypes showed consistent moderate resistance in the field as well as in vitro evaluations. Among the related Allium species, A. schoenoprasum and A. roylei showed the least disease index and can be used for interspecific hybridization with cultivated onion. Differential reaction analysis of three A. porri isolates (Apo-Chiplima, Apn-Nasik, Apg-Guntur in 43 genotypes revealed significant variation among the evaluated Allium species (P = 0.001. All together, the present study suggest that, the newly identified resistance sources can be used as potential donors for ongoing purple blotch resistance breeding program in India.

  7. Spatial and temporal distribution of Alternaria spores in the Iberian Peninsula atmosphere, and meteorological relationships: 1993-2009.

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    Aira, María-Jesús; Rodríguez-Rajo, Francisco-Javier; Fernández-González, María; Seijo, Carmen; Elvira-Rendueles, Belén; Abreu, Ilda; Gutiérrez-Bustillo, Montserrat; Pérez-Sánchez, Elena; Oliveira, Manuela; Recio, Marta; Tormo, Rafael; Morales, Julia

    2013-03-01

    This paper provides an updated of airborne Alternaria spore spatial and temporal distribution patterns in the Iberian Peninsula, using a common non-viable volumetric sampling method. The highest mean annual spore counts were recorded in Sevilla (39,418 spores), Mérida (33,744) and Málaga (12,947), while other sampling stations never exceeded 5,000. The same cities also recorded the highest mean daily spore counts (Sevilla 109 spores m(-3); Mérida 53 spores m(-3) and Málaga 35 spores m(-3)) and the highest number of days on which counts exceeded the threshold levels required to trigger allergy symptoms (Sevilla 38 % and Mérida 30 % of days). Analysis of annual spore distribution patterns revealed either one or two peaks, depending on the location and prevailing climate of sampling stations. For all stations, average temperature was the weather parameter displaying the strongest positive correlation with airborne spore counts, whilst negative correlations were found for rainfall and relative humidity.

  8. Altertoxins with potent anti-HIV activity from Alternaria tenuissima QUE1Se, a fungal endophyte of Quercus emoryi.

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    Bashyal, Bharat P; Wellensiek, Brian P; Ramakrishnan, Rajesh; Faeth, Stanley H; Ahmad, Nafees; Gunatilaka, A A Leslie

    2014-11-01

    Screening of a small library of natural product extracts derived from endophytic fungi of the Sonoran desert plants in a cell-based anti-HIV assay involving T-cells infected with the HIV-1 virus identified the EtOAc extract of a fermentation broth of Alternaria tenuissima QUE1Se inhabiting the stem tissue of Quercus emoryi as a promising candidate for further investigation. Bioactivity-guided fractionation of this extract led to the isolation and identification of two new metabolites, altertoxins V (1) and VI (2) together with the known compounds, altertoxins I (3), II (4), and III (5). The structures of 1 and 2 were determined by detailed spectroscopic analysis and those of 3-5 were established by comparison with reported data. When tested in our cell-based assay at concentrations insignificantly toxic to T-cells, altertoxins V (1), I (3), II (4), and III (5) completely inhibited replication of the HIV-1 virus at concentrations of 0.50, 2.20, 0.30, and 1.50 μM, respectively. Our findings suggest that the epoxyperylene structural scaffold in altertoxins may be manipulated to produce potent anti-HIV therapeutics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Identification of a polyketide synthase required for alternariol (AOH and alternariol-9-methyl ether (AME formation in Alternaria alternata.

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    Debjani Saha

    Full Text Available Alternaria alternata produces more than 60 secondary metabolites, among which alternariol (AOH and alternariol-9-methyl ether (AME are important mycotoxins. Whereas the toxicology of these two polyketide-based compounds has been studied, nothing is known about the genetics of their biosynthesis. One of the postulated core enzymes in the biosynthesis of AOH and AME is polyketide synthase (PKS. In a draft genome sequence of A. alternata we identified 10 putative PKS-encoding genes. The timing of the expression of two PKS genes, pksJ and pksH, correlated with the production of AOH and AME. The PksJ and PksH proteins are predicted to be 2222 and 2821 amino acids in length, respectively. They are both iterative type I reducing polyketide synthases. PksJ harbors a peroxisomal targeting sequence at the C-terminus, suggesting that the biosynthesis occurs at least partly in these organelles. In the vicinity of pksJ we found a transcriptional regulator, altR, involved in pksJ induction and a putative methyl transferase, possibly responsible for AME formation. Downregulation of pksJ and altR caused a large decrease of alternariol formation, suggesting that PksJ is the polyketide synthase required for the postulated Claisen condensations during the biosynthesis. No other enzymes appeared to be required. PksH downregulation affected pksJ expression and thus caused an indirect effect on AOH production.

  10. Phosphoproteome profiles of the phytopathogenic fungi Alternaria brassicicola and Botrytis cinerea during exponential growth in axenic cultures.

    Science.gov (United States)

    Davanture, Marlène; Dumur, Jérôme; Bataillé-Simoneau, Nelly; Campion, Claire; Valot, Benoît; Zivy, Michel; Simoneau, Philippe; Fillinger, Sabine

    2014-07-01

    This study describes the gel-free phosphoproteomic analysis of the phytopathogenic fungi Alternaria brassicicola and Botrytis cinerea grown in vitro under nonlimiting conditions. Using a combination of strong cation exchange and IMAC prior to LC-MS, we identified over 1350 phosphopeptides per fungus representing over 800 phosphoproteins. The preferred phosphorylation sites were found on serine (>80%) and threonine (>15%), whereas phosphorylated tyrosine residues were found at less than 1% in A. brassicicola and at a slightly higher ratio in B. cinerea (1.5%). Biological processes represented principally among the phoshoproteins were those involved in response and transduction of stimuli as well as in regulation of cellular and metabolic processes. Most known elements of signal transduction were found in the datasets of both fungi. This study also revealed unexpected phosphorylation sites in histidine kinases, a category overrepresented in filamentous ascomycetes compared to yeast. The data have been deposited to the ProteomeXchange database with identifier PXD000817 (http://proteomecentral.proteomexchange.org/dataset/PXD000817). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Genetic diversity and occurrence of the F129L substitutions among isolates of Alternaria solani in south-eastern Sweden.

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    Odilbekov, Firuz; Edin, Eva; Garkava-Gustavsson, Larisa; Hovmalm, Helena Persson; Liljeroth, Erland

    2016-01-01

    Early blight, caused by the fungus Alternaria solani, occurs on potato mainly in the south-eastern part of Sweden, but also in other parts of the country. The aim of this study was to investigate the genetic diversity of A. solani populations from different potato growing regions in south-eastern Sweden using AFLP marker analysis. In addition, the cultured isolates were examined for substitutions in the gene encoding cytochrome b , associated with loss of sensitivity against QoI fungicides. Nei's gene diversity index for the Swedish populations of A. solani revealed a gene diversity of up to 0.20. Also genetic differentiation was observed among populations of A. solani from different locations in south-eastern Sweden. The mitochondrial genotype of the isolates of A. solani was determined and both known genotypes, GI (genotype 1) and GII (genotype 2), were found among the isolates. The occurrence of the F129L substitution associated with a loss of sensitivity to strobilurins was confirmed among the GII isolates. In vitro conidial germination tests verified that isolates containing the F129L substitution had reduced sensitivity to azoxystrobin and, at a lower extent, to pyraclostrobin. Genetic diversity was relatively high among isolates of A. solani in south-eastern part of Sweden. F129L substitutions, leading to reduced sensitivity to strobilurins, have been established in field populations, which may have implications for the future efficacy of QoI fungicides.

  12. LaeA and VeA are involved in growth morphology, asexual development, and mycotoxin production in Alternaria alternata.

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    Estiarte, N; Lawrence, C B; Sanchis, V; Ramos, A J; Crespo-Sempere, A

    2016-12-05

    Alternaria alternata is a common filamentous fungus that contaminates various fruits, grains and vegetables causing important economic losses to farmers and the food industry. A. alternata is a mycotoxigenic mould, which may jeopardize human and animal health. Two of the most common A. alternata mycotoxins found in food and feed are alternariol and alternariol monomethyl ether. In this study we examined the role of LaeA and VeA, two regulatory proteins belonging to the velvet family, which have been described to be involved in several functions in many fungi including secondary metabolism. We found that deletion of laeA and veA genes, respectively, greatly reduced sporulation and strongly compromised mycotoxin production, both in vitro or during pathogenesis of tomato fruits. We have also studied how the loss of laeA and veA may affect expression of genes related to alternariol and alternariol monomethyl ether biosynthesis (pksJ and altR), and to melanin biosynthesis (cmrA, pksA). Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Encountering epidemic effects of leaf spot disease (Alternaria brassicae) on Aloe vera by fungal biocontrol agents in agrifields-An ecofriendly approach.

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    Ghosh, Swapan Kumar; Banerjee, Subhankar; Pal, Sujoy; Chakraborty, Niloy

    2018-01-01

    Aloe vera (L.) Burm.f. is a highly important and extensively cultivated medicinal plant and that is also extensively used in the cosmetic industry. It has been frequently reported to suffer from Alternaria leaf spot disease in various parts of the world. Various fungicides used to combat this disease, have deleterious effects on the environment and on pharmacologically important constituents of Aloe vera. To avoid the harmful effects of fungicides an ecofriendly approach has been adopted here. A weekly survey was conducted during 2013-2015 in and around North 24 Parganas (West Bengal) to obtain the percentage of disease index (PDI). For biological control of the disease, screening of the antagonistic efficacy of biocontrol agents was carried out through the in vitro dual-culture-plate method and scanning electron microscopy (SEM) was used to study the mechanism. The in vitro effects of fungicides on the radial growth of the pathogen were evaluated through the poison food method and were compared with potent antagonistic fungi. Field application of potent antagonistic fungi was conducted through the dip-and-spray method. The results showed that, the PDI peaked during the hot and humid conditions of May to September (76.57%-98.57%) but decreased during the winter, December-January (35.71-46.66%). Trichoderma asperellum exerted the greatest inhibition of the radial growth of A. brassicae acting through non volatile (70.39%) and volatile metabolites (72.17%). A SEM study confirmed the hyperparasitic nature of T. asperellum through hyphal coiling-T. asperellum was similar to 2% blitox-50 (73.92%) and better than 2% bavistin (59.77%) (in vitro). In agricultural field trials (2013-15), Trichoderma application restricted the disease to the smallest area (PDI 24.00-29.33%) in comparison to untreated plots (73.33%). In conclusion, saplings treated with the dip method (108 spores / mL) and sprayed 4 times with a spore suspension of biocontrol agents such as T. asperellum, T

  14. A compatible interaction of Alternaria brassicicola with Arabidopsis thaliana ecotype DiG: evidence for a specific transcriptional signature

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    Gepstein Shimon

    2009-03-01

    Full Text Available Abstract Background The interaction of Arabidopsis with Alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. Infection of most ecotypes, including the widely-studied line Col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. This study examines an ecotype, Dijon G (DiG, which is considered sensitive to A. brassicicola. Results We show that the interaction has the characteristics of a compatible one, with expanding rather than limited lesions. To ask whether DiG is merely more sensitive to the pathogen or, rather, interacts in distinct manner, we identified genes whose regulation differs between Col-0 and DiG challenged with A. brassicicola. Suppression subtractive hybridization was used to identify differentially expressed genes, and their expression was verified using semi-quantitative PCR. We also tested a set of known defense-related genes for differential regulation in the two plant-pathogen interactions. Several known pathogenesis-related (PR genes are up-regulated in both interactions. PR1, and a monooxygenase gene identified in this study, MO1, are preferentially up-regulated in the compatible interaction. In contrast, GLIP1, which encodes a secreted lipase, and DIOX1, a pathogen-response related dioxygenase, are preferentially up-regulated in the incompatible interaction. Conclusion The results show that DiG is not only more susceptible, but demonstrate that its interaction with A. brassicicola has a specific transcriptional signature.

  15. Influence of water activity and temperature on growth and mycotoxin production by Alternaria alternata on irradiated soya beans.

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    Oviedo, Maria Silvina; Ramirez, Maria Laura; Barros, Germán Gustavo; Chulze, Sofia Noemi

    2011-09-15

    The aim of this study was to determine the effects of water activity (a(w)) (0.99-0.90), temperature (15, 25 and 30°C) and their interactions on growth and alternariol (AOH) and alternariol monomethyl ether (AME) production by Alternaria alternata on irradiated soya beans. Maximum growth rates were obtained at 0.980 a(w) and 25°C. Minimum a(w) level for growth was dependent on temperature. Both strains were able to grow at the lowest a(w) assayed (0.90). Maximum amount of AOH was produced at 0.98 a(w) but at different temperatures, 15 and 25°C, for the strains RC 21 and RC 39 respectively. Maximum AME production was obtained at 0.98 a(w) and 30°C for both strains. The concentration range of both toxins varied considerably depending on a(w) and temperature interactions. The two metabolites were produced over the temperature range 15 to 30°C and a(w) range 0.99 to 0.96. The limiting a(w) for detectable mycotoxin production is slightly greater than that for growth. Two-dimensional profiles of a(w)× temperature were developed from these data to identify areas where conditions indicate a significant risk from AOH and AME accumulation on soya bean. Knowledge of AOH and AME production under marginal or sub-optimal temperature and a(w) conditions for growth can be important since improper storage conditions accompanied by elevated temperature and moisture content in the grain can favour further mycotoxin production and lead to reduction in grain quality. This could present a hazard if the grain is used for human consumption or animal feedstuff. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Alternaria toxin-induced resistance in rose plants against rose aphid (Macrosiphum rosivorum): effect of tenuazonic acid.

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    Yang, Fa-zhong; Yang, Bin; Li, Bei-bei; Xiao, Chun

    2015-04-01

    Many different types of toxins are produced by the fungus, Alternaria alternata (Fr.) Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography (HPLC) analyses demonstrated that tenuazonic acid (TeA) was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 μg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated responses in rose plants to intensively enhance the plant's resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants.

  17. Inhibitory activity of Indian spice plant Cinnamomum zeylanicum extracts against Alternaria solani and Curvularia lunata, the pathogenic dematiaceous moulds

    Directory of Open Access Journals (Sweden)

    Sharma Bechan

    2009-03-01

    Full Text Available Abstract Background Dematiaceous moulds are pathogenic microorganisms and act as etiological agents of mycoses with different degrees of severity in humans and animals. These moulds also cause loss of food crops and storage food products. The information regarding antimicrobial efficacy of the plant preparations on these moulds is scanty. The present study reveals phytochemical characterization and the effect of bark and leaf extracts of Indian spice plant, Cinnamomum zeylanicum (Cz, against the growth of two species of dematiaceous moulds, Alternaria solani and Curvularia lunata. Methods Cz bark and leaf samples were sequentially extracted in different solvents using Soxhlet apparatus. Phytochemical analyses of extracts were done as per standard protocols. The antifungal bioassay of extracts was done by hanging drop technique. The inhibition of fungal spore germination was monitored under influence of three different concentrations of extracts. Results The lowest test concentration (50 μg/ml of extracts of Cz bark prepared into acetone and that of Cz leaf into petroleum ether and ethanol exhibited complete inhibition (100% of spore germination in both the moulds. At 100 μg/ml concentration all the extracts showed about 50 to 100% inhibition. However, the treatment of the spores of the two fungal species with highest concentration (500 μg/ml of bark and leaf extracts in all the solvents showed 100% fungicidal activity as it completely arrested the germination of spores. Relatively lower activity of aqueous extracts at 50 and 100 μg/ml concentrations suggests that the antifungal ingredients present in Cz bark and leaf are more soluble in organic solvents than water. Conclusion The results demonstrated that the Cz bark and leaves contain certain fungicidal constituents exhibiting potential antimould activity against A. solani and C. lunata.

  18. Fungal-specific transcription factor AbPf2 activates pathogenicity in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yangrae; Ohm, Robin A. [US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA; Grigoriev, Igor V. [US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA; Srivastava, Akhil [Plant and Environmental Protection Sciences, University of Hawaii at Manoa, 3190 Maile Way, St John 317, Honolulu, HI, 96822, USA

    2013-05-24

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. To identify molecular determinants of pathogenicity, we created non-pathogenic mutants of a transcription factor-encoding gene, AbPf2. The frequency and timing of germination and appressorium formation on host plants were similar between the non-pathogenic abpf2 mutants and wild-type A. brassicicola. The mutants were also similar in vitro to wild-type A. brassicicola in terms of vegetative growth, conidium production, and responses to a phytoalexin, reactive oxygen species and osmolites. The hyphae of the mutants grew slowly but did not cause disease symptoms on the surface of host plants. Transcripts of the AbPf2 gene increased exponentially soon after wild-type conidia contacted their host plants . A small amount of AbPf2 protein, as monitored using GFP fusions, was present in young, mature conidia. The protein level decreased during saprophytic growth, but increased and was located primarily in fungal nuclei during pathogenesis. Levels of the proteins and transcripts sharply decreased following colonization of host tissues beyond the initial infection site. When expression of the transcription factor was induced in the wild-type during early pathogenesis, 106 fungal genes were also induced in the wild-type but not in the abpf2 mutants. Notably, 33 of the 106 genes encoded secreted proteins, including eight putative effector proteins. Plants inoculated with abpf2 mutants expressed higher levels of genes associated with photosynthesis, the pentose phosphate pathway and primary metabolism, but lower levels of defense-related genes. Our results suggest that AbPf2 is an important regulator of pathogenesis, but does not affect other cellular processes in A. brassicicola.

  19. Incidência de Mancha Púrpura (Alternaria porri Ell. Cif.) em cultivares e híbridos de cebola (Allium cepa L.), em Manaus, Am. ()

    OpenAIRE

    Alves, Maria Luiza Braz; Paiva, Waldelice Oliveira; Assis, Luís Alberto Guimarães

    1982-01-01

    Resumo Avaliou-se, em Manaus, AM, a intensidade do ataque de Alternaria porri em híbridos e cultivares de cebola (Allium cepa L.) A doença ocorreu naturalmente e efetuaram-se as observações ao final do ciclo vegetativo. Considerou-se o total de plantas avaliadas como 100% e as plantas, de acordo com a porcentagem de infecção, foram enquadradas nas seguintes classes: I ((0-10%); II (10-30%); III (30-50%); IV (50-70%) e V (> 70%). O híbrido (Px-76) foi o único a apresentar plantas na classe com...

  20. ACTIVIDAD ANTAGÓNICA DE Trichoderma spp. SOBRE Alternaria porri Y SU EFECTO EN LA ACTIVIDAD ENZIMÁTICA DE CEBOLLA

    OpenAIRE

    Camacho Luna, Valeria

    2015-01-01

    Los hongos del género Trichoderma son utilizados por su actividad antagónica para controlar fitopatógenos ya sea por ataque directo contra el patógeno ó por inducción de la resistencia sistémica de las plantas. Alternaria porri es un patógeno foliar de la cebolla que ocasiona la enfermedad “mancha púpura” que afecta a toda la planta. En este trabajo se identificó morfológicamente aislamientos de T. asperellum obtenidas de raíz de cebolla (TC1, TC2 Y TC3); y T. atroviridae y T. ...

  1. Identification of Alternaria alternata Mycotoxins by LC-SPE-NMR and Their Cytotoxic Effects to Soybean (Glycine max Cell Suspension Culture

    Directory of Open Access Journals (Sweden)

    Edson Rodrigues-Filho

    2013-02-01

    Full Text Available This present work describes the application of liquid chromatograpy-solid phase extraction-nuclear magnetic resonance spectroscopy to analyse Alternaria alternata crude extracts. Altenusin (1, alternariol (2, 3'-hydroxyalternariol monomethyl ether (3, and alternariol monomethyl ether (4, were separated and identified. High-resolution mass spectrometry confirmed the proposed structures. The cytotoxic effects of these compounds towards plants were determined using soybean (Glycine max cell cultures as a model. EC50 values which range from 0.11 (±0.02 to 4.69 (±0.47 μM showed the high cytotoxicity of these compounds.

  2. Characterization of effective bio-control agent Bacillus sp. SRB 27 ...

    African Journals Online (AJOL)

    Rhizoctonia solani and Alternaria solani was obtained from forest soil sample by carrying out in vitro and in vivo screening techniques. This study reports the identification and characterization of a Bacillus sp. SRB 27 that may be used as a bio-control agent against the plant diseases in crop plants. It was identified as ...

  3. Alternaria alternata challenge at the nasal mucosa results in eosinophilic inflammation and increased susceptibility to influenza virus infection.

    Science.gov (United States)

    Ma, M; Redes, J L; Percopo, C M; Druey, K M; Rosenberg, H F

    2018-06-01

    Eosinophils in the nasal mucosa are an elemental feature of allergic rhinitis. Our objective was to explore eosinophilic inflammation and its impact on respiratory virus infection at the nasal mucosa. Inflammation in the nasal mucosae of mice was evaluated in response to repetitive stimulation with strict intranasal volumes of a filtrate of Alternaria alternata. Mice were then challenged with influenza virus. Repetitive stimulation with A. alternata resulted in eosinophil recruitment to the nasal passages in association with elevated levels of IL-5, IL-13 and eotaxin-1; eosinophil recruitment was diminished in eotaxin-1 -/- mice, and abolished in Rag1 -/- mice. A. alternata also resulted in elevated levels of nasal wash IgA in both wild-type and eosinophil-deficient ∆dblGATA mice. Interestingly, A. alternata-treated mice responded to an influenza virus infection with profound weight loss and mortality compared to mice that received diluent alone (0% vs 100% survival, ***P < .001); the lethal response was blunted when A. alternata was heat-inactivated. Minimal differences in virus titre were detected, and eosinophils present in the nasal passages at the time of virus inoculation provided no protection against the lethal sequelae. Interestingly, nasal wash fluids from mice treated with A. alternata included more neutrophils and higher levels of pro-inflammatory mediators in response to virus challenge, among these, IL-6, a biomarker for disease severity in human influenza. Repetitive administration of A. alternata resulted in inflammation of the nasal mucosae and unanticipated morbidity and mortality in response to subsequent challenge with influenza virus. Interestingly, and in contrast to findings in the lower airways, eosinophils recruited to the nasal passages provided no protection against lethal infection. As increased susceptibility to influenza virus among individuals with rhinitis has been the subject of several clinical reports, this model may be

  4. Bazı Fungisitlerin Elmada Alternaria mali Roberts (Nekrotik Yaprak Lekesi Üzerine Etkinliğinin Belirlenmesi

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    Yasin KAŞ

    2016-12-01

    Full Text Available Bu çalışmada, farklı fungisitlerin Alternaria mali’nin 6 izolatı üzerine in vitro’da misel gelişimi, spor çimlenmesi, çimlenen sporların hifsel gelişimi ve in vivo’da elma fidanlarında hastalık şiddeti (% üzerine etkileri araştırılmıştır. Fungisitlerin farklı dozlarının (0-500 ppm artan konsatrasyonları A. mali’nin misel gelişmesi, spor çimlenmesi ve çimlenen sporların hif uzunluklarını değişen oranlarda azaltmış veya tamamen engellemiştir. Fungisitlerden, Maneb 250 ppm dozunda patojenin M-2K, AK1-K, G1-B ve GK-30 izolatlarını ve Iprodione, izolatların tümünün misel gelişmesini tamamen engellemiştir. Bakır hidroksit 350 ppm dozunda A1-B, M2-K ve AK1-K izolatlarının misel gelişmesini tamamen durdurmuştur. Difenoconazole, izolatlar arasında değişkenlik göstermekle birlikte, 450-500 ppm’de misel gelişmesini tamamen engellemiştir. Chlorothalonil ve Thiophanate-Methyl doz artışı ile birlikte misel gelişmesini azaltmıştır. Fungisitler A. mali’nin spor çimlenmesi üzerine 0-100 ppm arasında değişen oranlarda etki göstermiştir. Maneb, çimlenen sporların hif uzunluklarını izolatlara göre 50-100 ppm dozlarında tamamen engellemiştir. Fidanlarda hastalık şiddetini Bakır hidroksit % 61.6-% 87.2 ve Iprodione % 59.3-%70.9 oranlarında azaltmıştır.

  5. The inhibitory effect of the various seed coating substances against rice seed borne fungi and their shelf-life during storage.

    Science.gov (United States)

    Thobunluepop, Pitipong

    2009-08-15

    Presently, chemical seed treatments are in discussion due to their directly or indirectly impacts on human health or other living organisms. They may also negatively affect the ecosystem and the food chain. In rice seeds, chemicals may cause phytotoxic effects including seed degradation. Eugenol is the main component of clove (Eugenia caryophillis) oil, which was proved to act simultaneously as bactericide, virocide and especially fungicide. The in vitro study was aimed to compare the inhibitory effect of the following seed treatment substances against seed borne fungi and their shelf-life during 12 months of storage; conventional captan (CA), chitosan-lignosulphonate polymer (CL), eugenol incorporated into chitosan-lignosulphonate polymer (E+CL) and control (CO). The obtained results of fungi inhibition were classified in three groups, which showed at first that CA treatment led to a better, i.e., longer, inhibitory effect on Alternaria padwickii, Rhizoctonia solani, Curvularia sp., Aspergillus flavus and Aspergillus niger than E+CL. Secondly, E+CL coating polymer showed the longest inhibitory effect against Bipolaris oryzae and Nigrospora oryzae compared to CA and CL coating polymer. Finally, both CA and E+CL coating polymer had non-significant difference inhibitory effect on Fusarium moniliforme. The variant of CL coating polymer for seed coating was only during the first 6 months of storage able to inhibit all species of the observed seed borne fungi, whereas CA and E+CL coating polymer were capable to inhibit most of the fungi until 9 months of storage.

  6. Survey and prevalence of species causing Alternaria leaf spots on brassica species in Pernambuco Levantamento e prevalência de espécies causadoras da alternariose em brássicas em Pernambuco

    Directory of Open Access Journals (Sweden)

    Sami J Michereff

    2012-06-01

    Full Text Available Brassicaceae family comprises plant species that are very important as vegetable crops, such as the species complex Brassica oleracea and Brassica rapa. Alternaria brassicicola and A. brassicae are among the most important pathogens of Brassicaceae causing Alternaria leaf spot disease. The occurrence and prevalence of Alternaria species causing leaf spots in brassica crops in Pernambuco was acessed, as well as the existence of a possible preference by vegetable host for these pathogens. Twenty-eight fields were surveyed in the Agreste region of Pernambuco state, in the 2005 and 2006 growing seasons. In each year, 10 Chinese cabbage, six cabbage, six cauliflower and six broccoli fields were visited. In each field, 50 leaves showing at least five lesions were randomly collected. Species identification was performed taking into account morphology of the conidia that was compared with literature data. Among the two Alternaria species found, A. brassicae was found in all Chinese cabbage fields while A. brassicicola was found in all fields of cabbage, cauliflower and broccoli. Overall, A. brassicicola was more prevalent than A. brassicae. In Chinese cabbage there was predominance of A. brassicae, with mean prevalence of 91.0% and 96.5% in 2005 and 2006. On the other hand, in broccoli and cabbage there was high predominance of A. brassicicola, with mean prevalence between 95.1% and 99.8%. In cauliflower, although the prevalence has been of A. brassicicola, high frequency of A. brassicae was noted. The frequency of co-occurrence of both Alternaria species was very low. The results of this study reinforce the hypothesis of existence of host preference within species of Alternaria that cause leaf spots in brassica crops, especially when Chinese cabbage, broccoli and cabbage are considered. This information is critical to developing strategies for managing Alternaria leaf spots in Brassicaceae species.A família Brassicaceae possui espécies importantes

  7. Aislamiento, identificación y pruebas in vitro de cepas autóctonas de Bacillus subtilis como agente de biocontrol de Alternaria spp en Brassica oleracea var.italica.

    OpenAIRE

    Ñacato Suntaxi, Carolina Aracely; Valencia Gordón, María Fernanda

    2016-01-01

    There is an increasing consumer demand for quality food, a concept which mainly involves the availability of disease-free products and harmful to human health chemical waste, which is why the need for new options for sustainable management arises broccoli crop against the causative pathogen damage in inflorescence. The disease caused by the phytopathogenic fungus Alternaria spp is a major cause of damage to broccoli cultivars. Field sampling and laboratory investigations w...

  8. A Zinc-Finger-Family Transcription Factor, AbVf19, Is Required for the Induction of a Gene Subset Important for Virulence in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Akhil [Univ. of Hawaii, Manoa, HI (United States); Ohm, Robin A. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Oxiles, Lindsay [Univ. of Hawaii, Manoa, HI (United States); Brooks, Fred [Univ. of Hawaii, Manoa, HI (United States); Lawrence, Christopher B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Grigoriev, Igor V. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Cho, Yangrae [Univ. of Hawaii, Manoa, HI (United States)

    2011-10-26

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen with a broad host range within the family Brassicaceae. It produces secondary metabolites that marginally affect virulence. Cell wall degrading enzymes (CDWE) have been considered important for pathogenesis but none of them individually have been identified as significant virulence factors in A. brassicicola. In this study, knockout mutants of a gene, AbVf19, were created and produced considerably smaller lesions than the wild type on inoculated host plants. The presence of tandem zinc-finger domains in the predicted amino acid sequence and nuclear localization of AbVf19- reporter protein suggested that it was a transcription factor. Gene expression comparisons using RNA-seq identified 74 genes being downregulated in the mutant during a late stage of infection. Among the 74 downregulated genes, 28 were putative CWDE genes. These were hydrolytic enzyme genes that composed a small fraction of genes within each family of cellulases, pectinases, cutinases, and proteinases. The mutants grew slower than the wild type on an axenic medium with pectin as a major carbon source. This study demonstrated the existence and the importance of a transcription factor that regulates a suite of genes that are important for decomposing and utilizing plant material during the late stage of plant infection.

  9. Determination of six Alternaria toxins with UPLC-MS/MS and their occurrence in tomatoes and tomato products from the Swiss market.

    Science.gov (United States)

    Noser, Jürg; Schneider, Patrick; Rother, Martin; Schmutz, Hansruedi

    2011-11-01

    An ultra performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS) method was developed for the determination of the Alternaria toxins tenuazonic acid, alternariol, alternariol monomethyl ether, altenuene, altertoxin I and tentoxin. Owing to its instability, altenusin could not be determined. The sample preparation includes an acidic acetonitrile/water/methanol extraction, followed by SPE clean-up step, before injection into the UPLC-MS/MS system. The separation was made on an Acquity UPLC column using a water/acetonitrile gradient with ammonium hydrogen carbonate as a modifier. Matrix compounds of real samples led to enhancement as well as suppression of the target compounds, depending on analyte and matrix. The recoveries were between 58 and 109% at a level of 10 μg/kg. Eighty-five tomato products, consisting of peeled and minced tomatoes, soup and sauces, tomato purées and concentrates, ketchup as well as dried and fresh tomatoes, were taken from the Swiss market in 2010. Tenuazonic acid was found most frequently (81 out of 85 samples) and in the highest levels of up to 790 μg/kg. Alternariol and alternariol monomethyl ether were found in lower concentrations, ranging from <1 to 33 μg/kg for alternariol and <5 to 9 μg/kg for alternariol monomethyl ether. Only a few samples were positive for altenuene and tentoxin. Altertoxin I was never detected.

  10. IP3 production in the hypersensitive response of lemon seedlings against Alternaria alternata involves active protein tyrosine kinases but not a G-protein

    Directory of Open Access Journals (Sweden)

    XIMENA ORTEGA

    2005-01-01

    Full Text Available IP3 increase and de novo synthesis of scoparone are produced in the hypersensitive response (HR of lemon seedlings against the fungus Alternaria alternata. To elucidate whether a G-protein and/or a protein tyrosine kinase (PTK are involved in signal transduction leading to the production of such a defensive response, we studied the HR in this plant system after treatment with G-protein activators alone and PTK inhibitors in the presence of fungal conidia. No changes in the level of IP3 were detected in response to the treatment with the G-protein activators cholera toxin or mastoparan, although the HR was observed in response to these compounds as determined by the scoparone synthesis. On the contrary, the PTK inhibitors lavendustin A and 2,5-dihidroxy methyl cinnamate (DHMC not only prevented the IP3 changes observed in response to the fungal inoculation of lemon seedlings but also blocked the development of the HR. These results suggest that the IP3 changes observed in response to A. alternata require a PTK activity and are the result of a G-protein independent Phospholipase C activity, even though the activation of a G-protein can also lead to the development of a HR. Therefore, it appears that more than one signaling pathway may be activated for the development of HR in lemon seedlings: one involving a G-protein and the other involving a PTK-dependent PLC.

  11. Modelling the effect of temperature, water activity and carbon dioxide on the growth of Aspergillus niger and Alternaria alternata isolated from fresh date fruit.

    Science.gov (United States)

    Belbahi, A; Leguerinel, I; Méot, J-M; Loiseau, G; Madani, K; Bohuon, P

    2016-12-01

    To quantify and model the combined effects of temperature (T) (10-40°C), water activity (a w ) (0·993-0·818) and CO 2 concentration (9·4-55·1%, v/v) on the growth rate of Aspergillus niger and Alternaria alternata that cause spoilage during the storage and packaging of dates. The effects of environmental factors were studied using the γ-concept. Cardinal models were used to quantify the effect of studied environmental factors on the growth rates. Firstly, the cardinal parameters were estimated independently from experiments carried out on potato dextrose agar using a monofactorial design. Secondly, model performance evaluation was conducted on pasteurized date paste. The boundary between growth and no-growth was predicted using a deterministic approach. Aspergillus niger displayed a faster growth rate and higher tolerance to low a w than Al. alternata, which in turn proved more resistant to CO 2 concentration. Minimal cardinal parameters of T and a w were lower than those reported in the literature. The combination of the a w and CO 2 effects significantly affected As. niger and Al. alternata growth. The γ-concept model overestimated growth rates, however, it is optimistic and provides somewhat conservative predictions. The developed model provides a decision support tool for the choice of the date fruit conservation mode (refrigeration, drying, modified atmospheric packaging or their combination) using T, a w and CO 2 as environmental factors. © 2016 The Society for Applied Microbiology.

  12. Characterization and Comparison of the CPK Gene Family in the Apple (Malus × domestica and Other Rosaceae Species and Its Response to Alternaria alternata Infection.

    Directory of Open Access Journals (Sweden)

    Menghan Wei

    Full Text Available As one of the Ca2+ sensors, calcium-dependent protein kinase (CPK plays vital roles in immune and stress signaling, growth and development, and hormone responses, etc. Recently, the whole genome of apple (Malus × domestica, pear (Pyrus communis, peach (Prunus persica, plum (Prunus mume and strawberry (Fragaria vesca in Rosaceae family has been fully sequenced. However, little is known about the CPK gene family in these Rosaceae species. In this study, 123 CPK genes were identified from five Rosaceae species, including 37 apple CPKs, 37 pear CPKs, 17 peach CPKs, 16 strawberry CPKs, and 16 plum CPKs. Based on the phylogenetic tree topology and structural characteristics, we divided the CPK gene family into 4 distinct subfamilies: Group I, II, III, and IV. Whole-genome duplication (WGD or segmental duplication played vital roles in the expansion of the CPK in these Rosaceae species. Most of segmental duplication pairs in peach and plum may have arisen from the γ triplication (~140 million years ago [MYA], while in apple genome, many duplicated genes may have been derived from a recent WGD (30~45 MYA. Purifying selection also played a critical role in the function evolution of CPK family genes. Expression of apple CPK genes in response to apple pathotype of Alternaria alternata was verified by analysis of quantitative real-time RT-PCR (qPCR. Expression data demonstrated that CPK genes in apple might have evolved independently in different biological contexts. The analysis of evolution history and expression profile laid a foundation for further examining the function and complexity of the CPK gene family in Rosaceae.

  13. A Pectate Lyase-Coding Gene Abundantly Expressed during Early Stages of Infection Is Required for Full Virulence in Alternaria brassicicola.

    Directory of Open Access Journals (Sweden)

    Yangrae Cho

    Full Text Available Alternaria brassicicola causes black spot disease of Brassica species. The functional importance of pectin digestion enzymes and unidentified phytotoxins in fungal pathogenesis has been suspected but not verified in A. brassicicola. The fungal transcription factor AbPf2 is essential for pathogenicity and induces 106 genes during early pathogenesis, including the pectate lyase-coding gene, PL1332. The aim of this study was to test the importance and roles of PL1332 in pathogenesis. We generated deletion strains of the PL1332 gene, produced heterologous PL1332 proteins, and evaluated their association with virulence. Deletion strains of the PL1332 gene were approximately 30% less virulent than wild-type A. brassicicola, without showing differences in colony expansion on solid media and mycelial growth in nutrient-rich liquid media or minimal media with pectins as a major carbon source. Heterologous PL1332 expressed as fusion proteins digested polygalacturons in vitro. When the fusion proteins were injected into the apoplast between leaf veins of host plants the tissues turned dark brown and soft, resembling necrotic leaf tissue. The PL1332 gene was the first example identified as a general toxin-coding gene and virulence factor among the 106 genes regulated by the transcription factor, AbPf2. It was also the first gene to have its functions investigated among the 19 pectate lyase genes and several hundred putative cell-wall degrading enzymes in A. brassicicola. These results further support the importance of the AbPf2 gene as a key pathogenesis regulator and possible target for agrochemical development.

  14. Salicylic acid-mediated establishment of the compatibility between Alternaria brassicicola and Brassica juncea is mitigated by abscisic acid in Sinapis alba.

    Science.gov (United States)

    Mazumder, Mrinmoy; Das, Srirupa; Saha, Upala; Chatterjee, Madhuvanti; Bannerjee, Kaushik; Basu, Debabrata

    2013-09-01

    This work addresses the changes in the phytohormonal signature in the recognition of the necrotrophic fungal pathogen Alternaria brassicicola by susceptible Brassica juncea and resistant Sinapis alba. Although B. juncea, S. alba and Arabidopsis all belong to the same family, Brassicaceae, the phytohormonal response of susceptible B. juncea towards this pathogen is unique because the latter two species express non-host resistance. The differential expression of the PR1 gene and the increased level of salicylic acid (SA) indicated that an SA-mediated biotrophic mode of defence response was triggered in B. juncea upon challenge with the pathogen. Compared to B. juncea, resistant S. alba initiated enhanced abscisic acid (ABA) and jasmonic acid (JA) responses following challenge with this pathogen, as revealed by monitoring the expression of ABA-related genes along with the concentration of ABA and JA. Furthermore, these results were verified by the exogenous application of ABA on B. juncea leaves prior to challenge with A. brassicicola, which resulted in a delayed disease progression, followed by the inhibition of the pathogen-mediated increase in SA response and enhanced JA levels. Therefore, it seems that A. brassicicola is steering the defence response towards a biotrophic mode by mounting an SA response in susceptible B. juncea, whereas the enhanced ABA response of S. alba not only counteracts the SA response but also restores the necrotrophic mode of resistance by enhancing JA biosynthesis. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  15. Characterization and Comparison of the CPK Gene Family in the Apple (Malus × domestica) and Other Rosaceae Species and Its Response to Alternaria alternata Infection.

    Science.gov (United States)

    Wei, Menghan; Wang, Sanhong; Dong, Hui; Cai, Binhua; Tao, Jianmin

    2016-01-01

    As one of the Ca2+ sensors, calcium-dependent protein kinase (CPK) plays vital roles in immune and stress signaling, growth and development, and hormone responses, etc. Recently, the whole genome of apple (Malus × domestica), pear (Pyrus communis), peach (Prunus persica), plum (Prunus mume) and strawberry (Fragaria vesca) in Rosaceae family has been fully sequenced. However, little is known about the CPK gene family in these Rosaceae species. In this study, 123 CPK genes were identified from five Rosaceae species, including 37 apple CPKs, 37 pear CPKs, 17 peach CPKs, 16 strawberry CPKs, and 16 plum CPKs. Based on the phylogenetic tree topology and structural characteristics, we divided the CPK gene family into 4 distinct subfamilies: Group I, II, III, and IV. Whole-genome duplication (WGD) or segmental duplication played vital roles in the expansion of the CPK in these Rosaceae species. Most of segmental duplication pairs in peach and plum may have arisen from the γ triplication (~140 million years ago [MYA]), while in apple genome, many duplicated genes may have been derived from a recent WGD (30~45 MYA). Purifying selection also played a critical role in the function evolution of CPK family genes. Expression of apple CPK genes in response to apple pathotype of Alternaria alternata was verified by analysis of quantitative real-time RT-PCR (qPCR). Expression data demonstrated that CPK genes in apple might have evolved independently in different biological contexts. The analysis of evolution history and expression profile laid a foundation for further examining the function and complexity of the CPK gene family in Rosaceae.

  16. Report and characterization of alternaria alternata (fr.) keissler on avicennia marina (forsk.) vierh forests of industrial yanb'a city, saudi arabia

    International Nuclear Information System (INIS)

    Abeer, H.; Huqail, A.A.; Allah, E.F.A.; Alqarawi, A.A.

    2014-01-01

    The present study was carried out to investigate the leaf spot disease of Avicennia marina (Forski) Vierh in Saudi Arabia. The leaf spot disease is reported for the first time in mangrove plants of SA. The symptoms of leaf spot disease and the morphological characters of the causal organism are also described. The radial growth and sporulation of A. alternata were variable with obvious trend on the different growth media. The optimum pH range for maximum growth was 6.0 to 6.5 and any fluctuation in pH caused significant decrease in linear growth of the mold. The chromatographic (TLC) analysis of chloroform extract of fungal culture broth indicated clearly that the mold was able to produce both alternariol and alternariol monomethyl ether. The gas liquid chromatographic analysis of mycelial fatty acids demonstrated the presence of caproic, caprylic, lauric, myristic, palmitic, margaric, stearic, arachidic, myristoleic, palmitoleic, oleic, linoleic, ? linolenic, Cis-11 eicosenoic, eicosatrienoic and arachidonic fatty acids in the mycelia of the causal organism. The analysis of free amino acids in the mycelia of causal organism indicated the presence of 13 amino acids namely, alanine, threonine, valine, proline, methionine, tryptophan, tyrosine, lysin, cystin, glycine, asparatic acid, tyrosine, and phenyl alanine. The PCR product amplified with A. alternata DNA indicates that the 370-bp PCR product is a useful diagnostic tool to identify the causal organism in mangrove leaves. This study demonstrated that the causal organism of leaf spot disease of A. marina was typically similar to Alternaria alternata (Fr.) Keissler via classical, biochemical and molecular characterization. (author)

  17. A Major Facilitator Superfamily Transporter-Mediated Resistance to Oxidative Stress and Fungicides Requires Yap1, Skn7, and MAP Kinases in the Citrus Fungal Pathogen Alternaria alternata.

    Directory of Open Access Journals (Sweden)

    Li-Hung Chen

    Full Text Available Major Facilitator Superfamily (MFS transporters play an important role in multidrug resistance in fungi. We report an AaMFS19 gene encoding a MFS transporter required for cellular resistance to oxidative stress and fungicides in the phytopathogenic fungus Alternaria alternata. AaMFS19, containing 12 transmembrane domains, displays activity toward a broad range of substrates. Fungal mutants lacking AaMFS19 display profound hypersensitivities to cumyl hydroperoxide, potassium superoxide, many singlet oxygen-generating compounds (eosin Y, rose Bengal, hematoporphyrin, methylene blue, and cercosporin, and the cell wall biosynthesis inhibitor, Congo red. AaMFS19 mutants also increase sensitivity to copper ions, clotrimazole, fludioxonil, and kocide fungicides, 2-chloro-5-hydroxypyridine (CHP, and 2,3,5-triiodobenzoic acid (TIBA. AaMFS19 mutants induce smaller necrotic lesions on leaves of a susceptible citrus cultivar. All observed phenotypes in the mutant are restored by introducing and expressing a wild-type copy of AaMFS19. The wild-type strain of A. alternata treated with either CHP or TIBA reduces radial growth and formation and germination of conidia, increases hyphal branching, and results in decreased expression of the AaMFS19 gene. The expression of AaMFS19 is regulated by the Yap1 transcription activator, the Hog1 and Fus3 mitogen-activated protein (MAP kinases, the 'two component' histidine kinase, and the Skn7 response regulator. Our results demonstrate that A. alternata confers resistance to different chemicals via a membrane-bound MFS transporter.

  18. Site-directed mutagenesis of α-L-rhamnosidase from Alternaria sp. L1 to enhance synthesis yield of reverse hydrolysis based on rational design.

    Science.gov (United States)

    Xu, Li; Liu, Xiaohong; Yin, Zhenhao; Liu, Qian; Lu, Lili; Xiao, Min

    2016-12-01

    The α-L-rhamnosidase catalyzes the hydrolytic release of rhamnose from polysaccharides and glycosides and is widely used due to its applications in a variety of industrial processes. Our previous work reported that a wild-type α-L-rhamnosidase (RhaL1) from Alternaria sp. L1 could synthesize rhamnose-containing chemicals (RCCs) though reverse hydrolysis reaction with inexpensive rhamnose as glycosyl donor. To enhance the yield of reverse hydrolysis reaction and to determine the amino acid residues essential for the catalytic activity of RhaL1, site-directed mutagenesis of 11 residues was performed in this study. Through rationally designed mutations, the critical amino acid residues which may form direct or solvent-mediated hydrogen bonds with donor rhamnose (Asp 252 , Asp 257 , Asp 264 , Glu 530 , Arg 548 , His 553 , and Trp 555 ) and may form the hydrophobic pocket in stabilizing donor (Trp 261 , Tyr 302 , Tyr 316 , and Trp 369 ) in active-site of RhaL1 were analyzed, and three positive mutants (W261Y, Y302F, and Y316F) with improved product yield stood out. From the three positive variants, mutant W261Y accelerated the reverse hydrolysis with a prominent increase (43.7 %) in relative yield compared to the wild-type enzyme. Based on the 3D structural modeling, we supposed that the improved yield of mutant W261Y is due to the adjustment of the spatial position of the putative catalytic acid residue Asp 257 . Mutant W261Y also exhibited a shift in the pH-activity profile in hydrolysis reaction, indicating that introducing of a polar residue in the active site cavity may affect the catalysis behavior of the enzyme.

  19. Efeito de meios de cultura e fatores físicos no crescimento e esporulação de Alternaria dauci e A. solani Effect of culture media and physical factors on growth and sporulation of Alternaria dauci and A. solani

    Directory of Open Access Journals (Sweden)

    Pablo Pulz

    2009-06-01

    Full Text Available Alternaria dauci e Alternaria solani são espécies / 24 h. O método desenvolvido neste trabalho foi comparado ao reconhecidamente difíceis de esporular em meios de cultura. Este tradicionalmente utilizado (BDA, 25 ºC, 12 h luz branca / 12 h trabalho teve o objetivo de verificar a influência de alguns meios escuro e raspagem da colônia. O meio V8-ágar, temperatura de 25 de cultura e fatores fisicos sobre o crescimento micelial e a ºC, luz NUV e raspagem das colônias exerceram influência mais esporulação dessas espécies. Testaram-se os meios de cultura BDA, marcante no crescimento e esporulação. O fotoperíodo 12 h luz NUV Aveia e V8; temperaturas (15ºC, 20ºC, 25ºC, 30ºC e 35ºC / 12 h escuro foi o que mais estimulou a esporulação. Observou-se que, comprimentos de onda da luz durante a incubação (amarelo, azul, de modo geral, períodos de escuro maiores que os períodos de luz, branco, NUV, verde e vermelho; tipos de injúria aplicados à aplicados após injúria da colônia, favoreceram a esporulação. O colônia (raspagem, UV, irradiação de microondas, e temperatura método desenvolvido mostrou-se nitidamente superior ao de 100 ºC e fotoperíodos (luz / escuro, respectivamente, de 24 h tradicionalmente utilizado, para crescimento e esporulação de ambas / 0 h, 22 h / 2 h, 17 h / 7 h, 12 h / 12 h, 7 h / 17 h, 2 h / 22 e 0 h as espécies.Alternaria dauci and A. solani are fungal species known for h and 0 h / 24 h were tested. The method developed in this study was difficult sporulation in culture media. This study had the objective of compared to the traditional procedure (BDA, 25 ºC, 12 h white / 12 verifying the influence of some physical factors on mycelia growth h dark light and scratching of the colony. V8-agar medium, and sporulation of these two species. Culture media (BDA, oat and temperature of 25 ºC, NUV light and scratching of the colonies had a V8, temperature (15ºC, 20ºC, 25ºC, 30ºC and 35ºC, light

  20. A method for the determination of two Alternaria toxins, alternariol and alternariol monomethyl ether, in tomato products Um método para determinação de duas toxinas de Alternaria, alternariol monometil éter e alternariol, em produtos de tomate

    Directory of Open Access Journals (Sweden)

    Silvana da Motta

    2000-10-01

    Full Text Available Tomatoes, as any soft skinned fruit, are easily susceptible to fungal rot. Alternaria is the genus most frequently encountered in tomatoes. A. alternata and other spp. have been shown to produce the toxins alternariol monomethyl ether (AME and alternariol (AOH in tomatoes. A method for determining AME and AOH in tomato products was developed and evaluated. The method involves extraction with methanol, clarification with ammonium sulfate, and partition to chloroform. Quantification was conducted by high performance liquid chromatography with diode array detector (DAD. Average recoveries were 98.7% and 84.1% for AME and AOH, respectively. The quantification limits of the method, defined as the minimum amount that allowed quantification and confirmation by the DAD detector, were 2.0 ng/g for AME and 5.0 ng/g for AOH.Tomates são frutas de pele fina e assim facilmente susceptíveis a deterioração por fungos. Alternaria é o gênero que mais freqüentemente invade tomates. A. alternata e outras espécies deste gênero produzem as toxinas alternariol (AOH e alternariol monometil (AME. Um método analítico para determinação de AME e AOH em produtos de tomate foi desenvolvido e avaliado. O método consiste em uma extração com metanol, clarificação com sulfato de amônio e partição para clorofórmio. Quantificação foi executada por cromatografia líquida de alta eficiência com detetor de arranjo de diodos (DAD. Recuperações médias foram 98,7% e 84,1% para AME e AOH, respectivamente. Os limites de detecção do método, definidos como a menor quantidade das toxinas que permitiu quantificação e confirmação pelo DAD, foram 2,0 ng/g para AME e 5,0 ng/g para AOH.

  1. Effect of Different Growth Stages and Dew Period Length on Disease Development of Alternaria alternata as a Biological Control Agent for Convolvulus arvensis

    Directory of Open Access Journals (Sweden)

    E Zeidali

    2012-02-01

    Full Text Available Abstract Field bindweed is an important perinial weed of agricultural crops word-wide. There are plant pathogen fungus which could cause necrotic spots on the leaves and stems of convolvulus arvensis under natural coditions. In order to evaluate the effects of weed growth stage and length of dew period on disease development causes by Aletrnaria alternata and Fusarium sp. two expriments were performed in the greenhouse based on a completely randomized design in factorial arrangement with four replications during 2006-2007. Spore concentration for both experiments was 107 spores per ml of distilled water. In the first experiment, treatments were different growth stages of field bindweed (cotyledon, 4-leaf, 6-leaf, 9-11-leaf stages. Results showed that disease development in the fungus of A. alternata was higher than Fusarium sp. The most susceptable growth stage of field bindweed plants to A. alternata was 2-4-leave stage. The second expriment was performed in order to study the effect of dew period length (6, 12, 24 and 48 hour dew periods on disease development at 4-leaf growth stage of field bindweed. The maximum disease development and minimum weed dry weight were observed with application of the fungus of A. alternata at dew periods of 24 and 48 hour, however, plant damage was also observed with a length of 6 hours dew period.

  2. Characterization of rhizosphere bacteria for control of phytopathogenic fungi of tomato.

    Science.gov (United States)

    Pastor, Nicolás; Carlier, Evelin; Andrés, Javier; Rosas, Susana B; Rovera, Marisa

    2012-03-01

    Fluorescent Pseudomonas spp., isolated from rhizosphere soil of tomato and pepper plants, were evaluated in vitro as potential antagonists of fungal pathogens. Strains were characterized using the API 20NE biochemical system, and tested against the causal agents of stem canker and leaf blight (Alternaria alternata f. sp. lycopersici), southern blight (Sclerotium rolfsii Sacc.), and root rot (Fusarium solani). To this end, dual culture antagonism assays were carried out on 25% Tryptic Soy Agar, King B medium, and Potato Dextrose Agar to determine the effect of the strains on mycelial growth of the pathogens. The effect of two concentrations of FeCl(3) on antagonism against Alternaria alternata f. sp. lycopersici was also tested. In addition, strains were screened for ability to produce exoenzymes and siderophores. Finally, the selected Pseudomonas strain, PCI2, was evaluated for effect on tomato seedling development and as a potential candidate for controlling tomato damping-off caused by Sclerotium rolfsii Sacc., under growth chamber conditions. All strains significantly inhibited Alternaria alternata f. sp. lycopersici, particularly in 25% TSA medium. Antagonistic effect on Sclerotium rolfsii Sacc. and Fusarium solani was greater on King B medium. Protease was produced by 30% of the strains, but no strains produced cellulase or chitinase. Growth chamber studies resulted in significant increases in plant stand as well as in root dry weight. PCI2 was able to establish and survive in tomato plants rhizosphere after 40 days following planting of bacterized seeds. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Development of a high performance liquid chromatography tandem mass spectrometry based analysis for the simultaneous quantification of various Alternaria toxins in wine, vegetable juices and fruit juices.

    Science.gov (United States)

    Zwickel, Theresa; Klaffke, Horst; Richards, Keith; Rychlik, Michael

    2016-07-15

    An analytical method based on high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS) detection for the simultaneous quantification of 12 Alternaria toxins in wine, vegetable juices and fruit juices was developed. Excellent chromatographic performance was demonstrated for tenuazonic acid (TeA) in a multi-analyte method. This comprehensive study is also the first to report the determination of TeA, alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and altenuene (ALT), altertoxin I (ATX-I), altertoxin II (ATX-II), altenuisol (ATL), iso-altenuene (isoALT), altenuic acid III (AA-III) and the AAL toxins TB1 und TB2 in samples from the German market. Several types of HPLC columns were tested for the liquid chromatographic separation of the toxins of interest that widely differ in their polarities. The focus was on gaining suitable retention while avoiding derivatization steps especially for TeA and AA-III. Three atmospheric pressure ionization techniques used with liquid chromatography (electrospray, chemical and photo ionization) were tested to obtain the best selectivity and sensitivity. Samples were diluted with sodium hydrogen carbonate buffer and extracted on a diatomaceous earth solid phase extraction cartridge. Method validation was carried out by using tomato juice, citrus juice and white wine as blank matrices. Limits of detection ranged from 0.10 to 0.59μgL(-1) and limits of quantification ranged from 0.4-3.1μgL(-1) depending on the toxin and matrix. Recoveries were around 100±9% for all toxins except stemphyltoxin III (STTX-III) and altenusin (ALS) due to instability during sample clean up. Matrix-induced effects leading to ion suppression especially for ATX-I, ATX-II and AA-III were investigated. Relative standard deviations of repeatability (RSDr) and intermediate reproducibility (RSDR) were ≤9.3 and ≤17.1, respectively, for the toxins in different matrices at levels of 5 and 30μgL(-1). Finally, 103

  4. Levantamento da intensidade da alternariose e da podridão negra em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina Survey of the intensity of Alternaria black spot and black rot on brassica species under organic farming systems in Pernambuco and Santa Catarina states, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz A M Peruch

    2006-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a intensidade da alternariose, causada por Alternaria brassicicola e/ou Alternaria brassicae, e da podridão negra, causada por Xanthomonas campestris pv. campestris, em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina. Os levantamentos foram realizados no período de novembro de 2001 a fevereiro de 2002, num total de 103 cultivos orgânicos de várias espécies de brássicas. Foram registradas elevadas prevalências das doenças nos estados, com exceção em couve-chinesa em Santa Catarina. A prevalência da alternariose foi 100% nos cultivos de brócolis em Pernambuco, bem como em couve-flor nos dois estados, enquanto a podridão negra atingiu esse nível nos cultivos de brócolis e couve-flor em Santa Catarina. Na média das diferentes espécies de brássicas, as doenças foram mais prevalentes em Pernambuco que Santa Catarina. Entretanto, as médias de severidade de cada doença no conjunto das brássicas não foram diferentes entre os estados, embora as condições climáticas tenham sido nitidamente distintas. A severidade da alternariose variou entre as espécies de brássicas somente em Pernambuco, com a menor severidade registrada em couve-manteiga. Em relação à podridão negra, apenas em Santa Catarina houve diferença na severidade entre as brássicas, sendo registrados os menores níveis em couve-chinesa. Não foram constatadas correlações significativas entre os níveis de severidade da alternariose e da podridão negra, bem como da severidade destas com o número total de plantas e a idade das plantas nos cultivos.The objective of this research was to evaluate the intensity of Alternaria black spot, caused by Alternaria brassicicola and/or Alternaria brassicae, and black rot, caused by Xanthomonas campestris pv. campestris in organic cultivation of brassicas in Pernambuco and Santa Catarina. The survey was carried aut from November 2001 to February 2002, in 103 fields under

  5. Intensidade de ataque de tripes, de alternaria e da queima-das-pontas em cultivares de cebola Intensity of attacks of thrips, purple blotch and gray mold on onion cultivars

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    Germano L.D. Leite

    2004-03-01

    Full Text Available Avaliou-se a intensidade de ataque de Thrips tabaci Lind., a incidência de Alternaria porri (Ellis e Botrytis squamosa J.C. Walker em nove cultivares de cebola [Aurora, Primavera, CNPH 6400, Crioula Alto-Vale, Vale-Ouro (IPA 11, Franciscana (IPA-16, Piraouro, Conquista e Serrana], num experimento no delineamento em blocos casualizados com cinco repetições. Foram feitas avaliações semanais, do transplantio até a colheita, em dez plantas/parcela do número de T. tabaci presente na bainha das folhas bem como da percentagem de área foliar danificada pelo mesmo a partir da primeira folha expandida e também da presença ou da ausência de lesões causadas por A. porri e B. squamosa. A cv. Franciscana mostrou-se mais resistente em relação às demais ao ataque de T. tabaci. Não houve diferença significativa de plantas afetadas por A. porri e B. squamosa. T. tabaci e A. porri foram ambos afetados positiva e negativamente pela temperatura e pela umidade relativa do ambiente, respectivamente.The intensity of attack of T. tabaci and incidence of Alternaria porri (Ellis Cif and Botrytis squamosa J.C. Walker in nine onion cultivars [Aurora, Primavera, CNPH 6400, Crioula Alto-Vale, Vale-Ouro (IPA 11, Franciscana (IPA-16, Piraouro, Conquista and Serrana] was evaluated, in an experiment in randomized blocks design, with five replications. Weekly evaluations were done from the transplanting until harvesting date, in ten plants/parcel of the number of T. tabaci on the leaves, the percentage of damaged foliar area from the first expanded leaf up and the presence or absence of injuries caused by A. porri and B. squamosa. The cv. Franciscana was more resistant to the attack of T. tabaci in comparison to the other onion cultivars. There was no significant difference between cvs for A. porri and Botrytis squamosa resistance. T. tabaci and A. porri were influenced positively and negatively by temperature and relative humidity, respectively.

  6. Irradiation in the control of post harvest losses- a NRL contribution

    International Nuclear Information System (INIS)

    Roy, M.K.; Prasad, H.H.

    1994-01-01

    In-vitro growth of Phytophthora parasitica is completely prevented by a dose of 1.5kGy of gamma radiation and that of Phomopsis vexans by a dose of 4.0kGy. These doses, however cannot prevent the growth of other three studied fungi viz. Fusarium ceoruleum, Geotrichum candidum and Alternaria alternata and exerted only a reversible effect on their growth. Irradiation as a method for the control of harvest losses in fruits, tomato, rice etc. were studied at Nuclear Research Laboratory (NRL) and the results are given. 2 figs., 8 tabs

  7. Research Regarding the Simultaneous Control of the Pathogens on Tomatoes Crops under High Plastic Tunnels

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    Gabriela ŞOVĂREL

    2017-05-01

    Full Text Available In Romania the most important pathogens on tomatoes crops are Alternaria porri f.sp. solani, Botrytis cinerea, Fulvia fulva, Phytophthora infestans and Erysiphe sp. During period of vegetation, the attack of mentioned pathogens are frequently overlapping. For simultaneously control of pathogenswere used some combination with different active substances (chlorothalonil 500g/l, iprodione 500 g/l, fenhexamid 500 g/l, thiophanate methyl 500g/l, metiram 80%, dimethomorph 9%, mancozeb 60%, difenoconazole 250 g/l , fenamidone 75g/l, propamocarb HCL 375 g/l. The best results for controlling Alternaria porri f.sp. solani, Botrytis cinerea and Fulvia fulva are metiram 80% 0.2% + thiophanate methyl 500g/l 0.14% with 93.5% efficacy. In the untreated check the degree of attack was 78.6% (44.3% A.solani, 7.0% B.cinerea and 27.3% F. Fulva. For controlling Phytophthora infestans, Erysiphe sp. and Fulvia fulva (fenamidone 75g/l + propamocarb HCL 375 g/l    0.2% +  difenoconazole 250 g/l 0.05% with 94.5% efficacy. In the untreated check the degree of attack is 81.2% (38.4% P. infestans, 27.4% Erysiphe sp. , 15.4% F. fulva.

  8. Volatilization of Selenium by Alternaria alternata

    OpenAIRE

    Thompson-Eagle, E. T.; Frankenberger, W. T.; Karlson, U.

    1989-01-01

    Seleniferous water continues to be a serious problem to wildlife in the central valley of California. Water samples collected from Kesterson Reservoir, Peck Ranch, and Lost Hills evaporation pond facilities contained between 0.005 and 5 mg of Se per liter. The objective of this study was to isolate Se-methylating organisms in evaporation pond water and to assess, through enrichment and manipulation of their optimal growth parameters, the environmental factors which govern microbial Se methyla...

  9. First report of alternaria leaf spot of banana caused by Alternaria alternata in the United States

    Science.gov (United States)

    Research efforts were initiated in 2003 to identify and introduce banana (Musa spp.) cultivars suitable for production in Georgia. In spring and summer 2012, seven of the cultivars (Veinte Cohol, Novaria, Cacambou, Chinese Cavendish, Raja Puri, Blue Torres Island, and African Red) grown in the field...

  10. Signum, a new fungicide for control of leaf diseases in outdoor vegetables.

    Science.gov (United States)

    Callens, D; Sarrazyn, R; Evens, W

    2005-01-01

    During three years, the new fungicide Signum, containing 6.7% pyraclostrobine + 26.7 % boscalid and developed by BASF. has been evaluated in leek, carrots and cabbages in several outdoor field experiments under practical conditions and during one year in outdoor lettuce. In leek, Phytophthora porri is one of the major leaf diseases causing lesions on differ ent places on the leaves, resulting in at least extra labour costs for trimming or even worse sometimes resulting in complete crop loss. So far, crop protection consists of repeated applications of fungicides especially during autumn and winter. Pyraclostrobin + boscalid has been evaluated in comparison with the fungicides mancozeb, mancozeb + metalaxyl-M and azoxystrobin. The progress of the disease during the growth season is discussed. For all parameters evaluated, pyraclostrobin + boscalid gave comparable or even better results than reference products. Especially during 2003, a small drop of the activity of benalaxyl against P. porri has been observed after repeated applications. In carrots, Erisiphe heraclei and Alternaria dauci are both the most common leaf diseases causing yield and quality loss. During periods of very high pressure of A. dauci, pyraclostrobin + boscalid, applied in a three weeks interval, revealed a superior activity compared with triazole references or compared with azoxystrobin. Against E. heraclei, a good control but also a clear dose response activity have been observed with pyraclostrobin + boscalid. Yield gain was approximately 30 ton /ha compared wih untreated. In Brussels sprouts, good efficacy was obtained against Mycosphaerella spp., Albugo candida and Alternaria spp. In outdoor lettuce Botrytis cinerea and Sclerotinia sclerotiorum are the most important diseases causing crop damage and reducing the quality of the heads. Pyraclostrobin + boscalid was evaluated in comparison with the standard fungicide iprodione. The plant protection was better with the new fungicide

  11. Микромицеты рода Alternaria на однолетних цветочно-декоративных растениях

    OpenAIRE

    МАРЧЕНКО А.Б.

    2014-01-01

    На однолетних цветочно-декоративных растениях микромицеты рода Alternaria представлены 13 видами: A. alternata, A. brassicae, A. penicillata, A. calendulae, A. japonica, A. porri, A. solani, A. zinniae, A. celosiae, A. petalicolor, A. florigena, A. helianthi, A. brassicicola. В условиях Лесостепи Украины они представлены 6 видами: A. calendulae, A. zinniae, A. helianthi, A. alternata, A. brassicae, A. japonica. На однолетних цветочно-декоративных культурах виды A. zinniae, A. alternata, A.bra...

  12. Biological control of dodder (Cuscuta campestris L. by fungi pathogens

    Directory of Open Access Journals (Sweden)

    F. Fallahpour

    2016-04-01

    Full Text Available Parasite weeds are the most important yield reducing factors, and among them dodder (Cuscuta campestris L. is an obligate parasite of many plant families. In order to find a suitable biocontrol agent for dodder a study was conducted based on a randomized complete design with four replications at research greenhouse of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran during 2007-2009. Diseased dodders sampled from sugarbeet farms of Chenaran, Iran. After culturing and isolating exiting fungi from infected tissues of dodder, Fusarium sp., Alternaria sp. and Colletotrichum sp. were recognized. Inoculation of isolates was carried out with concenteration of 1×108 spores per ml sterile water at different growth stages of dodder in labratoary and greenhouse. Among different fungi, isolate of 323 of F. oxysporum showed an effective control on germination of dodder seeds and the highest level of plant pathogencity was before the contact of dodder with host and infection in older plants decreased. Infection of this isolate with crops such as sugarbeet (Beta vulgaris L., alfalfa (Medigago sativa L., basil (Ocimum basilicum L., wheat (Triticum aestivum L. and barley (Hordeum vulgare L. showed no symptoms.

  13. Antifungal activity of indigenous Bacillus spp. isolated from soil

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    Bjelić Dragana Đ.

    2017-01-01

    Full Text Available Biocontrol using plant growth-promoting rhizobacteria (PGPR represents an alternative approach to disease management, since PGPR are known to promote growth and reduce diseases in various crops. Among the different PGPR, members of the genus Bacillus are prefered for most biotechnological uses due to their capability to form extremely resistant spores and produce a wide variety of metabolites with antimicrobial activity. The objective of this research was to identify antagonistic bacteria for management of the plant diseases. Eleven isolates of Bacillus spp. were obtained from the soil samples collected from different localities in the Province of Vojvodina. The antifungal activity of bacterial isolates against five fungal species was examined using a dual plate assay. Bacillus isolates exhibited the highest antifungal activity against Fusarium proliferatum, Fusarium oxysporum f. sp. cepae and Alternaria padwickii, while they had the least antagonistic effect on Fusarium verticillioides and Fusarium graminearum. Molecular identification showed that effective bacterial isolates were identified as Bacillus safensis (B2, Bacillus pumilus (B3, B11, Bacillus subtilis (B5, B7 and Bacillus megaterium (B8, B9. The highest antagonistic activity was exhibited by isolates B5 (from 39% to 62% reduction in fungal growth and B7 (from 40% to 71% reduction in fungal growth. These isolates of B. subtilis could be used as potential biocontrol agents of plant diseases. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-31073

  14. The effect of biological and chemical control agents on the health status of the very early potato cultivar Rosara

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    Cwalina-Ambroziak Bożena

    2015-12-01

    Full Text Available The external appearance and quality of table potatoes are determined, among other factors, by the health status of the plants during the growing season. Chemical control methods are often combined with biocontrol agents to effectively fight potato pathogens. Potatoes of the very early cultivar Rosara were grown in experimental plots. The plots were located in Tomaszkowo (NE Poland, 2007-2009. The experiment involved the following treatments: 1 biological control − mycorrhizal Glomus spp. inoculum was applied to the roots, − tubers were dressed and plants were sprayed with Polyversum three times during the growing season, 2 chemical control - at two-week intervals, plants were sprayed with the following fungicides: Infinito 687.5 SC and Tanos 50 WG, Valbon 72 WG and Tanos 50 WG. In the control treatment, potato plants were not protected against pathogens. During the growing season, the severity of late blight and early blight was evaluated on a nine-point scale. The composition of fungal communities colonising potato stems was analysed. The fungistatic properties of the fungicides used in the field experiment were evaluated in an in vitro test. The symptoms of infections caused by Phytophthora infestans and Alternaria spp. were significantly reduced in the treatment which used the integrated chemical and biological control. The least diverse fungal community was isolated from fungicide-treated plants. In the in vitro test, fungicides at all analysed concentrations inhibited the linear mycelial growth of selected pathogens.

  15. Chronic environmental exposure to Alternaria tenuis may manifest ...

    African Journals Online (AJOL)

    Their major complaints were: weakness and numbness in legs, dizziness, loss of memory, light-headedness and vertigo, fatigue, getting lost in familiar territory, and confused thoughts. The subjects were evaluated by testing immunologic, basic EEG, and comprehensive neuropsychological tests. Abnormal antibodies to ...

  16. Variability Pattern for Resistance to Purple Blotch (Alternaria porri ...

    African Journals Online (AJOL)

    ABSTRACT: Five onion cultivars Red Creole, Kaharda, Koumassa, Sokoto local and ori were selected on the .... Red. Creole. Seminis Vegetable Seeds. Los. Angeles, California, U.S.A.. Red, long storage, flattened, globe shape. Long season to maturity and low yields, short day .... and eventually causing the bulb to rot.

  17. Biodecolorization of acid violet 19 by Alternaria solani | Ali | African ...

    African Journals Online (AJOL)

    African Journal of Biotechnology ... Microorganisms are the nature's tools for cleaning the environment. Bioremediation using bacteria, fungi and algae is becoming an attractive option for the treatment of industrial effluents containing a

  18. Mycosynthesis of iron nanoparticles by Alternaria alternata and its ...

    African Journals Online (AJOL)

    aghomotsegin

    2015-04-08

    Apr 8, 2015 ... Full Length Research Paper. Mycosynthesis of ... Iron nanoparticles show more antimicrobial activity to ... has gained much attention due to their unique size- dependent ... Nanoparticles with antifungal effects are of great interest in ... The preliminary detection of Fe-NPs was carried out by visual observation ...

  19. Phytoalexins as Possible Controlling Agents of Microbial Spoilage of Irradiated Fresh Fruit and Vegetables During Storage

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed, S. A. [Radiobiology Department, Nuclear Research Center, Atomic Energy Commission, Cairo (Egypt)

    1978-04-15

    The decline in bio generating capacity to form natural antibiotic compounds (phytoalexins), rishitin and lubimin in potato tubers and rishitin in tomatoes, after gamma irradiation seems to be the essence of the suppression of natural immunity exhibited by an increase in per cent of rotted tubers and fruits during storage. In vitro studies postulated that the rot-causing fungi Phytophthora infestons (Mond) De Bary, Alternaria solani (Ellis and Martin) James and Grout, Botrytis cinerea Persson., Fusarium oxysporum Syder and Hansen and Rhizopus stolonifer Ehrenberg were significantly controlled by the application of phytoalexins that had been initially formed by potato tubers (rishitin), tomato fruits (rishitin) and pepper fruits (capsidiol). In vivo studies revealed that post-irradiation treatment of potato tubers and tomato fruits with phytoalexins that had been produced by the same plant organ or by another of the same family seems to be experimentally feasible to reduce the radiation dose or increase the efficiency of irradiation in controlling microbial spoilage during storage of irradiated potatoes and tomatoes. (author)

  20. CONTROL OF POSTHARVEST TOMATO ROT BY SPORE SUSPENSION AND ANTIFUNGAL METABOLITES OF TRICHODERMA HARZIANUM

    Directory of Open Access Journals (Sweden)

    Momein H. El-Katatny

    2012-06-01

    Full Text Available Rot of cherry tomato (Lycopersicon esculentum fruits caused by several fungal pathogens is a detrimental disease leading to substantial yield loses worldwide. Alternaria isolates were the most common fungal species isolated from healthy or rotten fruits. Trichoderma harzianum spore suspension and culture filtrate were tested for their antagonistic activity on controlling tomato fruit rot. T. harzianum isolates suppressed or interfered with the growth of different postharvest tomato fungal pathogens albeit at different degrees. Their culture filtrate inhibited pathogen spore germination possibly due to the released extracellular diffusible metabolite(s. Besides, aberrant morphology of conidia was observed with deformation of hyphal tips. Furthermore, the resulting mycelia appeared desiccated with coagulated protoplasm leading to complete collapse of protoplasm in presence of T. harzianum culture filtrate. Application of T. harzianum spores to tomato fruits decreased disease severity significantly with the most profound effect at higher spore concentrations (108 cells per ml. Similarly, culture filtrate of T. harzianum prevented pathogen spore germination on the surface of tomato fruits leading to decreased incidence of rot symptoms at high culture filtrate concentrations. This work provides strong evidence that T. harzianum is a competent antagonist and its spore suspension and culture filtrate can be used efficiently to control postharvest tomato rot.

  1. Phytoalexins as possible controlling agents of microbial spoilage of irradiated fresh fruit and vegetables during storage

    International Nuclear Information System (INIS)

    El-Sayed, S.A.

    1978-01-01

    The decline in biogenerating capacity to form natural antibiotic compounds (phytoalexins), rishitin and lubimin in potato tubers and rishitin in tomatoes, after gamma irradiation seems to be the essence of the suppression of natural immunity exhibited by an increase in per cent of rotted tubers and fruits during storage. In vitro studies postulated that the rot-causing fungi Phytophthora infestans (Mond) De Bary, Alternaria solani (Ellis and Martin) James and Grout, Botrytis cinerea Persson., Fusarium oxysporum Syder and Hansen and Rhizopus stolonifer Ehrenberg were significantly controlled by the application of phytoalexins that had been initially formed by potato tubers (rishitin), tomato fruits (rishitin) and pepper fruits (capsidiol). In vivo studies revealed that post-irradiation treatment of potato tubers and tomato fruits with phytoalexins that had been produced by the same plant organ or by another of the same family seems to be experimentally feasible to reduce the radiation dose or increase the efficiency of irradiation in controlling microbial spoilage during storage of irradiated potatoes and tomatoes. (author)

  2. Disease control effect of strevertenes produced by Streptomyces psammoticus against tomato fusarium wilt.

    Science.gov (United States)

    Kim, Jeong Do; Han, Jae Woo; Lee, Sung Chul; Lee, Dongho; Hwang, In Cheon; Kim, Beom Seok

    2011-03-09

    During screening of microorganisms producing antifungal metabolites, Streptomyces psammoticus strain KP1404 was isolated. The culture extract of this strain showed potent disease control efficacy against Fusarium wilt on tomato plants. The antifungal metabolites ST-1 and ST-2 were isolated from the culture extract using a variety of chromatographic procedures. On the basis of MS and NMR spectrometric analysis, the structures of the antifungal active compounds ST-1 and ST-2 were determined to be the polyene antibiotics strevertene A and strevertene B, respectively. In vitro, strevertenes A and B showed inhibitory effects against the mycelial growth of Alternaria mali , Aspergillus oryzae , Cylindrocarpon destructans , Colletotrichum orbiculare , Fusarium oxysporum f.sp. lycopersici, and Sclerotinia sclerotiorum , even at concentrations of 4-16 μg/mL. Fusarium wilt development on tomato plants was strongly retarded by treatment with 1 μg/mL of these strevertenes. The disease control efficacies of strevertenes on Fusarium wilt were as remarkable as that of benomyl.

  3. Control of Black Rot Disease in Tomato Fruits by Using Formulated Ginger Essential oil Treated by Gamma Radiation

    International Nuclear Information System (INIS)

    Helal, I.M.; Abdeldaiem, M.H.

    2008-01-01

    Ginger essential oil (Zingiber officinale) treated by gamma radiation at dose of 10 kGy was selected as an active ingredient for formulation of the biocide. Liquid formulations (emulsifiable concentrates) were prepared using different emulsifiers (Emulgator B.L.M. and tween 80 or tween 20) and additive oil (soybean oil). Physicochemical properties of the formulated oil (spontaneous emulsification, emulsion stability; cold stability and heat stability, viscosity, surface tension and ph) were measured. The formulated oil was tested in vivo to investigate its efficiency for controlling the growth of Alternaria alternata inoculated into tomato fruits. The results indicated that soaking inoculated tomato fruits in the formulated oil (ginger essential oil + soybean oil + emulgator B.L.M. + tween 80) treatment at concentration of 300 ppm for a period of 12 minute was the most effective for controlling the growth of the tested fungus. In addition, the formulated oil had efficiency for controlling the rot development on tomato fruits when applied as therapeutic and protective agents

  4. Real and perceived risks for mycotoxin contamination in foods and feeds: challenges for food safety control.

    Science.gov (United States)

    Milićević, Dragan R; Skrinjar, Marija; Baltić, Tatjana

    2010-04-01

    Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic moulds in the Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys genera occurring in food and feed commodities both pre- and post-harvest. Adverse human health effects from the consumption of mycotoxins have occurred for many centuries. When ingested, mycotoxins may cause a mycotoxicosis which can result in an acute or chronic disease episode. Chronic conditions have a much greater impact, numerically, on human health in general, and induce diverse and powerful toxic effects in test systems: some are carcinogenic, mutagenic, teratogenic, estrogenic, hemorrhagic, immunotoxic, nephrotoxic, hepatotoxic, dermotoxic and neurotoxic. Although mycotoxin contamination of agricultural products still occurs in the developed world, the application of modern agricultural practices and the presence of a legislatively regulated food processing and marketing system have greatly reduced mycotoxin exposure in these populations. However, in developing countries, where climatic and crop storage conditions are frequently conducive to fungal growth and mycotoxin production, much of the population relies on subsistence farming or on unregulated local markets. Therefore both producers and governmental control authorities are directing their efforts toward the implementation of a correct and reliable evaluation of the real status of contamination of a lot of food commodity and, consequently, of the impact of mycotoxins on human and animal health.

  5. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  6. Control rod control device

    International Nuclear Information System (INIS)

    Seiji, Takehiko; Obara, Kohei; Yanagihashi, Kazumi

    1998-01-01

    The present invention provides a device suitable for switching of electric motors for driving each of control rods in a nuclear reactor. Namely, in a control rod controlling device, a plurality of previously allotted electric motors connected in parallel as groups, and electric motors of any selected group are driven. In this case, a voltage of not driving predetermined selected electric motors is at first applied. In this state an electric current supplied to the circuit of predetermined electric motors is detected. Whether integration or failure of a power source and the circuit of the predetermined electric motors are normal or not is judged by the detected electric current supplied. After they are judged normal, the electric motors are driven by a regular voltage. With such procedures, whether the selected circuit is normal or not can be accurately confirmed previously. Since the electric motors are not driven just at the selected time, the control rods are not operated erroneously. (I.S.)

  7. Control Areas

    Data.gov (United States)

    Department of Homeland Security — This feature class represents electric power Control Areas. Control Areas, also known as Balancing Authority Areas, are controlled by Balancing Authorities, who are...

  8. Control of control charts

    NARCIS (Netherlands)

    Sri Nurdiati, S.N.

    2005-01-01

    Although the Shewhart chart is widely used in practice because of its simplicity, applying this control chart to monitor the mean of a process may lead to two types of problems. The first concerns the typically unknown parameters involved in the distribution, while the second concerns the validity

  9. PENGARUH APLIKASI PSEUDOMONAS FLUORESCENS P60 TERHADAP MUTU PATOLOGIS, MUTU FISIOLOGIS, DAN PERTUMBUHAN BIBIT PADI IR 64

    Directory of Open Access Journals (Sweden)

    Lisa Navitasari

    2014-08-01

    Full Text Available Effect of Pseudomonas fluorescens P60 on pathological and physiological quality and growth of rice IR 64  seedlings. The research objectives were (1 detection and identification of seed-borne pathogens of IR 64 rice, (2 testing Pseudomonas fluorescents P60 in inhibiting the in vitro growth of seed-borne pathogens colonies, (3 testing P. fluorescents P60 for pathological and physiological seed quality, and (4 testing P. fluorescents P60 on the growth of seedlings in the greenhouse. The results showed that some seed-borne pathogens can be found both on farmers’ IR 64 rice and factory’s; they were Aspergillus flavus, Alternaria padwickii, Pseudomonas glumae, and P. syringae. Application of P. flourescens P60 was able to inhibit the in vitrogrowth of colonies of all seed-borne pathogens, except P. syringae.  Related to pathological quality, the effect of P. flourescens P60 on percentage of seed-borne pathogens attack did not significantly different from that of benomil but smaller than distilled water. On the physiological quality of seeds, treatment of P. flourescens P60 has the same effect with benomil and distilled water, with  germination rate was more than 80%. In the greenhouse study,treatment of seed immersion time  in P. flourescens P60 suspension showed that the effect of immersion time as long as15 minutes and 25 minutes on  seedling height, root length, and seedling dry weightdid not significantly different. were. However, 25 minutes immersion time resulted in fresh seedling weight and root dry weight higher than that of 15 minutes immersion time.

  10. Dream controller

    Science.gov (United States)

    Cheng, George Shu-Xing; Mulkey, Steven L; Wang, Qiang; Chow, Andrew J

    2013-11-26

    A method and apparatus for intelligently controlling continuous process variables. A Dream Controller comprises an Intelligent Engine mechanism and a number of Model-Free Adaptive (MFA) controllers, each of which is suitable to control a process with specific behaviors. The Intelligent Engine can automatically select the appropriate MFA controller and its parameters so that the Dream Controller can be easily used by people with limited control experience and those who do not have the time to commission, tune, and maintain automatic controllers.

  11. Controllable dose; Dosis controlable

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J T; Anaya M, R A [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2004-07-01

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  12. POTENCIAL DE PRODUTOS BIÓTICOS E ABIÓTICOS COMO INDUTORES DE RESISTÊNCIA NO CONTROLE DE PODRIDÕES PÓS-COLHEITA EM MANGA, NO SUBMÉDIO SÃO FRANCISCO

    Directory of Open Access Journals (Sweden)

    MARIA DALVA DA CONCEIÇÃO SILVA DE MOURA

    2012-01-01

    Full Text Available With the purpose to minimize the incidence of stem-end rot, mango, caused by Lasiodiplodia theobromae, Fusicoccum aesculi, and Colletotrichum gloeosporioides, five resistance inductors were tested under field conditions: (T1 absolute control (no treatment; (T2 Fosetyl-AL; (T3 Agromós; (T4 Calcium Phosphite; (T5 Potassium Phosphite: (K30 and (T6 Acibenzolar-S-methyl; which were compared to the control treatment, to the conventional treatment on the farm (T7 compound: Pyraclostrobin; Thiophanate methyl; Azoxystrobin; Difeconazole; Tebuconazole; Thiabendazol; Tetraconazole. The sprayings were performed using a knapsack sprayer in a total of seven applications with 15-day intervals. The statistical design was a randomized block design with seven treatments and four replications, with each plant being considered a repetition, totaling 28 plants. Incidence of post-harvest rot was obtained for 77.9% of the treated fruit. No significant difference between the tested resistance inducers was observed, not even regarding the control. However, the conventional treatment (T7, adopted by the farm, showed a 25% disease incidence only and diverged statistically from the others. Studying the etiology of the rot, high indices of C. gloeosporioides, with 75% incidence, were verified, followed by L. theobromae, F. aesculi, A. niger and Alternaria sp, with incidence of 11%, 5.5%, 2.7% and 1.3%, respectively. Moreover, 4.3% of non-identified micro-organisms were detected.

  13. Control of Passion Fruit Fungal Diseases Using Essential Oils Extracted from Rosemary (Rosmarinus officinalis) and Eucalyptus (Eucalyptus agglomerata) in Egerton University Main Campus Njoro, Kenya.

    Science.gov (United States)

    Waithaka, Paul Njenga; Gathuru, Eliud Mugu; Githaiga, Benson Muriuki; Kimani, Salome Nduta

    2017-01-01

    Growth of fruits which form an important part of human diet has been jeopardized by the many fungal diseases that are present today. This study was conceived to isolate the most common fungal pathogens in passion fruits. Fungi were isolated using potato dextrose agar in addition to characterization using morphological, cultural, and biochemical means. Extraction of essential oils from rosemary ( Rosmarinus officinalis ) and eucalyptus ( Eucalyptus agglomerata ) was done. Before carrying the sensitivity test of essential oils to the fungal isolates, constituents of the essential oils were determined. The most common fungal pathogens isolated from passion fruits were Alternaria spp. (45%), Fusarium spp. (22%), Colletotrichum spp. (17%), and Penicillium spp. (16%). There was a relationship between heating time and yield of essential oils in rosemary ( r = 0.99) and eucalyptus ( r = 0.99). Conversely, there was no significant difference in the amount of essential oils produced by rosemary and eucalyptus ( P = 0.08). Furthermore, there was a significant difference in growth inhibition of the fungal pathogens between essential oils from rosemary and eucalyptus ( P = 0.000438). Fungal pathogens isolated from passion fruits can be controlled using essential oils from rosemary and eucalyptus. The oils need to be produced in large scale.

  14. Efectividad de Cuatro Fungicidas en el Control de "La Quemazón de las Hojas" en Cebolla (Allium Cepa, Causada por Altemaria Porri

    Directory of Open Access Journals (Sweden)

    Quintero Serpa Lumar

    1960-06-01

    Full Text Available En el presente trabajo, se considera la efectividad de cuatro fungicidas comerciales, bajo condiciones de campo, en el control de "la quemazón de las hojas" en cebolla, enfermedad causada por el Alternaria porri. Considerando como base para comprar la efectividad de los fungicidas el peso de los bulbos cosechados en cada tratamiento, se concluyó que el empleo de fungicidas aumentaba el rendimiento de las cosechas. El orden de efectividad de los cuatro fungicidas en el presente trabajo fue: Manzate, Parzate, Dithane Z-78 y Oxicob. Las conclusiones del presente trabajo deben considerarse como una contribución a este tema y solo a manera de trabajo preliminar; pero el hecho de haberse presentado diferencias considerables entre la producción de las parcelas tratadas y la testigo, sugiere la necesidad de experimentar más al respecto, con el fin de reforzar estos primeros resultados y averiguar sobre la efectividad de otros productos.

  15. Mosquito Control

    Science.gov (United States)

    ... Labs and Research Centers Contact Us Share Mosquito Control About Mosquitoes General Information Life Cycle Information from ... Repellent that is Right for You DEET Mosquito Control Methods Success in mosquito control: an integrated approach ...

  16. Birth Control

    Science.gov (United States)

    Birth control, also known as contraception, is designed to prevent pregnancy. Birth control methods may work in a number of different ... eggs that could be fertilized. Types include birth control pills, patches, shots, vaginal rings, and emergency contraceptive ...

  17. Neurofuzzy Control

    DEFF Research Database (Denmark)

    Jantzen, Jan

    1997-01-01

    These notes are for a course in fuzzy control and neural networks. By neural networks we more precisely mean neurofuzzy systems rather than pure neural network theory. The notes are an extension to the existing notes on fuzzy control (Jantzen, Fuzzy Control, 1994).......These notes are for a course in fuzzy control and neural networks. By neural networks we more precisely mean neurofuzzy systems rather than pure neural network theory. The notes are an extension to the existing notes on fuzzy control (Jantzen, Fuzzy Control, 1994)....

  18. Control rod position control device

    International Nuclear Information System (INIS)

    Ubukata, Shinji.

    1997-01-01

    The present invention provides a control rod position control device which stores data such as of position signals and driving control rod instruction before and after occurrence of abnormality in control for the control rod position for controlling reactor power and utilized the data effectively for investigating the cause of abnormality. Namely, a plurality of individual control devices have an operation mismatching detection circuit for outputting signals when difference is caused between a driving instruction given to the control rod position control device and the control rod driving means and signals from a detection means for detecting an actual moving amount. A general control device collectively controls the individual control devices. In addition, there is also disposed a position storing circuit for storing position signals at least before and after the occurrence of the control rod operation mismatching. With such procedures, the cause of the abnormality can be determined based on the position signals before and after the occurrence of control rod mismatching operation stored in the position storing circuit. Accordingly, the abnormality cause can be determined to conduct restoration in an early stage. (I.S.)

  19. Control rods

    International Nuclear Information System (INIS)

    Maruyama, Hiromi.

    1984-01-01

    Purpose: To realize effective utilization, cost reduction and weight reduction in neutron absorbing materials. Constitution: Residual amount of neutron absorbing material is averaged between the top end region and other regions of a control rod upon reaching to the control rod working life, by using a single kind of neutron absorbing material and increasing the amount of the neutron absorber material at the top end region of the control rod as compared with that in the other regions. Further, in a case of a control rod having control rod blades such as in a cross-like control rod, the amount of the neutron absorbing material is decreased in the middle portion than in the both end portions of the control rod blade along the transversal direction of the rod, so that the residual amount of the neutron absorbing material is balanced between the central region and both end regions upon reaching the working life of the control rod. (Yoshihara, H.)

  20. Control apparatus

    International Nuclear Information System (INIS)

    Doll, D.W.

    1977-01-01

    A nuclear reactor system is described in which flexible control rods are used to enable insertion of the control rods into guide holes in the core which are distributed over an area larger than the cross section of the control rod penetration in the reactor pressure vessel. Guide tubes extend from the penetration and fan out to the guide holes for guiding the control rods from the penetration to the guide holes

  1. Gaining control

    NARCIS (Netherlands)

    Enden, van der E.; Laan, van der R.

    2008-01-01

    The article reports on the efforts of companies to find a solution for tax risk management, tax accounting and being in control. In trying to find a solution, companies work towards an integrated tax control framework (TCF), a tax risk management and control environment embedded in the internal

  2. Associational control

    DEFF Research Database (Denmark)

    Hvid, Helge Søndergaard; Lund, Henrik Lambrecht; Grosen, Sidsel Lond

    2010-01-01

    Over the last 30 years, the concept of control has had a central position in research into the psychological working environment. Control has been understood as individual autonomy and individual opportunities for development. This article examines whether the concept of control has the same key...

  3. Essential Oils as Biocides for the Control of Fungal Infections and Devastating Pest (Tuta absoluta) of Tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Bouayad Alam, Samira; Dib, Mohammed El Amine; Djabou, Nassim; Tabti, Boufeldja; Gaouar Benyelles, Nassira; Costa, Jean; Muselli, Alain

    2017-07-01

    Thymus capitatus and Tetraclinis articulata essential oils as well their major components (carvacrol and α-pinene) were evaluated for their antifungal and insecticidal activities. Both oils showed good in vitro antifungal activity against Fusarium oxysporum, Aspergillus niger, Penicillium sp., Alternaria alternata, and Botrytis cinerea, the fungi causing tomato rot. In vivo results indicate the efficacies of both essential oils and carvacrol of reduce postharvest fungal pathogens, such as B. cinerea and Al. alternata that are responsible of black and gray rot of tomato fruit. Disease incidence of Al. alternata and B. cinerea decreased on average from 55% to 80% with essential oil of Th. capitatus and pure carcvacrol, while Te. articulata essential oil exhibited inhibition of fungal growth of 55% and 25% against Al. alternata and B. cinerea, respectively, with concentration of 0.4 μl/l air. The insecticidal activity of Th. capitatus and Te. articulata essential oils exhibited also a good insecticidal activity. At the concentration of 0.2 μl/ml air, the oils caused mortality over 80% for all larval stages of Tuta absoluta and 100% mortality for the first-instar after 1.5 h only of exposure. α-Pinene presented lower insecticidal and antifungal activities compared to essential oils of Th. capitatus, Te. articulata and pure carvacrol. Thus, these essential oils can be used as a potential source to develop control agents to manage some of the main pests and fungal diseases of tomato crops. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  4. Optimal control

    CERN Document Server

    Aschepkov, Leonid T; Kim, Taekyun; Agarwal, Ravi P

    2016-01-01

    This book is based on lectures from a one-year course at the Far Eastern Federal University (Vladivostok, Russia) as well as on workshops on optimal control offered to students at various mathematical departments at the university level. The main themes of the theory of linear and nonlinear systems are considered, including the basic problem of establishing the necessary and sufficient conditions of optimal processes. In the first part of the course, the theory of linear control systems is constructed on the basis of the separation theorem and the concept of a reachability set. The authors prove the closure of a reachability set in the class of piecewise continuous controls, and the problems of controllability, observability, identification, performance and terminal control are also considered. The second part of the course is devoted to nonlinear control systems. Using the method of variations and the Lagrange multipliers rule of nonlinear problems, the authors prove the Pontryagin maximum principle for prob...

  5. Taking Control

    Centers for Disease Control (CDC) Podcasts

    2007-11-01

    This podcast gives action steps and reasons to control diabetes.  Created: 11/1/2007 by National Diabetes Education Program (NDEP), a joint program of the Centers for Disease Control and Prevention and the National Institutes of Health.   Date Released: 11/2/2007.

  6. Control Theory.

    Science.gov (United States)

    Toso, Robert B.

    2000-01-01

    Inspired by William Glasser's Reality Therapy ideas, Control Theory (CT) is a disciplinary approach that stresses people's ability to control only their own behavior, based on internal motivations to satisfy five basic needs. At one North Dakota high school, CT-trained teachers are the program's best recruiters. (MLH)

  7. CONTROL ROD

    Science.gov (United States)

    Walker, D.E.; Matras, S.

    1963-04-30

    This patent shows a method of making a fuel or control rod for a nuclear reactor. Fuel or control material is placed within a tube and plugs of porous metal wool are inserted at both ends. The metal wool is then compacted and the tube compressed around it as by swaging, thereby making the plugs liquid- impervious but gas-pervious. (AEC)

  8. Birth Control

    Science.gov (United States)

    ... even if you aren’t going for birth control. What doesn’t work to prevent pregnancy? top It’s ... and taking care of a baby’s many needs. What if I need birth control in an emergency? top Emergency contraception (EC) is ...

  9. Integrated controls

    International Nuclear Information System (INIS)

    Hollaway, F.W.

    1985-01-01

    During 1984, all portions of the Nova control system that were necessary for the support of laser activation and completion of the Nova project were finished and placed in service on time. The Nova control system has been unique in providing, on schedule, the capabilities required in the central control room and in various local control areas throughout the facility. The ambitious goal of deploying this system early enough to use it as an aid in the activation of the laser was accomplished; thus the control system made a major contribution to the completion of Nova activation on schedule. Support and enhancement activities continued during the year on the VAX computer systems, central control room, operator consoles and displays, Novanet data communications network, system-level software for both the VAX and LSI-11 computers, Praxis control system computer language, software management tools, and the development system, which includes office terminals. Computational support was also supplied for a wide variety of test fixtures required by the optical and mechanical subsystems. Significant new advancements were made in four areas in integrated controls this year: the integration software (which includes the shot scheduler), the Praxis language, software quality assurance audit, and software development and data handling. A description of the accomplishments in each of these areas follows

  10. Controlling Hypertension

    Centers for Disease Control (CDC) Podcasts

    A recent study found an increase in self-reported high blood pressure among U.S. adults, and an increase in the use of medications to control high blood pressure. This podcast discusses the importance of controlling high blood pressure.

  11. Experiencing control

    NARCIS (Netherlands)

    Monaci, G.; Braspenning, R.A.C.; Meerbeek, B.W.; Bingley, P.; Rajagopalan, R.; Triki, M.

    2009-01-01

    This report describes the activities carried out in the first part of the Experiencing Control project (2008-324). The guiding idea of the project is to make control part of the experience, exploring new interaction solutions for complex, engaging interactions with Philips devices in the living

  12. Control rod

    International Nuclear Information System (INIS)

    Kawakami, Kazuo; Shimoshige, Takanori; Nishimura, Akira

    1979-01-01

    Purpose: A control rod has been developed, which provided a plurality of through-holes in the vicinity of the sheath fitting position, in order to flatten burn-up, of fuel rods in positions confronting a control rod. Thereby to facilitate the manufacture of the control rods and prevent fuel rod failures. Constitution: A plurality of through-holes are formed in the vicinity of the sheath fitting position of a central support rod to which a sheath for the control rod is fitted. These through-holes are arranged in the axial direction of the central support rod. Accordingly, burn-up of fuel rods confronting the control rods can be reduced by through-holes and fuel rod failures can be prevented. (Yoshino, Y.)

  13. Describing control

    International Nuclear Information System (INIS)

    Fouet, J.M.; Starynkevitch, B.

    1987-01-01

    Incremental development and maintenance of large systems imply that control be clearly separated from knowledge. Finding efficient control for a given class of knowledge is itself a matter of expertise, to which knowledge-based methods may and should be applied. We present here two attempts at building root systems that may later be tuned by knowledge engineers, using the semantics of each particular application. These systems are given heuristics in a declarative manner, which they use to control the application of heuristics. Eventually, some heuristics may be used to compile others (or themselves) into efficient pieces of programmed code

  14. Drug Control

    Science.gov (United States)

    Leviton, Harvey S.

    1975-01-01

    This article attempts to assemble pertinent information about the drug problem, particularily marihuana. It also focuses on the need for an educational program for drug control with the public schools as the main arena. (Author/HMV)

  15. Institutional Controls

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of institutional control data from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different...

  16. Control rooms

    International Nuclear Information System (INIS)

    Preuss, W.

    1990-01-01

    The current state of knowledge about screen systems for application in traffic (e.g., flight control), process control, and production is presented. The 29 lectures, 5 of which relate to aviation, deal with the optimization of the man-machine interface with respect to unusual operating situations and adequate presentation and action methods on the basis of taks and event analyses integrating the users. (DG) [de

  17. Controlling Hypertension

    Centers for Disease Control (CDC) Podcasts

    Hypertension, or high blood pressure, affects one third of U.S. adults and is a leading cause of heart disease and stroke. A recent study found an increase in self-reported high blood pressure among U.S. adults, and an increase in the use of medications to control high blood pressure. In this podcast, Dr. Fleetwood Loustalot discusses the importance of controlling high blood pressure.

  18. Potenciais alternativas com extratos vegetais no controle da pinta preta do tomateiro

    Directory of Open Access Journals (Sweden)

    Edvan Nilson de Almeida

    2017-10-01

    Full Text Available Objetivou-se com o presente estudo avaliar o potencial antifúngico de três espécies de plantas medicinais: Zingiber officinale (gengibre, Allium sativum L. (alho e Caryophyllus aromaticus L. (cravo-da-índia in vitro e in vivo, para o controle do patógeno Alternaria solani, agente causal da pinta preta. Avaliou-se in vitro o crescimento micelial, germinação de esporos e o tamanho de tubos germinativos de A. solani nas concentrações de 1,0, 5,0, 10, 15 e 20%. Para a avaliação in vivo sementes de tomateiro cv. Santa Cruz Kada foram semeadas em bandejas de isopor de 200 células contendo substrato comercial. Após 30 dias as mudas foram transplantadas para vasos de 5 L contendo solo e mantidas em casa de vegetação. Os tratamentos para o ensaio em in vivo foram extrato aquoso de gengibre, alho e cravo-da-índia na concentração de 20%. As aplicações foram iniciadas após 47 dias do transplante das mudas para casa de vegetação, sendo realizada uma vez por semana até o momento da colheita. Foram realizadas avaliações da área abaixo da curva de progresso da doença (AACPD, número médio e peso de frutos. Os experimentos foram conduzidos em delineamento inteiramente casualizado, com cinco repetições. Os extratos de cravo-da-índia, alho e gengibre apresentaram efeito inibidor direto sobre o fungo e reduziram a AACPD em 55,8, 29,5 e 22,5% em relação à testemunha água, respectivamente. Esses resultados indicam potencial dos extratos vegetais avaliados no controle da pinta preta do tomateiro, com destaque para o extrato de cravo-da-índia.

  19. Control rods

    International Nuclear Information System (INIS)

    Koga, Isao; Masuoka, Ryuzo.

    1979-01-01

    Purpose: To prevent fuel element failures during power conditioning by removing liquid absorbents in poison tubes of control rods in a fast power up step and extracting control rods to slightly increase power in a medium power up step. Constitution: A plurality of poison tubes are disposed in a coaxial or plate-like arrangement and divided into a region capable of compensating the reactivity from the initial state at low temperature to 40% power operation and a region capable of compensating the reactivity in the power up above 40% power operation. Soluble poisons are used as absorbers in the poison tubes corresponding to above 40% power operation and they are adapted to be removed independently from the driving of control rods. The poison tubes filled with the soluble absorbers are responsible for the changes in the reactivity from the initial state at low temperature to the medium power region and the reactivity control is conducted by the elimination of liquid absorbers from the poison tubes. In the succeeding slight power up region above the medium power, power up is proceeding by extracting the control rods having remaining poison tubes filled with solid or liquid absorbers. (Seki, T.)

  20. Losing control

    DEFF Research Database (Denmark)

    Leppink, Eric; Odlaug, Brian Lawrence; Lust, Katherine

    2014-01-01

    picking disorder). CONCLUSIONS: Assaultive behavior appears fairly common among college students and is associated with symptoms of depression and impulse control disorders. Significant distress and diminished behavioral control suggest that assaultive behaviors may often be associated with significant......OBJECTIVE: Assaultive behaviors are common among young people and have been associated with a range of other unhealthy, impulsive behaviors such as substance use and problem gambling. This study sought to determine the predictive ability of single assaultive incidents for impulse control disorders......, an association that has yet to be examined, especially in young adults. METHODS: The authors conducted a university-wide email survey in the spring of 2011 on 6000 university students. The survey examined assaultive behavior and associated mental health variables (using a clinically validated screening...

  1. Coordinating controls

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-07-15

    While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics.

  2. Helicopter Controllability

    Science.gov (United States)

    1989-09-01

    106 3. Program CC Systems Technology, Inc. (STI) of Hawthorne, CA., develops and markets PC control system analysis and design software including...is marketed in Palo Alto, Ca., by Applied i and can be used for both linear and non- linear control system analysis. Using TUTSIM involves developing...gravity centroid ( ucg ) can be calculated as 112 n m pi - 2 zi acg n i (7-5) where pi = poles zi = zeroes n = number of poles m = number of zeroes If K

  3. Coordinating controls

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics

  4. Topology control

    NARCIS (Netherlands)

    Buchin, K.; Buchin, M.; Wagner, D.; Wattenhofer, R.

    2007-01-01

    Information between two nodes in a network is sent based on the network topology, the structure of links connecting pairs of nodes of a network. The task of topology control is to choose a connecting subset from all possible links such that the overall network performance is good. For instance, a

  5. Control mental

    OpenAIRE

    Bueno i Torrens, David, 1965-

    2013-01-01

    La revista especialitzada NeuroReport ha publicat un article que m'ha aportat nous elements de reflexió sobre els mecanismes neurals de control mental que, de forma innata, realitzem les persones com a part de la nostra vida social.

  6. Control rod

    International Nuclear Information System (INIS)

    Igarashi, Takao; Yoshimoto, Yuichiro; Sugawara, Satoshi; Fukumoto, Takashi; Endo, Zen-ichiro; Saito, Shozo; Shinpo, Katsutoshi; Nishimura, Akira; Ozawa, Michihiro

    1988-01-01

    Purpose: To provide a sufficient shutdown margin upon reactor shutdown, prevent sheath deformation without decreasing neutron absorbents and prevent impact shocks exerted to structural materials. Constitution: The control rod of the present invention comprises a neutron absorption region, a sheath deformation means attached to the side wall and means for restricting and supporting axial movement of the neutron absorbent rod. Then, the amount of absorptive nuclei chained absorbents in the lower region is reduced than that in the upper region. In this way, effective neutron absorbing performance can be obtained relative to the neutron importance distribution during reactor shutdown. In addition, since the operationability is improved by reducing the weight of the control rod and the absorptive nuclei chained neutron abosrbers are used, mechanical nuclear life of the control rod can be increased. Thus, it is possible to prevent the outward deformation of the sheath, as well as prevent collision between the neutron absorber rod and the structural material on the side of inserting the control rod generated upon reactor scram by a simple structure. (Kamimura, M.)

  7. COPD - control drugs

    Science.gov (United States)

    Chronic obstructive pulmonary disease - control drugs; Bronchodilators - COPD - control drugs; Beta agonist inhaler - COPD - control drugs; Anticholinergic inhaler - COPD - control drugs; Long-acting inhaler - COPD - control drugs; ...

  8. Environmental controls

    International Nuclear Information System (INIS)

    Brown, S.

    1996-01-01

    Members of the public are exposed to environmental radiations from a variety of sources. In terms of average dose received the major component is from natural sources of radiation for which there is little or no scope to reduce exposure. Where such opportunities do exist, in those homes with high radon concentrations, the householders tend to ignore the risks despite the availability of comparatively straightforward and inexpensive remediation measures. By comparison there is significant public concern about radioactive waste management and the disposal and discharge of radioactivity to the environment despite strict environmental controls. This paper describes the controls and the wider policy context for radioactive waste management following a major review of policy last year. (author)

  9. Controllable dose

    International Nuclear Information System (INIS)

    Alvarez R, J.T.; Anaya M, R.A.

    2004-01-01

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  10. quality control

    International Nuclear Information System (INIS)

    Skujina, A.; Purina, S.; Riekstina, D.

    1999-01-01

    The optimal objects: soils, spruce needles and bracken ferns were found for the environmental monitoring in the regions of possible radioactive contamination - near SalaspiIs nuclear reactor and Ignalina nuclear power plant. The determination of Sr-90 was based on the radiochemical separation of Sr-90 (=Y-90) by HDEHP extraction and counting the Cerenkov radiation. The quality control of the results was carried out. (authors)

  11. Vehicle Controller

    Science.gov (United States)

    1985-01-01

    UNISTICK is an airplane-like joystick being developed by Johnson Engineering under NASA and VA sponsorship. It allows a driver to control a vehicle with one hand, and is based upon technology developed for the Apollo Lunar Landings of the 1970's. It allows severely handicapped drivers to operate an automobile or van easily. The system is expected to be in production by March 1986.

  12. Control rod

    International Nuclear Information System (INIS)

    Takeda, Toshikazu; Inoue, Kotaro.

    1979-01-01

    Purpose: To flatten the power distribution in the reactor core without impairing neutron economy by disposing pins containing elements of lower atomic number in the central region of a shroud and loading pins containing depleted uranium in the periphery region thereof. Constitution: The shroud has a layer of pins containing depleted uranium in the peripheral region and a layer of pins containing elements of lower atomic number such as beryllium in the central region. Heat removal from those pins containing depleted uranium and elements of lower atomic number (neutron moderator) is effected by sodium flow outside of the cladding material. The control rod operation is conducted by inserting or extracting the central portion (pins containing elements of lower atomic number such as beryllium) inside of the stainless pipe. Upon extraction of the control rod, the moderator in the central region is removed whereby high speed neutrons are no more deccelerated and the absorption rate to the depleted uranium is decreased. This can flatten the power distribution in the reactore core with the disposition of a plurality of control rods at a better neutron economy as compared with the use of neutron absorber such as boron. (Seki, T.)

  13. Control rod

    International Nuclear Information System (INIS)

    Fukumoto, Takashi; Hirakawa, Hiromasa; Kawashima, Norio; Goto, Yasuyuki.

    1994-01-01

    Neutron absorbers are contained in a tubular member comprising, integrally a tubular portion and four corners disposed at the outer circumference of the tubular portion at every 90deg, to provide a neutron absorbing tube. A plurality of neutron absorbing tubes are arranged in parallel in the lateral direction, and adjacent corners are joined, into a blade to constitute a control rod. Such a control rod has a great structural strength, simple in the structure and relatively light in weight and can contain a great amount of neutron absorbers. Upon formation of the control rod by arranging the blades in a cross-like shape, at least a portion thereof is constituted with short neutron absorbing tubes shorter than the entire length of the blade, and gaps are formed at positions in adjacent in the axial direction. With such a constitution, there is no worry that a wing end of the blade collides against or be abraded with a fuel channel box or a fuel support. Even if fuel channels are vibrated upon scram of the reactor, such as occurrence of earthquakes, it can be inserted to the reactor easily. (N.H.)

  14. Controlled fragmentation

    International Nuclear Information System (INIS)

    Arnold, Werner

    2002-01-01

    Contrary to natural fragmentation, controlled fragmentation offers the possibility to adapt fragment parameters like size and mass to the performance requirements in a very flexible way. Known mechanisms like grooves inside the casing, weaken the structure. This is, however, excluded for applications with high accelerations during launch or piercing requirements for example on a semi armor piercing penetrator. Another method to achieve controlled fragmentation with an additional grid layer is presented with which the required grooves are produced 'just in time' inside the casing during detonation of the high explosive. The process of generating the grooves aided by the grid layer was studied using the hydrocode HULL with respect to varying grid designs and material combinations. Subsequent to this, a large range of these theoretically investigated combinations was contemplated in substantial experimental tests. With an optimised grid design and a suitable material selection, the controlled fragment admits a very flexible adaptation to the set requirements. Additional advantages like the increase of perforation performance or incendiary amplification can be realized with the grid layer

  15. Elevated atmospheric carbon dioxide concentrations amplify Alternaria alternata sporulation and total antigen production

    Science.gov (United States)

    Background: Although the association between rising levels of carbon dioxide, the principle anthropogenic greenhouse gas, and pollen production has been established, few data are available regarding the function of rising carbon dioxide on quantitative or qualitative changes in allergenic fungal sp...

  16. Cutaneous infection by different Alternaria species in a liver transplant recipient

    Directory of Open Access Journals (Sweden)

    Susana Brás

    2015-06-01

    To our knowledge this is the first case of cutaneous concomitant infection due to those two species reported not only in Portugal but also worldwide. The patient was treated with surgical excision of the lesions and oral itraconazol without relapse.

  17. Survival of Alternaria brassicae in seeds and crop debris of rapeseed and mustard in Nepal

    DEFF Research Database (Denmark)

    Shrestha, S.K.; Munk, Lisa; Mathur, S.

    2003-01-01

    Contributions from The Danish Government Institute of Seed Pathology for Developing Countries - Copenhagen, Denmark, No. 166......Contributions from The Danish Government Institute of Seed Pathology for Developing Countries - Copenhagen, Denmark, No. 166...

  18. Successful Posaconazole Therapy of Disseminated Alternariosis due to Alternaria infectoria in a Heart Transplant Recipient

    Czech Academy of Sciences Publication Activity Database

    Lysková, P.; Kubánek, M.; Hubka, Vít; Sticová, E.; Voska, L.; Kautznerová, D.; Kolařík, Miroslav; Hamal, P.; Vašáková, M.

    2017-01-01

    Roč. 182, 3-4 (2017), s. 297-303 ISSN 0301-486X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Heart transplantation * Phaeohyphomycosis * Pulmonary infection Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.710, year: 2016

  19. Phylogenetic prediction of Alternaria leaf blight resistance in wild and cultivated species of carrots (Daucus, Apiaceae)

    Science.gov (United States)

    Plant scientists make inferences and predictions from phylogenetic trees to solve scientific problems. Crop losses due to disease damage is an important problem that many plant breeders would like to solve, so the ability to predict traits like disease resistance from phylogenetic trees derived from...

  20. Brown Midrib (Low Lignin) Sorghum Mutations Result in Restricted Growth of Fusarium and Alternaria spp

    Science.gov (United States)

    To increase usability of sorghum for bioenergy and forages, two different brown midrib (bmr) genes, bmr6 and bmr12, were backcrossed into five elite backgrounds, resulting in reduced lignin near-isogenic genotypes. When compared with wild-type, field-grown grain from bmr6 and bmr12 plants had signif...

  1. Enhanced cellulase and β-glucosidase production by a mutant of Alternaria alternata

    International Nuclear Information System (INIS)

    Macris, B.J.

    1984-01-01

    The cellulolytic activity of the wild type and a mutant strain of A. alternata was investigated. Mutants were induced by gamma radiation. A suspension of about 10 5 condidia/mL in 0.05M phosphate buffer pH 5 were irradiated in a gamma-cell-type (Cammacell 220, Atomic Energy of Canada Limited, Ottawa, Canada) 60 Co source with a dose rate of 2.5 krad/min. The amount of radiation given was 70 krad which resulted in about 10% survival level. The stock culture was maintained on a sterile growth medium supplemented with 1% cellulose 123 and 0.3% agar. Following the incubation period, the fungal biomass was harvested by centrifugation (5000g for 10 min) and the clarified supernatant was used as the source of cellulase and β-glucosidase

  2. Alternaria infectoria brain abscess in a child with chronic granulomatous disease

    NARCIS (Netherlands)

    Hipolito, E.; Faria, E.; Alves, A.; de Hoog, G.S.; Anjos, J.; Goncalves, T.; Morais, P.V.; Estevao, H.

    2009-01-01

    In the present report, we describe the first case of a phaeohyphomycotic brain abscess in a 5-year-old boy with chronic granulomatous disease (CGD) admitted to hospital with seizures. A computed tomography (CT) scan revealed a cerebral abscess and the microbiology study showed a dark,

  3. Analysis of a suppressive subtractive hybridization library of Alternaria alternata resistant to 2-propenyl isothiocyanate

    Directory of Open Access Journals (Sweden)

    Heriberto García-Coronado

    2015-07-01

    Conclusions: The fungal response showed that natural compounds could induce tolerance/resistance mechanisms in organisms in the same manner as synthetic chemical products. The response of A. alternata to the toxicity of 2-pITC is a sophisticated phenomenon including the induction of signaling cascades targeting a broad set of cellular processes. Whole-transcriptome approaches are needed to elucidate completely the fungal response to 2-pITC.

  4. Chemical and morphological segregation of Alternaria alternata, A-gaisen and A-longipes

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Krøger, Elisabeth; Roberts, R.G.

    2001-01-01

    and the diameter measurements were subjected to principal component analysis. Analysis of chemical and physiological data showed that the 39 isolates segregated into the same distinct groups that are morphologically identifiable as A. alternata, A. longipes or A. gaisen. The results showed that A. longipes. A...

  5. Automated and unbiased image analyses as tools in phenotypic classification of small-spored Alternaria species

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Hansen, Michael Edberg; Smedsgaard, Jørn

    2005-01-01

    often has been broadly applied to various morphologically and chemically distinct groups of isolates from different hosts. The purpose of this study was to develop and evaluate automated and unbiased image analysis systems that will analyze different phenotypic characters and facilitate testing...

  6. Arabidopsis Responds to Alternaria alternata Volatiles by Triggering Plastid Phosphoglucose Isomerase-Independent Mechanisms

    Czech Academy of Sciences Publication Activity Database

    Sanchez-Lopez, A.M.; Bahaji, A.; De Diego, N.; Baslam, M.; Li, J.; Munoz, F.J.; Almagro, G.; Garcia-Gomez, P.; Ameztoy, K.; Ricarte-Bermejo, A.; Novák, Ondřej; Humplík, J.F.; Spíchal, L.; Doležal, Karel; Ciordia, S.; Mena, M. C.; Navajas, R.; Baroja-Fernandez, E.; Pozueta-Romero, J.

    2016-01-01

    Roč. 172, č. 3 (2016), s. 1989-2001 ISSN 0032-0889 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : tandem mass-spectrometry * exceptionally high-levels * starch biosynthesis * functional-characterization * glucose translocator * thaliana * mutants * cytokinin * tissues * leaves Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.456, year: 2016

  7. Flow Control

    Science.gov (United States)

    2013-04-08

    can be written as â fj (t) =WO tanh( WIx (t)+bI)+bO, (38) where WI , WO are the input and output matrices, respectively, and bI and bO are the input...applications, present on envisioned airborne optical platforms . One of the problems is that all adaptive optical systems rely on mechanically moving some...of successfully controlling the optical aberration due to the flow over the aperture of airborne optical platforms . As outlined above, systems

  8. Control rod

    International Nuclear Information System (INIS)

    Igarashi, Takao; Sugawara, Satoshi; Yoshimoto, Yuichiro; Saito, Shozo; Fukumoto, Takashi.

    1987-01-01

    Purpose: To reduce the weight and thereby obtain satisfactory operationability of control rods by combining absorbing nuclear chain type neutron absorbers and conventional type neutron absorbers in the axial direction of blades. Constitution: Neutron absorber rods and long life type neutron absorber rods are disposed in a tie rod and a sheath. The neutron absorber rod comprises a poison tube made of stainless steels and packed with B 4 C powder. The long life type neutron absorber rod is prepared by packing B-10 enriched boron carbide powder into a hafnium metal rod, hafnium pipe, europium and stainless made poison tube. Since the long life type absorber rod uses HF as the absorbing nuclear chain type neutron absorber, it absorbs neutrons to form new neutron absorbers to increase the nuclear life. (Yoshino, Y.)

  9. Control Valve

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Wayne R.

    2018-03-20

    A control valve includes a first conduit having a first inlet and a first outlet and defining a first passage; a second conduit having a second inlet and a second outlet and defining a second passage, the second conduit extending into the first passage such that the second inlet is located within the first passage; and a valve plate disposed pivotably within the first passage, the valve plate defining a valve plate surface. Pivoting of the valve plate within the first passage varies flow from the first inlet to the first outlet and the valve plate is pivotal between a first position and a second position such that in the first position the valve plate substantially prevents fluid communication between the first passage and the second passage and such that in the second position the valve plate permits fluid communication between the first passage and the second passage.

  10. Control Prenatal

    Directory of Open Access Journals (Sweden)

    P. Susana Aguilera, DRA.

    2014-11-01

    Full Text Available Los principales objetivos del control prenatal son identificar aquellos pacientes de mayor riesgo, con el fin de realizar intervenciones en forma oportuna que permitan prevenir dichos riesgos y así lograr un buen resultado perinatal. Esto se realiza a través de la historia médica y reproductiva de la mujer, el examen físico, la realización de algunos exámenes de laboratorio y exámenes de ultrasonido. Además es importante promover estilos de vida saludables, la suplementación de ácido fólico, una consejería nutricional y educación al respecto.

  11. Custom controls

    Science.gov (United States)

    Butell, Bart

    1996-02-01

    Microsoft's Visual Basic (VB) and Borland's Delphi provide an extremely robust programming environment for delivering multimedia solutions for interactive kiosks, games and titles. Their object oriented use of standard and custom controls enable a user to build extremely powerful applications. A multipurpose, database enabled programming environment that can provide an event driven interface functions as a multimedia kernel. This kernel can provide a variety of authoring solutions (e.g. a timeline based model similar to Macromedia Director or a node authoring model similar to Icon Author). At the heart of the kernel is a set of low level multimedia components providing object oriented interfaces for graphics, audio, video and imaging. Data preparation tools (e.g., layout, palette and Sprite Editors) could be built to manage the media database. The flexible interface for VB allows the construction of an infinite number of user models. The proliferation of these models within a popular, easy to use environment will allow the vast developer segment of 'producer' types to bring their ideas to the market. This is the key to building exciting, content rich multimedia solutions. Microsoft's VB and Borland's Delphi environments combined with multimedia components enable these possibilities.

  12. Control rods

    International Nuclear Information System (INIS)

    Hirukawa, Koji.

    1979-01-01

    Purpose: To ensure the fuel safety by constituting a control rod with a plurality of poison bodies suspended in a cross-like section and shorter length poison bodies made movable and engageable in the gap between each of the above poison bodies thereby maintaining the function of the shorter length poison constant. Constitution: Cross-like supports are secured to the upper and lower parts of a driving shaft journaled in a sheath and poison bodies composed of neutron absorber poisons of a large thermal neutron absorption cross section and neutron absorber poison tubes for containing them are suspended from the supports. A movable cross-like support is mounted slidably at its base to the lower part of the driving shaft and poison bodies shorter than the above poison bodies and composed of neutron absorber poisons having a greater absorption cross section at the neutron energy region higher than thermal neutron region and neutron poison tubes for containing them are suspended to the movable support at the position capable of engaging in the gap between each of the poison bodies. (Kawakami, Y.)

  13. Radiation control

    International Nuclear Information System (INIS)

    Uchida, Akira

    1981-01-01

    This paper describes on how the condition of radiation level in the ring (storage ring) experimentation room changes corresponding to the operating stage of SOR-ring (synchrotron radiation storage ring), and does not describe on the present radiation control in the SOR facility. The operating stage of SOR is divided into the following five: (1) 307 MeV electron injection, (2) 307 MeV electron storage (used for SOR experiments), (3) energy increase from 307 to 380 MeV, (4) 380 MeV electron storage, (5) re-injection and completion of operation. Gamma and X ray levels are shown when electron beam is injected from the electron synchrotron to the SOR-ring. Two main causes of the high level are reported. Spatial dose rate in storing 307 MeV electrons in also illustrated. This is sufficiently lower than that at electron incidence. The measurement of radiation level at the time of energy increase from 307 to 380 MeV has just started. Since the radiation level in 380 MeV storage, measured at the points about 20 cm apart from the electron orbit, showed several mR/h, the level seems to be negligible at the points where experiments are carried out, 1 m away from the measurement points. The radiation level in electron reinjection and completion of operation may be large during a short period (a few Roentgen) like the time of energy increase. Therefore, the beam shall be re-injected or decreased after confirming that all experimenters have retreated into the predetermined place. (Wakatsuki, Y.)

  14. Active vibration control by robust control techniques

    International Nuclear Information System (INIS)

    Lohar, F.A.

    2001-01-01

    This paper studies active vibration control of multi-degree-of-freedom system. The control techniques considered are LTR, H/sup 2/ and H/sup infinite/. The results show that LTR controls the vibration but its respective settling time is higher than that of the other techniques. The control performance of H/sup infinite/ control is similar to that of H/sup 2/ control in the case of it weighting functions. However, H/sup infinite/ control is superior to H/sup 2/ control with respect to robustness, steady state error and settling time. (author)

  15. Controlling Separation in Turbomachines

    Science.gov (United States)

    Evans, Simon; Himmel, Christoph; Power, Bronwyn; Wakelam, Christian; Xu, Liping; Hynes, Tom; Hodson, Howard

    2010-01-01

    Four examples of flow control: 1) Passive control of LP turbine blades (Laminar separation control). 2) Aspiration of a conventional axial compressor blade (Turbulent separation control). 3) Compressor blade designed for aspiration (Turbulent separation control). 4.Control of intakes in crosswinds (Turbulent separation control).

  16. Control panel for CMC 8080 crate controller

    International Nuclear Information System (INIS)

    Masayuki Inokuchi

    1978-01-01

    The main features of Control Panel for CAMAC Crate Controller CMC 8080 are described. The control panel can be directly connected with CRATE CONTROLLER's front panel connector with a 50 lines cable without any changes in CMC 8080 system circuits. (author)

  17. Uniting Control Lyapunov and Control Barrier Functions

    NARCIS (Netherlands)

    Romdlony, Zakiyullah; Jayawardhana, Bayu

    2014-01-01

    In this paper, we propose a nonlinear control design for solving the problem of stabilization with guaranteed safety. The design is based on the merging of a Control Lyapunov Function and a Control Barrier Function. The proposed control method allows us to combine the design of a stabilizer based on

  18. Interaction between production control and quality control

    NARCIS (Netherlands)

    Bij, van der J.D.; Ekert, van J.H.W.

    1999-01-01

    Describes a qualitative study on interaction between systems for production control and quality control within industrial organisations. Production control and quality control interact in a sense. Good performance for one aspect often influences or frustrates the performance of the other. As far as

  19. Control of ergosterol producer fungi contaminating cereal grains by certain environmental conditions and gamma rays

    International Nuclear Information System (INIS)

    Shahin, A.A.M.

    2007-01-01

    Existence of ergosterol in grains usually gives an indication that these grains are contaminated by ergosterol producing fungi. So, ergosterol concentration could be a suitable marker for estimation of fungal contamination range in cereal grains. Thirty eight fungal isolates were isolated from maize, sorghum and barley grains. Alternaria, Cladosporium and Aspergillus were the most common fungal genera among these isolates and they were tested for ergosterol production. The highest ergosterol producing fungi were identified as Alternaria alternaria, Cladosporium herbarum and Aspergillus niger var.niger. The present results indicate that the most suitable conditions for producing ergosterol by these strains in maize grains were found to be at 25 degree C for 30 days. Exposing the artificially contaminated maize grains by the above three strains (10 7 CFU/ml) to increasing dose levels of gamma rays up to 10 kGy and storing for 30 days, gradually decreased the production of ergosterol to 7.9, 6.2 and 1.5 mg/g dry weight of grains by A. alternata and C.herbarum and A. niger var. niger, respectively. D 10 values of the tested three isolates in maize grains were found to be 2, 1.61, and 1.2 kGy, respectively. The results showed that cold storage (10 degree C) clearly decreased the activity of the tested fungi for producing ergosterol during the storage periods, and a dose level of 15 kGy was quite enough to free the grains from A. alternata, Cladosporium herbarum and A. niger var. niger, regardless the contamination level of grains with these ergosterol producer fungus

  20. Control heeft vele gezichten

    NARCIS (Netherlands)

    Steens, H.B.A.

    The editorial summarizes several perspectives of control, including the control conducted by supervisors, control based on classical budgeting, control by analytics, et cetera, and relates these angles to the papers in this issue of the journal.

  1. Hierarchical Control of Thermostatically Controller Loads for Primary Frequency Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Huang, Shaojun

    2016-01-01

    reserve references. At the middle level, distribution substations estimate the available power of TCLs based on the aggregated bin model, and dispatch control signals to individual TCLs. At the local level, a supplementary frequency control loop is implemented at the local controller, which makes TCLs...... respond to the frequency event autonomously. Case studies show that the proposed controller can efficiently respond to frequency events and fulfill the requirement specified by the system operator. The users’ comforts are not compromised and the short cycling of TCLs is largely reduced. Due...... to the autonomous control, the communication requirement is minimized....

  2. Incoherent control of locally controllable quantum systems

    International Nuclear Information System (INIS)

    Dong Daoyi; Zhang Chenbin; Rabitz, Herschel; Pechen, Alexander; Tarn, T.-J.

    2008-01-01

    An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective measurement of the amplified state, and (3) final optimization by a unitary controlled transformation. The first step increases the amplitudes of some desired eigenstates and the corresponding probability of observing these eigenstates, the second step projects, with high probability, the amplified state into a desired eigenstate, and the last step steers this eigenstate into the target state. Within this scheme, two control algorithms are presented for two classes of quantum systems. As an example, the incoherent control scheme is applied to the control of a hydrogen atom by an external field. The results support the suggestion that projective measurements can serve as an effective control and local controllability information can be used to design control laws for quantum systems. Thus, this scheme establishes a subtle connection between control design and controllability analysis of quantum systems and provides an effective engineering approach in controlling quantum systems with partial controllability information.

  3. Covariance upperbound controllers for networked control systems

    International Nuclear Information System (INIS)

    Ko, Sang Ho

    2012-01-01

    This paper deals with designing covariance upperbound controllers for a linear system that can be used in a networked control environment in which control laws are calculated in a remote controller and transmitted through a shared communication link to the plant. In order to compensate for possible packet losses during the transmission, two different techniques are often employed: the zero-input and the hold-input strategy. These use zero input and the latest control input, respectively, when a packet is lost. For each strategy, we synthesize a class of output covariance upperbound controllers for a given covariance upperbound and a packet loss probability. Existence conditions of the covariance upperbound controller are also provided for each strategy. Through numerical examples, performance of the two strategies is compared in terms of feasibility of implementing the controllers

  4. Output Control Using Feedforward And Cascade Controllers

    Science.gov (United States)

    Seraji, Homayoun

    1990-01-01

    Report presents theoretical study of open-loop control elements in single-input, single-output linear system. Focus on output-control (servomechanism) problem, in which objective is to find control scheme that causes output to track certain command inputs and to reject certain disturbance inputs in steady state. Report closes with brief discussion of characteristics and relative merits of feedforward, cascade, and feedback controllers and combinations thereof.

  5. Controlling chaotic systems via nonlinear feedback control

    International Nuclear Information System (INIS)

    Park, Ju H.

    2005-01-01

    In this article, a new method to control chaotic systems is proposed. Using Lyapunov method, we design a nonlinear feedback controller to make the controlled system be stabilized. A numerical example is given to illuminate the design procedure and advantage of the result derived

  6. Personal exposure control system

    International Nuclear Information System (INIS)

    Tanabe, Ken-ichi; Akashi, Michio

    1994-01-01

    Nuclear power stations are under strict radiation control. Exposure control for nuclear workers is the most important operation, and so carefully thought out measures are taken. This paper introduces Fuji Electric's personal exposure control system that meets strict exposure control and rationalizes control operations. The system has a merit that it can provide required information in an optimum form using the interconnection of a super minicomputer and exposure control facilities and realizes sophisticated exposure control operations. (author)

  7. Introduction of digital control

    International Nuclear Information System (INIS)

    Kim, Sang Jin

    1988-01-01

    This book is one of mechatronics series. It deals with digital control, which includes what is digital control?, display way of control system, output of primary system, secondary system like example of system and display way of the system, stabilizing of control system such as method to decide stability and system out of control, displaying equation of state into vector, good control such as the right characteristic, transient behavior and design of position control system using DC servo motor.

  8. Solid state controller three axes controller

    Science.gov (United States)

    Bailey, C. L., Jr. (Inventor)

    1973-01-01

    The reported flight controller features a handle grip which is mounted on a longitudinally extending control element. The handle grip is pivotally mounted on the control element about a pitch axis which is perpendicular to the longitudinal axis through the control element. The pivotal mounting includes a resilient force mounting mechanism which centers the grip relative to the control element. Rotation of the handle grip produces a direct rotation of a transducer element in a transducer which provides an electrical indication of the rotative movement about three mutually perpendicular axes.

  9. PID control with robust disturbance feedback control

    DEFF Research Database (Denmark)

    Kawai, Fukiko; Vinther, Kasper; Andersen, Palle

    2015-01-01

    Disturbance Feedback Control (DFC) is a technique, originally proposed by Fuji Electric, for augmenting existing control systems with an extra feedback for attenuation of disturbances and model errors. In this work, we analyze the robustness and performance of a PID-based control system with DFC...... and performance (if such gains exist). Finally, two different simulation case studies are evaluated and compared. Our numerical studies indicate that better performance can be achieved with the proposed method compared with a conservatively tuned PID controller and comparable performance can be achieved when...... compared with an H-infinity controller....

  10. Organizational Control: Two Functions

    Science.gov (United States)

    Ouchi, William G.; Maguire, Mary Ann

    1975-01-01

    Distinguishes between two modes of organizational control, personal surveillance (behavior control) and the measurement of outputs (output control). Output control occurs in response to a manager's need to provide legitimate evidence of performance, while behavior control is exerted when means-ends relations are known and appropriate instruction…

  11. Structural Pest Control.

    Science.gov (United States)

    Kahn, M. S.; Hoffman, W. M.

    This manual is designed for those who seek certification as pesticide applicators for industrial, institutional, structural, and health-related pest control. It is divided into six sections covering general pest control, wood-destroying organisms, bird control, fumigation, rodent control, and industrial weed control. The manual gives information…

  12. BSF control system

    International Nuclear Information System (INIS)

    Irie, Y.; Ishii, K.; Ninomiya, S.; Sasaki, H.; Sakai, I.

    1982-08-01

    The booster synchrotron utilization facility (BSF) is a facility which utilizes the four fifths of available beam pulses from the KEK booster synchrotron. The BSF control system includes the beam line control, interactions with the PS central control room and the experimental facilities, and the access control system. A brief description of the various components in the control system is given. (author)

  13. Motion control report

    CERN Document Server

    2013-01-01

    Please note this is a short discount publication. In today's manufacturing environment, Motion Control plays a major role in virtually every project.The Motion Control Report provides a comprehensive overview of the technology of Motion Control:* Design Considerations* Technologies* Methods to Control Motion* Examples of Motion Control in Systems* A Detailed Vendors List

  14. Integrated Control Using the SOFFT Control Structure

    Science.gov (United States)

    Halyo, Nesim

    1996-01-01

    The need for integrated/constrained control systems has become clearer as advanced aircraft introduced new coupled subsystems such as new propulsion subsystems with thrust vectoring and new aerodynamic designs. In this study, we develop an integrated control design methodology which accomodates constraints among subsystem variables while using the Stochastic Optimal Feedforward/Feedback Control Technique (SOFFT) thus maintaining all the advantages of the SOFFT approach. The Integrated SOFFT Control methodology uses a centralized feedforward control and a constrained feedback control law. The control thus takes advantage of the known coupling among the subsystems while maintaining the identity of subsystems for validation purposes and the simplicity of the feedback law to understand the system response in complicated nonlinear scenarios. The Variable-Gain Output Feedback Control methodology (including constant gain output feedback) is extended to accommodate equality constraints. A gain computation algorithm is developed. The designer can set the cross-gains between two variables or subsystems to zero or another value and optimize the remaining gains subject to the constraint. An integrated control law is designed for a modified F-15 SMTD aircraft model with coupled airframe and propulsion subsystems using the Integrated SOFFT Control methodology to produce a set of desired flying qualities.

  15. ISABELLE control system

    International Nuclear Information System (INIS)

    Humphrey, J.W.; Frankel, R.S.; Niederer, J.A.

    1980-01-01

    Design principles for the Brookhaven ISABELLE control intersecting storage ring accelerator are described. Principal features include a locally networked console and control computer complex, a system wide process data highway, and intelligent local device controllers. Progress to date is summarized

  16. Control Measure Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EPA Control Measure Dataset is a collection of documents describing air pollution control available to regulated facilities for the control and abatement of air...

  17. Olivo-Cerebellar Controller

    National Research Council Canada - National Science Library

    Bandyopadhyay, Promode R

    2008-01-01

    ...) used in a maneuvering controller or control system of an underwater vehicle. In order to attain the objects described, the present invention provides closed-loop control of multiple inferior olives (IOs...

  18. Birth control pills - combination

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000655.htm Birth control pills - combination To use the sharing features on ... both progestin and estrogen. What Are Combination Birth Control Pills? Birth control pills help keep you from ...

  19. Riot Control Agents

    Science.gov (United States)

    ... Submit What's this? Submit Button Facts About Riot Control Agents Interim document Recommend on Facebook Tweet Share Compartir What riot control agents are Riot control agents (sometimes referred to ...

  20. Essure Permanent Birth Control

    Science.gov (United States)

    ... Prosthetics Essure Permanent Birth Control Essure Permanent Birth Control Share Tweet Linkedin Pin it More sharing options ... Print Essure is a a permanently implanted birth control device for women (female sterilization). Implantation of Essure ...

  1. Wisdom Appliance Control System

    Science.gov (United States)

    Hendrick; Jheng, Jyun-Teng; Tsai, Chen-Chai; Liou, Jia-Wei; Wang, Zhi-Hao; Jong, Gwo-Jia

    2017-07-01

    Intelligent appliances wisdom involves security, home care, convenient and energy saving, but the home automation system is still one of the core unit, and also using micro-processing electronics technology to centralized and control the home electrical products and systems, such as: lighting, television, fan, air conditioning, stereo, it composed of front-controller systems and back-controller panels, user using front-controller to control command, and then through the back-controller to powered the device.

  2. Test Control Center (TCC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Test Control Center (TCC) provides a consolidated facility for planning, coordinating, controlling, monitoring, and analyzing distributed test events. ,The TCC...

  3. A new controllable damper with neuro controller

    International Nuclear Information System (INIS)

    Kobayashi, N.; Kobayashi, H.; Saito, O.; Yokoi, R.; Morishita, S.

    1993-01-01

    A new controllable damper is proposed for suppressing the vibration of the piping system for wide frequency range. Electro-Rheological fluid (ER fluid) is enclosed in the damper casing in place of oil, and the apparent viscosity of ER fluid can be varied by applying electric field strength (E.F.S.), which is controlled by an adaptive neural network controller. The shaking test is conducted about a simplified L-shaped piping model with a prototype controllable damper. The test results show the effectiveness of the presented controllable damper for suppressing very small amplitude vibration of the piping system. Furthermore an application of neural network is discussed to control E.F.S. of the electrode. (author)

  4. Digital control programmer for temperature control

    International Nuclear Information System (INIS)

    Rajore, S.B.; Kumar, S.V.

    1993-01-01

    This report describes a PC based digital control programmer for controlling and programming temperature of a high vacuum resistance heating furnace and the software developed to control power using PID algorithm. It also describes the amplifier specially developed to suit the input requirement of the non-standard W5 thermocouple and the software and hardware protections introduced in the system. (author). 5 refs., 8 figs., 1 appendix

  5. Control and optimal control theories with applications

    CERN Document Server

    Burghes, D N

    2004-01-01

    This sound introduction to classical and modern control theory concentrates on fundamental concepts. Employing the minimum of mathematical elaboration, it investigates the many applications of control theory to varied and important present-day problems, e.g. economic growth, resource depletion, disease epidemics, exploited population, and rocket trajectories. An original feature is the amount of space devoted to the important and fascinating subject of optimal control. The work is divided into two parts. Part one deals with the control of linear time-continuous systems, using both transfer fun

  6. Reactor control device

    International Nuclear Information System (INIS)

    Fukami, Haruo; Morimoto, Yoshinori.

    1981-01-01

    Purpose: To operate a reactor always with safety operation while eliminating the danger of tripping. Constitution: In a reactor control device adapted to detect the process variants of a reactor, control a control rod drive controlling system based on the detected signal to thereby control the driving the control rods, control the reactor power and control the electric power generated from an electric generator by the output from the reactor, detection means is provided for the detection of the electric power from said electric generator, and a compensation device is provided for outputting control rod driving compensation signals to the control rod driving controlling system in accordance with the amount of variation in the detected value. (Seki, T.)

  7. Controle da pinta-preta em tomateiro e da mancha-zonada em pepino por meio de bicarbonato de sódio e óleo vegetal Control of early blight on tomato and net spot on cucumber through application of sodium bicarbonate and vegetal oil

    Directory of Open Access Journals (Sweden)

    Juan Roberto Ramírez-Otárola Sarmiento

    1999-07-01

    Full Text Available Foram realizados dois ensaios, em condições de campo, na UNESP/ FCAV, Jaboticabal (SP. O primeiro (maio a outubro de 1993 teve como objetivo avaliar a eficiência de pulverizações semanais de bicarbonato de sódio (10 g/l, óleo vegetal 'Natur'l óleo (10 ml/l e iprodione (0,75 g/l, aplicados isoladamente ou em combinação dois a dois, no controle da pinta-preta (Alternaria solani em tomateiro, cultivar Jumbo AG-592. No segundo ensaio (março a junho de 1993, o objetivo foi determinar a eficiência de pulverizações semanais em diferentes doses de bicarbonato de sódio (5, 10 e 15 g/l comparadas ao benomil (0,5 g/l, no controle da mancha-zonada (Leandria momordicae em pepino híbrido 'Premier'. Utilizou-se o delineamento experimental de blocos ao acaso com quatro repetições para ambos os experimentos. Foram utilizadas parcelas de 40 plantas distribuídas em 4 fileiras de 5,0 e 2,5 m de comprimento para os experimentos com pepino e tomate, respectivamente. As avaliações da severidade da doença foram feitas a cada quatorze dias (as cinco primeiras e a cada sete dias (as duas últimas e foram iniciadas 39 dias após o transplante do tomate. Para o pepino, foram realizadas cinco avaliações, iniciadas 28 dias após o transplante e repetidas a cada quatorze dias. Foram determinadas as curvas de progresso das doenças e a produtividade dentro de cada tratamento para cada cultura. Pela observação dos valores dos coeficientes de determinação das diferentes curvas epidemiológicas, concluiu-se que a quinta folha e a transformação logística se mostraram mais adequadas para o estudo epidemiológico da pinta-preta do tomateiro, enquanto a quarta folha e a transformação logística se mostraram mais adequadas para o estudo epidemiológico da mancha-zonada. Constatou-se o efeito positivo do iprodione no controle de pinta-preta, isolado ou quando misturado ao bicarbonato de sódio ou ao óleo vegetal, não havendo diferença estat

  8. Power control device

    International Nuclear Information System (INIS)

    Fukawa, Naohiro.

    1982-01-01

    Purpose: To alleviate the load of an operator by automatically operating the main controller, the speed controller, etc. of a recirculation control system and safely operating them without erroneous operation for long period of time, thereby improving the efficiency of a plant. Constitution: An electric type hydraulic control device controls loads of a turbine and a generator and outputs a control signal also to the main controller of a recirculation flow rate control system. At this time, the main controller is set at an automatic position, and the speed controller receives a recirculation pump speed signal from the main controller at the automatic position. The speed controller outputs a pump speed control signal to the recirculation pump system, and a reactor generates a power corresponding thereto. When the power control is automatically performed by the recirculation flow rate control, an operator sets a rate of change of the recirculation pump speed and the rate of change of the mean power range monitor at a change rate setting unit. Therefore, the control of the recirculation flow rate under the power control can be substantially entirely automated. (Yoshigara, H.)

  9. Process and apparatus for controlling control rods

    International Nuclear Information System (INIS)

    Gebelin, B.; Couture, R.

    1987-01-01

    This process and apparatus is characterized by 2 methods, for examination of cluster of nuclear control rods. Foucault current analyzer which examines fraction by fraction all the control rods. This examination is made by rotation of the cluster. Doubtful rods are then analysed by ultrasonic probe [fr

  10. Robust control charts in statistical process control

    NARCIS (Netherlands)

    Nazir, H.Z.

    2014-01-01

    The presence of outliers and contaminations in the output of the process highly affects the performance of the design structures of commonly used control charts and hence makes them of less practical use. One of the solutions to deal with this problem is to use control charts which are robust

  11. Try to Control Yourself!

    Science.gov (United States)

    Esque, Timm J.

    1996-01-01

    Conventional management controls employees, but successful management encourages and enables employees to control themselves. Where control resides in an organization can be determined by examining its performance tracking systems. Most are management information systems. The best are owned and used by the employees to control and adjust their own…

  12. Evaluation of Internal Control

    OpenAIRE

    Gheorghe Suciu; Pipu-Nicolae Barsan

    2013-01-01

    Performance is indissolubly tied to control. Performance cannot be obtained without a strong, adequate control, regardless if it is in the public or private sector. Control is one of management’s attributes and it must be organized, implemented and evaluated in every company, regardless of its size. Each person from a company participates to a greater or lesser extent in the control activities.

  13. Programmable dc motor controller

    Science.gov (United States)

    Hopwood, J. E.

    1982-11-01

    A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

  14. Exotic biological control agents

    NARCIS (Netherlands)

    Hajek, Ann E.; Hurley, Brett P.; Kenis, Marc; Garnas, Jeffrey R.; Bush, Samantha J.; Wingfield, Michael J.; Lenteren, van Joop C.; Cock, Matthew J.W.

    2016-01-01

    Biological control is a valuable and effective strategy for controlling arthropod pests and has been used extensively against invasive arthropods. As one approach for control of invasives, exotic natural enemies from the native range of a pest are introduced to areas where control is needed.

  15. Optimal decoupling controllers revisited

    Czech Academy of Sciences Publication Activity Database

    Kučera, Vladimír

    2013-01-01

    Roč. 42, č. 1 (2013), s. 1-16 ISSN 0324-8569 R&D Projects: GA TA ČR(CZ) TE01020197 Institutional support: RVO:67985556 Keywords : linear systems * fractional representations * decoupling control lers * stabilizing control lers * optimal control lers Subject RIV: BC - Control Systems Theory

  16. Automatic control systems engineering

    International Nuclear Information System (INIS)

    Shin, Yun Gi

    2004-01-01

    This book gives descriptions of automatic control for electrical electronics, which indicates history of automatic control, Laplace transform, block diagram and signal flow diagram, electrometer, linearization of system, space of situation, state space analysis of electric system, sensor, hydro controlling system, stability, time response of linear dynamic system, conception of root locus, procedure to draw root locus, frequency response, and design of control system.

  17. Catastrophes control problem

    International Nuclear Information System (INIS)

    Velichenko, V.V.

    1994-01-01

    The problem of catastrophe control is discussed. Catastrophe control aims to withdraw responsible engineering constructions out of the catastrophe. The mathematical framework of catastrophes control systems is constructed. It determines the principles of systems filling by the concrete physical contents and, simultaneously, permits to employ modern control methods for the synthesis of optimal withdrawal strategy for protected objects

  18. Adaptive Extremum Control and Wind Turbine Control

    DEFF Research Database (Denmark)

    Ma, Xin

    1997-01-01

    This thesis is divided into two parts, i.e., adaptive extremum control and modelling and control of a wind turbine. The rst part of the thesis deals with the design of adaptive extremum controllers for some processes which have the behaviour that process should have as high e ciency as possible...... in parameters, and thus directly lends itself to parameter estimation and adaptive control. The extremum control law is derived based on static optimization of a performance function. For a process with nonlinearity at output the intermediate signal between the linear part and nonlinear part plays an important....... Firstly, it is assumed that the nonlinear processes can be divided into a dynamic linear part and static nonlinear part. Consequently the processes with input nonlinearity and output nonlinearity are treated separately. With the nonlinearity at the input it is easy to set up a model which is linear...

  19. HYDRAULIC SERVO CONTROL MECHANISM

    Science.gov (United States)

    Hussey, R.B.; Gottsche, M.J. Jr.

    1963-09-17

    A hydraulic servo control mechanism of compact construction and low fluid requirements is described. The mechanism consists of a main hydraulic piston, comprising the drive output, which is connected mechanically for feedback purposes to a servo control piston. A control sleeve having control slots for the system encloses the servo piston, which acts to cover or uncover the slots as a means of controlling the operation of the system. This operation permits only a small amount of fluid to regulate the operation of the mechanism, which, as a result, is compact and relatively light. This mechanism is particuiarly adaptable to the drive and control of control rods in nuclear reactors. (auth)

  20. Precision digital control systems

    Science.gov (United States)

    Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

    This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

  1. CONTROLLING AND BUSINESS EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Tina Vuko

    2013-02-01

    Full Text Available Managing business successfully in dynamic environment requires effective controlling system. Controlling is the process of defining objectives, planning and management control so that every decision maker can act in accordance with agreed objectives. Controlling function as a separate department contributes business efficiency trough ensuring transparency of business result and business processes. Controlling takes place when manager and controller cooperate. The aim of this paper is to investigate the effectiveness of controlling function (i.e. controlling department in Croatian companies and to address the specific features of the function that contribute significantly to overall business performance. The research is conducted on the sample of companies listed on the Regulated market of the Zagreb Stock Exchange. Survey is used as a method to collect the data regarding the controlling function, while financial data necessary for the research are extracted from the published financial statements. Results of the research indicate that controlling department has positive effects on the business performance.

  2. Undergraduate reactor control experiment

    International Nuclear Information System (INIS)

    Edwards, R.M.; Power, M.A.; Bryan, M.

    1992-01-01

    A sequence of reactor and related experiments has been a central element of a senior-level laboratory course at Pennsylvania State University (Penn State) for more than 20 yr. A new experiment has been developed where the students program and operate a computer controller that manipulates the speed of a secondary control rod to regulate TRIGA reactor power. Elementary feedback control theory is introduced to explain the experiment, which emphasizes the nonlinear aspect of reactor control where power level changes are equivalent to a change in control loop gain. Digital control of nuclear reactors has become more visible at Penn State with the replacement of the original analog-based TRIGA reactor control console with a modern computer-based digital control console. Several TRIGA reactor dynamics experiments, which comprise half of the three-credit laboratory course, lead to the control experiment finale: (a) digital simulation, (b) control rod calibration, (c) reactor pulsing, (d) reactivity oscillator, and (e) reactor noise

  3. Control of Bioprocesses

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted

    2015-01-01

    The purpose of bioprocess control is to ensure that the plant operates as designed. This chapter presents the fundamental principles for control of biochemical processes. Through examples, the selection of manipulated and controlled variables in the classical reactor configurations is discussed, so...... are control objectives and the challenges in obtaining good control of the bioreactor. The objective of this chapter is to discuss the bioreactor control problems and to highlight some general traits that distinguish operation of bioprocesses from operation of processes in the conventional chemical process...... industries. It also provides a number of typical control loops for different objectives. A brief introduction to the general principles of process control, the PID control algorithm is discussed, and the design and effect of tuning are shown in an example. Finally, a discussion of novel, model-free control...

  4. Foundations Of Fuzzy Control

    DEFF Research Database (Denmark)

    Jantzen, Jan

    The objective of this textbook is to acquire an understanding of the behaviour of fuzzy logic controllers. Under certain conditions a fuzzy controller is equivalent to a proportional-integral-derivative (PID) controller. Using that equivalence as a link, the book applies analysis methods from...... linear and nonlinear control theory. In the linear domain, PID tuning methods and stability analyses are transferred to linear fuzzy controllers. The Nyquist plot shows the robustness of different settings of the fuzzy gain parameters. As a result, a fuzzy controller is guaranteed to perform as well...... as any PID controller. In the nonlinear domain, the stability of four standard control surfaces is analysed by means of describing functions and Nyquist plots. The self-organizing controller (SOC) is shown to be a model reference adaptive controller. There is a possibility that a nonlinear fuzzy PID...

  5. Reactor control device

    International Nuclear Information System (INIS)

    Kameda, Akiyuki.

    1979-01-01

    Purpose: To enable three types of controls, that is, level control, scram control and excess reactivity control required for a reactor by a same mechanism by feeding neutron absorber liquid and pressure control gas to several blind pipes provided in the reactor core. Constitution: A plurality of blind pipes are disposed spaced apart in a reactor core and connected by way of injection pipes to a neutron absorber liquid tank. A pressure regulator is connected to the blind pipes, to which pressure control gas is supplied. The neutron absorber liquid used herein consists of sodium, potassium or their alloy, or mercury as a basic substance incorporated with one or more selected from boron, tantalum, rhenium, europium or their compounds. The level control, scram control and excess reactivity control can be attained by moderating the pressure changes in the pressure control gas or by regulating the fluctuation in the liquid level. (Horiughi, T.)

  6. Applied predictive control

    CERN Document Server

    Sunan, Huang; Heng, Lee Tong

    2002-01-01

    The presence of considerable time delays in the dynamics of many industrial processes, leading to difficult problems in the associated closed-loop control systems, is a well-recognized phenomenon. The performance achievable in conventional feedback control systems can be significantly degraded if an industrial process has a relatively large time delay compared with the dominant time constant. Under these circumstances, advanced predictive control is necessary to improve the performance of the control system significantly. The book is a focused treatment of the subject matter, including the fundamentals and some state-of-the-art developments in the field of predictive control. Three main schemes for advanced predictive control are addressed in this book: • Smith Predictive Control; • Generalised Predictive Control; • a form of predictive control based on Finite Spectrum Assignment. A substantial part of the book addresses application issues in predictive control, providing several interesting case studie...

  7. Control rod drives

    International Nuclear Information System (INIS)

    Nakamura, Akira.

    1984-01-01

    Purpose: To enable to monitor the coupling state between a control rod and a control rod drive. Constitution: After the completion of a control rod withdrawal, a coolant pressure is applied to a control rod drive being adjusted so as to raise only the control rod drive and, in a case where the coupling between the control rod drive and the control rod is detached, the former is elevated till it contacts the control rod and then stopped. The actual stopping position is detected by an actual position detection circuit and compared with a predetermined position stored in a predetermined position detection circuit. If both of the positions are not aligned with each other, it is judged by a judging circuit that the control rod and the control rod drives are not combined. (Sekiya, K.)

  8. TFTR diagnostic vacuum controller

    International Nuclear Information System (INIS)

    Olsen, D.; Persons, R.

    1981-01-01

    The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller

  9. Trust and controlling

    OpenAIRE

    Bieńkowska Agnieszka; Zabłocka-Kluczka Anna

    2016-01-01

    The purpose of this study is to discuss the trust within and towards an organisation in the context of implementation of controlling therein. In this context the essence of trust and its importance in organisation management was presented, as well as trust in the contemporary management methods and concepts. Controlling as a trust-building factor inside an organisation was pointed out. Especially controlling and control were described. Moreover management by considering deviations in controll...

  10. Arduino based laser control

    OpenAIRE

    Bernal Muñoz, Ferran

    2015-01-01

    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  11. Pneumatic control technology

    International Nuclear Information System (INIS)

    Tae, Seong Gil; Kim, Won Hoe; Nam, Dae Hyun

    1993-03-01

    This book contains property of pneumatic pressure drive, pneumatic pressure device like air cleaning, pressure control, lubricators, air pressure pipe, kinds and function of pneumatic pressure equipment like pneumatic cylinders, pneumatic motor, flow control valve, direction control valve, design of pneumatic control circuit, pneumatic system design, cause and measurement of pneumatic circuit failure, PLC and pneumatic control like introduction and system application and method of PLC programing.

  12. Control rod drives

    International Nuclear Information System (INIS)

    Hayakawa, Hiroyasu.

    1979-01-01

    Purpose: To enable rapid control in a simple circuit by providing a motor control device having an electric capacity capable of simultaneously driving all of the control rods rapidly only in the inserting direction as well as a motor controlling device capable of fine control for the insertion and extraction at usual operation. Constitution: The control rod drives comprise a first motor control device capable of finely controlling the control rods both in inserting and extracting directions, a second motor control device capable of rapidly driving the control rods only in the inserting direction, and a first motor switching circuit and a second motor switching circuit switched by switches. Upon issue of a rapid insertion instruction for the control rods, the second motor switching circuit is closed by the switch and the second motor control circuit and driving motors are connected. Thus, each of the control rod driving motors is driven at a high speed in the inserting direction to rapidly insert all of the control rods. (Yoshino, Y.)

  13. SODR Memory Control Buffer Control ASIC

    Science.gov (United States)

    Hodson, Robert F.

    1994-01-01

    The Spacecraft Optical Disk Recorder (SODR) is a state of the art mass storage system for future NASA missions requiring high transmission rates and a large capacity storage system. This report covers the design and development of an SODR memory buffer control applications specific integrated circuit (ASIC). The memory buffer control ASIC has two primary functions: (1) buffering data to prevent loss of data during disk access times, (2) converting data formats from a high performance parallel interface format to a small computer systems interface format. Ten 144 p in, 50 MHz CMOS ASIC's were designed, fabricated and tested to implement the memory buffer control function.

  14. Controlling chaos in Internet congestion control model

    International Nuclear Information System (INIS)

    Chen Liang; Wang Xiaofan; Han Zhengzhi

    2004-01-01

    The TCP end-to-end congestion control plus RED router queue management can be modeled as a discrete-time dynamical system, which may create complex bifurcating and chaotic behavior. Based on the basic features of the TCP-RED model, we propose a time-dependent delayed feedback control algorithm to control chaos in the system by perturbing the accessible RED parameter p max . This method is able to stabilized a router queue occupancy at a level without knowing the exact knowledge of the network. Further, we study the situation of the presence of the UDP traffic

  15. Generic device controller for accelerator control systems

    International Nuclear Information System (INIS)

    Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.

    1987-01-01

    A new distributed intelligence control system has become operational at the AGS for transport, injection, and acceleration of heavy ions. A brief description of the functionality of the physical devices making up the system is given. An attempt has been made to integrate the devices for accelerator specific interfacing into a standard microprocessor system, namely, the Universal Device Controller (UDC). The main goals for such a generic device controller are to provide: local computing power; flexibility to configure; and real time event handling. The UDC assemblies and software are described

  16. Controlling chaos in Internet congestion control model

    Energy Technology Data Exchange (ETDEWEB)

    Chen Liang E-mail: chenmoon110@yahoo.com.cn; Wang Xiaofan; Han Zhengzhi

    2004-07-01

    The TCP end-to-end congestion control plus RED router queue management can be modeled as a discrete-time dynamical system, which may create complex bifurcating and chaotic behavior. Based on the basic features of the TCP-RED model, we propose a time-dependent delayed feedback control algorithm to control chaos in the system by perturbing the accessible RED parameter p{sub max}. This method is able to stabilized a router queue occupancy at a level without knowing the exact knowledge of the network. Further, we study the situation of the presence of the UDP traffic.

  17. Vehicle Dynamics and Control

    CERN Document Server

    Rajamani, Rajesh

    2012-01-01

    Vehicle Dynamics and Control provides a comprehensive coverage of vehicle control systems and the dynamic models used in the development of these control systems. The control system applications covered in the book include cruise control, adaptive cruise control, ABS, automated lane keeping, automated highway systems, yaw stability control, engine control, passive, active and semi-active suspensions, tire-road friction coefficient estimation, rollover prevention, and hybrid electric vehicle. In developing the dynamic model for each application, an effort is made to both keep the model simple enough for control system design but at the same time rich enough to capture the essential features of the dynamics. A special effort has been made to explain the several different tire models commonly used in literature and to interpret them physically. In the second edition of the book, chapters on roll dynamics, rollover prevention and hybrid electric vehicles have been added, and the chapter on electronic stability co...

  18. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Søren

    This paper focuses on the leadership challenge of balancing trust and control. The relation between trust and control has for a long time been a puzzling issue for management researchers. In the paper I first show that there has been a dramatic change in the way the relation between trust...... and control has been conceptualized in trust research. While the relation between trust and control earlier was conceptualized as a more or less stable balance between trust and control, more recent research conceptualizes the relation between trust and control more as a dynamical process that involves...... an ongoing process of balancing the relation between trust and control. Second, taking the departure in the recent conceptualization of the balance between trust and control as an interactive process I discuss the challenges for management in handling this more subtle balancing of trust and control...

  19. CAMAC multipurpose microprocessor controller

    International Nuclear Information System (INIS)

    Belyakova, M.P.; Nemesh, T.; Buj Zoan Chong.

    1978-01-01

    The use of CAMAC controllers in an autonomous system of data acquisition and measurement is considered. The system consists of a control intelligence controller, memory modules, and user modules in the CAMAC standard. The controller and all the modules have an output into the highway and this permits to exchange data among them without using special external cables. To increase the servicing rate, an auxiliary controller which has direct access to memory and controls the user modules, is additionally connected to the data acquisition and measurement system. In this case, the intelligence controller is passive. The system of data acquisition can be realized in the form of a multiple system with branch usage. The controller module width is three units, and the controller incorporates the Intel-8080-type microprocessor and the following interfaces: of CAMAC highways, of interruption, of memory bootstrap, and of data sequence channel

  20. Control rod shutdown system

    International Nuclear Information System (INIS)

    Miyamoto, Yoshiyuki; Higashigawa, Yuichi.

    1996-01-01

    The present invention provides a control rod terminating system in a BWR type nuclear power plant, which stops an induction electric motor as rapidly as possible to terminate the control rods. Namely, the control rod stopping system controls reactor power by inserting/withdrawing control rods into a reactor by driving them by the induction electric motor. The system is provided with a control device for controlling the control rods and a control device for controlling the braking device. The control device outputs a braking operation signal for actuating the braking device during operation of the control rods to stop the operation of the control rods. Further, the braking device has at least two kinds of breaks, namely, a first and a second brakes. The two kinds of brakes are actuated by receiving the brake operation signals at different timings. The brake device is used also for keeping the control rods after the stopping. Even if a stopping torque of each of the breaks is small, different two kinds of brakes are operated at different timings thereby capable of obtaining a large stopping torque as a total. (I.S.)

  1. Plasma position control device

    International Nuclear Information System (INIS)

    Takase, Haruhiko.

    1987-01-01

    Purpose: To conduct position control stably to various plasmas and reduce the burden on the control coil power source. Constitution: Among the proportional, integration and differentiation controls, a proportional-differentiation control section and an integration control section are connected in parallel. Then, a signal switching circuit is disposed to the control signal input section for the proportional-differentiation control section such that either a present position of plasmas or deviation between the present plasma position and an aimed value can be selected as a control signal depending on the control procedures or the state of the plasmas. For instance, if a rapid response is required for the control, the deviation between the present plasma position and the aimed value is selected as the input signal to conduct proportional, integration and differentiation controls. While on the other hand, if it is intended to reduce the burden on the control coil power source, it is adapted such that the control signal inputted to the proportional-differentiation control section itself can select the present plasma position. (Yoshihara, H.)

  2. Control rod assembly

    International Nuclear Information System (INIS)

    Takahashi, Akio.

    1982-01-01

    Purpose: To enable reliable insertion and drops of control rods, as well as insure a sufficient flow rate of coolants flowing through the control rods for attaining satisfactory cooling thereof to enable relexation of thermal stress resulted to rectifying mechanisms or the likes. Constitution: To the outer circumference of a control rod contained vertically movably within a control rod guide tube, resistive members are retractably provided in such a way as to project to close the gap between outer circumference of the control rod and the inner surface of the control rod guide tube upon engagement of a gripper of control rod drives, and retract upon release of the engagement of the gripper. Thus, since the resistive members project to provide a greater resistance to the coolants flowing between them and the control rod guide tube in the normal operation where the gripper is engaged to drive the control rod by the control rod drives, a major part of the coolant flowing into the control rod guide tube flows into the control rod. This enables to cool the control rod effectively and make the temperature distribution uniform for the coolant flowing from the upper end of the control rod guide tube to thereby attain the relaxation of the thermal stress resulted in the rectifying mechanisms or the likes. (Moriyama, K.)

  3. Control rod displacement

    International Nuclear Information System (INIS)

    Nakazato, S.

    1987-01-01

    This patent describes a nuclear reactor including a core, cylindrical control rods, a single support means supporting the control rods from their upper ends in spaced apart positions and movable for displacing the control rods in their longitudinal direction between a first end position in which the control rods are fully inserted into the core and a second end position in which the control rods are retracted from the core, and guide means contacting discrete regions of the outer surface of each control rod at least when the control rods are in the vicinity of the second end position. The control rods are supported by the support means for longitudinal movement without rotation into and out of the core relative to the guide means to thereby cause the outer surface of the control rods to experience wear as a result of sliding contact with the guide means. The support means are so arranged with respect to the core and the guide means that it is incapable of rotation relative to the guide means. The improvement comprises displacement means being operatively coupled to a respective one of the control rods for periodically rotating the control rod in a single angular direction through an angle selected to change the locations on the outer surfaces of the control rods at which the control rods are contacted by the guide means during subsequent longitudinal movement of the control rods

  4. Intelligent control-III: fuzzy control system

    International Nuclear Information System (INIS)

    Nagrial, M.H.

    2004-01-01

    During the last decade or so, fuzzy logic control (FLC) has emerged as one of the most active and fruitful areas of research and development. The applications include industrial process control to medical diagnostic and financial markets. Many consumer products using this technology are available in the market place. FLC is best suited to complex ill-defined processes that can be controlled by a skilled human operator without much knowledge of their underlying dynamics. This lecture will cover the basic architecture and the design methodology of fuzzy logic controllers. FLC will be strongly based on the concepts of fuzzy set theory, introduced in first lecture. Some practical applications will also be discussed and presented. (author)

  5. Control and automation systems

    International Nuclear Information System (INIS)

    Schmidt, R.; Zillich, H.

    1986-01-01

    A survey is given of the development of control and automation systems for energy uses. General remarks about control and automation schemes are followed by a description of modern process control systems along with process control processes as such. After discussing the particular process control requirements of nuclear power plants the paper deals with the reliability and availability of process control systems and refers to computerized simulation processes. The subsequent paragraphs are dedicated to descriptions of the operating floor, ergonomic conditions, existing systems, flue gas desulfurization systems, the electromagnetic influences on digital circuits as well as of light wave uses. (HAG) [de

  6. Electricity sequence control

    International Nuclear Information System (INIS)

    Shin, Heung Ryeol

    2010-03-01

    The contents of the book are introduction of control system, like classification and control signal, introduction of electricity power switch, such as push-button and detection switch sensor for induction type and capacitance type machinery for control, solenoid valve, expression of sequence and type of electricity circuit about using diagram, time chart, marking and term, logic circuit like Yes, No, and, or and equivalence logic, basic electricity circuit, electricity sequence control, added condition, special program control about choice and jump of program, motor control, extra circuit on repeat circuit, pause circuit in a conveyer, safety regulations and rule about classification of electricity disaster and protective device for insulation.

  7. VOC emissions control systems

    International Nuclear Information System (INIS)

    Spessard, J.E.

    1993-01-01

    The air pollution control equipment marketplace offers many competing technologies for controlling emissions of volatile organic compounds (VOC) in air. If any technology was economically and technically superior under all conditions, it would be the only one on the market. In fact, each technology used to control VOCs is superior under some set of conditions. The reasons for choosing one control technology over another are situation-specific. Some general guidelines to VOC control technologies and the situations where each may be appropriate are presented in this article. The control technologies and applications are summarized in a table

  8. Programmable Digital Controller

    Science.gov (United States)

    Wassick, Gregory J.

    2012-01-01

    An existing three-channel analog servo loop controller has been redesigned for piezoelectric-transducer-based (PZT-based) etalon control applications to a digital servo loop controller. This change offers several improvements over the previous analog controller, including software control over proportional-integral-derivative (PID) parameters, inclusion of other data of interest such as temperature and pressure in the control laws, improved ability to compensate for PZT hysteresis and mechanical mount fluctuations, ability to provide pre-programmed scanning and stepping routines, improved user interface, expanded data acquisition, and reduced size, weight, and power.

  9. Robot welding process control

    Science.gov (United States)

    Romine, Peter L.

    1991-01-01

    This final report documents the development and installation of software and hardware for Robotic Welding Process Control. Primary emphasis is on serial communications between the CYRO 750 robotic welder, Heurikon minicomputer running Hunter & Ready VRTX, and an IBM PC/AT, for offline programming and control and closed-loop welding control. The requirements for completion of the implementation of the Rocketdyne weld tracking control are discussed. The procedure for downloading programs from the Intergraph, over the network, is discussed. Conclusions are made on the results of this task, and recommendations are made for efficient implementation of communications, weld process control development, and advanced process control procedures using the Heurikon.

  10. Control system design method

    Science.gov (United States)

    Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  11. Robust Self Tuning Controllers

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad

    1985-01-01

    The present thesis concerns robustness properties of adaptive controllers. It is addressed to methods for robustifying self tuning controllers with respect to abrupt changes in the plant parameters. In the thesis an algorithm for estimating abruptly changing parameters is presented. The estimator...... has several operation modes and a detector for controlling the mode. A special self tuning controller has been developed to regulate plant with changing time delay.......The present thesis concerns robustness properties of adaptive controllers. It is addressed to methods for robustifying self tuning controllers with respect to abrupt changes in the plant parameters. In the thesis an algorithm for estimating abruptly changing parameters is presented. The estimator...

  12. Control integral systems; Sistemas integrales de control

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Estrella [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1999-12-31

    Almost two third of the electric power generation in Mexico are obtained from hydrocarbons, for that reasons Comision Federal de Electricidad (CFE) dedicated special commitment in modernizing the operation of fossil fuel central stations. In attaining this objective the control systems play a fundamental roll, from them depend a good share of the reliability and the efficiency of the electric power generation process, as well as the extension of the equipment useful life. Since 1984 the Instituto de Investigaciones Electricas (IIE) has been working, upon the request of CFE, on the development of digital control systems. To date it has designed and implemented a logic control system for gas burners, which controls 32 burners of the Unit 4 boiler of the Generation Central of Valle de Mexico and two systems for distributed control for two combined cycle central stations, which are: Dos Bocas, Veracruz Combined cycle central, and Gomez Palacio, Durango combined cycle central. With these two developments the IIE enters the World tendency of implementing distributed control systems for the fossil fuel power central update [Espanol] Casi las dos terceras partes de la generacion electrica en Mexico se obtienen a partir de hidrocarburos, es por eso que la Comision Federal de Electricidad (CFE) puso especial empeno en modernizar la operacion de las centrales termoelectricas de combustibles fosiles. En el logro de este objetivo los sistemas de control desempenan un papel fundamental, de ellos depende una buena parte la confiabilidad y la eficiencia en el proceso de generacion de energia electrica, asi como la prolongacion de la vida util de los equipos. Desde 1984 el Instituto de Investigaciones Electricas (IIE) ha trabajado, a solicitud de la CFE, en el desarrollo de sistemas digitales de control. A la fecha se han disenado e implantado un sistema de control logico de quemadores de gas, el cual controla 32 quemadores de la caldera de la unidad 4 de la central de generacion

  13. Control integral systems; Sistemas integrales de control

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Estrella [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    Almost two third of the electric power generation in Mexico are obtained from hydrocarbons, for that reasons Comision Federal de Electricidad (CFE) dedicated special commitment in modernizing the operation of fossil fuel central stations. In attaining this objective the control systems play a fundamental roll, from them depend a good share of the reliability and the efficiency of the electric power generation process, as well as the extension of the equipment useful life. Since 1984 the Instituto de Investigaciones Electricas (IIE) has been working, upon the request of CFE, on the development of digital control systems. To date it has designed and implemented a logic control system for gas burners, which controls 32 burners of the Unit 4 boiler of the Generation Central of Valle de Mexico and two systems for distributed control for two combined cycle central stations, which are: Dos Bocas, Veracruz Combined cycle central, and Gomez Palacio, Durango combined cycle central. With these two developments the IIE enters the World tendency of implementing distributed control systems for the fossil fuel power central update [Espanol] Casi las dos terceras partes de la generacion electrica en Mexico se obtienen a partir de hidrocarburos, es por eso que la Comision Federal de Electricidad (CFE) puso especial empeno en modernizar la operacion de las centrales termoelectricas de combustibles fosiles. En el logro de este objetivo los sistemas de control desempenan un papel fundamental, de ellos depende una buena parte la confiabilidad y la eficiencia en el proceso de generacion de energia electrica, asi como la prolongacion de la vida util de los equipos. Desde 1984 el Instituto de Investigaciones Electricas (IIE) ha trabajado, a solicitud de la CFE, en el desarrollo de sistemas digitales de control. A la fecha se han disenado e implantado un sistema de control logico de quemadores de gas, el cual controla 32 quemadores de la caldera de la unidad 4 de la central de generacion

  14. Embedded controllers for local board-control

    CERN Document Server

    Neufeld, Niko; Mini, Giuseppe; Sannino, Mario; Guzik, Zbigniew; Jacobsson, Richard; Jost, Beat

    2005-01-01

    The LHCb experiment at CERN has a large number of custom electronic boards performing high-speed data-processing. Like in any large experiment the control and monitoring of these crate-mounted boards must be integrated into the overall control-system. Traditionally this has been done by using buses like VME on the back-plane of the crates. LHCb has chosen to equip every board with an embedded micro-controller and connecting them in a large Local Area Network. The intelligence of these devices allows complex (soft) real-time control and monitoring, required for modern powerful FPGA driven electronics. Moreover each board has its own, isolated control access path, which increases the robustness of the entire system. The system is now in pre-production at several sites and will go into full production during next year. The hardware and software will be discussed and experiences from the R&D and pre-production will be reviewed, with an emphasis on advantages and difficulties of this approach to board-control.

  15. Advanced Emissions Control Development Program: Mercury Control

    International Nuclear Information System (INIS)

    Evans, A.P.; Redinger, K.W.; Holmes, M.J.

    1997-07-01

    McDermott Technology, Inc. (a subsidiary of Babcock ampersand Wilcox) is conducting the Advanced Emissions Control Development Project (AECDP) which is aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (HAPS) from coal-fired electric utility plants. The need for such controls may arise as the US Environmental Protection Agency (EPA) proceeds with implementation of requirements set forth in the Clean Air Act Amendments (CAAA's) of 1990. Promulgation of air toxics emissions regulations for electric utility plants could dramatically impact utilities burning coal, their industrial and residential customers, and the coal industry. AECDP project work will supply the information needed by utilities to respond to potential HAPs regulations in a timely, cost-effective, enviromnentally-sound manner which supports the continued use of the Nation's abundant reserves of coal, such as those in the State of Ohio. The development work is being carried out using the 10 MW Clean Environment Development Facility wherein air toxics emissions control strategies can be developed under controlled conditions. The specific objectives of the project are to (1) measure and understand production and partitioning of air toxics species for a variety of coals, (2) optimize the air toxics removal performance of conventional flue gas cleanup systems, (3) develop advanced air toxics emissions control concepts, (4) develop and validate air toxics emissions measurement and monitoring techniques, and (5) establish a comprehensive, self-consistent air toxics data library. This project is supported by the Department of Energy, the Ohio Coal Development Office within the Ohio Department of Development and Babcock ampersand Wilcox. A comprehensive assessment of HAP emissions from coal-fired electric utility boilers sponsored by the Department of Energy and the Electric Power Research Institute concluded that with the exception of

  16. Control room design

    International Nuclear Information System (INIS)

    Zinke, H.

    1980-01-01

    To control a 1300 megawatt nuclear power plant, about 15000 plant parameters must be collected together to control and operate the plant. The control room design therefore is of particular importance. The main design criteria are: Required functions of the power plant process - Level of Automation - Ergonomics - Available Technology. Extensive analysis has resulted in a control room design method. This ensures that an objective solution will be reached. Resulting from this methodical approach are: 1. Scope, position and appearance of the instrumentation. 2. Scope, position and appearance of the operator controls. Process analysis dictates what instrumentation and operator controls are needed. The priority and importance of the control and instrumentation (this we define as the utilisation areas), dictates the rough layout of the control room. (orig./RW)

  17. Intelligent Mission Controller Node

    National Research Council Canada - National Science Library

    Perme, David

    2002-01-01

    The goal of the Intelligent Mission Controller Node (IMCN) project was to improve the process of translating mission taskings between real-world Command, Control, Communications, Computers, and Intelligence (C41...

  18. NGS Survey Control Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Survey Control Map provides a map of the US which allows you to find and display geodetic survey control points stored in the database of the National...

  19. Method of controlling reactivity

    International Nuclear Information System (INIS)

    Tochihara, Hiroshi.

    1982-01-01

    Purpose: To improve the reactivity controlling characteristics by artificially controlling the leakage of neutron from a reactor and providing a controller for controlling the reactivity. Method: A reactor core is divided into several water gaps to increase the leakage of neutron, its reactivity is reduced, a gas-filled control rod or a fuel assembly is inserted into the gap as required, the entire core is coupled in a system to reduce the leakage of the neutron, and the reactivity is increased. The reactor shutdown is conducted by the conventional control rod, and to maintain critical state, boron density varying system is used together. Futher, a control rod drive is used with that similar to the conventional one, thereby enabling fast reactivity variation, and the positive reactivity can be obtained by the insertion, thereby improving the reactivity controlling characteristics. (Yoshihara, H.)

  20. The remote control system

    International Nuclear Information System (INIS)

    Jansweijer, P.P.M.

    1988-01-01

    The remote-control system is applied in order to control various signals in the car of the spectrometer at distance. The construction (hardware and software) as well as the operation of the system is described. (author). 20 figs

  1. Systems and Control Engineering

    Indian Academy of Sciences (India)

    activities directed towards the students and the general public. Designed .... attention has been directed towards the use of control and automation to mitigate the effects of those ... The history of automatic control can be divided into four main.

  2. A modular control system

    International Nuclear Information System (INIS)

    Cruz, B.; Drexler, J.; Olcese, G.; Santome, D.

    1990-01-01

    The main objective of the modular control system is to provide the requirements to most of the processes supervision and control applications within the industrial automatization area. The design is based on distribution, modulation and expansion concepts. (Author) [es

  3. Birth Control Shot

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Shot KidsHealth / For Teens / Birth Control Shot What's ...

  4. Birth Control Ring

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

  5. Birth Control Pill

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Pill KidsHealth / For Teens / Birth Control Pill What's ...

  6. Birth Control Patch

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Patch KidsHealth / For Teens / Birth Control Patch What's ...

  7. Birth control pills overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002599.htm Birth control pill overdose To use the sharing features on ... the medicine was prescribed for the person Poison Control Your local poison center can be reached directly ...

  8. Poison Control Centers

    Science.gov (United States)

    ... 1222 immediately. Name State American Association of Poison Control Centers Address AAPCC Central Office NOT A POISON ... not for emergency use. Arkansas ASPCA Animal Poison Control Center Address 1717 S. Philo Road, Suite 36 Urbana, ...

  9. Cholera Prevention and Control

    Science.gov (United States)

    ... name=”commit” type=”submit” value=”Submit” /> Prevention & Control Recommend on Facebook Tweet Share Compartir Prevention of ... of cholera and other diarrheal disease prevention. Prevention & Control Topics Ending Cholera: The Global Roadmap to 2030 ...

  10. SPECT quality control tests

    International Nuclear Information System (INIS)

    Robilotta, C.C.; Rebelo, M.F.S.; Oliveira, M.A.; Abe, R.

    1987-01-01

    Quality control tests of tomographic system composed by a rotatory chamber (CGR Gammatomome T-9000) and a microcomputer are presented. Traditional quality control tests for scintilation chambers and specific tests for tomographic systems are reported. (M.A.C.) [pt

  11. Identification for Control

    DEFF Research Database (Denmark)

    Tøffner-Clausen, S.

    1995-01-01

    Identification of model error bounds for robust control design has recently achieved much attention.......Identification of model error bounds for robust control design has recently achieved much attention....

  12. The LHCb Run Control

    CERN Document Server

    Alessio, F; Callot, O; Duval, P-Y; Franek, B; Frank, M; Galli, D; Gaspar, C; v Herwijnen, E; Jacobsson, R; Jost, B; Neufeld, N; Sambade, A; Schwemmer, R; Somogyi, P

    2010-01-01

    LHCb has designed and implemented an integrated Experiment Control System. The Control System uses the same concepts and the same tools to control and monitor all parts of the experiment: the Data Acquisition System, the Timing and the Trigger Systems, the High Level Trigger Farm, the Detector Control System, the Experiment's Infrastructure and the interaction with the CERN Technical Services and the Accelerator. LHCb's Run Control, the main interface used by the experiment's operator, provides access in a hierarchical, coherent and homogeneous manner to all areas of the experiment and to all its sub-detectors. It allows for automated (or manual) configuration and control, including error recovery, of the full experiment in its different running modes. Different instances of the same Run Control interface are used by the various sub-detectors for their stand-alone activities: test runs, calibration runs, etc. The architecture and the tools used to build the control system, the guidelines and components provid...

  13. Fine motor control

    Science.gov (United States)

    ... gross (large, general) motor control. An example of gross motor control is waving an arm in greeting. Problems ... out the child's developmental age. Children develop fine motor skills over time, by practicing and being taught. To ...

  14. Cell Control Engineering

    DEFF Research Database (Denmark)

    Lynggaard, Hans Jørgen Birk; Alting, Leo

    1996-01-01

    The engineering process of creating cell control systems is described, and a Cell Control Engineering (CCE) concept is defined. The purpose is to assist people, representing different disciplines in the organisation, to implement cell controllers by addressing the complexity of having many systems...... in physically and logically different and changing manufacturing environments. The defined CCE concept combines state-of-the-art of commercially available enabling technologies for automation system software development, generic cell control models and guidelines for the complete engineering process...

  15. System for controlling apnea

    Science.gov (United States)

    Holzrichter, John F

    2015-05-05

    An implanted stimulation device or air control device are activated by an external radar-like sensor for controlling apnea. The radar-like sensor senses the closure of the air flow cavity, and associated control circuitry signals (1) a stimulator to cause muscles to open the air passage way that is closing or closed or (2) an air control device to open the air passage way that is closing or closed.

  16. Strategies for humidity control

    Energy Technology Data Exchange (ETDEWEB)

    Baumgarth, S

    1987-01-01

    Humidity and temperature control in air-conditioning systems mostly involves coupled closed-loop control circuits. The author discusses their uncoupling and resulting consequences as well as energy-optimized control of recirculation air flaps or enthalpy recovering systems (h-x control) in detail. Special reference is made of the application of the DDC technology and its scope, limits and preconditions. In conclusions, the author presents pertinent measurement results. (orig.).

  17. Defining Quantum Control Flow

    OpenAIRE

    Ying, Mingsheng; Yu, Nengkun; Feng, Yuan

    2012-01-01

    A remarkable difference between quantum and classical programs is that the control flow of the former can be either classical or quantum. One of the key issues in the theory of quantum programming languages is defining and understanding quantum control flow. A functional language with quantum control flow was defined by Altenkirch and Grattage [\\textit{Proc. LICS'05}, pp. 249-258]. This paper extends their work, and we introduce a general quantum control structure by defining three new quantu...

  18. Quality control in radiotherapy

    International Nuclear Information System (INIS)

    Batalla, A.

    2009-01-01

    The authors discuss the modalities and periodicities of internal quality control on radiotherapy installations. They indicate the different concerned systems and the aspects and items to be controlled (patient and personnel security, apparatus mechanical characteristics, beam quality, image quality, isodose and irradiation duration calculation, data transfer). They present the measurement instruments and tools used for the mechanical controls, dose measurement, beam homogeneity and symmetry, anatomic data acquisition systems, and dose distribution and control imagery calculation

  19. Fuzzy Control Tutorial

    DEFF Research Database (Denmark)

    Dotoli, M.; Jantzen, Jan

    1999-01-01

    The tutorial concerns automatic control of an inverted pendulum, especially rule based control by means of fuzzy logic. A ball balancer, implemented in a software simulator in Matlab, is used as a practical case study. The objectives of the tutorial are to teach the basics of fuzzy control......, and to show how to apply fuzzy logic in automatic control. The tutorial is distance learning, where students interact one-to-one with the teacher using e-mail....

  20. Control rod velocity limiter

    International Nuclear Information System (INIS)

    Cearley, J.E.; Carruth, J.C.; Dixon, R.C.; Spencer, S.S.; Zuloaga, J.A. Jr.

    1986-01-01

    This patent describes a velocity control arrangement for a reciprocable, vertically oriented control rod for use in a nuclear reactor in a fluid medium, the control rod including a drive hub secured to and extending from one end therefrom. The control device comprises: a toroidally shaped control member spaced from and coaxially positioned around the hub and secured thereto by a plurality of spaced radial webs thereby providing an annular passage for fluid intermediate the hub and the toroidal member spaced therefrom in coaxial position. The side of the control member toward the control rod has a smooth generally conical surface. The side of the control member away from the control rod is formed with a concave surface constituting a single annular groove. The device also comprises inner and outer annular vanes radially spaced from one another and spaced from the side of the control member away from the control rod and positioned coaxially around and spaced from the hub and secured thereto by spaced radial webs thereby providing an annular passage for fluid intermediate the hub and the vanes. The vanes are angled toward the control member, the outer edge of the inner vane being closer to the control member and the inner edge of the outer vane being closer to the control member. When the control rod moves in the fluid in the direction toward the drive hub the vanes direct a flow of fluid turbulence which provides greater resistance to movement of the control rod in the direction toward the drive hub than in the other direction

  1. Tokamak control simulator

    International Nuclear Information System (INIS)

    Edelbaum, T.N.; Serben, S.; Var, R.E.

    1976-01-01

    A computer model of a tokamak experimental power reactor and its control system is being constructed. This simulator will allow the exploration of various open loop and closed loop strategies for reactor control. This paper provides a brief description of the simulator and some of the potential control problems associated with this class of tokamaks

  2. Reactor control system. PWR

    International Nuclear Information System (INIS)

    2009-01-01

    At present, 23 units of PWR type reactors have been operated in Japan since the start of Mihama Unit 1 operation in 1970 and various improvements have been made to upgrade operability of power stations as well as reliability and safety of power plants. As the share of nuclear power increases, further improvements of operating performance such as load following capability will be requested for power stations with more reliable and safer operation. This article outlined the reactor control system of PWR type reactors and described the control performance of power plants realized with those systems. The PWR control system is characterized that the turbine power is automatic or manually controlled with request of the electric power system and then the nuclear power is followingly controlled with the change of core reactivity. The system mainly consists of reactor automatic control system (control rod control system), pressurizer pressure control system, pressurizer water level control system, steam generator water level control system and turbine bypass control system. (T. Tanaka)

  3. Process control program development

    International Nuclear Information System (INIS)

    Dameron, H.J.

    1985-01-01

    This paper details the development and implementation of a ''Process Control Program'' at Duke Power's three nuclear stations - Oconee, McGuire, and Catawba. Each station is required by Technical Specification to have a ''Process Control Program'' (PCP) to control all dewatering and/or solidification activities for radioactive wastes

  4. Adaptive LQG controller tuning

    Czech Academy of Sciences Publication Activity Database

    Novák, Miroslav; Böhm, Josef; Nedoma, Petr; Tesař, Ludvík

    2003-01-01

    Roč. 150, č. 6 (2003), s. 655-665 ISSN 1350-2379 R&D Projects: GA ČR GA102/02/0204; GA AV ČR IBS1075102 Institutional research plan: CEZ:AV0Z1075907 Keywords : adaptive controller * LQG controller * controller design Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 0.745, year: 2003

  5. Survivability via Control Objectives

    Energy Technology Data Exchange (ETDEWEB)

    CAMPBELL,PHILIP L.

    2000-08-11

    Control objectives open an additional front in the survivability battle. A given set of control objectives is valuable if it represents good practices, it is complete (it covers all the necessary areas), and it is auditable. CobiT and BS 7799 are two examples of control objective sets.

  6. Worldwide Report, Arms Control

    Science.gov (United States)

    1985-09-21

    Intersoft- ware, Logic Control Control y Aplicaciones , Dielsa, Eliop, EISA, Sainco CTNE, Fagor Electronica, Standard CTNE, Fagor Electronica, Piher...regulation systems Industrial turbine of advanced design Alfa Sewing Machines Control y Aplicaciones , Danobat, Etxe-Tar C02, CO and ultraviolet lasers

  7. FFTF control system experience

    International Nuclear Information System (INIS)

    Warrick, R.P.

    1981-01-01

    The FFTF control systems provide control equipment for safe and efficient operation of the plant. For convenience, these systems will be divided into three parts for discussions: (1) Plant Protection System (PPS); (2) Plant Control System (PCS); and (3) General Observations. Performance of each of these systems is discussed

  8. Atomic Energy Control Act

    International Nuclear Information System (INIS)

    1970-01-01

    This act provides for the establishment of the Atomic Energy Control Board. The board is responsible for the control and supervision of the development, application and use of atomic energy. The board is also considered necessary to enable Canada to participate effectively in measures of international control of atomic energy

  9. Quality control of radiopharmaceuticals

    International Nuclear Information System (INIS)

    Verdera, E.S.

    1994-01-01

    The quality control of radiopharmaceuticals is based in physics, physics-chemical and biological controls. Between the different controls can be enumerated the following: visual aspect,side, number of particle beams,activity,purity,ph,isotonicity,sterility,radioinmunoessay,toxicity,stability and clinical essay

  10. Optimisation of load control

    International Nuclear Information System (INIS)

    Koponen, P.

    1998-01-01

    Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter

  11. Fluid control valves

    International Nuclear Information System (INIS)

    Rankin, J.

    1980-01-01

    A fluid control valve is described in which it is not necessary to insert a hand or a tool into the housing to remove the valve seat. Such a valve is particularly suitable for the control of radioactive fluids since maintenance by remote control is possible. (UK)

  12. Neutron generator control system

    International Nuclear Information System (INIS)

    Peelman, H.E.; Bridges, J.R.

    1981-01-01

    A method is described of controlling the neutron output of a neutron generator tube used in neutron well logging. The system operates by monitoring the target beam current and comparing a function of this current with a reference voltage level to develop a control signal used in a series regulator to control the replenisher current of the neutron generator tube. (U.K.)

  13. Optimisation of load control

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, P [VTT Energy, Espoo (Finland)

    1998-08-01

    Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter

  14. Distributed Power Flow Controller

    NARCIS (Netherlands)

    Yuan, Z.

    2010-01-01

    In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of

  15. Global marketing control

    NARCIS (Netherlands)

    John Rance; Galina Zhiltsova

    2009-01-01

    The reasoning issue of this work is to research and define the efficient methods of global marketing control. The report is focused on the following aspects: the importance of the control systems in global marketing environment, the relationship between planning and controlling, types and the

  16. Plasma control device

    International Nuclear Information System (INIS)

    Takase, Haruhiko.

    1987-01-01

    Purpose: To obtain the optimum controllability for the plasmas and the thermonuclear device by selectively executing control operation for proportion, integration and differentiation (PID) by first and second controllers respectively based on selection instruction signals. Constitution: Deviation between a vertical direction equilibrium position: Zp as the plasma status amount measured in a measuring section and an aimed value Zref thereof is inputted to a first PID selection controller. The first controller selectively executes one of the PID control operations in accordance with the first selection signal instruction instructed by a PID control operation instruction circuit. Further, Zp is also inputted to a second PID selection controller, which selectively executes one of the PID control operations in accordance with the second selection instruction signal in the same manner as in the first controller. The deviation amount u between operations signals u1 and u2 from the first and second PID selection controllers is inputted to a power source to thereby supply a predetermined current value to control coils that generate equilibrium magnetic fields for making the vertical direction equilibrium position of plasmas constant. (Kamimura, M.)

  17. Control of mitochondrial respiration

    NARCIS (Netherlands)

    Tager, J. M.; Wanders, R. J.; Groen, A. K.; Kunz, W.; Bohnensack, R.; Küster, U.; Letko, G.; Böhme, G.; Duszynski, J.; Wojtczak, L.

    1983-01-01

    The control theory of Kacser and Burns [in: Rate Control of Biological Processes (Davies, D.D. ed) pp. 65-104, Cambridge University Press, London, 1973] and Heinrich and Rapoport [Eur. J. Biochem. (1974) 42, 97-105] has been used to quantify the amount of control exerted by different steps on

  18. Microbial control of pollution

    Energy Technology Data Exchange (ETDEWEB)

    Fry, J C; Gadd, G M; Herbert, R A; Jones, C W; Watson-Craik, I A [eds.

    1992-01-01

    12 papers are presented on the microbial control of pollution. Topics covered include: bioremediation of oil spills; microbial control of heavy metal pollution; pollution control using microorganisms and magnetic separation; degradation of cyanide and nitriles; nitrogen removal from water and waste; and land reclamation and restoration.

  19. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...

  20. Optimal magnetic attitude control

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Markley, F.L.

    1999-01-01

    because control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis stabilization of a low earth orbit satellite. The problem of controlling the spacecraft attitude using only magnetic...

  1. Automobile control technology and traffic control

    Energy Technology Data Exchange (ETDEWEB)

    Takaba, Sadao [Univ. of Tokyo (Japan)

    1988-09-05

    In the field of automobile control technology, electronic was first adopted for the electronic fuel control as an answer to the exhaust gas regulations. The operations of the driving system, frame system or the automobile itself which is the combination of the two were optimized by adding sensors, computers, actuators, etc. to alleviate the burden of the driver, offering easier drivability and confortableness. For local driving control, measurement of distance up to obstacle has been practiced using the ultrasonic radar sensor. Research and development of microwave radar sensor have been carried out for years. Automatic driving has been a dream technology, and the study for the technology was started since early times. Remarkable progress was made recently in the navigation system for traffic control in wide area. New automobile traffic information communication and other systems are being developed. Historical description is made on the control and information systems for road transportation, dividing the period into the 1st, 2nd and 3rd generations. 10 references.

  2. Arbitrating Control of Control and Display Units

    Science.gov (United States)

    Sugden, Paul C.

    2007-01-01

    The ARINC 739 Switch is a computer program that arbitrates control of two multi-function control and display units (MCDUs) between (1) a commercial flight-management computer (FMC) and (2) NASA software used in research on transport aircraft. (MCDUs are the primary interfaces between pilots and FMCs on many commercial aircraft.) This program was recently redesigned into a software library that can be embedded in research application programs. As part of the redesign, this software was combined with software for creating custom pages of information to be displayed on a CDU. This software commands independent switching of the left (pilot s) and right (copilot s) MCDUs. For example, a custom CDU page can control the left CDU while the FMC controls the right CDU. The software uses menu keys to switch control of the CDU between the FMC or a custom CDU page. The software provides an interface that enables custom CDU pages to insert keystrokes into the FMC s CDU input interface. This feature allows the custom CDU pages to manipulate the FMC as if it were a pilot.

  3. Control rod drive

    International Nuclear Information System (INIS)

    Hawke, B.C.

    1986-01-01

    A reactor core, one or more control rods, and a control rod drive are described for selectively inserting and withdrawing the one or more control rods into and from the reactor core, which consists of: a support structure secured beneath the reactor core; control rod positioning means supported by the support structure for movably supporting the control rod for movement between a lower position wherein the control rod is located substantially beneath the reactor core and an upper position wherein at least an upper portion of the control rod extends into the reactor core; transmission means; primary drive means connected with the control rod positioning means by the transmission means for positioning the control rod under normal operating conditions; emergency drive means for moving the control rod from the lower position to the upper position under emergency conditions, the emergency drive means including a weight movable between an upper and a lower position, means for movably supporting the weight, and means for transmitting gravitational force exerted on the weight to the control rod positioning means to move the control rod upwardly when the weight is pulled downwardly by gravity; the transmission means connecting the control rod positioning means with the emergency drive means so that the primary drive means effects movement of the weight and the control rod in opposite directions under normal conditions, thus providing counterbalancing to reduce the force required for upward movement of the control rod under normal conditions; and restraint means for restraining the fall of the weight under normal operating conditions and disengaging the primary drive means to release the weight under emergency conditions

  4. Customs control of goods

    Directory of Open Access Journals (Sweden)

    Mentor Gashi

    2015-11-01

    Full Text Available Customs control, is regulated by law in different countries. Different countries define through the law, the control of goods.. Main purpose of this paper is to analyze two types of customs controls, and their effect in reducing avoidance of duty or tax evasion which may be caused by the import of goods of certain companies. For this reason we researched which model is implemented in developing countries and what results were reached through questionnaires. In this sense the next research question, consists in defining the moment of customs control pre or post-clearance control of goods.

  5. Internet congestion control

    CERN Document Server

    Varma, Subir

    2015-01-01

    Internet Congestion Control provides a description of some of the most important topics in the area of congestion control in computer networks, with special emphasis on the analytical modeling of congestion control algorithms. The field of congestion control has seen many notable advances in recent years and the purpose of this book, which is targeted towards the advanced and intermediate reader, is to inform about the most important developments in this area. The book should enable the reader to gain a good understanding of the application of congestion control theory to a number of applic

  6. [Controlling instruments in radiology].

    Science.gov (United States)

    Maurer, M

    2013-10-01

    Due to the rising costs and competitive pressures radiological clinics and practices are now facing, controlling instruments are gaining importance in the optimization of structures and processes of the various diagnostic examinations and interventional procedures. It will be shown how the use of selected controlling instruments can secure and improve the performance of radiological facilities. A definition of the concept of controlling will be provided. It will be shown which controlling instruments can be applied in radiological departments and practices. As an example, two of the controlling instruments, material cost analysis and benchmarking, will be illustrated.

  7. Span of control matters.

    Science.gov (United States)

    Cathcart, Deb; Jeska, Susan; Karnas, Joan; Miller, Sue E; Pechacek, Judy; Rheault, Lolita

    2004-09-01

    Prompted by manager concerns about span of control, a large, integrated health system set out to determine if span of control really mattered. Was there something to it, or was it just an excuse for poor performance? A team of middle managers studied the problem and ultimately demonstrated a strong relationship between span of control and employee engagement. Consequently, it was decided to add 4 management positions to note the effect. One year later, positive changes were observed in employee engagement scores in all 4 areas. This study suggests careful review of manager spans of control to address the untoward effects of large spans of control on employee engagement.

  8. Scheme of stepmotor control

    International Nuclear Information System (INIS)

    Grashilin, V.A.; Karyshev, Yu.Ya.

    1982-01-01

    A 6-cycle scheme of step motor is described. The block-diagram and the basic circuit of the step motor control are presented. The step motor control comprises a pulse shaper, electronic commutator and power amplifiers. The step motor supply from 6-cycle electronic commutator provides for higher reliability and accuracy than from 3-cycle commutator. The control of step motor work is realised by the program given by the external source of control signals. Time-dependent diagrams for step motor control are presented. The specifications of the step-motor is given

  9. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...... of the nominal feedback con-troller....

  10. Control rod drives

    International Nuclear Information System (INIS)

    Futatsugi, Masao.

    1980-01-01

    Purpose: To secure the reactor operation safety by the provision of a fluid pressure detecting section for control rod driving fluid and a control rod interlock at the midway of the flow pass for supplying driving fluid to the control rod drives. Constitution: Between a driving line and a direction control valve are provided a pressure detecting portion, an alarm generating device, and a control rod inhibition interlock. The driving fluid from a driving fluid source is discharged by way of a pump and a manual valve into the reactor in which the control rods and reactor fuels are contained. In addition, when the direction control valve is switched and the control rods are inserted and extracted by the control rod drives, the pressure in the driving line is always detected by the pressure detection section, whereby if abnormal pressure is resulted, the alarm generating device is actuated to warn the abnormality and the control rod inhibition interlock is actuated to lock the direction control valve thereby secure the safety operation of the reactor. (Seki, T.)

  11. A national control system

    International Nuclear Information System (INIS)

    Larsson, A.

    1975-01-01

    An effective control of nuclear fissionable material is dependent on three different kinds of control, the industry - laboratory management, a national control system and an international safeguards system. The national systems of control differ greatly between various industrialized countries. Two principal reasons for fact can be mentioned. The type and the amounts for nuclear material may be different depending upon the stage of development of the nuclear industry in the country in question. Another reason may be that the country may wish to establish a very elaborate national system of control in order to minimize the IAEA control as much as possible. The two safeguards agreements between the Agency and Sweden on one hand and the Agency and Japan on the other hand can serve as examples for the understanding of the latitude of the IAEA safeguards system under NPT due to the influence of the national control system. If it thus is apparent that the national control system is strongly interrelated to the international safeguards system it is equally influenced by the control and accountancy systems which exist at the nuclear plants and development laboratories. A detailed study of national control systems and their relations to plant management control would fall outside the scope of this article. Some important features will however be examined. (author)

  12. Control rod drive

    International Nuclear Information System (INIS)

    Okutani, Tetsuro.

    1988-01-01

    Purpose: To provide a simple and economical control rod drive using a control circuit requiring no pulse circuit. Constitution: Control rods in a BWR type reactor are driven by hydraulic pressure and inserted or withdrawn in the direction of applying the hydraulic pressure. The direction of the hydraulic pressure is controlled by a direction control valve. Since the driving for the control rod is extremely important in view of the operation, a self diagnosis function is disposed for rapid inspection of possible abnormality. In the present invention, two driving contacts are disposed each by one between the both ends of a solenoid valve of the direction control valve for driving the control rod and the driving power source, and diagnosis is conducted by alternately operating them. Therefore, since it is only necessary that the control circuit issues a driving instruction only to one of the two driving contacts, the pulse circuit is no more required. Further, since the control rod driving is conducted upon alignment of the two driving instructions, the reliability of the control rod drive can be improved. (Horiuchi, T.)

  13. Integrated Biological Control

    International Nuclear Information System (INIS)

    JOHNSON, A.R.

    2002-01-01

    Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects; and microorganisms such as molds that adversely affect the quality of the workplace environment). Biological control activities may be either preventive (apriori) or in response to existing contamination spread (aposteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and apriori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, aposteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response

  14. Control from the bridge

    International Nuclear Information System (INIS)

    Kesler, S.B.

    1986-01-01

    To improve the efficiency and to cut down on cost at the uranium mine at Roessing in SWA/Namibia, the control of all the various plants in the complex has been concentrated in one centralised control system. The processing of uranium ores is also discussed. The selection of future operators of the control system was made at the start of the project. Considerable effort went into conceptualising the role and skill requirements for their job, as well as into their training. The project was concluded in 1984. The original hardware installed in the central room was configured with two basic operating stations controlling the Uranium Plant and an additional station controlling the Acid Plant. Since full implementation of the central process control system, the uranium recovery has been significantly increased whilst tighter control of process parameters has enabled reductions to be made in consumable and utilities usage

  15. Controlling chaos faster

    International Nuclear Information System (INIS)

    Bick, Christian; Kolodziejski, Christoph; Timme, Marc

    2014-01-01

    Predictive feedback control is an easy-to-implement method to stabilize unknown unstable periodic orbits in chaotic dynamical systems. Predictive feedback control is severely limited because asymptotic convergence speed decreases with stronger instabilities which in turn are typical for larger target periods, rendering it harder to effectively stabilize periodic orbits of large period. Here, we study stalled chaos control, where the application of control is stalled to make use of the chaotic, uncontrolled dynamics, and introduce an adaptation paradigm to overcome this limitation and speed up convergence. This modified control scheme is not only capable of stabilizing more periodic orbits than the original predictive feedback control but also speeds up convergence for typical chaotic maps, as illustrated in both theory and application. The proposed adaptation scheme provides a way to tune parameters online, yielding a broadly applicable, fast chaos control that converges reliably, even for periodic orbits of large period

  16. Control rod drive mechanism

    International Nuclear Information System (INIS)

    Nakamura, Akira.

    1981-01-01

    Purpose: To ensure the scram operation of a control rod by the reliable detection for the position of control rods. Constitution: A permanent magnet is provided to the lower portion of a connecting rod in engagement with a control rod and a tube having a plurality of lead switches arranged axially therein in a predetermined pitch is disposed outside of the control rod drives. When the control rod moves upwardly in the scram operation, the lead switches are closed successively upon passage of the permanent magnet to operate the electrical circuit provided by way of each of the lead switches. Thus, the position for the control rod during the scram can reliably be determined and the scram characteristic of the control rod can be recognized. (Furukawa, Y.)

  17. Reactor control device

    International Nuclear Information System (INIS)

    Araki, Takao; Inoue, Toyokazu.

    1981-01-01

    Purpose: To protect the reactor floor by alleviating the shock imparted to the reactor floor by a dropped control rod when a wire rope accidentally breaks. Constitution: A control rod is hung by wire rope from a control rod drive, and shock absorbers are mounted at the upper and lower portions of the control rod. The outer diameter of the upper shock absorber is made larger than the inner diameter of a control rod inserting hole formed in the reactor core. If the control rod drops, the upper absorber is stopped at the upper tapered portion of the inserting hole. Thus, the dropping energy of the control rod can be sufficiently absorbed by the upper and lower shock absorbers. (Kamimura, M.)

  18. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Søren

    2010-01-01

    of balancing trust and control becomes an issue that deserve ongoing attention. This paper adds to the discussion on the relation between trust and control by showing that the process perspective reframes the problem of balancing trust and control. More generally, by demonstrating the importance of the process......The purpose of this paper is to show that conceptualizing trust and control as interactively related processes, as opposed to more static conceptualizations of the two concepts and the relations between them, adds importantly towards understanding the challenges involved in balancing of trust...... on trust and control made the problem of finding a balance between trust and control a once and for all decision the process perspective introduced here implies that balancing trust and control is an ongoing process of balancing and rebalancing. The implication for management is that the problem...

  19. Controllable Elastohydrodynamics With Examples

    DEFF Research Database (Denmark)

    Santos, Ilmar; Haugaard, Martin Asger

    dynamic properties. The actively controlled bearing surface profiles can be generated by attaching any kind of actuator (hydraulic, electromagnetic or piezoelectric) to deformable bushes. In this paper the elastohydrodynamic model is used to investigate static and dynamic properties of a tilting-pad......Due to the development of high performance rotating machinery, growing attention has been paid to the design of new active (mechatronic) devices able to actively control vibrations and improve its dynamic behavior, i.e. magnetic bearings piezoelectric bearing pushers, hydraulic actuator journal...... journal bearing under hybrid elastohydrodynamics (open loop control) as well as controllable radial oil injection (closed loop control). The bearing dynamic coefficients are heavily influenced by the control parameters and pad compliance. Strong synergy between elastohydrodynamics and active control...

  20. Elements on reactor control

    International Nuclear Information System (INIS)

    Bruna, G.B.

    1998-01-01

    In order to achieve the two-fold goal of maximizing the energy obtained from reactor fuel and ensuring the large flexibility of plant operation in respect to safety regulations and keeping the reactor integrity the control of PWRs is generally based on real time monitoring and analysing of independent neutronic parameters: thermal power release, axial power distribution in the core and temperatures of the primary loop. Two control chains more or less coupled according to the control chosen mode are in charge of the control of these parameters. With the brief history of control in French power reactors the advanced X control mode adopted by Framatome for N4 plants is described in detail. A summary of N4 reactor control and protection system is included

  1. Integrated control systems

    International Nuclear Information System (INIS)

    Smith, D.J.

    1991-01-01

    This paper reports that instrument manufacturers must develop standard network interfaces to pull together interrelated systems such as automatic start-up, optimization programs, and online diagnostic systems. In the past individual control system manufacturers have developed their own data highways with proprietary hardware and software designs. In the future, electric utilities will require that future systems, irrespective of manufacturer, should be able to communicate with each other. Until now the manufactures of control systems have not agreed on the standard high-speed data highway system. Currently, the Electric Power Research Institute (EPRI), in conjunction with several electric utilities and equipment manufactures, is working on developing a standard protocol for communicating between various manufacturers' control systems. According to N. Michael of Sargent and Lundy, future control room designs will require that more of the control and display functions be accessible from the control room through CRTs. There will be less emphasis on traditional hard-wired control panels

  2. Trust and controlling

    Directory of Open Access Journals (Sweden)

    Bieńkowska Agnieszka

    2016-12-01

    Full Text Available The purpose of this study is to discuss the trust within and towards an organisation in the context of implementation of controlling therein. In this context the essence of trust and its importance in organisation management was presented, as well as trust in the contemporary management methods and concepts. Controlling as a trust-building factor inside an organisation was pointed out. Especially controlling and control were described. Moreover management by considering deviations in controlling and the teamwork in controlling were described. The role of controlling in process of trust-building to an organisation was presented. Establishing relations with the environment and systems of measurement of organisation’s achievements were presented, too.

  3. Controlling chaos faster.

    Science.gov (United States)

    Bick, Christian; Kolodziejski, Christoph; Timme, Marc

    2014-09-01

    Predictive feedback control is an easy-to-implement method to stabilize unknown unstable periodic orbits in chaotic dynamical systems. Predictive feedback control is severely limited because asymptotic convergence speed decreases with stronger instabilities which in turn are typical for larger target periods, rendering it harder to effectively stabilize periodic orbits of large period. Here, we study stalled chaos control, where the application of control is stalled to make use of the chaotic, uncontrolled dynamics, and introduce an adaptation paradigm to overcome this limitation and speed up convergence. This modified control scheme is not only capable of stabilizing more periodic orbits than the original predictive feedback control but also speeds up convergence for typical chaotic maps, as illustrated in both theory and application. The proposed adaptation scheme provides a way to tune parameters online, yielding a broadly applicable, fast chaos control that converges reliably, even for periodic orbits of large period.

  4. Advanced AC Motor Control

    Energy Technology Data Exchange (ETDEWEB)

    Kazmierkowski, M.P. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warszawa (Poland)

    1997-12-31

    In this paper a review of control methods for high performance PWM inverter-fed induction motor drives is presented. Starting from the description of an induction motor by the help of the space vectors, three basic control strategic are discussed. As first, the most popular Field Oriented Control (FOC) is described. Secondly, the Direct Torque and Flux vector Control (DTFC) method, which - in contrast to FOC - depart from idea of coordinate transformation and analogy with DC motor, is briefly characterized. The last group is based on Feedback Linearization Control (FLC) and can be easy combined with sliding mode control. The simulation and experimental oscillograms that illustrate the performance of the discussed control strategies are shown. (orig.) 35 refs.

  5. Intelligent control systems 1990

    International Nuclear Information System (INIS)

    Shoureshi, R.

    1991-01-01

    The field of artificial intelligence (Al) has generated many useful ideas and techniques that can be integrated into the design of control systems. It is believed and, for special cases, has been demonstrated, that integration of Al into control systems would provide the necessary tools for solving many of the complex problems that present control techniques and Al algorithms are unable to do, individually. However, this integration requires the development of basic understanding and new fundamentals to provide scientific bases for achievement of its potential. This book presents an overview of some of the latest research studies in the area of intelligent control systems. These papers present techniques for formulation of intelligent control, and development of the rule-based control systems. Papers present applications of control systems in nuclear power plants and HVAC systems

  6. Control of SMES

    International Nuclear Information System (INIS)

    Murakami, Y.; Sugita, M.; Kiuchi, T.; Okuda, H.

    1981-01-01

    The use of a thyristor Graetz bridge as the interface between the 3-phase ac source and the superconducting magnet (SM) has become standard in superconducting magnetic energy storage (SMES). In the future, the bridge will be DDC (direct digital control) controlled by microprocessors and the higher computations, such as the strategy for economical operation of the SMES plant will be computed by a large-scale computer resulting in a hierarchical control scheme. Some of the problems of DDC control of a SM are discussed, control schemes for effective and reactive power are compared, and the control system for the sequential control of a 0.5 MJ pulsed magnet, which is under construction, is described

  7. Controlling chaos faster

    Energy Technology Data Exchange (ETDEWEB)

    Bick, Christian [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); Bernstein Center for Computational Neuroscience (BCCN), 37077 Göttingen (Germany); Institute for Mathematics, Georg–August–Universität Göttingen, 37073 Göttingen (Germany); Kolodziejski, Christoph [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); III. Physical Institute—Biophysics, Georg–August–Universität Göttingen, 37077 Göttingen (Germany); Timme, Marc [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); Institute for Nonlinear Dynamics, Georg–August–Universität Göttingen, 37077 Göttingen (Germany)

    2014-09-01

    Predictive feedback control is an easy-to-implement method to stabilize unknown unstable periodic orbits in chaotic dynamical systems. Predictive feedback control is severely limited because asymptotic convergence speed decreases with stronger instabilities which in turn are typical for larger target periods, rendering it harder to effectively stabilize periodic orbits of large period. Here, we study stalled chaos control, where the application of control is stalled to make use of the chaotic, uncontrolled dynamics, and introduce an adaptation paradigm to overcome this limitation and speed up convergence. This modified control scheme is not only capable of stabilizing more periodic orbits than the original predictive feedback control but also speeds up convergence for typical chaotic maps, as illustrated in both theory and application. The proposed adaptation scheme provides a way to tune parameters online, yielding a broadly applicable, fast chaos control that converges reliably, even for periodic orbits of large period.

  8. The Parrot UAV Controlled by PID Controllers

    OpenAIRE

    Koszewnik Andrzej

    2014-01-01

    The paper presents the process of modeling and designing control laws for four-rotor type of the Parrot UAV. The state space model is obtained by using several phenomena like gyroscopic effects for rigid bodies, propellers and rotors. The obtained model has been used to design PID control laws for roll, pitch, yaw angle and altitude, respectively. The numerical simulations of the closed loop model are shown that system in satisfy way stabilize flight of the quadro-rotor in all considered dire...

  9. The Parrot UAV Controlled by PID Controllers

    Directory of Open Access Journals (Sweden)

    Koszewnik Andrzej

    2014-08-01

    Full Text Available The paper presents the process of modeling and designing control laws for four-rotor type of the Parrot UAV. The state space model is obtained by using several phenomena like gyroscopic effects for rigid bodies, propellers and rotors. The obtained model has been used to design PID control laws for roll, pitch, yaw angle and altitude, respectively. The numerical simulations of the closed loop model are shown that system in satisfy way stabilize flight of the quadro-rotor in all considered directions.

  10. Alternaria sp. MG1, a resveratrol-producing fungus: isolation, identification, and optimal cultivation conditions for resveratrol production

    Science.gov (United States)

    Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4-trihydroxystilbene) has attracted great research interest. The objective of this study was to identify the microorganisms that possess resveratrol producing capability from selected plants and optimize ...

  11. First report of Alternaria alternata causing leaf spot on the whorled sunflower (Heilianthus verticillatus) in the southeast United States

    Science.gov (United States)

    The whorled sunflower, Helianthus verticillatus (Small), is an endangered, herbaceous perennial plant endemic to limited small tracts of land in west Tennessee, east Alabama, and west Georgia. In October 2015, plants from wild populations in Georgia and Alabama exhibited small, circular brown, necro...

  12. Chemical and morphological segregation of Alternaria arborescens, A-infectoria and A-tenuissima species-groups

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Krøger, Elisabeth; Roberts, R.G.

    2002-01-01

    yeast extract sucrose agar (DRYES). After extraction, all isolates were analysed by a high performance liquid chromatograph equipped with a diode array detector and the resulting metabolite profiles were subjected to multivariate statistic analyses. The analyses of metabolite profiles showed...

  13. Position control device for a control rod

    International Nuclear Information System (INIS)

    Ono, Takehiko; Kusaka, Shuji.

    1976-01-01

    Purpose: To reliably prevent dangerous operation in the control of the position of the control rod by checking for abnormal pulse motor coil excitation voltage and, at the time of occurrence of abnormality, immediately holding the control rod stationary lest it should be moved to an unsafe position, this being accomplished excitation from a compensating excitation system. Constitution: In an FBR reactor, a circuit for memorizing the correct output states of individual drive signals at arbitrary instants and consequtively producing the memorized results is provided, and the output of the circuit and the actual drive signal are compared at all times to discriminate whether the drive signal being compared is normal or not. When the actual drive signal is abnormal, a series signal varying after a predetermined pattern is shifted to enable replacement of the actual drive signal, so that irrespective of whether the problem drive signal is ''on'' or ''off'', a drive signal of the correct pattern may be supplied to the pulse motor to hold the control rod and prevent it from being moved toward the dangerous side due to its own weight or other causes. (Horiuchi, T.)

  14. Generic device controller for accelerator control systems

    International Nuclear Information System (INIS)

    Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.

    1987-01-01

    Distributed intelligence for accelerator control systems has become possible as a result of advances in microprocessor technology. A system based on distributed intelligence is inherently versatile, readily expandable, and reduces both information flow across the system and software complexity in each unit

  15. Price control and macromarketing

    Directory of Open Access Journals (Sweden)

    Kancir Rade

    2003-01-01

    Full Text Available Price control at macro level is part of integral macro marketing strategic control system, or more precisely, part of social marketing mix control. Price impact is direct, if it is regarded in the context of needs satisfaction, and indirect, within the context of resource allocation. These two patterns of price impact define control mechanism structuring. Price control in sense of its direct impact at process of need satisfaction should comprise qualitative and quantitative level of needs satisfaction at a given price level and its structure, informational dimension of price and different disputable forms of corporate pricing policies. Control of price allocation function is based at objectives of macro marketing system management in the area of resource allocation and the role of price as allocator in contemporary market economies. Control process is founded, on one hand, at theoretical models of correlation between price and demand in different market structures, and on the other hand, at complex limits that price as allocator has, and which make whole control process even more complex because of reduction of the degree of determinism in functioning of contemporary economic systems. Control of price allocation function must be continuous and dynamic process if it is to provide for convergence with environmental changes and if it is to provide for placing control systems at micro marketing levels in the function of socially valid objectives.

  16. Tango for experiment control

    International Nuclear Information System (INIS)

    Meyer, J.; Claustre, L.; Petitdemange, S.; Svensson, O.; Götz, A.; Coutinho, T.; Klora, J.; Picca, F.; Ounsy, M.; Buteau, A.

    2012-01-01

    The Tango control system framework allows you to control an accelerator complex as well as single equipment. The framework contains the communication bus with the standard communication modes (synchronous, asynchronous, event driven) as well as the basic hardware access modules, GUI tools and development kits, bindings to commercial products (LabView, Matlab, IgorPro) and services (administration, archiving, access control) to set up a control system. Tango was mainly developed by several synchrotron light sources that have to support not only the accelerator complex but also a lot of experimental end stations. For synchrotron experiments we have to control the whole process from basic hardware access over data taking to data analysis. This paper describes in the first part the special features of Tango allowing flexible experiment control. The dynamic configuration, the rapid hardware interface development and the sequencing and scanning framework are some examples. The second part gives an overview of some packages developed in the Tango community for experiment control: A HKL library for diffraction computation and diffractometer control, a library to control 2D detectors and a data analysis workbench with workflow engine for on-line and off-line data analysis. These packages are not part of Tango and can be used with other control systems. (author)

  17. Fission reactor control rod

    International Nuclear Information System (INIS)

    Irie, Tomoo.

    1991-01-01

    The present invention concerns a control rod in a PWR type reactor. A control rod has an inner cladding tube and an outer cladding tube disposed coaxially, and a water draining hole is formed at the inside of the inner cladding tube. Neutron absorbers are filled in an annular gap between the outer cladding tube and the inner cladding tube. The water draining hole opens at the lower end thereof to the top end of the control rod and at the upper end thereof to the side of the upper end plug of the control rod. If the control rod is dropped to a control rod guide thimble for reactor scram, coolants from the control rod guide thimble are flown from the lower end of the water draining hole and discharged from the upper end passing through the water draining hole. In this way, water from the control rod guide thimble is removed easily when the control rod is dropped. Further, the discharging amount of water itself is reduced by the provision of the water draining hole. Accordingly, sufficient control rod dropping speed can be attained. (I.N.)

  18. Integration of Fire Control, Flight Control and Propulsion Control Systems.

    Science.gov (United States)

    1983-08-01

    pourront etre enploy6s. Avant l’attaque, des profils de vole contr~lant I’Anergie seront 6tablis pour augmenter au maximum l’dnergie disponible do...VERIIATION PROCEDURES NTRTO PERFORM CONTROL SYSTEM REPEAT TESTS WITH ACTUAL ENGIRE ITEATO INTEGRATION TO TIENMO. RUUINED TE VALIDATE TESTING TESI ...fonrtionnement est disponible . Teat-dea rodur d’nrf /sortie .an. scs i lquiesent posslde ce* deux dispositife, on test des rodeurs et sx~fiutA *Sur une vote do

  19. Artificial locomotion control

    DEFF Research Database (Denmark)

    Azevedo, Christine; Poignet, Philippe; Espiau, Bernard

    2004-01-01

    of postural and walking control; use of evolutive optimization objectives; on-line event handling and environment adaptation and anticipation. This leads to the synthesis of an original control scheme based on non-linear model predictive control: Trajectory Free NMPC. The movement is specified implicitly......This paper concerns the simultaneous synthesis and control of walking gaits for biped robots. The goal is to propose an adaptable and reactive control law for two-legged machines. The problem is addressed with human locomotion as a reference. The starting point of our work is an analysis of human...... walking from descriptive (biomechanics) as well as explicative (neuroscience and physiology) points of view, the objective being to stress the relevant elements for the approach of robot control. The adopted principles are then: no joint trajectory tracking; explicit distinction and integration...

  20. Control of training instrument

    International Nuclear Information System (INIS)

    Seo, K. W.; Joo, Y. C.; Park, J. C.; Hong, C. S.; Choi, I. K.; Cho, B. J.; Lee, H. Y.; Seo, I. S.; Park, N. K.

    1996-01-01

    This report describes the annual results on control of training instrument. The scope and contents are the following: 1. Control of Compact Nuclear Simulator 2. Control of Radiation/Radioactivity Measurement 3. Control of Non-Destructive Testing Equipment 4. Control of Chemical Equipment 5. Control of Personal Computer 6. Other related Lecture Aid Equipment. Efforts were employed to upgrade the training environment through retrofitting experimental facilities, compiling teaching materials and reforcing audio-visual aids. The Nuclear Training Center executed the open-door training courses for 2,496 engineers/scientists from the nuclear regulatory, nuclear industries, research institutes and other related organizations by means of offering 45 training courses during the fiscal year 1995. (author). 15 tabs., 7 figs., 13 refs

  1. Quality Control Applications

    CERN Document Server

    Chorafas, Dimitris N

    2013-01-01

    Quality control is a constant priority in electrical, mechanical, aeronautical, and nuclear engineering – as well as in the vast domain of electronics, from home appliances to computers and telecommunications. Quality Control Applications provides guidance and valuable insight into quality control policies; their methods, their implementation, constant observation and associated technical audits. What has previously been a mostly mathematical topic is translated here for engineers concerned with the practical implementation of quality control. Once the fundamentals of quality control are established, Quality Control Applications goes on to develop this knowledge and explain how to apply it in the most effective way. Techniques are described and supported using relevant, real-life, case studies to provide detail and clarity for those without a mathematical background. Among the many practical examples, two case studies dramatize the importance of quality assurance: A shot-by-shot analysis of the errors made ...

  2. Tautological control systems

    CERN Document Server

    Lewis, Andrew D

    2014-01-01

    This brief presents a description of a new modelling framework for nonlinear/geometric control theory. The framework is intended to be—and shown to be—feedback-invariant. As such, Tautological Control Systems provides a platform for understanding fundamental structural problems in geometric control theory. Part of the novelty of the text stems from the variety of regularity classes, e.g., Lipschitz, finitely differentiable, smooth, real analytic, with which it deals in a comprehensive and unified manner. The treatment of the important real analytic class especially reflects recent work on real analytic topologies by the author. Applied mathematicians interested in nonlinear and geometric control theory will find this brief of interest as a starting point for work in which feedback invariance is important. Graduate students working in control theory may also find Tautological Control Systems to be a stimulating starting point for their research.

  3. Applied Control Systems Design

    CERN Document Server

    Mahmoud, Magdi S

    2012-01-01

    Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...

  4. Control Multivariable por Desacoplo

    Directory of Open Access Journals (Sweden)

    Fernando Morilla

    2013-01-01

    Full Text Available Resumen: La interacción entre variables es una característica inherente de los procesos multivariables, que dificulta su operación y el diseño de sus sistemas de control. Bajo el paradigma de Control por desacoplo se agrupan un conjunto de metodologías, que tradicionalmente han estado orientadas a eliminar o reducir la interacción, y que recientemente algunos investigadores han reorientado con objetivos de solucionar un problema tan complejo como es el control multivariable. Parte del material descrito en este artículo es bien conocido en el campo del control de procesos, pero la mayor parte de él son resultados de varios años de investigación de los autores en los que han primado la generalización del problema, la búsqueda de soluciones de fácil implementación y la combinación de bloques elementales de control PID. Esta conjunción de intereses provoca que no siempre se pueda conseguir un desacoplo perfecto, pero que sí se pueda conseguir una considerable reducción de la interacción en el nivel básico de la pirámide de control, en beneficio de otros sistemas de control que ocupan niveles jerárquicos superiores. El artículo resume todos los aspectos básicos del Control por desacoplo y su aplicación a dos procesos representativos: una planta experimental de cuatro tanques acoplados y un modelo 4×4 de un sistema experimental de calefacción, ventilación y aire acondicionado. Abstract: The interaction between variables is inherent in multivariable processes and this fact may complicate their operation and control system design. Under the paradigm of decoupling control, several methodologies that traditionally have been addressed to cancel or reduce the interactions are gathered. Recently, this approach has been reoriented by several researchers with the aim to solve such a complex problem as the multivariable control. Parts of the material in this work are well known in the process control field; however, most of them are

  5. Reset Control Systems

    CERN Document Server

    Baños, Alfonso

    2012-01-01

    Reset Control Systems addresses the analysis for reset control treating both its basic form which requires only that the state of the controller be reinitialized to zero (the reset action) each time the tracking error crosses zero (the reset condition), and some useful variations of the reset action (partial reset with fixed or variable reset percentage) and of the reset condition (fixed or variable reset band and anticipative reset). The issues regarding reset control – concepts and motivation; analysis tools; and the application of design methodologies to real-world examples – are given comprehensive coverage. The text opens with an historical perspective which moves from the seminal work of the Clegg integrator and Horowitz FORE to more recent approaches based on impulsive/hybrid control systems and explains the motivation for reset compensation. Preliminary material dealing with notation, basic definitions and results, and with the definition of the control problem under study is also included. The fo...

  6. Flight control actuation system

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Gaines, Louie T. (Inventor); Evans, Paul S. (Inventor); Kern, James I. (Inventor)

    2006-01-01

    A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.

  7. Spacecraft momentum control systems

    CERN Document Server

    Leve, Frederick A; Peck, Mason A

    2015-01-01

    The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

  8. Intelligent power supply controller

    International Nuclear Information System (INIS)

    Rumrill, R.S.; Reinagel, D.J.

    1991-01-01

    The authors have developed a new power supply controller which would combine 20-bit precision, simple interfacing, and versatile software control. It performs many tasks internal to the power supply and also communicates with an external host computer. Parameters can be entered and/or read over a serial link using one of the 82 command words. In addition, an optional remote control panel can be located up to thousands of feet away. This new controller will reduce the software development time normally spent by the user, while increasing the reliability of the system. The cost is less than buying the equivalent separate CAMAC system. Nonvolatile memory remembers all configuration data; one generic controller can thus be programmed to use anywhere from the smallest power supply to the largest. The controllers will be used at the Clinton P. Anderson Meson Facility at Los Alamos

  9. Control of Electric Vehicle

    OpenAIRE

    Huang, Qi; Chen, Yong; Li, Jian

    2010-01-01

    In this chapter, the modeling of electric vehicle is discussed in detail. Then, the control of electric vehicle driven by different motors is discussed. Both brushed and brushless DC (Direct Current) motors are discussed. And for AC (Alternative Current) motors, the discussion is focused on induction motor and permanent magnet synchronous motor. The design of controllers for different motor-driven electric vehicle is discussed in-depth, and the tested high-performance control strategies for d...

  10. The energy control

    International Nuclear Information System (INIS)

    2002-01-01

    Because of strong constraints, the energy control has not been a priority of the public choices. With the market liberalization, the framework of the energy control is modified. But the new program became not sufficient. This study aims to present the necessary new policy of the energy control, which must be integrated in the attitudes and must imply the local government. (A.L.B.)

  11. Control component retainer

    International Nuclear Information System (INIS)

    Walton, L.A.; King, R.A.

    1983-01-01

    An apparatus is described for retaining an undriven control component assembly disposed in a fuel assembly in a nuclear reactor of the type having a core grid plate. The first part of the mechanism involves a housing for the control component and the second part is a brace with a number of arms that reach under the grid plate. The brace and the housing are coupled together to firmly hold the control components in place even under strong flows of th coolant

  12. Temperature measurement and control

    CERN Document Server

    Leigh, JR

    1988-01-01

    This book treats the theory and practice of temperature measurement and control and important related topics such as energy management and air pollution. There are no specific prerequisites for the book although a knowledge of elementary control theory could be useful. The first half of the book is an application oriented survey of temperature measurement techniques and devices. The second half is concerned mainly with temperature control in both simple and complex situations.

  13. SDN controllers security issues

    OpenAIRE

    Imran, Ayesha

    2017-01-01

    Software-Defined Networking (SDN) is essentially varying the way we design and manage networks, which makes a communication network programmable. In SDN, a logically centralized controller has straight control over the packet-handling functions of the network switches, using a standard, open API (Application Programming Interface) such as OpenFlow. OpenFlow is a broadly used protocol for software-defined networks (SDNs) that presents a new model in which the control plane is inattentive from ...

  14. ISTTOK control system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Carvalho, Bernardo B.

    2013-10-15

    Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 μs control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 μs during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel{sup ®} Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators.

  15. ISTTOK control system upgrade

    International Nuclear Information System (INIS)

    Carvalho, Ivo S.; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Carvalho, Bernardo B.

    2013-01-01

    Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 μs control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 μs during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel ® Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators

  16. Controllability of nilpotent systems

    International Nuclear Information System (INIS)

    Bravo, V.A.; Martin, L.S.

    1993-02-01

    The purpose of this paper is to investigate algebraic conditions which give information about the controllability of invariant control systems on nilpotent Lie groups. With the same purpose, the authors use the co-adjoint representation and define the concept of symplectic vectors. We study the existence of these objects to analyze the controllability. In particular, we obtain a characterization when G is simply connected. (author). 9 refs

  17. Mathematical control theory

    International Nuclear Information System (INIS)

    Agrachev, A.A.

    2002-01-01

    This volume is based on the lecture notes of the minicourses given in the frame of the school on Mathematical Control Theory held at the Abdus Salam ICTP from 3 to 28 September 2001. Mathematical Control Theory is a rapidly growing field which provides strict theoretical and computational tools for dealing with problems arising in electrical and aerospace engineering, automatics, robotics, applied chemistry, and biology etc. Control methods are also involved in questions pertaining to the development of countries in the South, such as wastewater treatment, agronomy, epidemiology, population dynamics, control of industrial and natural bio-reactors. Since most of these natural processes are highly nonlinear, the tools of nonlinear control are essential for the modelling and control of such processes. At present regular courses in Mathematical Control Theory are rarely included in the curricula of universities, and very few researchers receive enough background in the field. Therefore it is important to organize specific activities in the form of schools to provide the necessary background for those embarking on research in this field. The school at the Abdus Salam ICTP consisted of several minicourses intended to provide an introduction to various topics of Mathematical Control Theory, including Linear Control Theory (finite and infinite-dimensional), Nonlinear Control, and Optimal Control. The last week of the school was concentrated on applications of Mathematical Control Theory, in particular, those which are important for the development of non-industrialized countries. The school was intended primarily for mathematicians and mathematically oriented engineers at the beginning of their career. The typical participant was expected to be a graduate student or young post-doctoral researcher interested in Mathematical Control Theory. It was assumed that participants have sufficient background in Ordinary Differential Equations and Advanced Calculus. The volume

  18. The arms race control

    International Nuclear Information System (INIS)

    Nemo, J.

    2010-01-01

    Written in 1961, this paper presents the content of a book entitled 'The arms race control' where the author outlined the difference between disarmament and arms control, described the economic and moral role of arms race, the importance of force balance for international security. He wandered whether arms control could ensure this balance and whether nuclear balance meant force balance. Force balance then appears to be a precarious and unsteady component of international security. He commented the challenges of disarmament, recalled some arguments for a nuclear disarmament. Then he discussed what would be an arms control with or without disarmament (either nuclear or conventional)

  19. An integrated gyrotron controller

    Energy Technology Data Exchange (ETDEWEB)

    Michel, Georg, E-mail: michel@ipp.mpg.de; Sachtleben, Juergen

    2011-10-15

    The ECRH system of W7-X is composed of 10 independent gyrotron modules. Each module consists of one gyrotron and its peripherals such as power supplies, cooling plants and distributed PLC systems. The fast real-time control functions such as the timing of the two high voltage supplies, trigger pulses, protection, modulation and communication with the central control of W7-X, is implemented in an integrated controller which is described in this paper. As long-term maintainability and sustainability are important for nuclear fusion experiments, the choice fell on an FPGA-based design which is exclusively based on free (as in 'freedom') software and configuration code. The core of the controller consists of a real-time Java virtual machine (JVM) that provides the TCP-IP connectivity as well as more complicated control functions, and which interacts with the gyrotron-specific hardware. Both the gyrotron-specific hardware and the JVM are implemented on the same FPGA, which is the main component of the controller. All 10 controllers are currently completed and operational. All parameters and functions are accessible via Ethernet. Due to the open, FPGA-based design, most hardware modifications can be made via the network as well. This paper discusses the capabilities of the controllers and their integration into the central W7-X control.

  20. Control systems engineering

    CERN Document Server

    Nise, Norman S

    1995-01-01

    This completely updated new edition shows how to use MATLAB to perform control-system calculations. Designed for the professional or engineering student who needs a quick and readable update on designing control systems, the text features a series of tightly focused examples that clearly illustrate each concept of designing control systems. Most chapters conclude with a detailed application from the two case studies that run throughout the book: an antenna asimuth control system and a submarine. The author also refers to many examples of design methods.