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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Calagem e biofungicida no manejo da h?rnia das cruc?feras em couve-flor no munic?pio de Nova Friburgo-RJ / Liming and biofungicide in the management of clubroot in cauliflower in the municipality of Nova Friburgo-RJ

SANTOS, Carlos Ant?nio dos 17 February 2017 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-09-06T18:21:23Z No. of bitstreams: 1 2017 - Carlos Ant?nio dos Santos.pdf: 1589290 bytes, checksum: fbf16019cb63898c65e615c045d17094 (MD5) / Made available in DSpace on 2018-09-06T18:21:23Z (GMT). No. of bitstreams: 1 2017 - Carlos Ant?nio dos Santos.pdf: 1589290 bytes, checksum: fbf16019cb63898c65e615c045d17094 (MD5) Previous issue date: 2017-02-17 / CAPES / CNPq / FAPERJ / The search for efficient strategies to reduce the losses caused by clubroot (Plasmodiophora brassicae) in cauliflower is essential due to the economic and social importance of this culture. Thus, the present study was developed with the objective of evaluating the effect of different treatments in the control of the disease, root development, biomass and inflorescences production under field and greenhouse conditions. The study consisted of three trials carried out in a family farmer's area in the municipality of Nova Friburgo, RJ, Brazil. In the first trial, it was tested the residual effect of four doses of calcined limestone (0, 1.0, 2.0 and 4.0 Mg.ha-1) associated to the application of Trichoderma harzianum biofungicide under field conditions. In the second trial, it was tested the effect of the liming associated to the application of T. harzianum and cyazofamid, under greenhouse conditions. In the third one, two ways of applying limestone were tested, in the planting pit, and applied by hand. The use of gypsum was evaluated in the field. The increase of the limestone doses promoted higher pH levels, and Ca+2 contents, and reduction of the toxic Al + 3 contents in the soil. There was also a reduction of root volume with galls, greater root development, and productivity in cauliflower. The use of T. harzianum was not effective to control the disease and did not favor the root development, either in field or in greenhouse conditions. The fungicide cyazofamid reduced the volume roots with galls, the severity, and the progression of the disease. The third rial revealed a discrete reduction in the severity of the disease when using limestone and gypsum combined. Although there was no effect of the treatments on the root system, limestone applied to the pit and by hand resulted in greater accumulations of fresh mass of inflorescence and productivity. The application of limestone by hand, in the pit, and combined with gypsum favored the accumulation of calcium in the plants. The application of limestone in the pit was equivalent to the hand application in terms of soil chemical attributes improvement, reduction of disease severity, and increase of productivity and accumulation of nutrients. / A busca por estrat?gias eficientes na redu??o das perdas causadas pela h?rnia das cruc?feras (Plasmodiophora brassicae) em couve-flor ? essencial devido ? import?ncia econ?mica e social dessa cultura. Com isso, desenvolveu-se o presente estudo com o objetivo de avaliar, em condi??es de campo e casa de vegeta??o, o efeito de diferentes tratamentos no controle da doen?a, desenvolvimento das ra?zes e produ??o de biomassa e infloresc?ncias em couve-flor. O trabalho foi constitu?do de tr?s ensaios realizados em ?rea de produtor familiar no munic?pio de Nova Friburgo, RJ. No primeiro ensaio, avaliou-se o efeito residual de quatro doses de calc?rio calcinado (0; 1,0; 2,0 e 4,0 Mg.ha-1), associado ? aplica??o de biofungicida a base de Trichoderma harzianum, em condi??es de campo. No segundo, avaliou-se o efeito da calagem associada ? aplica??o de T. harzianum e ciazofamida, em casa de vegeta??o. No terceiro, avaliou-se em campo duas formas de aplica??o de calc?rio, na cova e ? lan?o, e o uso de gesso agr?cola. O aumento das doses de calc?rio promoveu eleva??o do pH e dos teores de Ca+2 e redu??o do teor de Al+3 t?xico no solo. Ainda, houve redu??o do volume de ra?zes com h?rnias e maior desenvolvimento radicular e produtividade em couve-flor. O uso de T. harzianum n?o foi eficaz no controle da doen?a e n?o favoreceu o desenvolvimento radicular das plantas, seja nas condi??es de campo ou de casa de vegeta??o. O fungicida ciazofamida reduziu o volume de ra?zes doentes, a severidade e a progress?o da doen?a. Constatou-se no terceiro ensaio discreta redu??o da severidade da doen?a com o uso de calc?rio combinado com gesso. N?o houve efeito dos tratamentos sobre o sistema radicular, entretanto, calc?rio aplicado na cova e ? lan?o resultaram em maiores ac?mulos de massa fresca de infloresc?ncia e produtividade. A aplica??o de calc?rio ? lan?o, na cova, e calc?rio combinado com gesso favoreceram o ac?mulo de c?lcio nas plantas. O uso de calc?rio na cova foi equivalente ? sua aplica??o ? lan?o quanto a melhorias dos atributos qu?micos do solo, redu??o da severidade da doen?a, aumento da produtividade e ac?mulo de nutrientes.
122

Interactions between Sclerotinia sclerotiorum (Lib.) de Bary, Bradysia coprophila Lintner (dark-winged fungus gnat) and mycoparasitic fungi

Anas, Osama January 1988 (has links)
No description available.
123

Metabolic modelling and ¹³C flux analysis : application to biotechnologically important yeasts and a fungus /

Jouhten, Paula. January 1900 (has links) (PDF)
Thesis (doctoral)--Helsinki University of Technology, 2009. / Includes bibliographical references. Also available on the World Wide Web.
124

Evaluating the effectiveness of two Trichoderma species as biological control agents against damping-off caused by Pythium aphanidermatum (Edson) Fitzp. in cucumber seedlings and microgreen table beets

Collins, Christine Meredith. January 2009 (has links)
Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: Wallace G. Pill, Dept. of Plant & Soil Sciences. Includes bibliographical references.
125

Interactions between Sclerotinia sclerotiorum (Lib.) de Bary, Bradysia coprophila Lintner (dark-winged fungus gnat) and mycoparasitic fungi

Anas, Osama January 1988 (has links)
Sclerotinia sclerotiorum is a pathogen of crops grown in the muck soil regions of Quebec. Soil baiting tests indicated that the sclerotia of S. sclerotiorum are attacked and destroyed by the larvae of Bradysia coprophila and mycoparasites. Sclerotia with rinds partially damaged by the larvae were found to be more susceptible to mycoparasitism by Trichoderma viride. Increasing the organic matter content and porosity of soils resulted in increased damage to sclerotia when larvae were present. Studies conducted to determine if larvae could be reared on diets of various fungi and plant tissue showed that mycelia and sclerotia of S. sclerotiorum were the most successful food sources, followed by mycelia and sclerotia of Botrytis porri and Rhizoctonia solani. Adults produced on mycelia and sclerotia of Sclerotinia minor, Fusarium solani f. sp. pisi, and Botrytis cinerea seldom were fertile. Larvae generally failed to survive when reared on cultures of Trichoderma viride. Larval development occurred on all plants inoculated with the above pathogens but failed to occur on noninoculated healthy plants. Salivary gland secretions of the larvae were found to inhibit the germination of sclerotia. Analyses of the secretion determined that it contains 4.3% protein and had chitinase activity. Mechanically damaged and undamaged sclerotia exhibited an increase in eruptive mycelial germination when treated with 1.5 $ mu$g ml$ sp{-1}$ chitinase but germination decreased at 50, 100 and 150 $ mu$g ml$ sp{-1}$ chitinase concentrations. Noneruptive mycelial germination and carpogenic germination occurred when sclerotia were treated with acetate buffer and distilled water.
126

Potential of Trichoderma harzianum Rifai and its secondary metabolites in controlling seedling blight of maize incited by Fusarium moniliforme Sheld.

Hasan, Abbas el- January 2008 (has links)
Zugl.: Hohenheim, Univ., Diss., 2008
127

Application of green fluorescent protein (GFP) for studing interactions between Ophiostoma piceae and Trichoderma harzianum in freshly sawn Douglas-fir sapwood /

Xiao, Ying. January 2004 (has links)
Thesis (Ph. D.)--Oregon State University, 2004. / Printout. Includes bibliographical references. Also available on the World Wide Web.
128

Genômica estrutural e funcional de fungos do gênero Trichoderma

Steindorff, Andrei Stecca 16 March 2016 (has links)
Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2016. / Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2016-04-28T13:39:52Z No. of bitstreams: 1 2016_AndreiSteccaSteindorff.pdf: 3749164 bytes, checksum: 9a4a5c3bdc4e24bc0a92b9777e8680f2 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-04-28T20:07:09Z (GMT) No. of bitstreams: 1 2016_AndreiSteccaSteindorff.pdf: 3749164 bytes, checksum: 9a4a5c3bdc4e24bc0a92b9777e8680f2 (MD5) / Made available in DSpace on 2016-04-28T20:07:09Z (GMT). No. of bitstreams: 1 2016_AndreiSteccaSteindorff.pdf: 3749164 bytes, checksum: 9a4a5c3bdc4e24bc0a92b9777e8680f2 (MD5) / O controle biológico é um processo complexo que inclui diferentes mecanismos e uma diversidade de vias metabólicas. Espécies de Trichoderma harzianum são conhecidas por sua atividade de biocontrole contra patógenos de plantas. Para melhor entender os mecanismos utilizados por T. harzianum no controle biológico, no presente trabalho foi sequenciado o genoma do isolado TR274 usando sequenciamento Illumina, assim como seu respectivo transcritoma na interação direta com Scletotinia sclerotiorum ou na presença de sua parede celular. A montagem do genoma feita utilizando o programa AllPaths-LG cobertura máxima de 100x, resultou em 2282 contigs, tamanho do genoma de 40,8 Mb e um conteúdo GC de 47.7%, similar aos outros genomas de Trichoderma. Um total de 13932 genes foram anotados. Análise do Core Eukariotic Genes Dataset (CEGMA) sugere que o genoma está 100% completo e 97,9% das sequencias de RNA-seq alinharam corretamente no genoma. A análise filogenética usando proteínas ortólogas com todas as espécies de Trichoderma sequenciadas no JGI, confirmam a divisão nas seções Tricoderma (T. asperellum e T. atroviride), Longibrachiatum (T. reesei, T. citrinoviride e T. longibrachiatum) e Pachibasium (T. harzianum e T. virens). Das proteínas ortólogas anotadas, 8242 compõem proteínas compartilhadas por todas as espécies, as proteínas espécie específicas variam de 262 (T. reesei) a 1803 (T. longibrachiatum). Os dois genomas de T. harzianum analisados sugerem uma alta similaridade entre eles, mesmo tendo sido isolados de locais e continentes distintos, um de solo de cerrado no Brasil e outro de solo de jardim na Inglaterra. Análises de genes envolvidos com o metabolismo secundário, CAZymes, transportadores, proteases e fatores de transcrição foram feitas. A seção Pachibasium expandiu virtualmente todas as categorias analisadas quando comparada com as outras seções. Análise CAFE mostrou uma correlação positiva entre estas expansões e o tamanho dos genomas. O subgrupo C1 das quitinases foi completamente perdido pela seção Longibrachiatum. Estes resultados sugerem que estas famílias proteicas tem um importante papel nos seus respectivos fenótipos. As abordagens transcritômicas mostraram que a interação entre T. harzianum e S. sclerotiorum é bem complexa e envolve a produção de metabólitos secundários e síntese de transportadores antes e durante o contato, com uma modulação principalmente de enzimas hidrolíticas após o contato. Dos genes encontrados diferencialmente expressos na condição de crescimento em parede celular, 86,8% foram também encontrados diferencialmente expressos na interação direta. Cerca de 25% de todo o genoma de T. harzianum foi modulado durante a interação com S. sclerotiorum. _________________________________________________________________________________________________ ABSTRACT / Biological control is a complex process, which requires many mechanisms and a high diversity of biochemical pathways. Trichoderma harzianum species complex are well known for their biocontrol activity against many plant pathogens. To gain new insights into the biocontrol mechanism employed by T. harzianum, we sequenced genome of the isolate TR274 with its transcriptome during direct interaction with the fungal pathogen Sclerotinia sclerotiorum and its cell wall, using Illumina sequencing. Whole genome assembly was performed using AllPaths-LG, with a maximum coverage of 100x. The assembly resulted in 2282 contigs, with an estimated genome size of 40.8 Mb and GC content of 47.7%, similar to other Trichoderma genomes. Using the JGI Annotation Pipeline we predicted 13,932 genes, with high transcriptome support. Core Eukariotic Genes Dataset (CEGMA) tests suggested 100% genome completeness and 97.9% of RNA-SEQ reads mapped to the genome. The phylogenetic comparison using orthologous proteins with all Trichoderma genomes sequenced at JGI, corroborates the Trichoderma section division described previously (T. asperellum and T. atroviride), Longibrachiatum (T. reesei, T. citrinoviride and T. longibrachiatum) and Pachibasium (T. harzianum and T. virens). A Venn diagram was built with orthologs proteins, with 8242 composing the core protein group and species specific varying from 262 proteins (T. reesei) to 1803 (T. longibrachiatum). The comparison between two Trichoderma harzianum CBS 226.95 and TR274 isolates, suggests a high genome similarity. Analyses of the secondary metabolites, CAZymes, transporters, proteases and transcription factors were performed. The Pachybasium section expanded virtually all categories analyzed compared with the other sections. CAFE analysis showed positive correlation between these families and genome size. The chitinase subgroup C1 was completely absent in Longibrachiatum section members. These results suggest that these proteins families play an important role on their respective phenotypes. Transcriptome analysis suggests that the interaction between T. harzianum and S. sclerotiorum is complex, involving production of secondary metabolites and transporters before and during the contact, with a modulation of CAZymes after contact. A total of 86.8% of differentially expressed genes during growth on Sclerotinia sclerotiorum cell wall were found during direct interaction. Approximately the 25% of whole T. harzianum genome was seen to be modulated during the interaction with S. sclerotiorum.
129

Extração e avaliação da atividade reguladora do crescimento de plantas por compostos produzidos por Trichoderma spp / Extraction and evaluation of regulatory activity of plant growth by compounds produced by trichoderma spp

Dias, Maria Cecília Fernandes 24 February 2014 (has links)
Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-05-05T14:51:13Z No. of bitstreams: 1 texto completo.pdf: 592470 bytes, checksum: cc8ef864c2b3e01b5ab1475f19179564 (MD5) / Made available in DSpace on 2016-05-05T14:51:13Z (GMT). No. of bitstreams: 1 texto completo.pdf: 592470 bytes, checksum: cc8ef864c2b3e01b5ab1475f19179564 (MD5) Previous issue date: 2014-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Micro-organismos têm se mostrado como uma das fontes mais ricas e promissoras de novos compostos com atividade fitotóxica e reguladora do crescimento de plantas. Os Trichoderma spp. vêm se destacando como agentes de biocontrole bem como na promoção do crescimento de plantas. A atividade biológica desses fungos pode estar associada aos diferentes metabólitos voláteis produzidos por eles. Este trabalho teve como objetivo a avaliação dos extratos de Trichoderma asperellum, Trichoderma harzianum, Trichoderma pseudokonigii, Trichoderma viride e Trichoderma virens sobre a promoção o crescimento de plantas. A partir dos extratos obtidos do meio de mineral foi possível detectar metabólitos voláteis pela técnica de cromatografia gasosa acoplada a espectrometria de massas (CG-EM). Foram identificados diversos compostos, dentre eles ácido desidroacético, 2-feniletanol e ciclo prolina-isoleucina, o qual, até o presente momento, nunca havia sido descrito para Trichoderma sp. A lactona 6-pentilpiran-2-ona foi identificada em T. asperellum, T. harzianum e T. viride. As atividades fitotóxicas dos extratos foram avaliadas sobre o crescimento radicular e a germinação de sorgo (Sorghum bicolor L.) e pepino (Cucumis sativus L.) nas concentrações de 31,25; 62,50; 125; 500 e 1000; ppm. Os extratos não afetaram a germinação das sementes de pepino, mas influenciaram na germinação das sementes de sorgo. Os extratos induziram o crescimento radicular tanto do pepino quanto do sorgo, sendo que os extratos de T. pseudokoningii e T. asperellum aumentaram esse crescimento em 366 e 249% e em 43 e 33%, respectivamente. Em casa de vegetação, os extratos de T. viride e de T. virens foram os que aumentaram mais o crescimento radicular nas plântulas de pepino, em 95 e 88% respectivamente, e de sorgo em 44 e 41%, enquanto o extrato de T. virens aumentou em até 334% o crescimento da corda de viola (Ipomoea grandifolia). Verifica-se, portanto, que as espécies de fungo estudadas apresentam substâncias que promovem o crescimento vegetal. / Microorganisms have been shown to be one of the richest and most promising sources of new compounds with phytotoxic activity and regulating plant growth . Trichoderma spp. have been highlighted as biocontrol agents and promoting plant growth. The biological activity of these fungi can be associated with different volatile metabolites produced by them. This study aimed to evaluate the extracts Trichoderma asperellum, Trichoderma harzianum, Trichoderma pseudokonigii, Trichoderma viride and Trichoderma virens on promoting the growth of plants. From the extracts of the mineral medium volatile metabolites could be detected by the technique of gas chromatography-mass spectrometry (GC-MS). Various compounds, among them were identified dehydroacetic acid, 2 - phenylethanol and isoleucine- proline cycle, which, until now, had never been described for Trichoderma sp . The lactone 6- pentilpiran -2-one was identified in T. asperellum, T. harzianum and T. viride. The phytotoxic activities of the extracts were evaluated on root growth and germination of sorghum (Sorghum bicolor L.) and cucumber ( Cucumis sativus L.) at concentrations of 31.25 ; 62.50; 125 ; 500 and 1000 ; ppm. The extracts did not affect the germination of cucumber, but influenced the germination of sorghum seeds. The extracts induce root growth of cucumber so as sorghum, and extracts from T. pseudokoningii and T. asperellum this growth increased 366 and 249 % and in 43 and 33%, respectively. In the greenhouse, the extracts of T. viride and T. virens were increased more than root growth in cucumber seedlings at 95 and 88 % respectively, and sorghum in 44 and 41%, while the extract of T. virens increased by up to 334% growth string viola ( Ipomoea grandifolia ) . It is apparent, therefore, that the fungus species have studied substances which promote plant growth.
130

Potencial do Trichoderma deliquescens J-7 para produção de celulases e hemicelulases destinada a sacarificação e branqueamento da polpa Kraft / Potential of Trichoderma deliquescens J-7 for the production of cellulases and hemicellulases intended to saccharification and Kraft pulp bleaching

Leal, Tiago Ferreira 30 April 2015 (has links)
Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-06-07T11:46:42Z No. of bitstreams: 1 texto completo.pdf: 1307111 bytes, checksum: 9206e9e1d7450e4895b82477625ede32 (MD5) / Made available in DSpace on 2016-06-07T11:46:42Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1307111 bytes, checksum: 9206e9e1d7450e4895b82477625ede32 (MD5) Previous issue date: 2015-04-30 / A biotecnologia pode contribuir para tornar os processos industriais mais competitivos e sustentáveis. No processamento convencional da cana de açúcar, cerca de 50% do bagaço poderá ser utilizado como matéria prima para a produção do etanol de segunda geração, após a redução dos custos do processo, que atualmente inviabilizam o processo. No branqueamento da polpa Kraft, o emprego de enzimas leva à redução de resíduos tóxicos. Neste trabalho o isolado Trichoderma deliquescens J-7 foi avaliado quanto ao seu potencial para produção de enzimas lignocelulolíticas visando suas aplicações em processos biotecnológicos, mais precisamente, processos de sacarificação do bagaço de cana de açúcar e no branqueamento da polpa Kraft de eucalipto. O fungo foi cultivado em meio líquido contendo diferentes fontes de carbono e nitrogênio e, após sete dias de cultivo, os extratos produzidos foram coletados e analisados. A palha de milho foi a melhor opção para produção de celulases embora uma maior produção de β-glicosidase tenha sido observada para o cultivo com palha de cana. Testes estatísticos com delineamentos fatoriais foram então utilizados para avaliar o efeito das concentrações dos componentes do meio afim de se otimizar a produção das enzimas, sendo otimizada a produção de xilanase (784 U/mL). Contudo não foi possível ajustar um modelo para a atividade CMCase. As enzimas foram mais ativas entre 50 °C e 65 °C e no pH 4,5 a 5,5. O tempo de meia vida a 50 °C das celulases foi de aproximadamente 32 horas e da xilanase de 66 minutos a 60 °C. Na aplicação das enzimas foi observado um menor rendimento na conversão de glicose na sacarificação da biomassa comparando o extrato do T. deliquescens com o extrato comercial Multifect® CL. Entretanto o rendimento na conversão de xilana foi aproximadamente 4 vezes maior. Quando aplicada no branqueamento da polpa, a xilanase produzida pelo fungo possibilitou a uma redução de 14% da utilização de dióxido de cloro além de maiores níveis de alvura da polpa. Estes dados nos mostraram o grande potencial da utilização dos extratos enzimáticos produzidos pelo isolado J-7 de T. deliquescens nos processos estudados. / Biotechnology can help to make industrial processes more competitive and sustainable. In conventional processing of sugar cane, about 50% of the bagasse could be used as raw material for the production of second generation ethanol after reduction of process costs. In Kraft pulp bleaching, biotechnology with the use of enzymes leads to a reduction of toxic wastes. The Trichoderma deliquescens J-7 strain was evaluated for its potential to produce lignocellulolytic enzymes aiming their applications in biotechnological processes, more precisely, in saccharification of sugar cane bagasse and bleaching of eucalyptus kraft pulp. The fungus was grown in liquid medium with different sources of carbon and nitrogen and after seven days of growth, produced extracts were collected and analyzed. Corn husk proved to be the best option for production of cellulases while increased production of β- glucosidase was observed when using sugar cane straw. Statistical factorial designs were used to evaluate the concentrations of the medium components in order to optimize the production of enzymes, being optimized to produce xylanase (784 U/mL). However it was not possible to fit a model to CMCase activity. The enzymes are most active between 50 °C and 65 °C, pH 4.5 to 5.5. The half-life for cellulases at 50 °C was approximately 32 hours and for xylanase 66 minutes at 60 °C. In application of enzymes was observed lower yield on glucose conversion in the saccharification of biomass comparing T. deliquescens extract and the commercial extract Multifect® CL. However, the yield of xylan conversion was about 4 times higher. When applied in pulp bleaching, a GH11 xylanase produced by the fungus led to a 14% reduction in the use of chlorine dioxide as well as higher levels of pulp brightness. These data have shown us the great potential of the use of enzymatic extracts produced by the straiw J-7 of T. deliquescens in studied processes.

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