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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.
211

Processo argumentativo na (re)significa??o de concep??es ?tico/morais

Aguiar, Joelma Gomes de 09 March 2006 (has links)
Made available in DSpace on 2014-12-17T15:38:55Z (GMT). No. of bitstreams: 1 JoelmaGAS.pdf: 410605 bytes, checksum: 66cd9379cf7414999d27b75821e087d5 (MD5) Previous issue date: 2006-03-09 / This study analysed the relationship between the production of argumentative discourses and the development and (re)signification of ethical/moral concepts, conceptions and reasoning. It focused on ethical-argumentative reasoning concerning other people and their different points of view. The specific aims of this research were: (1) to investigate the considering alternative positions on adolescents previous views on a specific topic; (2) to verify whether the ability to generate counterarguments was associated with higher levels of moral reasoning, according to Kohlberg theory, and (3) to have a better comprehension of a possible relationship between adolescents abilities to use cognitive and verbal-argumentative strategies and the (re) signification of concepts/beliefs of an ethical/moral nature, and also the solution of conflicts of the same nature. The participants in this study were seventh grade students of private and public schools. Four empirical tasks were used in order to evaluate argumentative and moral reasoning. These tasks focused on: the evaluation of moral dilemmas (DIT); the evaluation of moral dilemmas with the presentation of a written justification for subjects responses; the production of arguments and the reaction to counterarguments. There was also a group-debate situation in which both argumentation and the discussion ethical/moral issues were observed. The moral dilemmas tasks aimed to evaluate the level of moral reasoning of the participants. The argumentation tasks investigated whether the adolescents generated and justified a point of view and how they dealt with counterarguments or alternative information which could lead the participants to modify their initial positions on the topic under discussion in a monological situation as well as in a group-debate setting. The results showed that, in a monological situation, most of the adolescents produced only a partial developed argumentative discourse, whereas in a more social-verbal interaction situation their discourse appeared to be more elaborated. As a general result, it was observed that the confrontation with the other s views, or dealing with counterarguments allow the adolescents to re-evaluate and re-elaborate their own views on a debatable topic. Regarding the relationship between counterargumentation and moral reasoning, it was verified that there was a subtle tendency associating the two processes. However, other factors, such as, social, emotional and cultural aspects might also influence the development of moral reasoning / A presente disserta??o procurou analisar a produ??o de discurso argumentativo como meio para constru??o/(re)significa??o de conceitos, concep??es e racioc?nios ?tico/morais. Teve como eixo o racioc?nio ?tico-argumentativo voltado para outras pessoas e seus diferentes pontos de vista. Prop?e, mais especificamente, tr?s objetivos: (1) investigar a considera??o de posi??es alternativas sobre as posi??es pr?vias dos adolescentes acerca de um tema controverso; (2) verificar se a capacidade dos jovens de considerar outras alternativas em rela??o ao seu ponto de vista, ou seja, se a capacidade de gerar contra-argumentos reflete-se em n?veis mais elevados de racioc?nio moral, segundo Kohlberg; (3) compreender a rela??o entre a capacidade do adolescente de usar estrat?gias cognitivas e verbais-argumentativas e a (re)significa??o de conceitos e cren?as de natureza ?tico/moral, bem como entender como solucionam os conflitos que derivam dessas quest?es. A pesquisa foi realizada com adolescentes da 7? s?rie do ensino fundamental II, das redes p?blicas e privadas de ensino. A coleta de dados deu-se atrav?s da aplica??o de quatro tarefas emp?ricas que observavam: a avalia??o de dilemas morais (DIT); a avalia??o dos dilemas morais, atrav?s da apresenta??o por escrito das respostas dos participantes; a produ??o de argumento e a rea??o ? contra-argumenta??o. Houve ainda uma situa??o de grupo-debate, na qual se observou tanto o processo de argumenta??o quanto a forma como os adolescentes lidavam com quest?es ?tico/morais. As tarefas referentes aos dilemas morais visavam investigar o n?vel de racioc?nio moral dos adolescentes. As de produ??o e avalia??o de contra-argumentos, observaram se os adolescentes eram capazes de gerar e justificar um ponto de vista, bem como a maneira como lidavam com contra-argumentos ou informa??es que poderiam levar a modificar suas posi??es iniciais, tanto em situa??o de argumenta??o monol?gica como em situa??o de grupo-debate. Os resultados mostram que, numa situa??o de argumenta??o monol?gica, a maioria dos adolescentes apresentou um discurso argumentativo com uma estrutura apenas parcialmente desenvolvida. Diferentemente, na situa??o de maior intera??o s?cio-verbal (grupo-debate), os adolescentes produziram argumentos mais elaborados. No geral, constatou-se que o confronto com contra-argumentos permite ao indiv?duo re-elaborar sua posi??o inicial. No que se refere ? rela??o entre contra-argumenta??o e racioc?nio moral, verificou-se que houve uma tend?ncia ainda que sutil ao se associar esses dois processos. No entanto, outros fatores como os aspectos sociais, emocionais e culturais podem tamb?m influenciar o desenvolvimento do racioc?nio moral
212

Dessulfurizacao oxidativa em diesel utilizando catalisadores abase de van?dio ou mangan?s

Mello, Mariele Iara Soares de 20 July 2012 (has links)
Made available in DSpace on 2014-12-17T15:41:59Z (GMT). No. of bitstreams: 1 Mariele ISM_DISSERT.pdf: 4704397 bytes, checksum: 9fa1538bc3d6948d492f9a6c378eaf62 (MD5) Previous issue date: 2012-07-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Processo de Dessulfuriza??o Oxidativa (ODS) de um diesel comercial foi realizado em condi??es suaves na presen?a de catalisadores a base de van?dio ou mangan?s, suportados em aluminas, argilas e ze?litas. A oxida??o e extra??o da mol?cula de dibenzotiofeno (DBT), representando os compostos de enxofre presentes no diesel, foram realizadas usando como solvente a acetonitrila e oxidante o per?xido de hidrog?nio a temperatura de 55?C. O processo mostrou-se eficiente, o DBT foi convertido para sua respectiva sulfona, e a quantidade que n?o foi convertida a sulfona foi extra?da pelo solvente. O sistema de rea??o apresentou remo??o e oxida??o de at? 100% do composto de enxofre com alguns catalisadores. Verificando que para a oxida??o os catalisadores foram mais ativos, e os catalisadores de mangan?s apresentaram melhores resultados na extra??o dos compostos de enxofre.
213

Obten??o e caracteriza??o do sistema comp?sito alginato de s?dio-di?xido de tit?nio em formas de p? e de membrana

Lisboa, Marcia Severiano 28 June 2011 (has links)
Made available in DSpace on 2014-12-17T15:42:14Z (GMT). No. of bitstreams: 1 MarciaSL_TESE.pdf: 4842135 bytes, checksum: b5c017ecd503f8ac8f797fb07359e645 (MD5) Previous issue date: 2011-06-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The alginates are copolymers of 1→4-linked β-D-mannuronic acid (M) and α-Lguluronic acid (G) residues that are arranjed in a block structure along a linear chain. Titanium dioxide, TiO2, is a ceramic material and can exist in three distinct crystallography forms: anatase, brookite and rutile. composites of organic and inorganic materials have better properties than the components alone. Thus, this study aims to synthesize, characterize and analyze the composite NaAlg-TiO2 in the form of powder and film. The synthesis of composite powders was performed using the sol-gel process and obtain the composite film was performed using the slow evaporation process, then the composites were analyzed by infrared spectroscopy, fluorescence x ray, thermal analysis, attenuated total reflection (ATR), x ray diffraction and impedance spectroscopy. The X ray diffraction patterns of composite powders show that with increasing calcination temperature, there were no complete transition of rutile-anatase crystalline phase, since at all temperatures studied (300, 500, 700, 900 and 1100?C) were observed peaks of anatase phase. Thermal analysis shows that at 400?C caused the decomposition of sodium alginate in sodium carbonate and above 600?C, we observe an exothermic peak related to the decomposition of sodium carbonate and in the presence of titanium dioxide becomes sodium titanate. The XRD results confirm the formation of sodium carbonate at 700?C and the formation sodium titanate in the temperature range 900-1100?C. The sodium titanate influenced the electrical properties of the material, because with increasing temperature there was a decrease in conductivity, probably due to the creation of Ti vacancies, since the sodium can induce the reduction of surface Ti4+ ions into Ti3+ species. The infrared spectra of the composites in the form of powder and film showed a small shift in the bands compared to the spectrum of pure alginate, indicating that these shifts, even small ones, have evidence of miscibility between the polymer and ceramic material / O alginato de s?dio, NaAlg, ? um polissacar?deo formado por liga??es do tipo 1-4 entre os ?cidos β-D-manur?nico e α-L-gulur?nico arranjados em bloco ao longo de uma cadeia linear. O di?xido de tit?nio, TiO2, ? um material cer?mico e existe em tr?s formas cristalinas: anat?sio, bruquita e rutilo. Os comp?sitos de materiais org?nicos e inorg?nicos apresentam melhores propriedades do que os componentes isoladamente. Dessa forma, o presente trabalho teve objetivo sintetizar, caracterizar e analisar os comp?sitos, NaAlg-TiO2, em formas de p? e de membrana. A s?ntese dos p?s comp?sitos foi realizada atrav?s do processo sol-gel e a obten??o dos comp?sitos em forma de membrana foi realizada atrav?s do processo de evapora??o lenta. Em seguida, os comp?sitos foram caracterizados por espectroscopia de infravermelho, difratometria de raios X, espectroscopia de imped?ncia, fluoresc?ncia de raios X, an?lise t?rmica e espectroscopia de reflect?ncia total atenuada-ATR. Os difratogramas de raios X dos p?s comp?sitos mostraram que, com o aumento da temperatura de calcina??o, n?o houve a completa transi??o de fase anat?sio-rutilo, uma vez que, em todas as temperaturas estudadas (300, 500, 700, 900 e 1100?C) foram observados picos da fase anat?sio. A an?lise t?rmica mostrou que em 400?C ocorreu ? decomposi??o do alginato de s?dio em carbonato de s?dio e, acima de 600?C, se observa um pico exot?rmico referente ? decomposi??o do carbonato de s?dio que, na presen?a do di?xido de tit?nio, transforma-se em titanato de s?dio, confirmados, tamb?m, atrav?s dos difratogramas de raios X, em que na temperatura de 700?C observa-se picos referentes ao carbonato de s?dio e em 900 e 1100?C picos relacionados ao titanato de s?dio. O titanato de s?dio influenciou nas propriedades el?tricas do material, pois com o aumento da temperatura houve um decr?scimo na condutividade, provavelmente, devido ? cria??o de vac?ncias de Ti, uma vez que, o Na+ induz a redu??o dos ?ons Ti+4 para esp?cies Ti+3. Os espectros de infravermelho dos comp?sitos em formas de p? e de membrana mostraram um pequeno deslocamento nas bandas, quando comparados ao espectro do alginato de s?dio puro, indicando que estes deslocamentos, mesmo que pequenos, t?m ind?cios de miscibilidade entre o pol?mero e o material cer?mico
214

Efeito de Alum?nio, Molibd?nio e de Estirpes de Riz?bio em Arachis pintoi / Effect of Aluminum, Molybdenum and strains of Riz?bio in Arachis pintoi

Silva, Humberto Ant?o de Sousa e 14 February 2007 (has links)
Made available in DSpace on 2016-04-28T14:58:56Z (GMT). No. of bitstreams: 1 2007-Humberto Antao de Sousa e Silva.pdf: 1812876 bytes, checksum: fc5dddb0fe3112c5b22807ccdce3e05b (MD5) Previous issue date: 2007-02-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In a modern cattle-breeding using pastures that allows a gain of weight is an essential factor. The Arachis pintoi is an option to a good alimentary diet and to the recuperation of degraded pastures, due to its potential in biological fixation of nitrogen and resistance to acid soil with high contents of aluminium. Experiments were conducted in greenhouse and growth chamber condition, in order to study the behavior of Arachis pintoi (Amarillo cv., Belmonte cv. and accession BRA-031534) in its relation to inoculation with rhizobial strains, aluminium tolerance and Mo influence. Strains CIAT-5067, CIAT-5083, CIAT-5087, BR-1432 e BR-1433 were used in inoculation experiments. In experiments with aluminium were used: a) A simple nutritive solution, initially with rates 10μM, 20μM, 40μM, 80μM and 160μM, and later 2μM, 4μM, 8μM, 16μM e 32μM, b) A complete nutritive solution with rates 20μM, 40μM, 80μM, 160μM and 320μM at Amarillo cv. and access BRA-031534 propagated by seeds and at the Amarillo and Belmonte cv. and access BRA-031534 vegetatively propagated. In the experiment with Mo, four rates of molybdenum (0g.ha-1, 50g.ha-1, 100g.ha-1 e 200g.ha-1), three levels of pH (4,0; 5,0 e 6,0) and two collection dates (49 days and 78 days) were used. The plants inoculated with CIAT strains, presented a good response to nodulation especially in relation to Belmonte cv., and with the same effectiveness of native strain. It was observed deleterious effect of nitrogen in the number of nodules. The results in simple nutritive solution had shown reduction in growth and dry mass of the root and a reduction evaluated in 27% by the relative root length between the concentration of 16μM and the control. In these experiments were observed responses to the concentration of aluminium, with appearance of mucilage and darkening of the primary root. In studies involving complete nutritional solution, Amarillo cultivar and accession BRA-031534 propagated by seeds had had reduction in the growth of the primary root and in relative length of the root in relation to the control. In the concentrations of 320μM and 160μM, a reduction of 51% and 49% respectively, in the Amarillo cultivar and access BRA-031534. It was also observed in this study with the Amarillo cultivar, roots with tip dark in the concentrations of 160μM and 320μM, and increase in the number of secondary roots from the concentration of 80μM. Pyrocatecol violet dyes seems to be promising in allowing a visualization of aluminum effects to Amarillo cultivar and accession BRA-031534. The aluminum in vegetative propagation influenced the cultivars and accession tested. Belmonte cultivar formed a higher number of adventitious roots when compared with Amarillo cv and accession BRA-031534, and with a concentration of 80μM a reduction in the adventitious roots length of the tested cultivars and access occurred. The molybdenum application promote answer in the second harvest in the pH 6,0 being obtained a larger number of nodules in the concentration of 200g.ha-1.The pH intervened in the nodulation. / Na pecu?ria moderna, o uso de pastagens que permitem um bom ganho de peso ? um fator imprescind?vel. A leguminosa Arachis pintoi apresenta-se como uma op??o tanto para uma dieta alimentar eficiente, como para recupera??o de pastagens degradadas devido ao seu potencial em fixa??o biol?gica de nitrog?nio e resist?ncia a solos ?cidos com teor elevado de alum?nio. Com a finalidade de estudar o comportamento do Arachis pintoi em rela??o ? inocula??o com estirpes de riz?bio, toler?ncia ao alum?nio e a influ?ncia do molibd?nio, foram conduzidos experimentos em condi??es de casa de vegeta??o e c?mara de crescimento. Nos experimentos de inocula??o utilizaram-se as estirpes CIAT-5067, CIAT-5083, CIAT-5087, BR-1432 e BR-1433. Nos experimentos com alum?nio foram utilizadas: a) Solu??o nutritiva simples, (10μM, 20μM, 40μM, 80μM e 160μM) e (2μM, 4μM, 8μM, 16μM e 32μM), na cultivar Amarillo. b) Solu??o nutritiva completa (20μM, 40μM, 80μM, 160μM e 320μM) na cultivar Amarillo e acesso BRA-031534 propagadas por sementes e nas cultivares Amarillo, Belmonte e acesso BRA-031534 propagadas vegetativamente. No experimento com molibd?nio, foi utilizada a cultivar Amarillo, quatro dosagens de molibd?nio (0gha-1, 50g.ha-1, 100g.ha-1 e 200g.ha-1), tr?s n?veis de pH (4,0; 5,0 e 6,0) e duas ?pocas de coleta (49 e 78 dias). Nos experimentos de sele??o de estirpes, as plantas inoculadas com as estirpes CIAT, apresentaram uma boa resposta ? nodula??o principalmente em rela??o ? cultivar Belmonte, e com a mesma efetividade que as estirpes nativas. Na cultivar Belmonte foi observado efeito delet?rio do nitrog?nio no n?mero de n?dulos por planta. Os resultados obtidos nos experimentos com Al, em solu??o nutritiva simples mostraram uma redu??o no crescimento, redu??o na massa seca da raiz e uma redu??o avaliada em 27% pelo comprimento radicular relativo entre as concentra??es de 16μM e o controle. Ocorreram nestes experimentos respostas ?s concentra??es de alum?nio, com aparecimento de mucilagem e escurecimento da raiz prim?ria. Nos estudos envolvendo solu??o nutritiva completa, as pl?ntulas da cultivar Amarillo e do acesso BRA-031534 propagadas por sementes tiveram redu??o no crescimento da raiz prim?ria e no comprimento relativo da raiz em rela??o ? testemunha. Nas concentra??es de 320μM e 160μM, observou-se uma redu??o de 51% e 49% respectivamente, na cultivar Amarillo e no acesso BRA-031534. Tamb?m foi observado na cultivar Amarillo, ra?zes com as extremidades escurecidas nas concentra??es de 160μM e 320μM e aumento no n?mero de ra?zes secund?rias a partir da concentra??o de 80μM. O corante violeta de pirocatecol parece promissor em permitir uma visualiza??o dos efeitos do alum?nio para a cultivar Amarillo e acesso BRA-031534. O alum?nio influenciou as cultivares e acesso testados com a cultivar Belmonte formando um maior n?mero de ra?zes advent?cias que a cv Amarillo e o acesso BRA-031534. A partir da concentra??o de 80μM, ocorreu uma redu??o no comprimento das ra?zes advent?cias das cultivares e acesso testados. A aplica??o de molibd?nio foi eficiente na segunda colheita no pH 6,0 sendo obtido um maior n?mero de n?dulos na concentra??o de 200g.ha-1. O pH interferiu na nodula??o.
215

Caracteriza??o e uso de bact?rias diazotr?ficas isoladas de diferentes cultivares de arroz origin?rias do estado do Maranh?o. / Characterization and use of diazotrophic bacteria isolated from different rice cultivars originated from Maranh?o State.

Ara?jo, Ant?nio Edilson da Silva 19 February 2008 (has links)
Made available in DSpace on 2016-04-28T14:58:59Z (GMT). No. of bitstreams: 1 2008 - Antonio Edilson da Silva Araujo.pdf: 1302543 bytes, checksum: cc20c323c83af0e996be61700810ba59 (MD5) Previous issue date: 2008-02-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Several works have shown that rice crop can benefit from the association with diazotrophic bacteria. However, the biological nitrogen fixation (BNF) in rice is dependent of a complex interaction among the plants, microorganisms and the ecosystem. The general objective of this work was to evaluate the contribution of BNF in varieties of rice originated from the State of Maranh?o. The specific objectives were: a- To isolate and characterize native diazotrophic bacteria originated from soil cultivated with rice in Maranh?o; b- to select the most efficient bacteria in relation to dry matter accumulation and grain yield; c- to study the relationship between FBN and the teor of proteins in the grains. For the isolation was used two rice varieties (IR42 and Diamante) and two traditional rice varieties of Maranh?o (Zebu Branco and Manteiga), grown in soil samples originated from three districts of Maranh?o, being one of high lands (Bacabal) and two of lowland area (Arari and Vitoria do Mearim). Samples of roots, stems and leaves were grounded and inoculated in nitrogen free semisolid semiselective media: NFB, JNFB, LGI, LGIP and JMV. Around 304 isolates were obtained and classified as belonging to the species Azospirillum amazonense, Azospirillum lipoferum and Azospirillum brasilense, Herbaspirillum spp. and Burkholderia spp and a non identified group that was clustered based only in the morphological characteristics. The genetic diversity of the isolates was evaluated through the amplification of 16S DNAr subunit using the Polymerize Chain Reaction (PCR) technique and digestion of the amplified products with restriction enzymes (ARDRA). Restriction fragment profiles confirmed the identity of most of the isolated and showed high diversity mainly for the bacterial isolates characterized as Burkholderia. Isolates representative from the different groups were tested in gnotobiotic conditions, in pots and in the field using different rice varieties originated from the Maranh?o State. Two other cultivars were used as controls. It was observed that among the isolates tested, the Azospirillum amazonense AR3122 and Herbaspirillum sp AR1122 howed potential to promote growth of rice plants and to increase the grain yield of this crop. / Diversos trabalhos t?m mostrado que a cultura do arroz pode se beneficiar da associa??o com bact?rias diazotr?ficas. Entretanto, a fixa??o biol?gica de nitrog?nio (FBN) em arroz ? dependente de uma intera??o complexa entre as plantas, os microrganismos e o ecossistema. Este trabalho teve como objetivo geral avaliar a contribui??o da FBN em variedades tradicionais de arroz do estado do Maranh?o. Como objetivos espec?ficos: a- isolar e caracterizar bact?rias diazotr?ficas nativas de solo cultivado com arroz no estado do Maranh?o; b- selecionar as bact?rias mais eficientes quanto ao ac?mulo de biomassa e produ??o de gr?os; c- verificar se existe rela??o entre a FBN e o teor de prote?nas nos gr?os. Para o isolamento foi utilizada como planta isca as cultivares IR42 e Diamante e mais duas variedades tradicionais de arroz do Maranh?o Zebu Branco e Manteiga, crescidas em amostras de solo, provenientes de tr?s munic?pios do Maranh?o, sendo uma de terras altas (Bacabal) e duas de ?rea de baixada (Arari e Vitoria do Mearim). Amostras de ra?zes, colmos e folhas foram maceradas e inoculadas em meios semi-s?lidos semi-seletivos, NFB, JNFB, LGI, LGIP e JMV, sem adi??o de nitrog?nio. Foram obtidos 304 isolados que foram classificados morfologicamente como pertencentes ?s esp?cies Azospirillum amazonense, Azospirillum lipoferum, Azospirillum brasilense, Herbaspirillum spp. e Burkholderia spp., al?m de um grupo n?o identificado. A diversidade gen?tica dos isolados foi avaliada por meio da amplifica??o da regi?o 16S DNAr por meio da rea??o da polimerase em cadeia (PCR) e da digest?o dos produtos de amplifica??o com enzimas de restri??o (ARDRA). O perfil de fragmentos de restri??o confirmou o g?nero da maioria dos isolados, al?m disso, mostrou alta diversidade, principalmente para os isolados bacterianos caracterizados morfologicamente como Burkholderia. Isolados representantes dos diferentes grupos foram testados em condi??es gnotobi?ticas, em vasos e em campo, em diferentes variedades procedentes do Maranh?o utilizando-se tamb?m duas cultivares como controle. Foi observado que entre os isolados testados, AR1122 de Herbaspirillum sp. e AR3122 de A. amazonense apresentaram maior potencial para promover o crescimento das plantas e aumentar a produ??o de gr?os na cultura do arroz.
216

Efeito de inibidores de crescimento e do tipo de poda em plantas utilizadas na arboriza??o urbana / Effect of growth inhibitors and of the type of pruning of plants used in the forestation

Polese, Val?ria 15 April 2013 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-05-03T11:26:21Z No. of bitstreams: 1 2013 - Valeria Polese.pdf: 1777501 bytes, checksum: c11ce694e66877535a131581bb746469 (MD5) / Made available in DSpace on 2017-05-03T11:26:21Z (GMT). No. of bitstreams: 1 2013 - Valeria Polese.pdf: 1777501 bytes, checksum: c11ce694e66877535a131581bb746469 (MD5) Previous issue date: 2013-04-15 / AMPLA Energia e Servi?os S. A. / LIGHT Servi?os de Eletricidade S.A. / The present study looked for alternatives of growth handling and of pruning in plants used in the urban forestation, seeking to the decrease of conflicts of these with electric power spinnings. In the chapter I experiments were accomplished with Flamboyant in soil and simple nutritious solution containing Al, with objective of studying handling alternatives seeking to reduce the growth and development of plantules Flamboyant. The aluminum atrophies roots could affect the growth. Six experiments were accomplished with plantules (soil and simple nutritious solution) in conditions of growth camera and vegetation house, Department of Fitotecnia - UFRRJ. In the soil experiments they were used two sources of sulfate of aluminum, being a commercial one and a pure source analytically, in the concetrations 0, 100, 200, 300 and 400 kg ha-1 in the soils Planossolo and Argissolo, with four repetitions. The experiments accomplished in simple nutritious solution just received calcium (0,001 mM) and they had as source AlCl3 with doses that varied from 0,075 to 5,0 mM. Through the results of the chapter I was ended that in same or superior conditions of soil concentrations to 0,4 Cmolc/dm3 of Al caused toxicity to the plantules of Flamboyant, with effects mainly in the length root, and in solution simple nutritious doses same or upper to 0,075 mM of AlCl3 paralyzed the growth root. Al can be used as inhibitor of vegetable growth in plantules of Flamboyant. The chapter II had as objective studies the effects of the pruning and association with growth inhibitors in arboreal species. Four experiments were accomplished with the plants Sabi?, Sombreiro, and Cucumber (phytotoxicity Evaluation the herbicides). The experiments were installed in the Department of Fitotecnia-UFRRJ, Serop?dica. In the experiment 1 (Sabi?) all the plants were cut off 2 m of height, and they were applied the treatments: control, 2.4-D+Picloram, and Picloram. In the experiment 2 (Sabi?) all the plants were pruned removing 1/3 of the cup and applying the treatments: control, HCl, AlCl3, Picloram and nearby Cut (Without pruning of 1/3 of the cup). The experiment 3 (Sombreiro) had as treatments cut types in relation to the main trunk: nearby, leaving stub of 20 cm and of 40 cm. The experiment 4 (Pepino) it was installed in the originating from soil the first experiment with Sabi?. In the experiment 1, the treatment with Picloram delayed the beginning of the regrowth, important factor for the present study, so that they delay to arrive to the electric power spinning. In the experiment 2, just the treatment Picloram presented length and diameter of sprouts a little smaller in relation to the other treatments. In the experiment 3 it was verified that the nearby cut didn't present new budding until the 145 days after the pruning. In the experiment 4 the cucumber presented more intense toxicity in the treatment with Picloram. Was ended that Picloram and 2,4-D+Picloram were efficient for budding handling in adult plants of Sabi?, because they presented budding with small lengths, delaying the accomplishment of new pruning. In plants of Sombreiro the nearby cut was efficient, not presenting budding. It happened toxicity for Picloram in plants of Pepino. / O presente estudo buscou alternativas de manejo de crescimento e de poda em plantas utilizadas na arboriza??o urbana, visando ? diminui??o de conflitos destas com fia??es de energia el?trica. No cap?tulo I foram realizados experimentos com Flamboyant em solo e solu??o nutritiva simples contendo Al, com objetivo de estudar alternativas de manejo visando diminuir o crescimento e desenvolvimento de pl?ntulas Flamboyant. O alum?nio atrofia ra?zes podendo afetar o crescimento. Foram realizados seis experimentos com pl?ntulas (Solo e solu??o nutritiva simples) em condi??es de c?mara de crescimento e casa de vegeta??o, Departamento de Fitotecnia - UFRRJ. Nos experimentos de solo foram utilizadas duas fontes de sulfato de alum?nio, sendo uma comercial e uma fonte pura analiticamente, nas concentra??es 0, 100, 200, 300 e 400 kg ha-1 nos solos Planossolo e Argissolo, com quatro repeti??es. Os experimentos realizados em solu??o nutritiva simples receberam apenas c?lcio (0,001 mM) e tiveram como fonte AlCl3 com doses que variaram de 0,075 a 5,0 mM. Atrav?s dos resultados do cap?tulo I conclui-se que em condi??es de solo concentra??es iguais ou superiores a 0,4 Cmolc/dm3 de Al causaram toxicidade ?s pl?ntulas de Flamboyant, com efeitos principalmente no comprimento radicular, e em solu??o nutritiva simples doses iguais ou superiores a 0,075 mM de AlCl3 paralisaram o crescimento radicular. O Al pode ser utilizado como inibidor de crescimento vegetal em pl?ntulas de Flamboyant. O cap?tulo II teve como objetivo estudar os efeitos da poda e da sua associa??o com inibidores de crescimento em esp?cies arb?reas. Foram realizados quatro experimentos com as plantas Sabi?, Sombreiro, e Pepino (Avalia??o de fitotoxidade a herbicidas). Os experimentos foram instalados no Departamento de Fitotecnia-UFRRJ, Serop?dica-RJ. No experimento 1 (Sabi?) todas as plantas foram decepadas a 2 m de altura, e foram aplicados os tratamentos: Testemunha; 2,4-D+Picloram; e Picloram. No experimento 2 (Sabi?) todas as plantas foram podadas retirando 1/3 da copa e aplicando os tratamentos: Testemunha, HCl, AlCl3, Picloram e Corte rente (Sem poda de 1/3 da copa). O experimento 3 (Sombreiro) teve como tratamentos tipos de corte em rela??o ao tronco principal: rente, deixando toco de 20 cm e de 40 cm. O experimento 4 (Pepino) foi instalado no solo proveniente do primeiro experimento com Sabi?. No experimento 1, o tratamento com Picloram atrasou o in?cio da rebrota, fator importante para o presente estudo, a fim de que demorem chegar ? fia??o de energia el?trica. No experimento 2, apenas o tratamento Picloram apresentou comprimento e di?metro de brotos um pouco menores em rela??o aos demais tratamentos. No experimento 3 foi verificado que o corte rente n?o apresentou novas brota??es at? os 145 dias ap?s a poda. No experimento 4 o pepino apresentou toxidez mais intensa no tratamento com Picloram. Conclui-se que o Picloram e 2,4-D+Picloram foram eficientes para manejo de brota??es em plantas adultas de Sabi?, pois apresentaram brota??es com comprimentos pequenos, atrasando a realiza??o de nova poda. Em plantas de Sombreiro o corte rente foi eficiente, n?o apresentando brota??es. Ocorreu toxidez por Picloram em plantas de Pepino
217

Quantifica??o da fixa??o biol?gica de nitrog?nio associada ? cultura da cana-de-a??car (saccharum officinarum L.) / Quantification of biological nitrogen fixation associated with sugarcane (saccharum officinarum L.)

Lima, Eduardo 14 April 1988 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-05-12T11:41:08Z No. of bitstreams: 1 1988 - Eduardo Lima.PDF: 3150825 bytes, checksum: ddbd74e342854046edd6ca9d5d6b4876 (MD5) / Made available in DSpace on 2017-05-12T11:41:08Z (GMT). No. of bitstreams: 1 1988 - Eduardo Lima.PDF: 3150825 bytes, checksum: ddbd74e342854046edd6ca9d5d6b4876 (MD5) Previous issue date: 1988-04-14 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / A nitrogen balance study was carried out in four commercial cultivars of sugarcane grown in pots containing 64 kg of soil, with the objective of quantifying possible contributions of the biological nitrogen fixation (BNF) to the plants. Vinasse was added in half the vessels and all treatments were repeated 10 times. The pots were kept in the field and fertilized with the equivalent of 80 kg of N / ha with 15N labeled urea fertilizer. After 12 months of growth the plants accumulated between 10 and 24% of the total N of the soil + Fertilizer added. In the next nine months of growth, without any further addition of nitrogen fertilizer, the plants accumulated the equivalent of 8.5 to 19% of the original soil N + fertilizer. The cultivar CB 47-89 accumulated significantly more N than the other cultivars. This difference was greater in the absence of vinasse, and in this treatment the 15 N enrichment in the CB 47-89 cultivar was half that of the other cultivars, suggesting that there was a contribution of unlabelled N of the air to this cultivar via FBN . After 21 months of cultivation the N content of soil and roots was determined in 5 replicates. These analyzes revealed that planted pots lost between 7.5 and 12.5 g of soil N + fertilizer, but all accumulated more than this in plant tissues. In the case of cultivar CB 47-89, in the absence of vinasse, the plants removed approximately 10 g of N from the soil and fertilizer but accumulated about 35 g of N. In a second experiment, sugarcane cultivars were planted in pots containing 100 kg of soil, using two sources of 15N - labeled organic matter and gypsum pellets - with the objective of quantifying the contribution of the biological fixation of Nitrogen at different stages of the culture, using the 15n isotopic dilution technique. Harvests were carried out at 4.8.12 and 16 months of plant growth. There was not a good development of the plants that was attributed to the problem of aeration of the soil due to strong capacity, and there were no significant differences in the enrichment of 15N of the cultivars, suggesting that FBN contribution of the same magnitude occurred. Organic matter proved to be a better supplier of 15N for the soil solution, as it allowed a more constant N-labeling of soil for long-term experiments than did gypsum pellets. These data constitute the first direct evidence of very significant contributions of FBN associated to a sugarcane cultivar. / Um estudo com balan?o de nitrog?nio foi realizado em quatro cultivares comerciais de cana-de-a??car crescidos em vasos contendo 64 Kg de solo, com o objetivo de quantificar poss?veis contribui??es da fixa??o biol?gica de nitrog?nio (FBN) para as plantas. Vinha?a foi adicionada na metade dos vasos e todos os tratamentos foram repetidos 10 vezes. Os vasos foram mantidos no campo e adubados com o equivalente a 80 Kg de N/ha com fertilizante ur?ia marcada 15N. Ap?s 12 meses de crescimento as plantas acumularam entre 10 e 24 % do N total do solo + Fertilizante adicionado . Nos nove meses de crescimento seguintes, sem qualquer nova adi??o de fertilizante nitrogenado, as plantas acumularam o equivalente a 8,5 at? 19% do N original do solo + fertilizante. O cultivar CB 47-89 acumulou significativamente mais N do que os demais cultivares. Esta diferen?a foi maior na aus?ncia de vinha?a e, neste tratamento, o enriquecimento de 15 N no cultivar CB 47-89 foi a metade do que o dos outros cultivares, sugerindo que houve uma contribui??o de N n?o marcado do ar para este cultivar via FBN. Decorridos 21 meses de cultivo o conte?do de N do solo e das ra?zes foi determinado em 5 repeti??es. Estas an?lises revelaram que os vasos plantados perderam entre 7,5 e 12,5 g de N do solo +fertilizante, mas todos acumularam mais do que isto nos tecidos das plantas. No caso do cultivar CB 47 - 89, na aus?ncia de vinha?a, as planta removeram aproximante 10 g de N do solo e do fertilizante mas acumularam cerca de 35 g de N. Em um segundo experimento, cultivares de cana-de-a??car foram plantados em vasos contendo 100 Kg de solo, utilizando-se duas fontes fornecedoras de 15N - mat?ria org?nica marcada e peletes de gesso - com o objetivo de quantificar a contribui??o da fixa??o biol?gica de nitrog?nio em diferentes fases da cultura, atrav?s da t?cnica da dilui??o isot?pica de 15n. Foram realizadas colheitas aos 4.8,12 e 16 meses de crescimento das plantas. N?o houve um bom desenvolvimento das plantas que foi atribuido ao problema de aera??o do solo em fun??o de forte capacita??o, n?o ocorrendo diferen?as significativas no enriquecimento de 15N dos cultivares, sugerindo ter ocorrido contribui??o da FBN de mesma magnitude. A mat?ria org?nica mostrou-se um melhor fornecedor de 15N para a solu??o do solo, pois permitiu uma marca??o do N do solo mais constante para experimentos de longa dura??o do que os peletes de gesso. Estes dados constituem a primeira evid?ncia direta de contribui??es muito significativas da FBN associada a um cultivar de cana-de-a??car.
218

Efeito da superexpress?o do fator de transcri??o OsDof25 sobre a efici?ncia de absor??o de nitrog?nio em Orysa sativa L. / Effect of superexpression of the transcription factor OsDof25 on the efficiency of nitrogen uptake in Orysa sativa L.

SILVA, Renata Aparecida Costa 15 February 2012 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-26T20:35:35Z No. of bitstreams: 1 2012 - Renata Aparecida Costa Silva.pdf: 1687897 bytes, checksum: 4d1af8e117daa1842ae1766319ddf8d6 (MD5) / Made available in DSpace on 2017-05-26T20:35:35Z (GMT). No. of bitstreams: 1 2012 - Renata Aparecida Costa Silva.pdf: 1687897 bytes, checksum: 4d1af8e117daa1842ae1766319ddf8d6 (MD5) Previous issue date: 2012-02-15 / CAPES / Nitrogen is one of the nutrient elements most limiting for plant growth. Thus, increasing plant nitrogen usage efficiency (NUE) is an essential factor for sustainable agriculture, leading to an increased food production with less fertilizer input and less environment impact. The aim of this study was to evaluate the effect of OsDof25 overexpression on N-NO3- and N-NH4+ uptake. In transgenic rice plants, OsDof25 was expressed under control of maize ubiquitin promoter (UBIL:OsDof25:3xHA). Two experiments were conducted: one to evaluate the kinetic parameters Vm?x and KM, and another to analyze the expression level of nitrate (NRT2.1~2.2 and NAR) and ammonium transporters (AMT1.1~1.3), both under high and low NO3- and NH4+ supply. The untransformed plants showed higher growth that transformed lineages. The L1 and L2 showed a lower value of the KM in the resupply treatment of 0.2 mM N-NO3-. In the resupply with 0.2 mM N-NH4 + the L4 showed higher Vmax and L1 lower KM. There were no large variations in uptake kinetics between the transformed and untransformed plants. At the root the NRT2 showed low expression in lineages L1 and L4, when under constant supply of N-NO3-, in contrast, in the treatment under resupply with 0.2 mM N-NO3-was increased expression of OsNTR2.1 ~ 2.2, and NAR in both transformed lineages, but in the root the concentration of NO3- was opposed to the expression of NRT2 and NAR, in both conditions. In the leaves, the line L4 showed high expression of the transporter OsNRT2.1 with the resupply of 0.2 and 2.0 mM N-NO3-. In plants grown under constant supply of N-NH4+, L1 showed lower expression of AMT1 in the root compared to L4 and untransformed plants. When subjected to nitrogen deficiency, there was an increased expression of the OsAMT1.2. However, there was no correlation between N transporter expression levels and NO3- and NH4+ content in the transformed plants, indicating a possible change in enzyme activity and reduction or assimilation of N in these plants. The transformed plants when subjected to resupply with low levels of nitrate and ammonium showed better response parameters Vmax and KM compared to the untransformed. In the plants transformed the resupply with nitrate at low concentration resulted in increasing the gene expression of the transporters (OsNTR2.1 ~ 2.2 and protein OsNAR2.1), and the treatment with constant supply provided greatest nitrate accumulation in these plants. The results of both kinetic parameters and accumulation of fresh matter suggest that plants transformed for the expression of the OsDof25 presented highest tolerance to nutritional stress. / O nitrog?nio ? um dos elementos minerais que mais limita o desenvolvimento das plantas. Assim, aumentar a efici?ncia de uso de nitrog?nio (EUN) ? um fator ? essencial para uma agricultura sustent?vel, levando a um aumento da produ??o de alimentos com menor uso de insumos e menos impactos ao ambiente. Este trabalho teve por objetivo avaliar o efeito da superexpress?o do fator de transcri??o OsDof25 sobre a absor??o de nitrog?nio em duas linhagens transformadas de arroz (L1 e L4) da variedade Nipponbare comparando-as com plantas n?o transformadas (WT). Nas plantas transformadas, o OsDof25 foi expresso sob o controle do promotor da ubiquitina 1 de milho (UBIL:OsDof25:3xHA). For feitos dois experimentos: um para avaliar os par?metros cin?ticos Vm?x e KM, sob condi??es de alto e baixo suprimento de N-NO3- e N-NH4+, e outro para analisar a express?o dos transportadores de NO3- (NRT2.1~2.2 e NAR) e NH4+ (AMT1.1~1.3) tamb?m sob alto e baixo suprimento desses ?ons. As plantas n?o transformadas apresentaram maior crescimento do que as linhagens transformadas. As L1 e a L2 mostraram menor valor de KM no tratamento com ressuprimento de 0,2 mM de N-NO3-. No ressuprimento com 0,2 mM de N-NH4+ a L4 apresentou maior Vm?x e L1 menor KM, mas, n?o houve grandes varia??es nos par?metros cin?ticos de absor??o entre as plantas transformadas e n?o transformadas. Na raiz os NRT2 mostraram baixa express?o nas linhagens L1 e L4 quando submetidas ao suprimento constante de N-NO3-, em contrapartida, no tratamento sob ressuprimento com 0,2 mM de N-NO3- ocorreu aumento de express?o dos OsNTR2.1~2.2 e NAR nas duas linhagens transformadas, por?m na raiz a concentra??o de N-NO3- foi oposta a express?o dos NRT2 e NAR, em ambas as situa??es. Nas folhas, a linhagem L4 apresentou alta express?o do transportador OsNRT2.1 com o ressuprimento de 0,2 e 2,0 mM de N-NO3-. Nas plantas submetidas ao suprimento constante de N-NH4+, a L1 apresentou menor express?o dos AMT1 na raiz quando comparada a L4 e a planta n?o transformada. Quando submetida a defici?ncia de N-NH4+, a express?o do OsAMT1.2 aumentou nas ra?zes de todas as plantas. Entretanto, n?o houve correla??o positiva entre a express?o dos transportadores de N e os teores de NO3- e NH4+ nas linhagens transformadas, indicando uma poss?vel altera??o na atividade das enzimas de redu??o e ou assimila??o de N. As plantas transformadas quando submetidas ao ressuprimento com baixos teores de nitrato e am?nio apresentaram melhor resposta dos par?metros Vm?x e KM em rela??o a n?o transformadas. Nas plantas transformadas o ressuprimento com nitrato em baixa concentra??o resultou em maior express?o dos genes dos transportadores OsNTR2.1~2.2 e da prote?na OsNAR2.1 e o tratamento com suprimento constante proporcionou maior ac?mulo de nitrato nestas plantas. Os resultados tanto dos par?metros cin?ticos quanto do ac?mulo de mat?ria fresca sugerem que as plantas transformadas para express?o do OsDof25 apresentaram maior toler?ncia ao estresse nutricional.
219

Modelagem qualitativa e simula????o em gest??o estrat??gica

Santos, Alberto Joaquim dos 27 August 2012 (has links)
Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-12T12:59:50Z No. of bitstreams: 1 AlbertoJoaquimdosSantosDissertacao2012.pdf: 2924586 bytes, checksum: b73c45b8d6c5823c680066ae0f398f0c (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-12T13:00:02Z (GMT) No. of bitstreams: 1 AlbertoJoaquimdosSantosDissertacao2012.pdf: 2924586 bytes, checksum: b73c45b8d6c5823c680066ae0f398f0c (MD5) / Made available in DSpace on 2017-04-12T13:00:02Z (GMT). No. of bitstreams: 1 AlbertoJoaquimdosSantosDissertacao2012.pdf: 2924586 bytes, checksum: b73c45b8d6c5823c680066ae0f398f0c (MD5) Previous issue date: 2012-08-27 / The Balanced Scorecard (BSC) is a widely adopted methodology for measuring and monitoring the implementation of organizational strategy. However, some authors are critical to the strategic maps derived from the BSC due to: (i) the relationship of causes and effects are one-way, (ii) the model is static and does not express the temporality, and (iii) the fact that its indicators capture only past facts. Given that actors, resources, and processes interact in a scenario for the execution of a strategic plan, it seems to be an interesting idea to apply modeling and simulation techniques to understand this dynamics. Complementarily, the great uncertainty of the variables involved in this scenario works as a strong driver to the adoption of qualitative representations instead of a precise numerical model. Thus, the Qualitative Modeling technique is studied in this research, exploring the variables values represented by intervals and distinct points in their respective domains. Two qualitative models were built, one related to the scenarios for strategic planning and other for representing the strategic map of an organization. Simulations on the models were conducted in order to enable: (i) a conceptual study of the relations between the components of the plan, showing how modeling and qualitative simulations can help in maintaining their alignment; (ii) the anticipation by the strategic level of the organization of problems arising from assumptions about the values of variables; and (iii) promoting organizational learning from the sensemaking process triggered by the analysis of the simulation results. A case study was carried out on the institutional strategic planning from the Brazilian General Attorney in order to enlighten the benefits from the proposed approach. / O Balanced Scorecard (BSC) ?? uma metodologia amplamente adotada para medir e monitorar a implementa????o da estrat??gia organizacional. No entanto, alguns autores s??o cr??ticos quanto aos mapas estrat??gicos oriundos do BSC por conta: (i) das rela????es de causa e efeito serem unidirecionais, (ii) de o modelo ser est??tico e n??o expressar temporalidade, e (iii) de seus indicadores de captarem apenas o passado. Visto que em um cen??rio de execu????o de um plano estrat??gico interagem atores, recursos e processos, a ideia de se aplicar t??cnicas de modelagem e simula????o para se entender essa din??mica ?? atrativa. A grande incerteza das vari??veis envolvidas neste cen??rio funciona como um forte incentivo para a ado????o de representa????es qualitativas em vez de um modelo num??rico preciso. Assim, a t??cnica Modelagem Qualitativa foi ?? estudado nesta pesquisa, explorando os valores das vari??veis representadas por intervalos e pontos distintos em seus respectivos dom??nios. Dois modelos qualitativos foram constru??dos, um relacionado com os cen??rios de planejamento estrat??gico e outro para representar o mapa estrat??gico de uma organiza????o. Simula????es sobre os modelos foram conduzidas a fim de permitir: (i) a combina????o de uma reflex??o concetual sobre as rela????es entre os componentes do plano, mostrando como a modelagem e simula????es qualitativos podem ajudar na manuten????o do seu alinhamento; (ii) que o n??vel estrat??gico da organiza????o antecipe problemas decorrentes de suposi????es sobre os valores das vari??veis; e (iii) a aprendizagem organizacional do processo de tomada de sentido desencadeada pela an??lise dos resultados da simula????o. Um estudo de caso foi realizado no planejamento estrat??gico institucional do Minist??rio P??blico Federal, a fim de se evidenciar os benef??cios da abordagem proposta.
220

Contribui??o das bact?rias diazotr?ficas no crescimento de Brachiaria brizhanta cv. Marandu / Contribution of diazotrophic bacteria in the growth of Brachiaria brizhanta cv. Marandu

SHOCKNESS, Leonardo dos Santos Fran?a 29 February 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-13T20:11:22Z No. of bitstreams: 1 2016 - Leonardo dos Santos Fran?a Shockness.pdf: 1003791 bytes, checksum: efd5f4204bec8c095ea24c37002fd302 (MD5) / Made available in DSpace on 2017-10-13T20:11:22Z (GMT). No. of bitstreams: 1 2016 - Leonardo dos Santos Fran?a Shockness.pdf: 1003791 bytes, checksum: efd5f4204bec8c095ea24c37002fd302 (MD5) Previous issue date: 2016-02-29 / CAPES / One of the main factors that affect growth and persistence of grasses in the tropics, thus increasing the degradation of pastures, is a nitrogen deficiency in the soil. However, nitrogen fertilizers much burden the production costs, and the demand for food increasing year by year, has emphasized the need for sustainable alternatives, such as biological nitrogen fixation. It is necessary to do more research on Biological Nitrogen Fixation (BNF) in forage grasses, especially about diversity among nitrogen-fixing bacteria associated with these plants, so that new bacteria can be discovered, as well as its potential to FBN. This study aimed to isolate diazotrophic bacteria of the genus Azospirillum spp. or Herbaspirillum spp., from two cultivars of B. brizhanta (Marandu and Xara?s) and one of B. decumbens (IPEAN), to test them, and to assess their contribution to the growth of Brachiaria brizhanta cv. Marandu identifying the three most promising. This study was conducted at Embrapa Agrobiology in Serop?dica - RJ, in two stages. The first was to isolate possible diazotrophic bacteria from Brachiaria brizantha and B. decumbens plants, using the cultivars Marandu and Xara?s B. brizantha, and the cultivar IPEAN of B. decumbens. The isolation was performed using three semi-solid media, NFB, LGI and JNFb, where the first two selected bacteria of the genus Azospirillum, and the third one Herbaspirillum bacteria. There were selected 46 isolates and, after purification, it was obtained 15 isolates pure, and made the phenotypic characterization thereof. Further biochemical tests were the phosphate solubilization, acetylene reduction analysis (ARA), and production of acid-3-indole acetic (IAA). All tested isolates produced ARA ethylene, even in small quantities, with prominence for isolates L2, L4, J3, J6, J7 and J8. In the phosphate solubilization the isolates N1, L1, J2, J3, J4, J5, J6, J7, J8, and T14 were able to solubilize phosphate. In the EIA production the isolates N1, J1, J2, J3, J4, J5, J6, J7, J8 and J9 excelled. In the second phase it was conducted an experiment to study plant - bacteria interaction. It consisted of the inoculation of 15 isolates from the first phase plus three isolates known as references (SP245, Z94, CBAMC) in B. brizhanta cultivar Marandu, plus the control without inoculation and without N. In this experiment the isolates L2, L4 and J6 outstand when compared to the other seven parameters evaluated. On the basis of this study we can conclude that there are nitrogen fixing bacteria, phosphate solubilizing, and that produce 3-indoleacetic acid, associated to Brachiaria brizhanta and Brachiaria decumbens. The isolated bacteria of the two B. brizhanta cultivars (Marandu and Xara?s), and the Brachiaria decumbens (IPEAN) cultivar were more efficient in the growth of B. brizhanta cultivar Marandu than the bacteria standards obtained from other plant species. Also, among the 15 isolates from Brachiaria plants, the J6, L2 and L4 were statistically different from the others, and are considered the three most promising. / Um dos principais fatores que afeta o crescimento e a persist?ncia de gram?neas nos tr?picos, aumentando assim a degrada??o das pastagens, ? a defici?ncia de nitrog?nio no solo. Entretanto, fertilizantes nitrogenados oneram muito os custos de produ??o, e com a demanda por alimentos crescendo ano a ano, tem-se enfatizado a necessidade de alternativas sustent?veis, tal como a fixa??o biol?gica de nitrog?nio. Faz-se necess?rio pesquisas com Fixa??o Biol?gica de Nitrog?nio (FBN) em gram?neas forrageiras, principalmente sobre diversidade de bact?rias diazotr?ficas associadas a essas plantas, para que novas bact?rias possam ser descobertas, assim como seu potencial de FBN. Este trabalho teve como objetivo isolar bact?rias diazotr?ficas do g?nero Azospirillum Spp. ou Herbaspirillum Spp., provenientes de duas cultivares de B. brizhanta (Marandu e Xar?es) e de uma cultivar de B. decumbens (Ipean), testar as mesmas, e avaliar sua contribui??o no crescimento de Brachiaria brizhanta cv. Marandu identificando as tr?s mais promissoras. O trabalho foi realizado na Embrapa Agrobiologia em Serop?dica ? RJ, em duas etapas. Na primeira foi feito o isolamento de poss?veis bact?rias dizotr?ficas provenientes de plantas de Brachiaria brizantha e Brachiaria decumbens, sendo utilizadas as cultivares Marandu e Xara?s de B. brizantha e a cultivar IPEAN de B. decumbens. O isolamento foi realizado utilizando tr?s meios semiss?lidos, NFB, LGI e JNFB, onde os dois primeiros selecionaram bact?rias do g?nero Azospirillum, e o terceiro bact?rias do g?nero Herbaspirillum. Foram selecionados 46 isolados, e ap?s a purifica??o obteve-se 15 isolados puros, sendo feita a caracteriza??o fenot?pica dos mesmos, e posteriormente os testes bioqu?micos de solubiliza??o de fosfato, an?lise da redu??o de acetileno (ARA) e produ??o de ?cido-3-indolac?tico (AIA). Na ARA todos isolados avaliados produziram etileno, mesmo em pequenas quantidades, tendo destaque os isolados L2, L4, J3, J6, J7, e J8. Na solubiliza??o de fosfato os isolados N1, L1, J2, J3, J4, J5, J6, J7, J8 e T14 foram capazes de solubilizar fosfato. Na produ??o de AIA se sobressa?ram os isolados N1, J1, J2, J3, J4, J5, J6, J7, J8 e J9. Na segunda etapa foi realizado o experimento de intera??o planta - bact?ria; que consistiu da inocula??o dos 15 isolados da primeira etapa, acrescidos de tr?s isolados conhecidos como padr?es (SP245, Z94, CBAMC) em B. brizhanta cv. Marandu, mais a testemunha n?o inoculada e sem N. Neste experimento os isolados L2, L4 e J6 se destacaram em rela??o aos outros nos sete par?metros avaliados. Com base neste trabalho podemos concluir que existem bact?rias fixadoras de nitrog?nio, solubilizadoras de fosfato e que produzem ?cido-3-indolac?tico associadas a Brachiaria brizhanta e Brachiaria decumbens. As bact?rias isoladas de duas cultivares de B. brizhanta (Marandu e Xar?es) e de uma cultivar de B. decumbens (Ipean) se mostraram mais eficientes no crescimento de B. brizhanta cv. Marandu do que as bact?rias padr?es provenientes de outras esp?cies de plantas. Ainda, dentre os 15 isolados de plantas do g?nero Brachiaria, os isolados J6, L2 e L4 diferiram estatisticamente dos demais, sendo considerados os tr?s mais promissores.

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