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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.
511

Uso de lipase vegetal a partir de sementes de mamona para a hidrólise enzimática de óleo de crambe / Use of castor bean seeds as lipase source for hydrolyisis of crambe oil

Tavares, Fernanda 16 May 2018 (has links)
Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-11-05T20:12:01Z No. of bitstreams: 1 Fernanda_Tavares_2018.pdf: 3497938 bytes, checksum: 33976a24dbef1bda196a346bd634eade (MD5) / Made available in DSpace on 2018-11-05T20:12:01Z (GMT). No. of bitstreams: 1 Fernanda_Tavares_2018.pdf: 3497938 bytes, checksum: 33976a24dbef1bda196a346bd634eade (MD5) Previous issue date: 2018-05-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Lipases are a class of enzymes responsible for breaking down the ester bonds of triglycerides; they can derivate from microbial, animal or vegetal origin, the last ones can be found mainly from the germination processes of oilseeds. Castor bean seeds have the advantage of having lipases in its composition even in non-germinated state. In this sense, the present work aims to evaluate the use of castor bean as a source of lipase in the hydrolysis of triglycerides to obtain free fatty acids, employing sonication and orbital agitation system, investigating the use of in natura seeds and seeds after oil extraction process, to enable its commercial use. In addition, the crambe oil is employed, an oil that is rich in monosaturated free fatty acids, easy obtainment and it is has no use in the food chain. Using CCRD experimental designs an optimum point was found for in natura seeds in the condition of temperature of 33 °C, 0.87 buffer/oil (m/m) and 0.31 catalyst/substrate (m/m) reaching a yield of 91% after 4 hours of reaction; for the incubated seeds the optimum condition was in the temperature of 43.8 °C, 1.8 buffer/oil (m/m) and 0.07 catalyst/substrate (m/m) in which approximately 88% yield was achieved after 4 hours of reaction. In order to optimize the reaction conditions, the use of ultrasound in the enzymatic hydrolysis was evaluated, as optimal conditions were approximately 70% of ultrasound power, 1.79 buffer/oil (m/m), 0.25 catalyst/substrate (m/m) for the in natura seeds, achieving approximately 86% of yield after 5 minutes of ultrasonic reaction and 91% after more 30 minutes of reaction with mechanical stirring and for incubated seeds approximately 68% of ultrasound power, 1.67 buffer/oil (m/m), 0.06 catalyst/substrate (m/m), reaching 73% of yield after 5 minutes of ultrasonic reaction and 77% after more 30 minutes of reaction with mechanical stirring. The best yield, therefore, was verified when in natura seeds were employed; these seeds don’t go through any preparation process and have emulsifying components that can help in the triglycerides hydrolysis. Besides that, a mathematical model was proposed and it was satisfactory to predict the experimental data of crambe oil enzymatic hydrolysis when in natura and incubated seeds were employed in mechanical-orbital agitation reactions and with ultrasonic emulsification. In this sense, the contribution of the present work is to give a better understanding for the enzymatic hydrolysis of triglycerides with the utilization of vegetal lipases from castor seeds, and employing an oil that has not been yet well studied and utilized. / Lipases são uma classe de enzimas responsáveis pela quebra de ligações éster de triglicerídeos e podem ser de origem microbiana, animal ou vegetal, sendo que as ultimas podem ser encontradas principalmente a partir do processo de germinação de sementes oleaginosas. As sementes da mamona possuem a vantagem de conterem lipase em sua composição mesmo em fase não germinativa. Dessa forma, o presente trabalho tem como objetivo avaliar o uso da semente de mamona como fonte de lipase na hidrólise de triglicerídeos para obtenção de ácidos graxos livres empregando ultrassom e sistema de agitação orbital, investigando o uso das sementes in natura e sementes após o processo de extração de óleo, para viabilizar seu uso comercial. Além disso, busca-se empregar o óleo de crambe, um óleo rico em ácidos graxos monoinsaturados, de fácil obtenção e que não é usado na cadeia alimentar. Empregando planejamentos experimentais DCCR verificou-se ponto ótimo para sementes in natura na condição de 33°C de temperatura, 0,87 solução tampão/óleo (m/m) e 0,31 catalisador/substrato (m/m) no qual atingiu-se 91% de rendimento após 4 horas de reação; para as sementes incubadas o ponto ótimo foi nas condições de 43,8°C de temperatura, 1,8 solução tampão/óleo (m/m) e 0,07 catalisador/substrato (m/m) no qual atingiu-se aproximadamente 88% de rendimento após 4 horas de reação. Visando otimizar as condições reacionais, foi avaliado o uso de ultrassom na hidrólise enzimática, as condições ótimas foram de aproximadamente 70% de potência do ultrassom, 1,79 tampão/óleo (m/m), 0,25 catalisador/substrato (m/m) para as sementes in natura, atingindo se aproximadamente 86% de rendimento após 5 minutos de reação em ultrassom e 91% após mais 30 minutos de reação com agitação mecânica-orbital e para as sementes incubadas aproximadamente 68% de potência do ultrassom, 1,67 tampão/óleo (m/m), 0,06 catalisador/substrato (m/m), atingindo se aproximadamente 73% de rendimento após 5 minutos de reação em ultrassom e 77% após mais 30 minutos de reação com agitação mecânica. Verificou-se, portanto, um melhor rendimento com a utilização das sementes in natura, que não passam por nenhum processo de preparo, e possuem componentes emulsificantes que auxiliam na hidrólise de triglicerídeos. Além disso, um modelo matemático foi proposto e foi satisfatório para predição dos dados experimentais das hidrólises enzimáticas do óleo de crambe empregando sementes in natura e incubadas em reações com agitação mecânica-orbital e em ultrassom. Dessa forma, o presente trabalho contribui de forma a melhorar o entendimento do mecanismo da reação de hidrólise enzimática de triglicerídeos com utilização de lipases vegetais a partir da semente de mamona, empregando um óleo ainda pouco utilizado e estudado, o crambe.
512

Avaliação agronômica da disponibilização de nitrogênio à cultura de feijão sob sistema de semeadura direta. / Agronomic evaluation of nitrogen availability to common bean crop carried out under no tillage system.

Eraldo Augusto de Carvalho 04 February 2003 (has links)
A combinação de nove tratamentos (T) foi utilizada com o objetivo de fazer uma avaliação agronômica da disponibilização de nitrogênio (N) na produção de feijão, quando inoculado com Rhizobium leguminosarum bv. Phaseoly (RL), cobalto (Co) e molibdênio (Mo), conduzidos sob sistema de semeadura direta (SSD). T1 disponibilizou N através do solo, T2 através da inoculação das sementes com RL (400 g por 50 kg de sementes) imediatamente antes da semeadura, T3 através da inoculação das sementes com RL e adubação nitrogenada em cobertura (60 kg.ha -1 ) (ANC60), utilizando como fonte de N o nitrato de amônio (NA) contendo 33% de N, T4 através inoculação das sementes com Co e Mo (116 g.ha -1 ), produto formulado contendo 1,5% de Co e 10,0% de Mo, T5 através da inoculação das sementes com Co e Mo e ANC60, T6 através da inoculação das sementes com Co, Mo e RL, T7 através da inoculação das sementes com Co, Mo e RL e ANC60, T8 através de ANC60, T9 através da adubação mineral na semeadura com NA (20 kg.ha -1 ) e ANC60. A área escolhida localiza-se no município de Piracicaba, SP (22º42'30" Sul e 47º38'30" Oeste) pertencente ao Departamento de Produção Vegetal da Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, onde o SSD vem sendo usado desde 1993, sendo que as culturas implantadas nessa área nunca foram inoculadas com bactérias fixadoras de N. O solo foi amostrado na camada de 0,0-0,2 m anualmente, de 1994 a 1999, mostrando evolução dos atributos químicos do solo. Os parâmetros utilizados na análise foram: número de nódulos, massa de matéria seca de raízes, nódulos, e parte aérea, número de vagens por planta, número de grãos por vagem, massa de 100 grãos, teor de nitrogênio na planta, índice de utilização de nitrogênio (IUN), coeficientes técnicos e custo de produção total, índice de lucratividade (IL) e rendimento de grãos (Rg). Os resultados evidenciaram que o T7 é uma alternativa para disponibilizar N à cultura, dentro do SSD, obtendo o maior Rg. O SSD foi eficiente na manutenção do teor de matéria orgânica no solo, mas não foi eficiente para suprir totalmente a demanda da planta por N, evidenciando a necessidade da adoção de métodos alternativos para incrementar sua disponibilidade no SSD. / To evaluate the nitrogen (N) availability to common bean grain yield under no tillage system (SSD) after inoculation with Rhizobium leguminosarum bv. phaseoly (RL), cobalt (Co) and molybdenum (Mo), nine treatments (T) were used. T1 supplied N from the soil, T2 supplied N through the inoculation of the seed prior to sowing with RL (400 g per 50 kg of seeds), T3 supplied N through the inoculation of the seed prior to sowing with RL and additional N was also added using a top dressing with 60 kg.ha -1 of ammonium nitrate (NA) with 33% of N (ANC60), T4 supplied N through inoculation of the seed prior to sowing with Co and Mo (116 g.ha -1 ) using a formulated product containing Co (1.5%) and Mo (10.0%), T5 supplied N through inoculation of the seed prior to sowing with Co and Mo and ANC60, T6 supplied N through inoculation of the seed prior to sowing with Co and Mo and RL, T7 supplied N through inoculation of the seed prior to sowing with Co and Mo and RL and ANC60, T8 supplied N through using a top dressing, T9 supplied N using NA in the sowing (20 kg.ha -1 ) and ANC60. The field experiment was carried out at Crop Science Department, Esalq, University of São Paulo, Piracicaba, Brazil (22°42'30" South and 47° 38' 30" West), where the SSD has been practiced since 1993, and the crop had never been inoculated with N fixing bacteria. The soil was sampled annually at 0.0 to 0.2 m depth, from 1993 to 1999, showing evolution in the soil chemical attributes. The following agronomic parameters related to common bean crop were used for statistical analysis: the number of nodules, roots and nodules dry biomass, shoot dry biomass, number of pods per plant and grains per pod, and 100 grains mass, the plant nitrogen content, the nitrogen utilization index (IUN), the technical crop production coefficients, the total production cost, the profitability index (IL) and grain yield (Rg). The results showed that T7 was an alternative to make nitrogen available to common bean crop inside SSD, reaching the best productivity. No tillage system was efficient in the maintenance of the soil organic matter, but it was not efficient enough to supply the total demand of the plant for nitrogen, showing the need of alternative methods adoption to increment its availability to the system.
513

Pesquisa e desenvolvimento no setor de sementes de arroz irrigado no Rio Grande do Sul / Research and development in the irrigated rice seeds sector in Rio Grande do Sul State

Marquesan, Fábio Freitas Schilling 06 August 2008 (has links)
Made available in DSpace on 2014-08-20T13:44:41Z (GMT). No. of bitstreams: 1 dissertacao_fabio_marquesan.pdf: 557738 bytes, checksum: 7bf17897cec926400356dcb76f522abb (MD5) Previous issue date: 2008-08-06 / The aim of this work was to investigate the ways in which the organizations dedicated to the research and development (R&D) of rice irrigated seeds in the Rio Grande do Sul State face the action of opportunist agents, which promote the commerce and the informal use of genetic materials protected by Law. The research problem was structured as the following questions: How do the agents involved in the R&D of rice irrigated seeds in RS face the difficulties of remuneration in the investments carried out during the development of new varieties of seeds; and how do these difficulties intervene in the management of competitive strategies? For answering this question, the vision of the responsible right-handers for the programs management in R&D, from five organizations that act in the sector, was investigated. The Theoretical Reference used in this research was based on the theories of Industrial Organization (IO), New Institutional Economy (NIE), Institutional Environment (IE) and Transactions Cost Economics (TCE). The research is an exploratory case study of applied nature, whose way of approach and data analysis is qualitative, of the type content analysis. The research also presents characteristics of a census, since there are five units that follow the study requirements and all of them have offered answers to the research questionnaire. The primary data collection was done through a transversal cut survey, carried out from March to July, 2008. The results have shown that, among the consulted organizations, only one did not have its seeds illegally used. However, all of them pointed out they have been affected by acts involving the inappropriate use of legally protected seeds. The five organizations have affirmed that the prescription gotten by the commerce of rice seeds in the RS State, up to the moment, is not enough to finance its activities of R&D. As consequence, there was a retraction in the number of launchings of rice seeds through the varieties. The strategies already adopted for the continuity of the investments are analyzed, necessarily, by the R&D of anti-reproductive attributes of the proper seeds. Thus, the majority of the resources were directed for the development of rice hybrids as the main strategy of the copyright protection. Some discredit from the sector in relation to the coordination role of the seeds production system and commercialization in the RS State was observed. In the consulted professionals view, it would be essential that more intensive institutional actions were undertaken in both inspection and in the control of such process. For them, the application of severe criminal punishment to the offenders would be an efficient way to promote the fulfillment of the Laws and, thus, trying to improve the coordination in the sector. It was also observed the awareness campaigns should be more stimulated in order that all the involved ones in the question could recognize the importance of royalties payment (or another way of investments remuneration) as a way to guarantee the maintenance of the R&D sector of the irrigated rice seeds in the RS State. / O objetivo deste trabalho foi investigar os meios pelos quais as organizações dedicadas à pesquisa e desenvolvimento (P&D) de sementes de arroz irrigado no Estado do Rio Grande do Sul fazem frente à ação de agentes oportunistas, os quais promovem o comércio e o uso informal de materiais genéticos protegidos por Lei. O problema da pesquisa foi estruturado conforme a seguinte pergunta: Como os agentes envolvidos na P&D de sementes de arroz irrigado no RS enfrentam as dificuldades de remuneração dos investimentos realizados no desenvolvimento de novas cultivares e de que maneira isso interfere na gestão de suas estratégias competitivas? Para responder à questão, buscou-se a visão dos responsáveis diretos pela gestão dos programas de P&D das cinco organizações que atuam no setor. O Referencial Teórico que embasou o trabalho amparou-se nas teorias de Organização Industrial (OI), Nova Economia Institucional (NEI), Ambiente Institucional (AI) e Economia dos Custos de Transação (ECT). A pesquisa enquadrou-se como um estudo de caso exploratório de natureza aplicada, cuja forma de abordagem e análise dos dados é qualitativa, do tipo análise de conteúdo. A obra guarda, ainda, características de um censo, pois são cinco as unidades que atendem aos requisitos do estudo e todas ofereceram respostas ao questionário da pesquisa. A coleta dos dados primários deu-se por meio de uma survey em corte transversal, realizada entre os meses de março e julho de 2008. Os resultados mostraram que, entre as organizações consultadas, apenas uma não teve suas sementes utilizadas de forma ilegal. Entretanto, todas apontaram que foram afetadas por atos envolvendo o uso indevido de sementes protegidas. As cinco organizações afirmaram que a receita obtida pelo comércio de sementes de arroz no RS, até o momento, é insuficiente para financiar suas atividades de P&D. Como conseqüência, houve retração no número de lançamentos de sementes de arroz por meio de variedades. As estratégias já adotadas para a continuidade dos investimentos passam, necessariamente, pela P&D de atributos anti-reprodutivos das próprias sementes. Assim, a maioria dos recursos foi direcionada para o desenvolvimento de híbridos de arroz como principal estratégia de proteção da propriedade intelectual. Observou-se certo descrédito do setor em relação ao papel de coordenação do sistema de produção e comercialização de sementes no Estado. Na visão dos profissionais consultados, seria fundamental que se empreendessem ações institucionais mais intensivas principalmente na fiscalização e controle desses processos. Para eles, a aplicação de punição criminal severa aos contraventores seria um modo eficaz de se promover o cumprimento das Leis e, assim, tentar melhorar a coordenação no setor. Salientou-se, ainda, que as campanhas de conscientização deveriam ser mais estimuladas, de modo que todos os envolvidos na questão reconhecessem a importância do pagamento de royalties (ou outro meio de remuneração dos investimentos) como forma de garantia da manutenção do setor de P&D de sementes de arroz irrigado no RS.
514

AVALIAÇÃO DA QUALIDADE DE SEMENTES E MUDAS DE ESPÉCIES FLORESTAIS NATIVAS / NATIVE FOREST SPECIES SEEDS AND SEEDLINGS QUALITY EVALUATION

Cherobini, Edicléia Aparecida Iensen 23 March 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The native forest species seeds are the responsible for the maintenance and perpetuation of those in nature, being for natural germination or by programs of seedlings formation for the forest recomposing. The use of fast tests to evaluate the seeds quality and to supply to the producer or nursery the specify information due to the sowing performance is the great importance in the process of seedlings production. The low germination or emergency percentage of plantules can be a consequence of problems as numbness of the seeds, low energy or due to the low physiologic and sanitary quality. The quality of the seeds is a sum of a series of aspects, among them the sanitary quality assumes fundamental importance. The association of pathogenic microorganisms in the seeds could influence the viability, longevity and the pathogenic transmission to the resulting plant. The present work had been evaluated four native forest species: Schizolobium parahyba (Vell.) S. F. Blake, Enterolobium contortisiliquum (Vell.) Morong, Cedrela fissilis (Vell.) and Sesbania virgata Poir, being justified by the economical and ecological importance that they present and their necessary studies, evaluating the seeds and seedlings quality of these species. The present study had been accomplished with the objective of determining the physiologic and sanitary quality of native forest species seeds, coming from Rio Grande do Sul, Santa Catarina and Paraná, through different tests. The experiments had been accomplished in the Phytosanitary Defense Laboratory and in the Forest Nursery. Germination, energy, and sanity tests had been conducted as well as seedlings evaluation starting from these seeds had been done to evaluate the potential of these ones in the good quality seedlings production. The present study had been showed that the pathogen presence as Aspergillus spp. and Penicillium spp. could cause losses in germination due to the seeds rottenness. The presence of these microorganisms is related to the collection and storage conditions in inadequate form. Fungus of Fusarium and Alternaria gender had been found in the seeds of different origins causing interference in the seedlings quality and consequently they had been reduced the establishment of the plants in the field. / As sementes de espécies florestais nativas são as responsáveis pela manutenção e perpetuação destas na natureza, seja pela germinação natural ou por programas de formação de mudas para a recomposição florestal. O uso de testes rápidos para avaliar a qualidade das sementes e fornecer ao produtor ou viveirista informações precisas quanto ao desempenho na semeadura é de grande importância no processo de produção de mudas. A qualidade das sementes é um somatório de uma série de aspectos, dentre os quais a qualidade sanitária assume importância fundamental. A associação de microorganismos patogênicos nas sementes pode influenciar na viabilidade, longevidade e na transmissão para a planta resultante. O presente estudo foi realizado com o objetivo de determinar a qualidade fisiológica e sanitária de sementes das espécies florestais nativas: Schizolobium parahyba (Vell.) S. F. Blake, Enterolobium contortisiliquum (Vell.) Morong, Cedrela fissilis (Vell.) e Sesbania virgata Poir, procedentes do Rio Grande do Sul, Santa Catarina e Paraná, através de diferentes testes. Os experimentos foram realizados no Laboratório de Fitopatologia e no Viveiro Florestal da UFSM. A avaliação da qualidade das sementes foi realizada através dos testes de germinação, vigor e sanidade. A avaliação da qualidade das mudas resultantes foi realizada através de testes em viveiro. O presente estudo mostrou que a presença de patógenos, como Aspergillus spp. e Penicillium spp., podem causar perdas na germinação devido ao apodrecimento de sementes. Fungos do gênero Fusarium e Alternaria, encontrados nas sementes das diferentes procedências, causam interferência na qualidade das mudas e, conseqüentemente, reduzem o estabelecimento das plantas no campo. Através dos testes realizados com as sementes coletadas nos diferentes Estados da Região Sul, foi possível verificar as diferenças dos níveis de vigor e a alta correlação com emergência de plantas no viveiro. Independente do Estado de origem, as sementes das diferentes espécies apresentaram variações na qualidade fisiológica e sanitária.
515

Colheita e Armazenamento de Sementes de Gabiroba (Campomanesia adamantium Camb.) e Implicações na Germinação / Harvesting and storage of gabiroba (Campomanesia adamantium CAMB.) seeds and their implication in the germination

Melchior, Saulo José 03 February 2006 (has links)
Made available in DSpace on 2016-01-26T18:56:19Z (GMT). No. of bitstreams: 1 gabiroba.pdf: 44060 bytes, checksum: d2030c93d48571bb92f419f7ff5fc34b (MD5) Previous issue date: 2006-02-03 / Gabiroba, Campomanesia adamantium, is a Brazilian Cerrado species with high frequency in the inferior extracts (diameter <5cm). It produces a fruit largely appreciated and with commercial potential of exploration. It is not cultivated and because of that is threatened by the extractive exploitation what makes necessary the acquisition of knowledge concerning to the specie propagation. The objective of this work was the verification of the gabiroba seed behaviour in relation to the harvesting, storage and their implications in the germination. The fruits used for characterization were obtained from seven plants in four repetitions of twenty fruits per plant to measure fruit diameter; fresh matter of peel, pulp and seed mass; seed number, Brix degrees corrected to 20ºC and fresh seeds germination. For the storability studies three experiments were conducted as completely random with four repetitions per treatment. The first experiment was constituted by seeds without storage (S), hermetically stored in laboratory conditions (HL), hermetically stored in refrigerator (HG) and stored in a porous bag at laboratory environment during 30 days. In the second experiment, seeds were extracted from fruits and left in the air during five days, and each day was a treatment. In the third one, fruits were stored at environmental temperature, under refrigeration and freezed during 22 days. Treatments were evaluated by germination (25ºC), germination velocity index and moisture determination. Results showed that. the harvesting point, for seed obtaining, was at least with 15.75ºBrix. Gabiroba seed behaviour showed that this specie must be classified as recalcitrant by not supporting low temperatures and its low tolerance to desiccation; it was not possible to establish a way of seed conservation being indicated the sowing just after fruit harvesting. / A gabiroba, Campomanesia adamantium Camb., é uma espécie dos Cerrados brasileiros muito freqüente É produtora de frutos muito apreciados, apresentando potencial de exploração econômica , por não ser cultivada, e tem sido alvo de extrativismo, tornando necessária a ampliação dos conhecimentos relativos à propagação da espécie. O objetivo deste trabalho foi estudar o comportamento de sementes de gabiroba em relação à colheita, ao armazenamento e implicações na germinação. Os frutos utilizados para caracterização da colheita, foram obtidos de sete plantas, em 4 repetições de 20 frutos por planta, em delineamento inteiramente casualizado, para verificação do diâmetro, massa fresca de casca, polpa e sementes, número de sementes por fruto, graus Brix corrigidos para 20oC e germinação das sementes frescas. Para o estudo de armazenamento, foram conduzidos três experimentos em delineamento inteiramente casualizado com quatro repetições por tratamento. O experimento 1 foi constituído por sementes sem armazenamento (S), armazenadas em embalagem hermética em ambiente de laboratório (HL), armazenadas em embalagem hermética em geladeira (HG) e armazenadas em embalagem porosa em laboratório (PL), por 30 dias. No experimento 2, as sementes foram extraídas dos frutos e deixadas ao ar por 5 dias, com cada dia representando um tratamento. No experimento 3, os frutos foram armazenados na temperatura ambiente, na geladeira e em congelador, por 22 dias. Os tratamentos foram avaliados pela germinação (25oC), pelo índice de velocidade de germinação e pela determinação do grau de umidade. Os resultados mostraram que; o ponto de colheita de frutos, para obtenção de sementes, foi determinado como sendo a partir 15,75ºBrix da polpa; as semente de gabiroba podem ser classificada como recalcitrantes e devem ser utilizadas para semeadura imediatamente após a extração dos frutos.
516

Colheita e Armazenamento de Sementes de Gabiroba (Campomanesia adamantium Camb.) e Implicações na Germinação / Harvesting and storage of gabiroba (Campomanesia adamantium CAMB.) seeds and their implication in the germination

Melchior, Saulo José 03 February 2006 (has links)
Made available in DSpace on 2016-07-18T17:51:04Z (GMT). No. of bitstreams: 1 gabiroba.pdf: 44060 bytes, checksum: d2030c93d48571bb92f419f7ff5fc34b (MD5) Previous issue date: 2006-02-03 / Gabiroba, Campomanesia adamantium, is a Brazilian Cerrado species with high frequency in the inferior extracts (diameter <5cm). It produces a fruit largely appreciated and with commercial potential of exploration. It is not cultivated and because of that is threatened by the extractive exploitation what makes necessary the acquisition of knowledge concerning to the specie propagation. The objective of this work was the verification of the gabiroba seed behaviour in relation to the harvesting, storage and their implications in the germination. The fruits used for characterization were obtained from seven plants in four repetitions of twenty fruits per plant to measure fruit diameter; fresh matter of peel, pulp and seed mass; seed number, Brix degrees corrected to 20ºC and fresh seeds germination. For the storability studies three experiments were conducted as completely random with four repetitions per treatment. The first experiment was constituted by seeds without storage (S), hermetically stored in laboratory conditions (HL), hermetically stored in refrigerator (HG) and stored in a porous bag at laboratory environment during 30 days. In the second experiment, seeds were extracted from fruits and left in the air during five days, and each day was a treatment. In the third one, fruits were stored at environmental temperature, under refrigeration and freezed during 22 days. Treatments were evaluated by germination (25ºC), germination velocity index and moisture determination. Results showed that. the harvesting point, for seed obtaining, was at least with 15.75ºBrix. Gabiroba seed behaviour showed that this specie must be classified as recalcitrant by not supporting low temperatures and its low tolerance to desiccation; it was not possible to establish a way of seed conservation being indicated the sowing just after fruit harvesting. / A gabiroba, Campomanesia adamantium Camb., é uma espécie dos Cerrados brasileiros muito freqüente É produtora de frutos muito apreciados, apresentando potencial de exploração econômica , por não ser cultivada, e tem sido alvo de extrativismo, tornando necessária a ampliação dos conhecimentos relativos à propagação da espécie. O objetivo deste trabalho foi estudar o comportamento de sementes de gabiroba em relação à colheita, ao armazenamento e implicações na germinação. Os frutos utilizados para caracterização da colheita, foram obtidos de sete plantas, em 4 repetições de 20 frutos por planta, em delineamento inteiramente casualizado, para verificação do diâmetro, massa fresca de casca, polpa e sementes, número de sementes por fruto, graus Brix corrigidos para 20oC e germinação das sementes frescas. Para o estudo de armazenamento, foram conduzidos três experimentos em delineamento inteiramente casualizado com quatro repetições por tratamento. O experimento 1 foi constituído por sementes sem armazenamento (S), armazenadas em embalagem hermética em ambiente de laboratório (HL), armazenadas em embalagem hermética em geladeira (HG) e armazenadas em embalagem porosa em laboratório (PL), por 30 dias. No experimento 2, as sementes foram extraídas dos frutos e deixadas ao ar por 5 dias, com cada dia representando um tratamento. No experimento 3, os frutos foram armazenados na temperatura ambiente, na geladeira e em congelador, por 22 dias. Os tratamentos foram avaliados pela germinação (25oC), pelo índice de velocidade de germinação e pela determinação do grau de umidade. Os resultados mostraram que; o ponto de colheita de frutos, para obtenção de sementes, foi determinado como sendo a partir 15,75ºBrix da polpa; as semente de gabiroba podem ser classificada como recalcitrantes e devem ser utilizadas para semeadura imediatamente após a extração dos frutos.
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Srovnání tří metod použitých při vyhodnocení schopnosti šíření semen a jejího významu pro kolonizaci opuštěných polí u druhů z čeledi Asteraceae / Comparison of three trials used for assassement of ability to disperse by wind and its importance for colonazition of abandoned fields in Asteraceae species

Vlasta, Tomáš January 2017 (has links)
Several methods are used for studying seed dispersal (seed traps, tracking individual seeds, tracking seeds coloured by fluorescent colours, etc.) However, only a few studies compared results obtained by several methods. In first part of this master thesis, I compared the three above mentioned methods used for studying seed dispersal using species from Asteraceae family. From previous research within the study area (Úštěcko), it is known that dry grassland species are able to colonize abandoned fields. Using seed dispersal data obtained within this theses, I tried to assess the role of seed dispersal on distribution of dry grassland species on abandoned fields both on local and regional scale. The results showed that dispersal curves obtained by the three methods differ significantly. This results may be due to different wind conditions during the experiments. Seed trap data show results from long-term seed dispersal influenced by highly variable wind conditions. In contrary, seed release experiments showed results based on single dispersal event under limited wind conditions. Tracking seeds coloured by fluorescent colours was shown to be not convenient for small seeds, but I can recommend this method for larger seeds. Influence of seed dispersal ability on abundance of dry grassland species on...
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Aspects of plant dispersal in the southwestern Cape with particular reference to the roles of birds as dispersal agents / Aspects of plant dispersal in the southwestern Cape with particular reference to the roles of birds as dispersal agents

Knight, Richard Spencer, Knight, Richard Spencer 22 November 2016 (has links)
The dispersal of plants with particular attention to the roles birds play as dispersal agents was studied in the southwestern Cape, South Africa from 1983 to 1985. The research was organized as ten inter-related studies, each with an independent data base. Each chapter focused on a different scale of plant dispersal processes ranging from regional assemblages of plant species to individual species. At the largest scale, the seven vegetation types commonly occurring in the southwestern Cape were examined for incidence of vertebrate-dispersed plants. Coastal Thicket and Afromontane Forest were found to be the richest in these species. The colonization of vertebrate-dispersed plants was examined in an artificially cleared area of Mountain Fynbos vegetation. Enhanced densities of vertebrate-dispersed species were found in areas where perches had been provided. The seasonal availability of vertebrate-dispersed species was found to be most continuous in Coastal Thicket vegetation. Fruit displays of vertebrate-dispersed indigenous plants were found to vary from those that were sporadic and inconspicuous, to those that were conspicuous and predictable, whereas those of alien plants were usually large and conspicuous. Avian use of these fleshy fruits in Coastal Thicket was examined and found to be proportional to their availability. A study of fruit presentation in relation to leaf number and stem thickness suggested that sessile, stem attached fruits have fewer local leaves at time of ripening than fruits which are presented in panicles. This may enhance accessibility and conspicuousness of stem attached fruits for dispersal by birds. Four autecological studies tested certain predictions arising from models developed to describe fruit/frugivore interactions. The dispersal of the alien Acacia cyclops seeds by the indigenous Black Korhaan Eupodotis afra suggested that successful fruit/frugivore relationships are not necessarily the product of reciprocal evolution. The study on Chrysanthemoides monilifera found that efficient dispersal systems are not limited to plants producing small quantities of lipid-rich fruits and to dispersal by obligate frugivores. The abiotic dispersal of Quercus robur was found to be efficient in relation to vertebrate-dispersal. The study on Protasparagus aethiopicus found that the morphology of fleshy fruits may also reflect attempts to overcome the effects of non-dispersing seed predators. 1It is concluded that a gradient from a predictable to unpredictable fruit availability provides a better basis for studying fruit/frugivore interactions than the coevolutionary models. previously presented.
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The effect of seed applied and root-applied growth regulators on the germination and growth of muskmelon

Becker, Caron Susan. January 1984 (has links)
Call number: LD2668 .T4 1984 B425 / Master of Science
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Emergence, seedling vigor, and stand establishment of pearl millet as affected by mesocotyl elongation and other seed and seedling traits

Mohamed, Ahmed Mahmoud. January 1985 (has links)
Call number: LD2668 .T4 1985 M63 / Master of Science

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