631 resultados para Germinação de semente


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The study was conducted to evaluate the efficacy of herbicides in desiccation Raphanus raphanistrum (wild radish) in different application times and their effects on weed seed germination. The experimental had a randomized block design with three replications. The herbicides used were: glyphosate (360; 720; and 1080 g ha(-1)), 2,4-D (335; 670; and 1005 g ha(-1)), glyphosate + 2,4-D (360 + 335; 720 + 670; and 1080 + 1005 g ha(-1)). Spraying was conducted at three different times: 1st season (full bloom) - at 62 days after emergence (DAE), 2nd season (beginning of pod formation) - at 92 DAE and 3rd season (end of pod formation) - at 108 DAE. At 14, 21, 28, 35, and 42 days after application (DAA), the desiccation was evaluated visually, and 42 DAA dry mass of shoots and seeds of the 2nd and 3rd times were collected for the test of germination. All chemical treatments tested were effective in controlling the plants of wild radish in the 1st and 2nd times, but in the 3rd time doses of 2,4-D applied singly were not effective and only the highest dose of glyphosate applied singly or in mixture provided a total plant control. In terms of percentage, the reduction in dry matter of plants was higher with the application of larger doses of chemical treatments. The herbicides affected the germination of seeds of wild radish, and the herbicide 2,4-D provided greater reduction in germination in the 2nd and 3rd seasons.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The brachytherapy braquiterapia is an x-ray modality radiotherapy in which stamped or halfstamped radioactive sources in format of seeds are used, wires or to one short distance, in contact or implanted to the fabric to be treated. All the treatment modalities require a previous planning. The formalism recommended for calculation of dose was considered by the AAPM for the first TG-43 Report. In it distributions of dose of isolated seeds measured and calculated by Monte Carlo method in water instead of with models half-empiricists. In this work we in accordance with present some preliminary results of the calculation of functions of radial anisotropy and of dose in the distance for seed of 192Ir, wide used in brachytherapy treatments of high tax of dose (HDR), with the aid of the program based on the Monte Carlo method MCNPX v2.50 (Mount Carlo N ParticleeXtended). The materials chosen in the simulation beyond water, had been MS20 and estriado muscle

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The brachytherapy braquiterapia is an x-ray modality radiotherapy in which stamped or halfstamped radioactive sources in format of seeds are used, wires or to one short distance, in contact or implanted to the fabric to be treated. All the treatment modalities require a previous planning.The formalism recommended for calculation of dose was considered by the AAPM for the first TG-43 Report. In it distributions of dose of isolated seeds measured and calculated by Monte Carlo method in water instead of with models half-empiricists.In this work we in accordance with present some preliminary results of the calculation of functions of radial anisotropy and of dose in the distance for seed of 192Ir, wide used in brachytherapy treatments of high tax of dose (HDR), with the aid of the program based on the Monte Carlo method MCNPX v2.50 (Mount Carlo N ParticleeXtended).The materials chosen in the simulation beyond water, had been MS20 and estriado muscle

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O ipê-branco é uma espécie de difícil propagação por sementes devido à sua curta longevidade. A cultura de tecidos tem possibilitado a melhor propagação de diversas espécies, tendo como base o crescimento de células, tecidos e órgãos em condições assépticas, possibilitando a rápida multiplicação da planta selecionada, obtendo mudas livres de patógenos. A primeira etapa da cultura de tecidos está baseada na desinfestação das sementes para obter as mudas in vitro, possibilitando as posteriores etapas do processo. Foram testadas diversas concentrações de álcool etílico e hipoclorito de sódio em busca da desinfestação mais efetiva. O melhor processo para a desinfestação das sementes do ipê branco está nos tratamentos de germinação em apenas ágar com a retirada das alas da semente após a sua lavagem, com passagem por 30 segundos em álcool etílico e 5 minutos em hipoclorito de sódio, com posterior transferência da plântula para meio MS suplementado com 0,7% de ágar e 3% de sacarose. Sobre as plantas germinadas in vitro foram aplicados tratamentos com hormônios vegetais em busca das melhores concentrações para a obtenção de novas mudas. Os explantes caulinares tratados com BAP a 4,0 mg L-1 apresentaram 93,3% de brotações bem desenvolvidas, enquanto em meio WPM a melhor concentração para brotação com BAP é a de 4,0 mg L-1, não promovendo no entanto um tratamento tão efetivo como em meio MS. Para cinetina, todos os tratamentos exibiram formação de calo e/ou ausência de brotações em meio MS, e baixa porcentagem de brotação em meio WPM. Os tratamentos realizados com AIB e ANA não tiveram rizogênese efetiva em meio MS, apresentando formação de raízes pouco desenvolvidas em apenas poucos explantes no tratamento de 4,0 mg L-1 de ANA em meio WPM

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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The aim of this study was to determine the best pre-germination treatments for seeds and the best size container for seedlings growing of coral tree Erythrina mulungu (Mart. ex. Benth). Among the treatments applied to seeds, scarification with sulfuric acid during 10 minutes and cutting stylus in the region opposite to hilum resulted, respectively, in highest values of germination percentage (82.8% and 82.1%) and rates of germination speed (1.15 and 1.71). The biometric variables indicated no effect of container size on leaf area and dry mass plants. At 63 days after sowing, although with Dickson quality score statistically similar (mean 0.26), only plants grown in small and large bags reached the diameter collect close to 5 mm, minimum recommended for field planting. According to the results, for initial development of coral tree, it is recommended pre-seed treatment with sulfuric acid commercial, sowing in plastic bags of 17 x 20 cm, and wait 63 days before planting in the field.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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In the seeds of pioneer plants, the application of treatments for breaking dormancy, and selection by colour and size, are strategies for obtaining seeds of less dormancy and better germination performance. The aim of this study was to evaluate the effect of the physical and physiological aspects of seeds of the tall fringe-rush (Fimbristylis dichotoma) on germination and dormancy. To do this, the seeds were submitted to the following treatments in three studies: (i) control, immersion in H2SO4 (98%, 36N) for 1 minute, immersion in KNO3 (1, 2 and 3%) for 15 minutes, seeding on a substrate moistened with KNO3 (0.2%) and exposure for 5 and 10 hours in a forced air circulation oven at 40 and 70 degrees C; (ii) classification of the seeds by colour (light and dark) and application of the following treatments: control, immersion of the seeds in H2SO4 (98%, 36N) for 1 and 2 minutes, immersion in KNO3 (5% and 10%) for 15 and 30 minutes and seeding on a substrate moistened with KNO3 (0.2%); (iii) classification by size (0.60, 0.50 and 0.40 mm) and germination on a substrate moistened with KNO3 (0.2%) or distilled H2O. The seeds were evaluated by germination test, first count and germination speed index. Moistening the substrate with KNO3 (0.2%), and heat treatment at 40 degrees C for 10 hours improve performance in seeds of the tall fringe-rush. Light-coloured seeds do not display dormancy. Medium-sized seeds of the tall fringe-rush show better performance in terms of percentage and speed of germination.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The tangerine 'Sunki' are highly relevant for the Brazilian citrus industry by presenting important traits for genetic improvement and to be considered a great portaenxento. In this context, the objective of the present work to study the characterization of the fruits of citrus rootstock 'Sunki', depending on the position on the plan and also the germination of their seeds. The physical characteristics evaluated were fruit weight, longitudinal and equatorial diameters of the fruit longitudinal diameter / equatorial diameter, number of buds per fruit, weight of buds and bark and number of viable seeds per fruit. As for the chemical characterization was evaluated titratable, acidity, soluble solid, "Ratio", pH and vitamin C. For the evaluation of these variables, the fruits were obtained from the northeast, southwest, northwest and southeast quadrants. Regarding the evaluation of seed germination, different doses of gibberellic acid and Stimulate were used. The seeds extracted from ripe fruit, washed, dried in the shade and stored in BOD. Immediately after, they were treated for 24 hours with plant growth regulators. After soaking, the seeds were placed in a germinator in germitest paper. After initiation of the germination process, the evaluations were performed daily until the thirty- fourth day. Fruits of 'Sunki'mandarin with uneven as the fruit position within the canopy, the use of gibberellic acid and growth promoter is promising for commercial use on seed germination of this rootstock.

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The objective of this work was to develop a methodology for seed processing and X-ray analysis and to study imbibition pattern in seeds of candeia (Eremanthus incanus). Seeds were gathered in 2001 and 2002 in Morro do Pilar and Lavras respectively, processed and stored in a cold chamber (5ºC/60%RH) until the start of experiments. In order to identify unfilled seeds, a protocol was developed for X-ray use combining radiation energy (Kv) and exposure time (seconds). For elimination of unfilled seeds, an experiment was conducted using a South Dakota seed blower whereby different opening settings and ventilation times were combined. Original seed lots and categorized lots following radiograph viewing were tested by germination tests, with seeds being cleansed in sodium hypochlorite and scattered over blotting paper in 'gerboxes' and then taken to germinators with alternating temperatures of 20º-30ºC and 10 hours of light, for up to 15 days. Imbibition curves were determined under the conditions 30ºC, 20º-30ºC/10 hours of light and 30º-20ºC/10 hours of light. The X-ray protocol that best allowed viewing of internal seed structures was 30Kv for 45 seconds. Seed separation using the blower setting at a 3.0 opening for 30 seconds raised the number of embryonic seeds to values exceeding 99%, also raising the germination rates as a consequence. The imbibition pattern is three-phased and the germination process is completed in 72 hours. Under alternate temperatures, primary root growth is favored.

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A Murraya paniculata, é conhecida popularmente como murta-de-cheiro ou falsamurta, pertence à família Rutaceae e é uma espécie nativa da Índia que foi introduzida no Brasil. Essa espécie é utilizada na arborização de ruas e em jardins das cidades graças à copa densa e sua resistência a condições adversas. Pode ser utilizada também para formação de cerca vivas e, sua madeira branca tem alta durabilidade podendo ser utilizada em marcenarias. Na Ásia, esta espécie é considerada medicinal e as folhas e raízes são utilizadas para o tratamento de problemas intestinais, de reumatismo e tosse. Do ponto de vista químico, esta espécie acumula principalmente cumarinas e flavonóides, além de derivados do ácido cinâmico e alcalóides. No presente trabalho propomos determinar as temperaturas cardeais para a germinação de sementes de Murraya paniculata, além disso, analisamos a influência do teor de água na germinação para determinar se as sementes são recalcitrantes ou ortodoxas, e a influencia do potencial hídrico induzido por polietilenoglicol (PEG 6000). O aprofundamento dos estudos dessa espécie se faz importante por conta desta ser hospedeira alternativa do psilídeo Diaphorina citri, transmissor do ―greening‖ dos citros, doença que diminuiu a produção de citros nos últimos anos