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Search Results: 1 - 10 of 182431 matches for " Daniela Cleide Azevedo de Abreu "
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Flash-drying for embryos desiccation Desidrata o ultra-rápida de embri es
Antonio Carlos de Souza Medeiros,Daniela Cleide Azevedo de Abreu
Pesquisa Florestal Brasileira , 2010, DOI: 10.4336/2012.pfb.54.119
Abstract: Seeds of several tree species from Brazilian wet forest are in dangerous situation and show recalcitrant characteristics. Therefore, it is not possible to store them by traditional methods adopted with orthodox seeds and it limits their genetic resources ex-situ conservation in seed banks. This situation encourages researches to find news technologies in order to store these species in genebanks. Therein, flash-drying method for embryos desiccation shows to be a promising technique in order to resolve seed conservation of Brazilian endogenous tree species in genebanks. This paper has an objective of to become known the flash-drying technique and to be accessible to seed physiologists Sementes de diversas espécies arbóreas das florestas úmidas brasileiras, grande parte delas amea adas de extin o, apresentam características recalcitrantes, significando que n o toleram desidrata o, n o sendo possível o seu armazenamento pelos métodos tradicionais realizados com sementes ortodoxas. Dessa forma, o comportamento "recalcitrante" das sementes limita a conserva o ex-situ dos recursos genéticos, especialmente dessas espécies florestais em bancos de sementes. Esse fato estimula pesquisadores a buscarem novas tecnologias visando a conserva o genética dessas espécies. Nesse sentido, a técnica denominada "flashdrying" ou desidrata o ultra-rápida de embri es mostra-se promissora para resolver ou amenizar o problema de conserva o de espécies brasileiras com sementes recalcitrantes. Este trabalho tem como objetivo reunir informa es e divulgar a técnica de desidrata o ultra-rápida ou "flash-drying", tornando-a amplamente acessível aos profissionais da área.
Caracteriza??o morfológica de frutos, sementes e germina??o de Allophylus edulis (St.-Hil.) Radlk. (Sapindaceae)
Abreu, Daniela Cleide Azevedo de;Kuniyoshi, Yoshiko Saito;Nogueira, Antonio Carlos;Medeiros, Antonio Carlos de Souza;
Revista Brasileira de Sementes , 2005, DOI: 10.1590/S0101-31222005000200009
Abstract: the aim of this research was to characterize morphologically internal and external structures of fruits and seeds and to describe and illustrate the external seedling morphology of allophylus edulis (st.- hil.) radk. from seed germination. in order to describe fruits, internal and external details related to texture, consistency, color, pilosity, brightness, shape, number of seeds per fruit and shedding were observed. some external aspects of seeds were analyzed, including size, color, texture, consistency, shape, hilum and micropyle position. regarding the internal characteristics the endosperm presence or absence and cotyledon, embryo axes and plumule type, shape and color. germination was considered from radicle protrusion to the protophilus emission and seedlings were considered stable when all the protophilus were expanded. the fruits of allophylus edulis are of the type coca, globose, indehiscent and monospermic. the seeds are ovoid, without endosperm and the embryo occupies the whole seed, more or less bent and slightly tablet. the germination of the seeds has beginning to the eighth day and it can be contained in the fifteenth day, after to planting.
Caracteriza??o morfolóica de frutos e sementes de cataia (Drimys brasiliensis Miers. - Winteraceae)
Abreu, Daniela Cleide Azevedo de;Kuniyoshi, Yoshiko Saito;Medeiros, Antonio Carlos de Souza;Nogueira, Antonio Carlos;
Revista Brasileira de Sementes , 2005, DOI: 10.1590/S0101-31222005000200010
Abstract: the aim of this research was to characterize morphologically internal and external structures of drimys brasiliensis miers fruits and seeds. in order to describe the fruits, internal and external details related to texture, consistency, pilosity, brightness, shape and number of seeds per fruit were observed. shedding was observed as well. some external aspects of the seeds were analyzed including size, color, texture, consistency, shape, hilum and micropyle position. the following internal characteristics were observed the presence or absence of endosperm and cotyledon, embryo axes and plumule type, shape and color. the heart, torpedo and mature stages were identified during embryo development. the fruits of d. brasiliensis are multiple, free, constituted by five little fruits, indehiscence and polispermic. the seeds are kedney form and they have great amount of endosperm, and they present dormancy for embryonic immaturity.
Efeito do substrato e da temperatura na germina??o de sementes de cataia (Drimys brasiliensis miers. winteraceae)
Abreu, Daniela Cleide A. de;Nogueira, Antonio Carlos;Medeiros, Antonio Carlos de Souza;
Revista Brasileira de Sementes , 2005, DOI: 10.1590/S0101-31222005000100019
Abstract: the aim of this research was to evaluate cataia (drimys brasiliensis miers. - winteraceae) seed germination under different, temperatures, substrate and stratification times. seeds were submitted to stratification method in green house, without controlled temperature, during 30, 60 and 90 days. filter paper, sand, vermiculite and agar 1% were tested as substrates. were compared constant temperatures of 17, 25 and 30oc under light, and alternate temperatures treatments of 20-30oc, adopting 20oc for 16 hours in absence of light and 30oc for 8 hours exposed to light. ivg (germination speed index) was obtained additionally as a vigor test, by counting normal seedlings everyday after sowing. cataia seeds showed 7% of moisture content (wet basis) at the beginning of the experiment. after 30, 60 and 90 days of sand stratification, these seeds presented 11,3%, 27,7% and 46,2% of moisture content, respectively. treatments with 30 and 60 days of sand stratification at 17oc obtained the highest germination percentage, of 67% and 52%, respectively. the highest percentage of germination was obtained after 30 days of sand stratification corresponding to 68% for substrates like agar, sand and filter paper, and 61% for vermiculite. for the treatment with 60 days of sand stratification, the highest germination percentages were 56%, 58% and 54% in agar, sand and filter paper, respectively, without statistic difference. the vigor seeds (ivg) were those that were sand stratified for 60 days and were transferred to agar, sand and filter paper to germinate, at 17oc, presenting germination rate of 0,55, 0,61 and 0,65. it was possible to conclude that 60 days of sand stratification is an efficient method to broken cataia seed dormancy. the higher rate an percentage of germination were obtained at constant temperature of 17oc with agar, sand and filter paper as substrates.
Efeito da rea??o do solo no zinco extraído pelas solu??es de dtpa e Mehlich-1
Abreu, Cleide Aparecida de;Van Raij, Bernardo;
Bragantia , 1996, DOI: 10.1590/S0006-87051996000200022
Abstract: soil testing can be adequate to evaluate the zn availability if a good method is chosen. this experiment was conducted in a greenhouse, in campinas, state of s?o paulo, brazil, in 1993, to evaluate the influence of liming on extractable zn from soils, using corn as a test plant. five rates of limestone were applied to four oxisols and one alfisol. before and after the cultivation of corn, soil samples were taken and analyzed by extracting procedures of dtpa and mehlich-1. five days after emergence, corn seedlings showed leaf yellowing and reduced plant height (typical zn deficiency symptoms), variable according to the liming level and soil studied. dtpa methodology showed the best results, with high and positive correlations estimated between plant-zn and soil-zn contents.
EDTA assisted phytorremediation of a Pb contamined soil: metal leaching and uptake by jack beans
Gabos, Mariana Bassetto;Abreu, Cleide Aparecida de;Coscione, Aline Reneé;
Scientia Agricola , 2009, DOI: 10.1590/S0103-90162009000400012
Abstract: lead (pb) is one of the main soil contaminants. it is also of difficult phytoremediation due to its low solubility and high retention on soil particles. edta application to soil is a strategy to increase heavy metal phytoextraction, but such chelants usually cause phytotoxicity and metal leaching side effects. therefore, these research work objectives were to evaluate the effects of single (0.5 g kg-1) and split (0.25 + 0.25 g kg-1) edta application on pb uptake by jack beans (canavalia ensiformis l.) as well as on pb vertical movement in a pb contaminated soil material. two sets of experiments were carried out under greenhouse conditions: in the first one, plants were grown in 3l-pots filled with a pb-contaminated soil to evaluate pb uptake by plants; for the second experiment, pvc-columns (42 cm height) were used to evaluate soil pb leaching: the upper half-column (20 cm) was filled up with pb-contaminated soil (1800 mg kg-1) whereas the lower half-column (20 cm) was filled with clean soil. ten 60 mm-rainfalls with a duration of five hours were simulated by dropping distilled water on the top of columns, and leachates were collected for chemical analysis. plants did not show any visual pb toxicity symptoms or reduction in dry matter yield. nevertheless, pb uptake by jack beans regarded as total plant pb accumulation was higher in edta-treated plants. vertical pb movement was observed mostly for the single edta application. edta addition to the soil favor pb-phytoextraction by jack beans and the split edta application decrease the metal leaching, indicating less risk of environmental contamination.
Bragantia , 1998, DOI: 10.1590/S0006-87051998000100021
Abstract: significant increase in the pb content in cultivated soils has been observed near industrial areas. the objective of this work was to evaluate the soil pb distribution profile near and distant of the lead emiting point, located between the presidente dutra highroad and the ca?apava velha city, state of s?o paulo, brazil and to compare the pb contents found by using dtpa and mehlich-3 extracting solutions. soil samples were collected at 500 and 1.000 m distant from the lead emiting point, in the n, s, e, and w directions, at depths of 0-5, 5-10, 10-20, 20-40 and 0-20 cm. samples were treated separately with dtpa and mehlich-3 solutions for the pb extraction. the highest pb concentrations were found in the soil samples collected close to the source of contamination. the results obtained using dtpa and mehlich-3 solutions showed clearly that the lead tends to accumulate in the surface ground layer, decreasing with the soil depth. this indicated that the procedures using either dtpa or mehlich-3 solutions as pb extractor from soils should be also considered as appropriate for environmental monitoring.
Bragantia , 1998,
Abstract: Tendo em vista a possibilidade de aumentos significativos no conteúdo de Pb em solos cultivados perto de pólos industriais, procurou-se, no presente trabalho, avaliar a distribui o desse elemento no perfil de solo próximo e distante de uma fonte geradora, localizada entre a Rodovia Presidente Dutra e o núcleo urbano de Ca apava Velha (SP) e comparar procedimentos analíticos para extra o de Pb em solos. Coletaram-se as amostras de solo a 500 e 1.000 m da fonte geradora, em quatro dire es (N, S, E e W) e nas profundidades de 0-5, 5-10, 10-20, 20-40 e 0-20 cm. A extra o de Pb foi feita com a solu o de DTPA e de Mehlich-3 (M-3), sendo as mais altas concentra es de Pb encontradas nas amostras de solos localizadas próximo à fonte geradora. Verificou-se claramente que o Pb tendeu a acumular-se na camada superficial, diminuindo com a profundidade. Concluiu-se que as solu es de DTPA e de M-3 foram eficientes para avaliar a contamina o por Pb, podendo ser utilizadas no monitoramento do impacto ambiental causado por esse elemento.
Métodos de determina??o da disponibilidade de cobre em substratos
Padua Junior, Alceu L;Abreu, Cleide Aparecida de;Furlani, Pedro Roberto;Abreu, M?nica F de;
Horticultura Brasileira , 2008, DOI: 10.1590/S0102-05362008000200015
Abstract: to improve the quality of plants grown under protected or semi-protected environments it is very important to adopt inert or less altered materials to use as soilless media. these materials, called substrates, depending on its origin could be organic, mineral, or synthetic. among the nutritional problems, the lack or excess of copper (cu) has been the main factor affecting seedling production. the objective of this research was to evaluate efficient methods to quantify available cu in substrates. the experiment was conducted under semi-controlled greenhouse conditions with rucula (eruca sativa l.) as plant-test grown on three substrates (coir, pinus bark, and peat). all the substrates received five cu doses (0; 0.5; 1.0; 2.0, and 3.0 mg dm-3). after the plant harvest a substrate sample was collected to extract cu by the following methods: dtpa at ph 2.6, dtpa + triethanolamine at ph 7.3, hno3 + h2o2 at 30%, k4p2o7, and naocl at ph 8.5 + dtpa. the acid solutions presented higher cu extractive capacity for all tested substrates. among the substrates, only the coir presented statistically significant values of r2 for all the extraction methods. however, when the substrates were analyzed together, all methods presented statistically significant regression coefficients (r2) higher than 0.51, indicating that all the extraction methods can be used to quantify available cu on these substrates.
Extratores aquosos para a caracteriza??o química de substratos para plantas
Abreu, M?nica Ferreira de;Abreu, Cleide Aparecida de;Sarzi, Isabele;Padua Junior, Alceu Linares;
Horticultura Brasileira , 2007, DOI: 10.1590/S0102-05362007000200011
Abstract: substrates used to grow plants have different origins and compositions and can be organic, mineral or synthetic materials. in the present work the effect of different water extracts (1:1.5; 1:2; 1:2'; 1:5; 1:5'; and 1:10) was evaluated and compared to saturated extracts for the determination of ph, electric conductivity, macro and micronutrients in commercially available products and some of their components. the results were compared to those with saturated extracts. nine substrates were evaluated, recommended for the cultivation of tobacco, coffee, flowers (2), forestry species, citrus and horticulture species (3), and eleven substrate components: carbonized rice hulls, peat, fiber peat, vermiculite, perlite, pinus bark compost (2), expanded clay, coir (coconut fiber), cork and 'xaxim' or 'samambaia-a?u' (dicksonia sellowiana). chemical analyses were made in the substrate extract solutions for the determination of ph, electrical conductivity (ec), and macronutrient and micronutrient concentrations. the ph and ec data showed the lowest coefficients of variation. the micronutrient concentrations in the water extracts were very close to the equipment detection limits. the macronutrient concentrations showed coefficients of variation ranging from 5.1% to 47.2%. the method using the ratio 1:2 was better to obtain the saturation extracts for either macro or micronutrients. in spite of that, for all the other water extracts studied good results were obtained in the evaluation of ph, ce and macronutrientes in the tested samples.
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