962 resultados para Plant mineral nutrition


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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The greenhouse production associated with the fertigation management, have established in Brazil as economical alternative for several horticultural species. With this strategy this study had as aim to evaluate possible impacts in the metabolism of plants of bell pepper (Capsicum annuum L.; cv Elisa) in response to the increase of mineral concentration in the soil. During the experiments, the some nutrient concentrations were altered, to obtain high values of electric conductivity (EC) in the soil solution. The EC values commonly observed in the traditional fertigation system were adopted, as control. It was also verified the possibility of reduction of the mineral stress impact by the application of organic matter in the soil. Parameters of the antioxidative response system, as the superoxide dismutase (SOD) and catalase enzyme activities besides the proline content were evaluated to measure the extension of the saline stress and their effects on the plants. The increase of EC of the soil induced to the increase of the proline concentration and the SOD activity. Unexpectedly, it was verified that the saline stress inhibited the activity of the enzyme catalase. It was also concluded that the monitoring of EC of the soil is an indispensable tool to reach success in the fertigation system and that the study of the activity of the enzymes of the antioxidative response system, and the proline contents can be assumed as indicators in of the levels of stress in bell pepper plants (Capsicum annuum L.; cv Elisa).

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

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The herbicide propanil has long been used in rice production in southern Brazil. Bacteria isolated from contaminated soils in Massaranduba, Santa Catarina, Brazil, were found to be able to grow in the presence of propanil, using this compound as a carbon source. Thirty strains were identified as Pseudomonas (86.7%), Serratia (10.0%), and Acinetobacter (3.3%), based on phylogenetic analysis of 16S rDNA. Little genetic diversity was found within species, more than 95% homology, suggesting that there is selective pressure to metabolize propanil in the microbial community. Two strains of Pseudomonas (AF7 and AF1) were selected in bioreactor containing chemotactic growth medium, with the highest degradation activity of propanil exhibited by strain AF7, followed by AF1 (60 and 40%, respectively). These strains when encapsulated in alginate exhibited a high survival rate and were able to colonize the rice root surfaces. Inoculation with Pseudomonas strains AF7 and AF1 significantly improved the plant height of rice. Most of the Pseudomonas strains produced indoleacetic acid, soluble mineral phosphate, and fixed nitrogen. These bacterial strains could potentially be used for the bioremediation of propanil-contaminated soils and the promotion of plant growth.

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The Corymbia citriodora is one of the most important forest species in Brazil and the reason is the diversity of its use, because it produces good quality wood and the leaves may be used for essential oil production. Although, there are not many studies about species and the handling effect in the nutritional balance. This study aimed to evaluate the biomass production and nutrient balance in the conventional production of essential oil and wood of Corymbia citriodora with sewage sludge application. The experiment design established was the randomized blocks, with four replicates and two treatments: 1 - fertilization with 10 tons ha(-1) (dry mass) of sewage sludge, supplemented with K and B, and 2 - mineral fertilization. It was evaluated the aerial biomass production, the nutrient export of the leaves, the essential oil and wood production at four years old. The trees that received application of sewage sludge produced 20 % more leaves biomass than the trees with mineral fertilization, resulting in larger oil production. Besides, the trees with sewage sludge application produced 14.2 tons ha(-1) yr(-1) of woody biomass that was 27 % higher than the treatment with mineral fertilization. For both treatments the N balance was negative, but treatment with sewage sludge application (-45 kg ha(-1)) was four times lower than the observed on mineral fertilization treatment (-185 kg ha(-1)). It may be concluded in this paper that the application of sewage sludge benefits the production of leaves biomass, essential oil and wood, besides result better nutritional balance of the Corymbia citriodora production system.

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The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizae fungi (AMF) and rhizobium on rooting, growth and nutrition of seedlings of angico-red (Anadenanthera macrocarpa (Benth) Brenan) propagated by minicutting. Six progenies were used, of which were prepared cuttings with a pair of complete leaves. It was used a 55 cm(3)container filled with commercial substrate Bioplant (R). Four treatments were tested: 8 kg m-3 of superphosphate (SS) added to substrate; 4 kg m-3 SS added to substrate; 4 kg m-3 SS added to substrate and adition of a suspension solution containing rhizobium; 4 kg m-3 SS and suspension solution containing rhizobium plus 5 g of soil contaminated by AMF spores. There was no interaction among treatments for survival rate of cuttings and roots observed at bottom of the container, evaluated in the greenhouse exit (30 days) and the shade house exit (40 days), probably because the root system was still in formation. There were differences among the progeny for survival rate of the shoots, the percentage of cuttings with roots observed at bottom of the container, height, stem diameter and shoot dry weight. The evaluations of the growth characteristics of the cuttings in, particularly with respect to survival at full sun (140 days), demonstrate the efficiency of rhizobium and AMF on seedling production of this species. We conclude that the symbiotic association with rhizobium and / or FMA favors the production of seedlings of A. macrocarpa by minicutting.

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Background: Several parameters are associated with high bone mineral density (BMD), such as overweight, black background, intense physical activity (PA), greater calcium intake and some medications. The objectives are to evaluate the prevalence and the main aspects associated with high BMD in healthy women. Methods: After reviewing the database of approximately 21,500 BMD scans performed in the metropolitan area of Sao Paulo, Brazil, from June 2005 to October 2010, high BMD (over 1400 g/cm(2) at lumbar spine and/or above 1200 g/cm2 at femoral neck) was found in 421 exams. Exclusion criteria were age below 30 or above 60 years, black ethnicity, pregnant or obese women, disease and/or medications known to interfere with bone metabolism. A total of 40 women with high BMD were included and matched with 40 healthy women with normal BMD, paired to weight, age, skin color and menopausal status. Medical history, food intake and PA were assessed through validated questionnaires. Body composition was evaluated through a GE-Lunar DPX MD + bone densitometer. Radiography of the thoracic and lumbar spine was carried out to exclude degenerative alterations or fractures. Biochemical parameters included both lipid and hormonal profiles, along with mineral and bone metabolism. Statistical analysis included parametric and nonparametric tests and linear regression models. P < 0.05 was considered significant. Results: The mean age was 50.9 (8.3) years. There was no significant difference between groups in relation to PA, smoking, intake of calcium and vitamin D, as well as laboratory tests, except serum C-telopeptide of type I collagen (s-CTX), which was lower in the high BMD group (p = 0.04). In the final model of multivariate regression, a lower fat intake and body fatness as well a better profile of LDL-cholesterol predicted almost 35% of high BMD in women. (adjusted R2 = 0.347; p < 0.001). In addition, greater amounts of lean mass and higher IGF-1 serum concentrations played a protective role, regardless age and weight. Conclusion: Our results demonstrate the potential deleterious effect of lipid metabolism-related components, including fat intake and body fatness and worse lipid profile, on bone mass and metabolism in healthy women.

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Four Citrus species (C. sinensis, cvs. Pera and Lima; C. latifolia Tanaka cv. Tahiti; C limettioides Tanaka cv. Sweet lime and C. reticulate, cv. Ponkan) grown in Brazil were characterised in relation to contents of minerals, ascorbic acid, total polyphenols and antioxidant capacity of pulps and peels. In general, the peels demonstrated significantly higher contents of all compounds than the pulps (p < 0.05), with the exception of the Pera orange pulp that presented the highest acid ascorbic content (68 mg/100 ml), while the Tahiti lime peel presented the lowest (8 mg/100 g). Citrus showed high levels of potassium, calcium and magnesium, and the peels were considered sources of these minerals. The Ponkan mandarin peel presented the highest antioxidant capacity. The antioxidant capacity of citrus was correlated both to vitamin C and phenolics. Aside from citrus pulps, the peels are also good sources of bioactive compounds and minerals, and can be explored for their health promoting values in food products. (C) 2012 Elsevier Ltd. All rights reserved.

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A seringueira na fase adulta possui um crescimento intermitente com o processo de troca de folhas, que é caracterizado pela senescência. Esse é um mecanismo que as árvores utilizam para reciclarem os nutrientes, por meio dos ciclos bioquímico e biogeoquímico. Estudos sobre o ciclo bioquímico são necessários para verificar o comportamento dos nutrientes minerais, nos diferentes estádios foliares, pois a conservação desses é importante, visto que os seringais são implantados em solos de baixa fertilidade. Desse modo, este trabalho teve por objetivo avaliar a dinâmica dos nutrientes minerais, durante os diferentes estádios foliares da seringueira. As folhas utilizadas foram provenientes de plantas do clone RRIM-600, de um seringal localizado em Nepomuceno, MG. Foram selecionadas oito árvores adultas que possuíam folhas nos diferentes estádios (B1, B2, C e D) e as senescentes (Sen.). As folhas nos estádios B1, B2, C e D foram coletadas nos quatro pontos ortogonais e as senescentes foram coletadas no solo após a agitação mecânica dos galhos. Observou-se que os nutrientes N, P, K, S, Cu e Zn diminuíram os seus teores nos diferentes estádios foliares da seringueira. No entanto, para Ca, Mg, B, Fe e Mn, verificarou-se um comportamento inverso. A redistribuição dos nutrientes foi maior para N, P, K e Cu. A ordem relativa dos teores de macronutrientes encontrados nas folhas foi: N>K>Ca>Mg>S>P e, para os micronutrientes, a ordem foi: Mn>Fe>Zn>B>Cu.

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O lodo de esgoto é um resíduo urbano-industrial que tem causado preocupação, quanto ao uso agrícola. Sua utilização pode ser viável, após a devida suplementação potássica, em substituição a fertilizantes minerais, especialmente em culturas como a do girassol. O presente trabalho objetivou avaliar a produtividade e nutrição mineral do girassol cv. CATISSOL 01, além da fertilidade de um Latossolo Vermelho eutroférrico adubado com lodo de esgoto, em comparação à adubação mineral, por dois anos consecutivos. O experimento utilizou delineamento em blocos casualizados, com 4 tratamentos (fertilização mineral, 5 t ha-1 ano-1, 10 t ha-1 ano-1 e 20 t ha-1 ano-1 de lodo de esgoto) e 5 repetições. Foram analisadas a produtividade de grãos de girassol, a concentração de macro e micronutrientes na folha diagnóstico e a fertilidade do solo. A produtividade de sementes do girassol adubado com o resíduo, em todas as doses, foi equivalente à adubação mineral, e os teores foliares situaram-se na faixa adequada, tanto para macro quanto para micronutrientes. O uso de lodo de esgoto, com suplementação potássica, mostrou-se eficiente na substituição total ou parcial da adubação mineral, sem prejudicar a produtividade da cultura do girassol.

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The main aim of this PhD research project was the evaluation of the biological effects of bioactive compounds derived from edible plants, with particular attention on their possibility to counteract oxidative damage and inflammation. After a preliminary study of in vitro antioxidant activity, regarding the modification eventually occurring after home freezing and cooking of edible vegetables, cultured mammalian cells were used as experimental model systems. Soluble extract and essential oils derived from different cultivars of Brassicaceae and Lamiaceae were tested as possible tools for the counteraction of the oxidative damage due to reactive oxygen species (ROS), underlining differences related to cultivar and agronomic techniques. Since accumulating evidence indicates that phytochemicals exhibit several additional properties in complex biological systems, a nutrigenomic approach was used to further explain the biological activity of a green tea extract, and to evidence the anti-inflammatory role of bioactive compounds derived from different foods. Overall, results obtained could contribute to a better understanding of the potential health benefit of plant foods.