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Registros recuperados: 26 | |
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Valença,David da Cunha; Carvalho,Daniel Fonseca de; Reinert,Fernanda; Azevedo,Ricardo Antunes; Pinho,Camila Ferreira de; Medici,Leonardo Oliveira. |
ABSTRACT: Concerns with water crisis involve all sectors of society and irrigated agriculture remains the main water consumer. This study evaluated an agricultural production system for lettuce cultivation in greenhouse, “organic potponics”, to economize water and manure use, using a Simplified Irrigation Controller (SIC), based on soil matric potential monitoring. Five irrigation volumes were evaluated in pots with 4.8 L, fertilized with 200 g of vermicompost. One of the volumes was controlled with the SIC. The other volumes represented 130, 80, 60 and 33 % of that controlled by the SIC and all treatments received water at the same time. Shoot fresh weight, head diameter and stomatal conductance (gs) increased linearly with irrigation volumes. For shoot... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactuca sativa; Water use efficiency; Production system; Water management; Automation. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162018000100052 |
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Bezerra,Ana Carolina Mendes; Valença,David da Cunha; Carvalho,Daniel Fonseca de; Pinho,Camila Ferreira de; Reinert,Fernanda; Gomes,Daniela Pinto; Gabetto,Fernanda Palmeira; Azevedo,Ricardo Antunes; Masseroni,Daniele; Medici,Leonardo Oliveira. |
ABSTRACT: Seedling production is an important step in the lettuce production system. However, there is a tendency to apply excessive irrigation at this stage. The aim of this study was to test the use of the Simplified Irrigation Controller (SIC) under two conditions: first, with the sensor installed in the substrate (measuring the soil water tension) and second, in the atmosphere (“atmospheric” - responding to vapor demand in the atmosphere) to control the irrigation of lettuce seedlings. The performance of the SIC was evaluated by monitoring plant traits. The lettuce seeds of the Regina cultivar were sown in styrofoam trays with commercial organic substrate. Both experiments were conducted under greenhouse conditions and evaluated under different SIC... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactuca sativa L.; Simplified Irrigation Controller; Water use efficiency. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019001200179 |
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Medici,Leonardo Oliveira; Gaziola,Salete Aparecida; Varisi,Vanderlei Aparecido; Paula,José Antonio Carmezini de; Ferreira,Renato Rodrigues; Azevedo,Ricardo Antunes. |
Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cereal; Opaque; Nitrogen; Proteins; Near infrared. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000200009 |
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Toro,Alejandro Alberto; Medici,Leonardo Oliveira; Sodek,Ladaslav; Lea,Peter John; Azevedo,Ricardo Antunes. |
For human nutrition the main source of vegetable proteins are cereal and legume seeds. The content of total soluble amino acids in mature endosperm of wild-type, opaque and floury maize (Zea mays L.) mutants were determined by HPLC. The total absolute concentration of soluble amino acids among the mutants varied depending on the mutant. The o11 and o13 mutants exhibited the highest average content, whereas o10, fl3 and fl1 exhibited the lowest average content. In general, the mutants exhibited similar concentrations of total soluble amino acids when compared to the wild-type lines, with the clear exception of mutants o11 and fl1, with the o11 mutant exhibiting a higher concentration of total soluble amino acids when compared to its wild-type counterpart... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Lysine; Threonine; Methionine. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000100014 |
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Ferreira,Renato Rodrigues; Vendemiatti,Ariane; Meinhardt,Lyndel Wayne; Lea,Peter John; Azevedo,Ricardo Antunes. |
Cereal seeds are poor in essential amino acids, particularly lysine, tryptophan and threonine. The amino acids lysine and threonine are synthesized in the aspartate pathway. Although most of the enzymes of the aspartate pathway have been isolated and characterized in higher plant species, the metabolism of lysine and threonine is totally unknown in sorghum. We have isolated two enzymes, aspartate kinase (AK) and homoserine dehydrogenase (HSDH) from sorghum. Optimum assay conditions were established for the determination of AK and HSDH activities. The highest level of activity was observed in immature seeds. AK was shown to be inhibited by threonine and lysine indicating the existence of at least two isoenzymes, one sensitive to threonine inhibition and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amino acids; Aspartate kinase; Homoserine dehydrogenase; Lysine; Threonine. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200005 |
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Fornazier,Ricardo Francisco; Azevedo,Ricardo Antunes; Ferreira,Renato Rodrigues; Varisi,Vanderlei Aparecido. |
Lysine is an essential amino acid, synthesized in plants in the aspartic acid pathway. The lysine catabolism is performed by the action of two consecutive enzymes, lysine 2-oxoglutarate reductase (LOR) and saccharopine dehydrogenase (SDH). The steady state of lysine is controlled by both, synthesis and catabolism rates, with the final soluble lysine concentration in cereal seeds a direct result of these processes. In the last 40 years, the enzymes involved in lysine biosynthesis have been purified and characterized from some plant species such as carrot, maize, barley, rice, and coix. Recent reports have revealed that lysine degradation might be related to various physiological processes, for instance growth, development and response to environmental... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amino acids; Lysine; Metabolism; Mutants. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100002 |
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Kato,Fabiana Hibary; Carvalho,Marcia Eugenia Amaral; Gaziola,Salete Aparecida; Piotto,Fernando Angelo; Azevedo,Ricardo Antunes. |
ABSTRACT: In general, the effects of Cadmium (Cd) on crop quality are evaluated solely by Cd accumulation in the edible plant parts; thus, the potential effects on several nutritional features are not often taken into account. This study evaluated Cd effects on the enzymatic activities of lysine (Lys) metabolism, storage protein and amino acid profile in maize. Stress parameters were also assessed. In vegetative organs, Cd was accumulated in the following decreasing order: roots > stems > leaves. Cadmium accumulation in grains decreased at grain maturity (from 0.25 to 0.07 µg g−1 DW). In leaves, neither hydrogen peroxide content nor superoxide dismutase, catalase, ascorbate peroxide and guaiacol peroxidase activities did not change in Cd-treated... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays L.; Aspartate kinase; Corn; Dihydrodipicolinate synthase; Heavy metal. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000101300 |
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Molina,Silvia Maria Guerra; Gaziola,Salete Aparecida; Lea,Peter John; Azevedo,Ricardo Antunes. |
A lisina é um aminoácido essencial cuja via de biossíntese faz parte da via metabólica do ácido aspártico, pela qual são também sintetizados os aminoácidos treonina, metionina e isoleucina. Além disso, a lisina é o principal aminoácido limitante em todos os cereais e por cerca de 30 anos a via do ácido aspártico tem sido estudada em plantas, com o intuito de desvendar e caracterizar os principais pontos chave na regulação das vias de biossíntese desses aminoácidos. Duas etapas distintas, uma primeira originada a partir do desenvolvimento da cultura de tecidos (anos 70-80) e a segunda a partir do desenvolvimento de técnicas para a transformação de plantas (anos 90), permitiram que mutantes bioquímicos e plantas trangênicas fossem produzidos com alterações... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lisina; Nutrição; Aminoácidos essenciais; Cereais. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162001000100032 |
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Gratão,Priscila Lupino; Prasad,Majeti Narasimha Vara; Cardoso,Patrícia Felippe; Lea,Peter John; Azevedo,Ricardo Antunes. |
The contamination of the environment by toxic metals poses a threat for "Man and biosphere", reducing agricultural productivity and damaging the health of the ecosystem. In developed nations, this problem is being addressed and solved to some extent by using "green technology" involving metal tolerant plants, to clean up the polluted soils. The use of naturally occurring metal tolerant plants and the application of genetic manipulation, should hasten the process of transferring this technology from laboratory to field. Therefore, it is essential to investigate and understand how plants are able to tolerate toxic metals and to identify which metabolic pathways and genes are involved in such a process. Recent advances in knowledge derived from the "omics",... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hyperaccumulator plants; Phytoremediation; Toxic metals. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100005 |
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Pompeu,Georgia Bertoni; Ambrosano,Guilherme Bovi; Vilhena,Milca Bartz; Carvalho,Rogério Falleiros; Gratão,Priscila Lupino; Andrino,Felipe; Lira,Simone Possedente de; Azevedo,Ricardo Antunes. |
ABSTRACT Uptake of nutrients and cadmium (Cd) are dependent upon many factors, including plant species, ions concentration and pH. Tolerance to Cd-induced oxidative stress can be modulated by phytohormones such as abscisic acid (ABA), which induce the production of reactive oxygen species, activating proteins and enzymes involved in stress response and possibly stress tolerance. The present study aimed to evaluate the biochemical variations induced by Cd in ABA-deficient sitiens tomato mutant (sit) and its wild-type counterpart, Micro-Tom (MT), grown at different pH conditions. The plants were cultivated in nutrient solution (pH 5, 6 and 7; 20-days) and were then further grown over a 48-h period in 0 or 50 ?M CdCl2 at pH 6. Before Cd addition, the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant enzymes; Micro-Tom; Mineral nutrition; Oxidative stress; Solanum lycopersicum. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052019000300317 |
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Carvalho,Rogério Falleiros; Piotto,Fernando Angelo; Schmidt,Daiana; Peters,Leila Priscila; Monteiro,Carolina Cristina; Azevedo,Ricardo Antunes. |
Seed priming with hormones has been an efficient method for increasing seed vigor as well as seedling growth under stressful conditions. These responses have in the past been attributed to the activation of antioxidant systems in a range of crops. The results described in this work show that hormonal priming with methyl jasmonate, salicylic acid or CEPA (chloroethylphosphonic acid), an ethylene (ET) releaser, does not induce the antioxidant activity of superoxide dismutase, catalase, ascorbate peroxidase or glutathione reductase in maize seedlings subjected to salt stress. The enhanced biomass of maize seedlings under salt stress that was observed only from ET priming indicates that the stress tolerance in maize from ethylene priming is a fundamental... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Antioxidant systems; Hormonal pretreatment; Salinity; Seedling growth. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162011000500014 |
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Martins,Paula Fabiane; Martinez,Camila Ortiz; Carvalho,Giselle de; Carneiro,Paulo Irajara Borba; Azevedo,Ricardo Antunes; Pileggi,Sônia Alvim Veiga; Melo,Itamar Soares de; Pileggi,Marcos. |
The aim of this work was to study herbicide degradation through selected microorganisms from humus and soil subjected to different plantation systems. The following bacterial species were identified: Klebsiella pneumoniae pneumoniae GC s.B strain 1, Pseudomonas alcaligenes, Enterobacter aerogenes GC s.A and Klebsiella pneumoniae pneumoniae GC s.B strain 2. Growth studies yet suggested the possibility of a very long lag phase. Although, culture with the herbicide presented biofilm formation and there were color changes in the herbicide that could have interfered with the espectrophotometry readings. After 5 days of incubation at 35ºC, the difference in the concentration of herbicide was 14.42% on average and after 10 days, 35.01%. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bioremediation; Biodegradation; S-Metolachlor; Herbicide. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000100019 |
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Kozak,Marcin; Azevedo,Ricardo Antunes. |
Studying relationships among plant and crop traits is crucial for crop scientists to understand complex biological systems that occur in plants and the field. Such knowledge constitutes the basis for more practical information on how to manage breeding and production to provide better or more suitable cultivars, higher yields, lower yield gaps, and resistance to pests etc. To acquire such knowledge, however, representative models of associations between plant and crop traits must be constructed. In path analysis - one of the major methods for analyzing multivariate relationships between quantitative traits - it is important to decide on an appropriate model for these associations, a model that is representative of the corresponding biological phenomena... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Interpretation; Relationships; Models; Statistics. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162014000600012 |
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Registros recuperados: 26 | |
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