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| Registros recuperados: 11 | |
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| Aucique-Perez,Carlos Eduardo; Daza,Edison Steve; Ávila-Diazgranados,Rodrigo Andrés; Romero,Hernán Mauricio. |
| ABSTRACT Bud rot (BR) caused by Phytophthora palmivora and lethal wilt (LW) whose causal agent is unknown, are two diseases currently posing a threat to the oil palm ( Elaeis guineensis . Jacq) industry. BR, first reported in 1964, has destroyed more than 85,000 ha. LW, first reported in 1994 in the Llanos Orientales in Colombia, has destroyed more than 5,000 ha. Chlorophyll a fluorescence is useful as a provider of information about the efficiency of the photosynthetic process when plants are subjected to biotic or abiotic stresses. Oil palms affected by BR and LW showed anomalies in the photosynthetic system, manifested by reductions in Fv / F M and ΦPSII. Changes in ΦPSII, variable fluorescence yield ( Fv ) and maximum fluorescence in light-adapted... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosystem II; PSII quantum efficiency; Plant-Pathogen Interaction; Severity. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000201201 |
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| Melo, Alberto Soares de; UEPB; Suassuna, Janivan Fernandes; UEPB; Fernandes, Pedro Dantas; UFCG; Brito, Marcos Eric Barbosa; UFCG; Suassuna, Antonio Fernandes; UEPB; Aguiar Netto, Antenor Oliveira; UFS. |
| Objetivou-se avaliar diferentes regimes hídricos sobre o comportamento morfofisiológico e o rendimento da melancieira em condições de campo no semiárido paraibano. O experimento foi realizado no Setor Experimental da Universidade Estadual da Paraíba, localizado em Catolé do Rocha (PB). Utilizou-se a cultivar Crimson Sweet espaçada de 2,2 m x 0,6 m, no delineamento em blocos ao acaso com quatro tratamentos [40, 70, 100 e 130% da evapotranspiração de referência (mm dia-1)] e oito repetições. As máximas expressões de crescimento foram verificadas na lâmina de água de 204 mm, com área foliar de 1,831 m2, índice de área foliar de 1,35 m2 m-2 e taxa de crescimento de 0,04 m2 dia-1. A resistência estomática foi maior à tarde, independentemente da lâmina de água.... |
| Tipo: Pesquisa experimental |
Palavras-chave: 5.01.00.00-9 Agronomia Citrullus lanatus Thumb. Mansf.; Transpiração; Irrigação; Fotossistema II 5.01.03.00-8 Citrullus lanatus Thumb. Mansf.; Transpiration; Irrigation; Photosystem II. |
| Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/2136 |
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| EL-Sheekh,Mostafa M.. |
| The effect of sodium chloride on the photosynthetic electron transport chain was investigated in the freshwater green alga Chlorella vulgaris. It was found that the rate of oxygen evolution under steady state and flash light conditions diminished by increasing salt concentrations. Salt treatment of cells also decreased the fluorescence and delayed luminescence yields. However, the fluorescence yield was almost completely restored by the addition of an artificial electron donor to the NaCl-treated cells. The oscillation pattern of the thermoluminescence B band as a function of flash number indicated that the S2<FONT FACE=Symbol>®</FONT>S3 transition of the water splitting system is inhibited by NaCl treatment. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorella; Electron transport; Photosystem II; Salinity. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100004 |
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| Nascimento, Clístenes Williams Araújo do; Marques, Marise Conceição. |
| The remediation of lead-contaminated areas poses a serious challenge to soil chemists because Pb has low solubility in soil. Thus, Pb phytostabilization is considered to be an attractive remediation technique. Castor bean (Ricinus communis) is an oilseed crop known for its tolerance to heavy metals, and our aim was to assess the early detection of Pb toxicity and the effects of Pb on the biomass, photosynthetic pigments, antioxidative enzyme activities, and total soluble proteins of this plant. Specimens were grown in a nutrient solution spiked with Pb concentrations of 25, 50, 100, 150, or 200 µmol L-1. A control without Pb was also grown. The results show that X-ray chlorophyll fluorescence is an efficient technique for the early detection of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tolerance; Oilseed crop; Photosystem II; Fr/FFr ratios.. |
| Ano: 2018 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/39392 |
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| Nascimento, Clístenes Williams Araújo do; Marques, Marise Conceição. |
| The remediation of lead-contaminated areas poses a serious challenge to soil chemists because Pb has low solubility in soil. Thus, Pb phytostabilization is considered to be an attractive remediation technique. Castor bean (Ricinus communis) is an oilseed crop known for its tolerance to heavy metals, and our aim was to assess the early detection of Pb toxicity and the effects of Pb on the biomass, photosynthetic pigments, antioxidative enzyme activities, and total soluble proteins of this plant. Specimens were grown in a nutrient solution spiked with Pb concentrations of 25, 50, 100, 150, or 200 µmol L-1. A control without Pb was also grown. The results show that X-ray chlorophyll fluorescence is an efficient technique for the early detection of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tolerance; Oilseed crop; Photosystem II; Fr/FFr ratios.. |
| Ano: 2018 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/39392 |
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| Takano,Hudson Kagueyama; Oliveira Junior,Rubem Silvério de; Constantin,Jamil; Braz,Guilherme Braga Pereira; Franchini,Luiz Henrique Morais; Burgos,Nilda Roma. |
| ABSTRACT Resistance to herbicides is a serious threat to crop production worldwide, especially in agronomic crops and cereals. This research evaluated the possible occurrence of Bidens pilosa resistant to imazethapyr and atrazine in Brazil. The resistant biotype was collected from an area with a history of repeated application of photosystem II (PSII) and ALS inhibitor herbicides. The susceptible biotype was collected from an area with no history of herbicide application. Resistance verification experiments were carried out in the greenhouse. The treatments were arranged in a 3 x 8 factorial scheme, where the first factor was populations [susceptible (S), parent resistant (PR), and resistant F1 (RF1)]; and the second factor was herbicide dose (0, 375, 750,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosystem II; Resistance level; Herbicide resistance. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542016000500547 |
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| ORTIZ,Daniel; MORENO,Flavio; DÍEZ,Maria Claudia. |
| ABSTRACT In the Amazon region, agroforestry systems (AFSs) are recommended as a sustainable production alternative for local communities. A common component in Amazonian AFSs are tropical fruit trees, which can form the canopy or grow in the understory. In this study, we evaluated the effect of high radiation on photosynthesis, growth and seedling survival of four Amazonian fruit-tree species: Theobroma cacao, Eugenia stipitata, Inga edulis and Psidium guajava. Growth, chlorophyll fluorescence, gas exchange, and leaf pigments were measured in seedlings of each species grown for 12 months inside shade houses with low (8%), medium (30%) and high relative illumination (100%). Eugenia stipitata and T. cacao had the lowest acclimation capacity to high solar... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acclimation; Agroforestry systems; Carotenoids; Chloroplasts; Photosystem II. |
| Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672021000100001 |
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| Falqueto,Antelmo Ralph; Cassol,Daniela; Magalhães Júnior,Ariano Martins de; Oliveira,Antônio Costa de; Bacarin,Marcos Antonio. |
| The objective of this work was to evaluate the physiological changes that occur in different leaves during the early and late grain-filling stages of two rice genotypes (Oryza sativa subsp. indica , BRS Pelota cultivar, and O. sativa subsp. japonica , BRS Firmeza cultivar), which present differences in grain yield potential. The plants were cultivated in greenhouse. Pigment content, chlorophyll fluorescence, electron transport and oxygen evolution rate were determined in the grain-filling stage, from the first to the forth leaf (top to bottom). Pigment content, photochemical efficiency of photosystem II and electron transport decreased significantly according to the position of leaves in 'BRS Pelota'. The BRS Firmeza cultivar shows higher pigment content... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Oxygen evolution rate; Photochemical quenching; Photosystem II; Photochemicol efficiency; Stay green. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009000700007 |
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| Vital,Roberto Gomes; Jakelaitis,Adriano; Silva,Fábia Barbosa; Batista,Priscila Ferreira; Almeida,Gabriel Martins; Costa,Alan Carlos; Rodrigues,Arthur Almeida. |
| ABSTRACT The maturing of drift used in the culture of sugar cane can have harmful effects on other crops grown in the vicinity of sugar cane plantations. Among these, sunflower grown in the off-season can have its growth and productivity affected by drift. The objective of this research was to evaluate whether the drift of trinexapac-ethyl and glyphosate promotes changes in the photosynthetic metabolism of sunflower plants. Two trials were carried out to evaluate the effects of these products on gas exchange, chlorophyll fluorescence, chloroplastid pigments, membrane permeability, sugar content, as well as shikimic acid and malondialdehyde concentration in the treated plants. In the first experiment, we tested glyphosate in doses of 0 (control); 3.6; 7.2;... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gibberellin; EPSPs; Photosystem II; Photochemical efficiency. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052017000100033 |
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| Lucena,Cicero Cartaxo de; Siqueira,Dalmo Lopes de; Martinez,Hermínia Emilia Prieto; Cecon,Paulo Roberto. |
| This study evaluated the tolerance of mango cultivars 'Haden', 'Palmer', 'Tommy Atkins' and 'Uba' grafted on rootstock 'Imbú' to salt stress using chlorophyll fluorescence. Plants were grown in modified Hoagland solution containing 0, 15, 30, and 45 mmol L-1 NaCl. At 97 days the parameters of the chlorophyll fluorescence (F0, Fm, Fv, F0/Fm, Fv/Fm, Fv'/Fm', ΦPSII = [(Fm'-Fs)/(Fm')], D = (1- Fv'/Fm') and ETR = (ΦPSII×PPF×0,84×0,5) were determined. At 100 days, the leaf emission and leaf area, toxicity and leaf abscission indexes were determined. In all cultivars evaluated, in different degree, there were decreases in photochemical efficiency of photosystem II, enhanced concentrations from 15 mmol L-1 NaCl. The decreases in the potential quantum yield of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mangifera indica L.; Photosystem II; Vegetative growth; Salt stress. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452012000400034 |
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| Registros recuperados: 11 | |
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