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| Registros recuperados: 15 | |
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| Barreto,Denize Caranhas de Sousa; Gonçalves,José Francisco de Carvalho; Santos Júnior,Ulysses Moreira dos; Fernandes,Andreia Varmes; Bariani,Adriana; Sampaio,Paulo de Tarso Barbosa. |
| The rosewood (Aniba rosaeodora Ducke) is a native tree species of Amazon rainforest growing naturally in acidic forest soils with reduced redox potential. However, this species can also been found growing in forest gaps containing oxide soils. Variations in the forms of mineral nitrogen (NO3- or NH4+) may be predicted in these different edaphic conditions. Considering that possibility, an experiment was carried out to analyze the effects of different NO3-:NH4+ ratios on the growth performance, mineral composition, chloroplastid pigment contents, photochemical efficiency photosystem II (PSII), and nitrate redutase activity (RN, E.C.1.6.6.1) on A. rosaeodora seedlings. Nine-month-old seedlings were grown in pots with a washed sand capacity of 7.5 kg and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chloroplastid pigments; Chlorophyll a fluorescence; Tree species. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672007000400008 |
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| Yang,Xiaoyu; Wang,Xiufeng; Wei,Min; Hikosaka,Shoko; Goto,Eiji. |
| The effects of three nitrate levels - 14(CK), 56(T-1), and 140 mmol L-1 (T-2) - on growth and photosynthetic capacity of cucumber (Cucumis sativus L. cv. Xintaimici) seedlings grown in hydroponic culture were investigated. The results showed that at 12 d after treatment plant height, stem diameter, leaf area, and leaf number of cucumber seedlings were stimulated by 56 mmol L-1 nitrate, whereas were inhibited significantly by 140 mmol L-1 nitrate compared with CK. Short-term stimulation in photosynthetic rate occurred under T-1 treatment, and then recovered to the level of CK. Photosynthetic rate of T-2 seedlings significantly decreased over treatment course with respect to CK. Photosynthetic pigment content of T-1 and T-2 increased during the first 2 d,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Hill reaction; Photosynthetic pigment content; Photosynthetic rate. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400007 |
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| Pereira,Silvia; Frosi,Gabriella; Oliveira,Marciel Teixeira de; Lustosa,Bruno Melo; Arruda,Emília Pereira; Santos,Mauro Guida. |
| ABSTRACT Studies addressing the physiological and anatomical responses of plants under different light intensities normally are performed in short term. Thus, the present study includes a long term analysis. This study aims to verify whether the phenotypic variability off attributes in two woody tropical specieis, Paquira aquatica and Sterculia foetida, are compatible both under short term exposure to different light availability levels (full-light and half-light local irradiance) and long-term exposure in the same conditions. The study was developed in two phases: phase I (short term) and phase II (long term). The variables measured were referent to CO2 assimilation responses to light intensity, chlorophyll a fluorescence, chlorophyll content,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Gas exchange; Plastic response; Light curve. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000300429 |
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| GONZÁLEZ-MENDOZA,DANIEL; TRONCOSO-ROJAS,ROSALBA; GONZALEZ-SOTO,TANIA; GRIMALDO-JUAREZ,ONECIMO; CECEÑA-DURAN,CARLOS; DURAN-HERNANDEZ,DAGOBERTO; GUTIERREZ-MICELI,FEDERICO. |
| ABSTRACT The aim of the present work is to evaluate the changes on the phenylalanine ammonia lyase (PAL) activity, phenolic compounds accumulation and photochemical efficiency in leaves of P. glandulosa treated with Cd2+ (0.001 M) and Cu2+ (0.52 M) concentrations for 96 h under hydroponic conditions. The results showed that only leaves treated with copper had a decrease in photochemical efficiency and leaf epidermal polyphenols in P. glandulosa leaves after 96 h of exposure. On the other hand the reverse-phase HPLC analysis revealed higher levels of phenolic compound (gallic, vanillic and caffeic acids) and flavonoids (rutin and kaempferol-3-O-glucosides) in plant leaves from Cu and Cd-treatments with respect to control plants. Finally, highest increments... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heavy metals; Prosopis glandulosa; Flavonoids; Chlorophyll a fluorescence. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000401465 |
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| Gonçalves,José F.C.; Santos Jr.,Ulysses M.; Nina Jr.,Adamir R.; Chevreuil,Larissa R.. |
| Plant adaptation under conditions of limited irradiance can be investigated by their efficiency while using the available energy with a minimal thermodynamic energy loss. For this reason, we compared the energetic fluxes and the performance index (PI ABS) in copaiba (Copaifera multijuga) and mahogany (Swietenia macrophyla) seedlings under both sunlight and shade. The experiment was carried out in Manaus (3º8'S, 59º52'W), Amazonas State, Brazil. The fluorescence transients were obtained in intact and healthy leaves using a Plant Efficiency Analyser (PEA) between 1200 h and 1300 h. Using the O-J-I-P test, the following parameters were calculated: 1) density of reaction centers per cross section (RC/CS), 2) maximum quantum yield for primary photochemistry of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Energy fluxes in photosystem II; Light acclimation; O-J-I-P transients; Tropical tree species. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300001 |
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| ROSA,DEREK B.C.J.; SCALON,SILVANA P.Q.; CREMON,THAIS; CECCON,FELIPE; DRESCH,DAIANE M.. |
| ABSTRACT The aim of this study was to evaluate gas exchange, efficiency of the photosynthetic apparatus, and antioxidant activity in Copaifera langsdorffii Desf. The seedlings were cultivated under different conditions of water availability, in order to improve the utilization efficiency of available water resources. The seedlings were cultivated in four different water retention capacities (WRC- 25%, 50%, 75%, and 100%), and evaluated at four different time (T- 30, 60, 90, and 120 days). During the experimental period, seedlings presented the highest values for carboxylation efficiency of Rubisco (A/Ci), intrinsic water use efficiency (IWUE = A/gs), chlorophyll index, and stomatal opening, when grown in the substrate with 75% WRC, but the stomatal index... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant enzymes; Chlorophyll a fluorescence; Photosynthesis; Water stress.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000603039 |
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| Gonçalves,José Francisco de Carvalho; Barreto,Denize Caranhas de Sousa; Santos Junior,Ulysses Moreira dos; Fernandes,Andreia Varmes; Sampaio,Paulo de Tarso Barbosa; Buckeridge,Marcos Silveira. |
| Aniba rosaeodora is an Amazonian tree species that belongs to the family Lauraceae. Due to intense exploitation for extraction of essential oils (mainly linalol), A. rosaeodora is now considered an endangered species. On the other hand, there is little information about its ecophysiology which would be useful to support future forest planting programs. Hence, the effect of different light intensities on the growth and photosynthetic characteristics of young plants of A. rosaeodora was studied. Nine-month-old plants were subjected to four light treatments (T1= 10 a 250 µmol.m-2.s-1 / control; T2=500 to 800, T3=700 to 1000 and T4=1300 to 1800 µmol.m-2.s-1 / full sunlight). Allometric variables, gas exchange, contents of pigments and chlorophyll a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Chloroplast pigment contents; Gas exchanges; Photochemical efficiency of photosystem II; Relative growth rate; Tropical species. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300007 |
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| Liberato,Maria Astrid Rocha; Gonçalves,José Francisco de Carvalho; Chevreuil,Larissa Ramos; Nina Junior,Adamir da Rocha; Fernandes,Andreia Varmes; Santos Junior,Ulysses Moreira dos. |
| The physiological performance of acariquara (Minquartia guianensis) seedlings submitted to water deficit and the recovery of physiological parameters during rehydration were investigated in a greenhouse experiment. The analyzed parameters were: leaf water potential, gas exchange and chlorophyll a fluorescence. After thirty-five days, non-irrigated plants exhibited a leaf water potential 70 % lower compared to control plants (irrigated daily) and the stomatal conductance reached values close to zero, inducing a severe decrease in gas exchange (photosynthesis and transpiration). Six days after the beginning of the rehydration of drought-stressed plants, the results demonstrated that water stress did not irreversibly affect gas exchange and quantum efficiency... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Photochemical efficiency of PSII; Stress physiology; Tree species; Water deficit. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200008 |
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| Costa,Ernany Santos; Bressan-Smith,Ricardo; Oliveira,Jurandi Gonçalves de; Campostrini,Eliemar; Pimentel,Carlos. |
| Bean (Phaseolus vulgaris L., cv. Carioca and cv. Negro Huasteco) and cowpea plants (Vigna unguiculata L. Walp cv. Epace 10) were grown in a growth chamber with PPF at leaf level of 200 mumol.m-2.s-1 and air temperature 25 + 1 ºC. The first fully expanded pair of leaves of 12-day-old plants was submitted to high temperature stress (25, 30, 35, 40, 45 and 48 ºC) for 1.5 h. The photochemical efficiency of PSII during recovery was monitored by means of chlorophyll a fluorescence at six different times (0.5, 1, 2, 4, 24, and 48 h) after stress, at 25 ºC, using a modulated fluorimeter. Increasing temperature promoted an increase in Fphi at 45 ºC, possibly associated with dissociation of the light harvesting complex from the reaction centre of PSII, but a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Heat stress; Photosynthesis. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200004 |
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| LIMA,G.R.; MACEDO,D.C.; BARROS,R.L.N.; MACHADO,A.F.L.; PIMENTEL,C.. |
| ABSTRACT: The objective of this study was to evaluate the effects of the application of contact herbicides recommended for common bean crops, as for chlorophyll a fluorescence parameters, leaf soluble proteins content (LSPC) and productivity. The experiment was conducted on the field with five treatments, which were the application of the following herbicides: bentazon (720 g ha-1), fluazifop-p-butil (187.5 g ha-1), fomesafen (250 g ha-1) fluazifop-p-butil + fomesafen (187.5 + 250 g ha-1), and a manually weeded control treatment without herbicide application, in a randomized block design with four replications. Bentazon was the only herbicide causing significant reductions, but only until the first day after herbicide application (DAA), on the following... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phaseolus vulgaris L.; Chlorophyll a fluorescence; Photosystems; Photoinhibition. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100291 |
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| Vitória,Angela Pierre; Lage-Pinto,Frederico; Silva,Leonardo Bernardo Campaneli da; Cunha,Maura da; Oliveira,Jurandi Gonçalves de; Rezende,Carlos Eduardo; Souza,Cristina Maria Magalhães de; Azevedo,Ricardo Antunes. |
| In this work, the structural and ecophysiological alterations (chlorophyll a fluorescence and photosynthetic pigments), and quantification of Cr, Pb and Zn in the leaf limb, petiole and younger and older roots of water hyacinth from the lower, medium and upper Paraíba do Sul river (PSR) and Imbé river were evaluated. The plants from the medium and upper PSR (more industrialized and populated regions) exhibited lower turgid cell in the root cortex, less root hairs and leaf epidermis, chloroplasts with plastoglobules and increased stroma volume. Higher concentrations of metals were observed in the younger and older roots from the medium PSR plants. The results suggested that the plants from more anthropized regions were able to maintain the maximum quantum... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Photosynthetic pigments; Energy dissipation; Morphological alterations; Metal evaluate. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000500025 |
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| Silva,Marcelo de A.; Jifon,John L.; Silva,Jorge A.G. da; Sharma,Vivek. |
| Drought is one of the major limitations to plant productivity worldwide. Identifying suitable screening tools and quantifiable traits would facilitate the crop improvement process for drought tolerance. In the present study, we evaluated the ability of four relatively physiological parameters (variable-to-maximum chlorophyll a fluorescence ratio, F v/F m; estimated leaf chlorophyll content via SPAD index; leaf temperature, LT; and, leaf relative water content, RWC) to distinguish between drought tolerant and susceptible sugarcane genotypes subjected to a 90-d drought cycle. Eight field-grown genotypes were studied. By 45 d after the onset of treatments, the F v/F m, SPAD index and RWC of drought-stressed plants had declined significantly in all genotypes... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Relative water content; Leaf temperature; Saccharum; Water deficit. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300003 |
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| Registros recuperados: 15 | |
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