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| Registros recuperados: 46 | |
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| Ribeiro,Rafael Vasconcelos; Santos,Mauro Guida dos; Pimentel,Carlos; Machado,Eduardo Caruso; Oliveira,Ricardo Ferraz de. |
| Low water availability and high temperatures occur under field conditions and we hypothesize that the critical temperature for photochemical damage (TC) in common bean (Phaseolus vulgaris L.) plants is increased by the occurrence of previous water deficit in a genotype-dependent manner. Five common bean cultivars A320, A222, Carioca, BAT477 and Ouro Negro were evaluated. Thirty days after seedlings emergence, one group of plants was exposed to water deficit for ten days and rehydrated and another one was maintained well hydrated during the experimental period. The minimum chlorophyll fluorescence (FO) was monitored in leaf discs exposed to temperatures ranging from 25 to 45 oC and the TC values estimated. The previous water deficit did not affect TC, which... |
| Tipo: Info:eu-repo/semantics/report |
Palavras-chave: Chlorophyll fluorescence; Hardening; Heat stress; Phaseolus vulgaris; Tolerance. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052015000400374 |
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| Bown,Horacio E; Mason,Euan G; Clinton,Peter W; Watt,Michael S. |
| Chlorophyll fluorescence responses to a factorial combination of nitrogen (N) and phosphorus (P) supply were measured in five clones of Pinus radiata cultivated in a greenhouse over twenty-four months. Chlorophyll fluorescence measurements were taken at months six (5 clones, 182 plants), nine (2 clones, 68 plants) and eighteen (2 clones, 48 plants). Plant growth in stem diameter, height, leaf area, fascicle mass, length and diameter were found to significantly increase with N and, to a lesser extent, P additions; and these values were greatest when both N and P were combined. Plant growth and fascicle size also varied significantly across clones and were generally consistent with the genotypic growth responses that were observed in the field. Dark (Fv /... |
| Tipo: Journal article |
Palavras-chave: Chlorophyll fluorescence; Quantum efficiency of PSII; Electron transport; Genotype; Nutrient limitation. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202009000300012 |
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| Frosi,Gabriella; Harand,Wolfgang; Oliveira,Marciel Teixeira de; Pereira,Silvia; Cabral,Simone Pereira; Montenegro,Abelardo Antônio de Assunção; Santos,Mauro Guida. |
| ABSTRACT The effects of water deficit on physiological and biochemical variables of young plants of two tropical woody species, Pachira aquatica and Sterculia foetida, and their recovery abilities were measured. Leaf water potential, gas exchange and selected carbon metabolism components were measured in a greenhouse experiment with control, moderate and severe water deficit treatments. Under severe drought stress, gas exchange and chlorophyll fluorescence decreased in both species compared to their respective controls. After rehydration, P. aquatica and S. foetida showed a partial and full recovery of the measured variables, respectively. In addition, a decrease and an increase in photosynthetic pigments were observed for P. aquatica and S. foetida,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll fluorescence; Climate changes; Gas exchange; Semiarid; Water deficit. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062017000200153 |
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| Jaimez,Ramón; Loor,Rey; Arteaga,Francisco; Márquez,Víctor; Tezara,Wilmer. |
| Abstract Cacao (Theobroma cacao L.) is not frequently cropped in water limited environments, however it is cultivated in several drought-prone regions, where soil water is gradually depleted on an annual cycle. In regions where cacao is subjected to long periods without precipitation, the physiological responses under field conditions may differ between cacao clones. Evaluation of these responses are required to select potential clones that could be used for breeding programs in the context of future climatic scenarios. In order to identify physiological and yield responses to drought of 10 Ecuadorian cacao clones, relative leaf water content (RWC), CO2 assimilation rate (A), transpiration (E), stomatal conductance (gs), water use efficiency (WUE),... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cacao; Chlorophyll fluorescence; Photochemical protection; Photosynthesis; Water deficit. |
| Ano: 2021 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122021000300274 |
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| FIGUEROA,FÉLIX L.; VIÑEGLA,BENJAMÍN. |
| The effects of solar ultraviolet (UV) radiation during daily cycles on photosynthesis and two key enzymes involved in carbon incorporation, the carbonic anhydrase, and in inorganic nitrogen reduction, the nitrate reductase, of macroalgae from southern Spain are presented. During daily cycles, photoinhibition in several intertidal macroalgae, expressed as decrease in the effective quantum yield from the morning to noon time, was linearly dependent on the daily integrated irradiance. However, recovery, expressed as the increase in the effective quantum yield from noon to the afternoon, presented a different pattern; full recovery was found below daily integrated irradiance of 1.0 x10(4) kJ m-2. However, recovery reached only 50 % at higher irradiances. The... |
| Tipo: Journal article |
Palavras-chave: Carbonic anhydrase; Chlorophyll fluorescence; Effective quantum yield; Nitrate reductase; Ultraviolet radiation. |
| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000200003 |
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| Ribeiro,Rafael Vasconcelos; Santos,Mauro Guida dos; Souza,Gustavo Maia; Machado,Eduardo Caruso; Oliveira,Ricardo Ferraz de; Angelocci,Luiz Roberto; Pimentel,Carlos. |
| Photosynthetic responses to daily environmental changes were studied in bean (Phaseolus vulgaris L.) genotypes 'Carioca', 'Ouro Negro', and Guarumbé. Light response curves of CO2 assimilation and stomatal conductance (g s) were also evaluated under controlled (optimum) environmental condition. Under this condition, CO2 assimilation of 'Carioca' was not saturated at 2,000 µmol m-2 s-1, whereas Guarumbé and 'Ouro Negro' exhibited different levels of light saturation. All genotypes showed dynamic photoinhibition and reversible increase in the minimum chlorophyll fluorescence yield under natural condition, as well as lower photosynthetic capacity when compared with optimum environmental condition. Since differences in g s were not observed between natural and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phaseolus vulgaris; Chlorophyll fluorescence; Gas exchange; Photosynthesis. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2004000700001 |
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| Legrand, Helene; Herlory, Olivier; Guarini, Jean-marc; Blanchard, Gerard; Richard, Pierre. |
| Atrazine and diuron are two herbicides present in sediments of the intertidal mudflats in the Pertuis Charentais (Atlantic coast, France). They may negatively affect photosynthesis processes in microphytobenthos, the most productive primary producer in these environments. The impact of these herbicides on benthic diatoms was investigated using PAM fluorimetry on natural microalgal communities, once extracted from sediment, by following the variations of the effective quantum yield of PSII (Phi(PSII)) during exposure to atrazine and diuron concentrations in a range 0.1 mu g L-1 (.) 10 mg L-1. No significant effect was noticed for 0.1 mu g L-1 concentrations, but progressive reduction in photosynthetic efficiency, always occurring within 15 min, was... |
| Tipo: Text |
Palavras-chave: Diuron; Atrazine; PAM; Chlorophyll fluorescence; Microphytobenthos. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3614.pdf |
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| Gevaert, F; Creach, A; Davoult, D; Migne, A; Levavasseur, G; Arzel, Pierre; Holl, Ac; Lemoine, Y. |
| Photosynthetic activity in thalli of Laminaria saccharina (Lamouroux) was followed in situ in the upper subtidal zone of a Northern Brittany rocky shore (Roscoff, France), using a submersible pulse amplitude modulated (PAM) fluorometer. Two fluorescence parameters, the effective quantum yield of photosystem II (Phi(PSII)) and the relative electron transport rate (rETR), were estimated at various stages of a tidal cycle from 10:00 to 18:30 h, and different light conditions due to variations of water depth and position of the sun. The Phi(PSII) decreased strongly during the ebb tide, essentially due to a drop in the maximal fluorescence level for light-adapted samples (F-m'). This was the result of increasing non-photochemical quenching (NPQ). Algae totally... |
| Tipo: Text |
Palavras-chave: Laminaria saccharina; Photoprotection; Xanthophyll cycle; Chlorophyll fluorescence; Diurnal tidal cycles; Diving PAM. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10191/7592.pdf |
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| Mengarda,Liana H. G.; Souza,Rogério L. F. de; Campostrini,Eliemar; Reis,Fabrício O.; Vendrame,Wagner A.; Cuzzuol,Geraldo R. F.. |
| The ecophysiological behavior of brazilwood (Caesalpinia echinata Lam.) plants was evaluated as affected by light quantity and quality. Nine-month-old plants were cultivated under 0%, 50%, and 80% artificial shading, and natural shading imposed by a closed canopy for a period of 392 days. At the end of that period growth parameters were measured, including relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf mass (SLM) and root:shoot ratio (R:S). Higher leaf area, dry mass and RGR were obtained under 50% artificial shade. Under full sunlight (0% shade), growth was satisfactory showing higher R:S and SLM. Growth was inhibited under 80% artificial and natural shading indicating that C. echinata is not... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll fluorescence; Gas exchange; Growth; Light stress; Shade; Tropical tree. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100007 |
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| Bautista,Anna I.N.; Necchi Jr.,Orlando. |
| Three freshwater Rhodophyta species (Audouinella eugenea, A. hermannii and Compsopogon coeruleus) were tested as to their responses (photosynthesis, growth and pigment concentration) to two irradiances (low light, LL, 65 µmol m-2 s-1 and high light, HL, 300 µmol m-2 s-1) and two periods (short time, ST, 4 d, and long time, LT, 28 d). Higher growth rates were consistently observed at LL but significant differences were observed only for A. hermannii. Higher values of photoinhibition at LL were found for the three species, which is consistent with the dynamic photoinhibition as a reversible photoprotective mechanism against high irradiance. Light-induced decreases of effective quantum yield (EQY) were observed in the three species consisting of pronounced... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll fluorescence; Growth; Irradiance; Photosynthesis; Pigment; Red algae. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100003 |
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| Registros recuperados: 46 | |
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