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| Registros recuperados: 46 | |
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| Brito,Cleiton F. B.; Donato,Sérgio L. R.; Arantes,Alessandro de M.; Donato,Paulo E. R.; Silva,João A. da. |
| ABSTRACT The objective of this study was to determine the photochemical efficiency of ‘Gigante’ cactus pear cultivated under different spacings and bovine manure doses in the semi-arid region. The experiment was conducted in a randomized block design in a 4 x 3 x 7 factorial scheme, with three replicates. The first factor consisted of four doses of organic fertilization (0, 30, 60 and 90 Mg ha-1 year-1 of bovine manure), the second one, of three spacings (1.0 x 0.5, 2.0 x 0.25 and 3.0 x 1.0 x 0.25 m) and the third one of seven reading times (6, 8, 10, 12, 14, 16 and 18 h). Chlorophyll a fluorescence readings were taken in cactus pear cladodes in the dry and rainy seasons using a pulse-modulated fluorometer. Cladodes of ‘Gigante’ cactus pear cultivated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Opuntia; Arrangement of plants; Chlorophyll fluorescence. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000500338 |
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| Miguel,Aurélio Antas; Oliveira,Luiz Edson Mota de; Cairo,Paulo Araquém Ramos; Oliveira,Davi Melo de. |
| This work proposed to investigate changes in the photosynthetic behavior during the leaf ontogeny of the during the leaf development. Up to the 32nd day of leaf age (stage B2), the net photosynthesis was negative due to the inefficiency of the photosynthetic system, and this fact was justified by the following factors: low chlorophyll content, less stomatal conductance, high rubber tree clones PB 235, RRIM 600 and GT 1, in Lavras, MG. The experiment was performed in 2004, between May and July, under field conditions, at the Universidade Federal de Lavras. During the leaf ontogeny, the following characteristics were evaluated: chlorophyll content, gaseous exchanges and chlorophyll fluorescence. The clones presented similar profiles of alterations in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rubber tree; Photosynthesis; Gaseous exchanges; Chlorophyll fluorescence. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542007000100014 |
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| Deus,Bruna Corrêa da Silva de; Figueiredo,Fábio Afonso Mazzei Moura de Assis; Almeida,Luciana Venturotti Braun de; Ferraz,Tiago Massi; Martins,Amanda Oliveira; Rodrigues,Weverton Pereira; Viana,Leandro Hespanhol; Esteves,Barbara dos Santos; Campostrini,Eliemar. |
| ABSTRACT: New techniques in tropical regions such as use of transparent plastic covering (TPC), have been employed in grapes to avoid the wetting leaves and fruits, which can reduce the occurrence of fungal diseases, reduce the use of sprays, and reduce damage caused by hail and high winds. TPC may significantly affect the photosynthetic rates of grapevines cultivated in tropical regions, and thus have strong effects on plant productivity and improve fruit quality. However, in the North of Rio de Janeiro region there are lacks of studies related to TPC effects on photosynthetic capacity. The objective of this study was to evaluate the photosynthetic capacity in 'Niagara Rosada' vines grown under TPC and without transparent plastic covering (WTPC). The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Chlorophyll fluorescence; Vitisla brusca; Covered system. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000600950 |
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| Dutra,Wellison F.; Melo,Alberto S. de; Dutra,Alexson F.; Brito,Marcos E. B.; Filgueiras,Luanna M. B.; Meneses,Carlos H. S. G.. |
| ABSTRACT To evaluate the photosynthetic efficiency, gas exchange and yield of castor bean intercropped with peanut under Brazilian semiarid conditions, a field experiment was set up with six treatments and four replicates arranged in a randomized block design. The experiment consisted of the cultivation of castor bean ‘BRS Energia’ in a monocrop system and intercropped with peanut ‘BR 1’. One treatment was formed by monocropped castor bean and the others by the castor bean intercropped with peanut with different intercrop establishment times, i.e. peanut sowing times (0, 10, 15, 20 and 25 days after castor bean sowing). The castor bean photosynthetic and carboxylation efficiencies were higher in the intercrop system with a 25-day interval between sowings.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll fluorescence; Photosynthesis; Ricinus communis L.; Yield. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000200106 |
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| PEREZ MARTINEZ,Laura Victoria; MELGAREJO,Luz Marina. |
| Gulupa, Passiflora edulis Sims (Passifloraceae), is an important fruit due to its organoleptic and nutritional characteristics and its demand in the international market; however, very few studies have been conducted for studying its Ecophysiology. Until now, this crop has spread throughout the country through empirical knowledge without data that indicate the zones that are more suitable for its cultivation. For this reason, gas exchange, chlorophyll fluorescence (photosystem II operating efficiency and maximum quantum efficiency of photosystem II photochemistry) and leaf water potential were measured in three different locations of Cundinamarca department (Chia [2610 m a.s.l., 14 °C], Granada [2230 m a.s.l., 15 °C] and Tena [2090 m a.s.l., 17 °C]), whose... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll fluorescence; Crop; Horticulture; Passion fruit; Photosynthesis; Plant physiology; Water. |
| Ano: 2015 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2015000100019 |
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| CASANOVA-KATNY,M. ANGÉLICA; BRAVO,LEÓN A; MOLINA-MONTENEGRO,MARCO; CORCUERA,LUIS J; CAVIERES,LOHENGRIN A. |
| Photosynthesis of Colobanthus quitensis and mesoclimatic conditions of air temperature and light intensity during the growing season were investigated at 2,650 m in the central Chilean Andes. On three typical days of the growing period (January, March and May), CO2 exchange and chlorophyll fluorescence were measured. In addition, a series of fluorescence response curves with increasing light intensity at different temperatures were performed to estimate the propensity of Andean C. quitensis populations to be photoinhibited. Net Photosynthesis (Pn) was low (ca. 2.0 mmol CO2 m-2s-1) during the morning and noon in days with high photosynthetic active radiation (PAR, above 1,800 mmol photons m-2s-1). Pn increased in the afternoon (3.5-4.8 mmol CO2 m-2s-1) when... |
| Tipo: Journal article |
Palavras-chave: Net photosynthesis; Chlorophyll fluorescence; NPQ; Alpine climate; Alpine plants; Andes. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000100004 |
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| Chaloub,Ricardo M.; Reinert,Fernanda; Nassar,Cristina A. G.; Fleury,Beatriz G.; Mantuano,Dulce G.; Larkum,Anthony W. D.. |
| Photosynthetic performance of distinct marine macroalgae, Ulva fasciata Delile (green alga), Lobophora variegata (J. V. Lamouroux) Womersley ex E. C. Oliveira (brown alga), and Plocamium brasiliensis (Greville) M. A. Howe & W. R. Taylor (red alga), were compared using a pulse amplitude-modulated fluorometer. The maximum quantum yield (Fv/Fm) ranged from 0.80 to 0.51, and the lowest value was found in P. brasiliensis. Under 400 µmol photons m-2 s-1 irradiance, the highest value of photochemical quenching (qP = 0.92 ± 0.13) was observed for U. fasciata. The red alga P. brasiliensis dissipated high amounts of excitation energy (qN = 0.56 ± 0.09), resulting in relatively low values for the effective quantum yield of PS-II (0.23 ± 0.04), as well as for... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll fluorescence; Lobophora variegata; Plocamium brasiliensis; Ulva fasciata. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042010000200017 |
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| JAIMEZ,Ramon Eduardo; AMORES PUYUTAXI,Freddy; VASCO,Alfonso; Gastón LOOR,Rey; TARQUI,Omar; QUIJANO,Grisnel; JIMENEZ,Juan Carlos; TEZARA,Wilmer. |
| ABSTRACT Cacao (Theobroma cacao L.) breeding programmes in Ecuador have focused on obtaining high-yield clones with improved disease resistance. Cacao clones should also have photosynthetic characteristics which support increased productivity. Regarding the weather conditions at the coast of Ecuador, where most of the year there are overcasts and low air evaporative demand, there is the possibility to grow cacao without overhead shade. This study focused on the photosynthetic response at two different photosynthetic photon flux densities (PPFD) of Ecuadorian cacao clones. Seven-year old cacao clones were evaluated: eight clones of Nacional type and two commercial clones (CCN 51 and EET 103), used as controls. All clones showed an increase of 35 % on... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cacao yield; Chlorophyll fluorescence; CO2 assimilation rate; Gas exchange. |
| Ano: 2018 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2018000100095 |
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| Souza,Rogéria Pereira de; Ribeiro,Rafael Vasconcelos; Machado,Eduardo Caruso; Oliveira,Ricardo Ferraz de; Silveira,Joaquim Albenísio Gomes da. |
| The aim of this study was to characterize gas exchange responses of young cashew plants to varying photosynthetic photon flux density (PPFD), temperature, vapor-pressure deficit (VPD), and intercellular CO2 concentration (Ci), under controlled conditions. Daily courses of gas exchange and chlorophyll a fluorescence parameters were measured under natural conditions. Maximum CO2 assimilation rates, under optimal controlled conditions, were about 13 mmol m-2 s-1 , with light saturation around 1,000 mmol m-2 s-1. Leaf temperatures between 25ºC and 35ºC were optimal for photosynthesis. Stomata showed sensitivity to CO2, and a closing response with increasing Ci. Increasing VPD had a small effect on CO2 assimilation rates, with a small decrease above 2.5 kPa.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anacardium occidentale; Gas exchange; Chlorophyll fluorescence; Temperature; Vapor-pressure deficit. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2005000800002 |
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| Zalamena,Jovani; Melo,George W.; Santos,Henrique P.; Silva,Leandro S. da; Fialho,Flavio B.; Brunetto,Gustavo. |
| ABSTRACTThis study aimed to evaluate the performance of grapevine rootstocks under increasing levels of Zn in the soil and to identify physiological variables that can be used as indicators of excess of Zn in the soil. The rootstocks SO4, Paulsen1103, IAC572, IAC313 and 420A were grown in pots containing soil, which received Zn doses of 0, 20, 40, 80 or 160 mg kg-1 of soil. Dry matter (DM), Zn content in shoots and roots, chlorophyll index, initial fluorescence (Fo), maximum fluorescence (Fm), maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield of photosystem II (Y-II) and non-photochemical quenching (NPQ) were evaluated. The increase of Zn levels in the soil decreased DM in all rootstocks, and IAC572 was superior to the others. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heavy metal; Toxicity; Chlorophyll fluorescence; Vitis spp.. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662015001000973 |
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| Heydarizadeh, Parisa; Boureba, Wafaa; Zahedi, Morteza; Huang, Bing; Moreau, Brigitte; Lukomska, Ewa; Couzinet-mossion, Aurelie; Wielgosz-collin, Gaetane; Martin-jezequel, Veronique; Bougaran, Gael; Marchand, Justine; Schoefs, Benoit. |
| In this study, we investigated the responses of Phaeodactylum tricornutum cells acclimated to 300 mu mol m(-2) s(-1) photon flux density to an increase (1000 mmol m(-2) s(-1)) or decrease (30 mmol m(-2)s(-1)) in photon flux densities. The light shift occurred abruptly after 5 days of growth and the acclimation to new conditions was followed during the next 6 days at the physiological and molecular levels. The molecular data reflect a rearrangement of carbon metabolism towards the production of phosphoenolpyruvic acid (PEP) and/or pyruvate. These intermediates were used differently by the cell as a function of the photon flux density: under low light, photosynthesis was depressed while respiration was increased. Under high light, lipids and proteins... |
| Tipo: Text |
Palavras-chave: Phaeodactylum tricornutum; Carbon metabolism; Light regulation; Photosynthesis; Chlorophyll fluorescence; Pyruvate hub. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00395/50620/52341.pdf |
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| Silva,Evandro Nascimento da; Ribeiro,Rafael Vasconcelos; Ferreira-Silva,Sérgio Luiz; Viégas,Ricardo Almeida; Silveira,Joaquim Albenisio Gomes. |
| Salinity is a major limiting factor to crop productivity in the world especially in semiarid regions. The aim of this study was to evaluate the photosynthetic resistance of Jatropha curcas (L.) young plants subjected to salt stress. The experiment was carried out in a completely randomized design with treatments in a 2 x 3 factorial: two NaCl levels (0 and 100 mmol L-1) and three harvest times: 7 and 14 days of salt exposure and three days of recovery. Leaf Na+ and Cl-concentrations and the K+/Na+ ratios, after seven days of salt exposure, did not reach ionic toxic levels, suggesting that the NaCl-induced osmotic effects prevailed over the ionic ones. Under this condition, the salt stress caused reduction in leaf gas exchange parameters, such as CO2... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Jatropha curcas; Chlorophyll fluorescence; Gas exchange; Ionic toxicity; Salinity. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162011000100010 |
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| Neves,Jose M. G.; Aquino,Leonardo A. de; Berger,Paulo G.; Neves,Júlio C. L.; Rocha,Genelício C.; Barbosa,Edimilson A.. |
| ABSTRACT The objective of this study was to evaluate the effect of Ca and Mg silicate and B on the gas exchange, leaf water potential and chlorophyll fluorescence parameters in the sunflower variety Embrapa 122 -V2000 under water stress conditions. The trial was conducted in Red Yellow Latosol with very clayey texture, with contrasting levels of Si and B and subjected to water deficit. The experimental design was randomized blocks in a 24 factorial arrangement, with five replicates. Treatments consisted of the combination of two acidity corrective agents (calcium magnesium silicate and dolomitic limestone), two levels of base saturation (30 and 70%), two levels of B (0.18 mg dm-3 - value available in the soil and 1.20 mg dm-3) and two water regimes (with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Helianthus annuus; Chlorophyll fluorescence; Gas exchange; Leaf water potential. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019000300175 |
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| Registros recuperados: 46 | |
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