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| Registros recuperados: 220 | |
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| Santos,Osvaldir F. dos; Lima,Sebastião F. de; Paiva Neto,Vespasiano B. de; Piati,Gabriel L.; Osório,Christian R. W. de S.; Souza,Hugo M. de. |
| ABSTRACT The objective of this work was to evaluate leaf gas exchanges of sweet corn as a function of defoliation when submitted to different irrigation depths. The experimental design was randomized blocks in split-plot scheme, with four irrigation depths in the plots [50, 75, 100 and 125% of crop evapotranspiration (ETc)], and three levels of defoliation in the subplots (0%, control; 35%, removal of four fully expanded leaves; 100%, total removal of the leaves - section of the aerial part) with three replicates. Defoliation was manually performed when the plant had four fully expanded leaves. It was verified that the dephs of irrigation and defoliation levels affect leaf gas exchanges in sweet corn plants, allowing the conclusion that the plant tends to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays L. var. saccharata; Water stress; Photosynthesis. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017001200822 |
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| CAMPOSTRINI,ELIEMAR; YAMANISHI,OSVALDO KIYOSHI. |
| Four papaya genotypes, two from the Solo group (Sunrise Solo TJ and Improved Sunrise Solo line 72/12) and two from the Formosa group (Tainung 02 and Know You 01) grown in ultisol under field conditions in Macaé, RJ, Brazil, were used in this study. Two different effective depths (ED) were determined in the area using a penetrographer with average soil moisture of 11.2%. The area with ED of 0.35 m with a maximum pressure of 4.12 MPa for penetration was defined as an area with restriction (WR) to root growth, while, the area with minimum ED of 0.60 m and a pressure lower than 2.30 MPa as an area with no restriction (NR). The net CO2 assimilation rate (A), stomatal conductance (g s), leaf temperature (Tl), intercellular partial pressure of CO2 (c i) and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carica papaya L.; Photosynthesis; Leaf temperature; Stomatal conductance; Intrinsic water use efficiency. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000200002 |
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| CAMPOSTRINI,ELIEMAR; YAMANISHI,OSVALDO KIYOSHI; MARTINEZ,CARLOS A.. |
| In this research, was used four papaya (Carica papaya L.) genotypes: three from the 'Solo ( Sunrise Solo TJ, Sunrise Solo 72/12 and Baixinho de Santa Amália) group and one from the 'Formosa' group (Know-You 01). They were grown in plastic pots containing a sandy-clay-loam soil subjected to pH correction and fertilization, under greenhouse conditions. Throughout the experimental period plants were subjected to periodic irrigation to maintain the soil humitidy around field capacity. The experiment was conducted 73 days after sowing. In all genotypes, leaf gas exchange characteristics were determined. The net photosynthetic rate (A, mumol m-2 s-1 ), stomatal conductance (g s mol m-2 s-1), leaf temperature (T I, 0C) and intercellular carbon dioxide... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Carica papaya; Stomatal conductance; Leaf temperature. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452001000300014 |
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| Lima Filho,José Moacir Pinheiro. |
| A study was carried out at Embrapa Semi-Árido, Petrolina-PE, Brazil, aiming to understand the gas exchange process of the umbu tree (Spondias tuberosa Arr. Cam.) in the dry and rainy seasons. Stomatal conductance, transpiration, photosynthesis and internal CO2 concentration were obtained with a portable infrared gas analyzer (IRGA). During the dry season the umbu tree showed a much lower stomatal conductance early in the morning, as soon as the vapor pressure deficit increased, apparently affecting CO2 assimilation more than transpiration. The highest values were detected around 6:00 am but decreased to the lowest points between 10:00 am and 2:00 pm. During the rainy season, however, stomatal conductance, transpiration and photosynthesis were significantly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spondias tuberosa; Stomatal conductance; Transpiration; Photosynthesis; CO2 internal concentration. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452004000200006 |
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| Baron,Daniel; Ferreira,Gisela; Rodrigues,João Domingos; Macedo,Ana Claudia; Amaro,Amanda Cristina Esteves. |
| This study aims to investigate the gas exchanges of different species of Annonaceae due to environmental variations provided by different types of crop protection. 'Araticum-de-terra-fria', 'araticum-mirim', 'biribá' and atemoya seedlings were cultived in three different crop protections: nursery, greenhouse and warm house. Gas exchanges were obtained in six plants, from 9:00 am to 11:00 am, with IRGA, LI-6400, at 180 Days After Transplanting. The different types of crop protection had a direct influence on gas exchanges of these species. Thus, nursery provided suitable conditions for 'araticum-de-terra-fria', 'araticum-mirim' and 'biribá', increasing their gas exchanges. To atemoya the best crop protection was the greenhouse. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Environmental condition; Annona emarginata; Annona mucosa; Annona squamosa L. x Annona cherimola Mill. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452014000500028 |
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| Barbosa,Eduardo Augusto Agnellos; Ayub,Ricardo Antonio; Luz,Ângela da; Pessenti,Isabela Leticia; Pereira,André Belmont. |
| Abstract The current study aimed at evaluating gas exchanges, yield, water use efficiency and fruit quality of cape gooseberry in response to different irrigation depths with or without mulching of oat residues on pots at greenhouse conditions. Four irrigation depths were tested: 50%, 100%, 125% e 150% of reference evapotranspiration (ETo). Leaf gas exchanges were evaluated by an infrared gas analyzer at different stages of the crop. Throughout the harvest, yield per plant and yield components were assessed in conjunction with water-use efficiency (WUE) and fruit quality responses. Stomata conductance at the flowering and fructification stages showed a smaller limitation under the treatments 125 and 150%ETo. It should be noticed that the aforementioned... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Physalis peruviana L.; Water stress; Stomata conductance; Photosynthesis; Fruit yield. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452019000406001 |
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| KLUMB,ELSA KUHN; RICKES,LETICIA NEUTZLING; BRAGA,EUGENIA JACIRA BOLACEL; BIANCHI,VALMOR JOÃO. |
| ABSTRACT The state of Rio Grande do Sul is the largest peach productor in Brazil; however, it still possesses poor yield values when compared with other states. One of the problems associated with this is the occurrence of soils with drainage problems, mainly in Pelotas region, which depending on the year period, may undergo water deficit or flooding situations in the great majority of the years, which harm the crop development and yield. Among the harmful effects caused by these stresses stand out, the decrease in the net assimilation rate, closure of stomata, reduction of the cell activities, production of reactive oxygen species, membrane and protein destabilization. Thus, the aim of this study was to investigate in what magnitude of the gaseous... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water stress; Photosynthesis; Peach tree; Plum tree. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452017000400706 |
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| Lopes,Marcos Neves; Lacerda,Claudivan Feitosa de; Cândido,Magno José Duarte; Pompeu,Roberto Cláudio Fernandes Franco; Silva,Rodrigo Gregório da; Lopes,José Wellington Batista; Fernandes,Francisco Ronaldo Belém; Bezerra,Francisco Marcus Lima. |
| The objective of this study was to evaluate gas exchange in the massai grass during establishment and regrowth cycles in a greenhouse, using five nitrogen (N) fertilization levels. A completely randomized split-plot design of five nitrogen levels (0; 150; 300; 450 and 600 mg Ndm-3 of soil) was employed with the N levels as plots, and the cycles (establishment, regrowth 1 and 2) as subplots, evaluated with five replicates. We evaluated leaf transpiration (E), leaf temperature (TFOL), leaf photosynthesis rate (A), leaf carbon dioxide concentration (Ci), stomatal conductance (gs), photosynthesis/transpiration ratio (A/E), photosynthesis/conductance ratio (A/gs), chlorophyll relative index (CRI), and nitrogen sufficiency index (NSI). Growth cycles influenced... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll; CO2 concentration; Panicum maximum; Photosynthesis. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000900004 |
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| HELBLING,E. WALTER; VILLAFAÑE,VIRGINIA E.; BARBIERI,ELENA S.. |
| During July of 1999 sampling was carried out in five Andean lakes to determine the sensitivity of winter phytoplankton communities to ultraviolet-B radiation (UV-B, 280-320 nm). The studied lakes, Moreno, El Trébol, Nahuel Huapi, Gutiérrez, and Morenito, located in the Patagonia region (41° S, 71° W, 800 m of altitude), had attenuation coefficients for UV-B that ranged from 0.36 m-1 (Lake Moreno) to 2.8 m-1 (Lake Morenito). The samples were inoculated with labeled carbon (NaH14CO3) and incubated in an illuminated chamber (UV-B = 0.35 W m-2, UV-A [320-400 nm] = 1.1 W m-2, and PAR [400-700 nm] = 10.8 W m-2) at 10 °C. The phytoplankton cells were exposed to UV radiation (280-400 nm) + PAR (quartz tubes), and to UV-A + PAR (quartz tubes covered with Mylar-D).... |
| Tipo: Journal article |
Palavras-chave: Ultraviolet-B radiation; Photosynthesis; Phytoplankton; Ozone; Andean lakes. |
| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000200005 |
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| MONTECINO,VIVIAN; MOLINA,XIMENA; MARTÏNEZ,GINGER; OLMEDO,M. ISABEL; RETAMAL,LEIRA; HANNACH,GABRIELA; ORELLANA,MÓNICA V.. |
| Marine microalgae exposed to ultraviolet radiation (UV) have complex adaptive responses provided by a series of protection and repair mechanisms. Interspecific differences in UV sensibility could result in differential selection of the more tolerant species, having consequences for the structure of phytoplankton assemblages. The relative importance of protection and photorepair mechanisms of microalgal cells exposed to potential UV-B stress was studied in monocultures with different taxonomic, ecological and size characteristics obtained from the Chilean coast. Differences in photosynthesis and growth rates were predicted, since the ability to effectively acclimate to UV is not universal between microalgal species. The dinoflagellate Alexandrium catenella... |
| Tipo: Journal article |
Palavras-chave: Photosynthesis; Absorbance; Photoreactivation; Growth; UV response. |
| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000200007 |
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| SIERRA-ALMEIDA,ÁNGELA; CASANOVA-KATNY,M. ANGÉLICA; BRAVO,LEÓN A; CORCUERA,LUIS J; CAVIERES,LOHENGRIN A. |
| Colobanthus quitensis (Kunth, 1831) Bartling (Caryophyllaceae) is characterized by a wide latitudinal distribution, ranging between the tropical high Andes and the Antarctic Peninsula. Although both habitat types are characterized by cold and freezing temperatures, important microclimatic differences exist during the growing season. Hence, important differences in the response of the photosynthetic apparatus to abiotic factors could be expected between Antarctic and Andean populations of C. quitensis. We studied the relationship between net photosynthesis, leaf temperature and light intensity in two populations of C. quitensis, one from La Parva in the Andes of central Chile and the other from King George Island, in the Maritime Antarctic. Plants from both... |
| Tipo: Journal article |
Palavras-chave: Photosynthesis; Colobanthus quitensis; Optimum leaf temperature; Light intensity. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2007000300007 |
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| GÓMEZ,I.. |
| Daylength is the major environmental factor affecting the seasonal photosynthetic performance of Antarctic macroalgae. For example, the "season anticipation" strategy of large brown algae such as Ascoseira mirabilis and Desmarestia menziesii are based on the ability of their photosynthetic apparatus to make use of the available irradiance at increasing daylengths in late winter-spring. The seasonal development and allocation of biomass along the lamina of A. mirabilis are related to a differential physiological activity in the plant. Thus, intra-thallus differentiation in O2-based photosynthesis and carbon fixation represents a morpho-functional adaptation that optimizes conversion of radiant energy to primary productivity. In Desmarestia menziesii,... |
| Tipo: Journal article |
Palavras-chave: Polar macroalgae; Antarctic; Photosynthesis; Daylength. |
| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000200004 |
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| CABELLO-PASINI,ALEJANDRO; ALBERTE,RANDALL S.. |
| Carbon is acquired through photosynthetic and non-photosynthetic processes in marine algae. However, little is known about the biochemical regulation of these metabolic pathways along the thallus of seaweeds. Consequently, the objective of this study was to assess the distribution of in vivo carboxylation pathways and to relate them to the in vitro activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (RUBISCO), phosphoenolpyruvate carboxykinase (PEPCK), and phosphoenolpyruvate carboxylase (PEPC) in the Phaeophyte Laminaria setchellii, the Chlorophyte Ulva lactuca, and the Rhodophyte Iridaea cordata. Chlorophyll-a levels did not vary in U. lactuca and I. cordata. However, pigment levels were significantly lower in the meristematic region of L.... |
| Tipo: Journal article |
Palavras-chave: Enzymatic activity; Chlorophyll; Light-independent carbon fixation; Photosynthesis. |
| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000200002 |
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| Rivas,C.; Navarro,N.; Huovinen,P.; Gómez,I.. |
| BACKGROUND: Photosynthetic characteristics and the effect of UV radiation and elevated temperature measured were studied in Chlorella sp. isolated from a snow microalgal community at King George Island, Maritime Antarctica through the chlorophyll florescence (rapid light curves and maximum quantum yield, respectively). The environmental context was monitored through measurements of spectral depth profiles of solar radiation (down to 40 cm) in the snowpack as well as a through continuous recording of temperature and PAR using dataloggers located at different depths (0-30 cm) within the snow column RESULTS: The photochemistry of Chlorella sp. was affected by UV radiation in a 12-h laboratory exposure under all studied temperatures (5, 10, 15, 20 °C): the... |
| Tipo: Journal article |
Palavras-chave: Antarctica; Snow algae; Chlorella sp; Photosynthesis; UV radiation; Temperature. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2016000100006 |
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| RAUTENBERGER,RALF; MANSILLA,ANDRÉS; GÓMEZ,IVÁN; WIENCKE,CHRISTIAN; BISCHOF,KAI. |
| For the first time, the photosynthetic performance of field-grown macroalgae from the Magellan Strait was evaluated with respect to their photoadaptation in the field and acclimation potential to ultraviolet radiation. Five macroalgal species were collected in the eulittoral and the upper sublittoral: Ulva intestinalis, Porphyra columbina, Adenocystis utricularis, Desmarestia confervoides and D. ligulata. Photosynthesis vs. irradiance (P-I) curves of macroalgae cultivated in the laboratory under low white light intensities more than a week were used to assess the acclimation potential to irradiance conditions in the field. Both, photosynthetic parameters referred to as maximum electron transport rate (ETRmax) and light saturation points of photosynthesis... |
| Tipo: Journal article |
Palavras-chave: UV-radiation; Macroalgae; Photosynthesis; Photoacclimation; Strait of Magellan. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2009000100003 |
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| Registros recuperados: 220 | |
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