|
|
|
| Registros recuperados: 68 | |
|
|
| Castano-Marín,Angela María; Riaño-Herrera,Nestor Miguel; Peña-Quiñones,Andrés Javier; Ramirez-Builes,Víctor Hugo; Valencia-Salazar,Arley; Figueroa-Casas,Apolinar; Góez-Vinasco,Gerardo Antonio. |
| Abstract This paper presents the conceptualization, methodological adjustment and experimental application of the micrometeorological technique eddy covariance - EC, to measure energy, water vapor and CO2 fluxes in two coffee agroecosystems: the first under full sunlight, and the second under shade, both with equatorial Andean hillslope conditions. With a footprint and fetch calculation, the required distance from the edge of the field in the prevailing wind direction to the EC tower is three times higher under shade than full sun. The shaded agroecosystem reached maximum average carbon fixation rates of 21.26 ± 2.469 μmolCO2.m-2s-1 (α = 0.05) (61% higher than under 100% sunlight) which gives a high carbon sink capacity to the association of coffee plants... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agroecosystem coffee; Andean hillslope; Eddy covariance; Energy fluxes; Gas exchange. |
| Ano: 2017 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122017000100027 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| Rossatto,Davi Rodrigo; Kolb,Rosana Marta. |
| Gochnatia is very common in different phytophysiognomies in the Cerrado of São Paulo State, occupying open and closed areas. In this study, we compared the leaf anatomy and some ecophysiological traits of two species of Gochnatia, one a shrub (Gochnatia barrosii Cabrera) and the other a tree (Gochnatia polymorpha (Less.) Cabrera), which both occur in an area of "cerradão" at the Estação Ecológica de Assis, SP. We found qualitative structural differences between the species, with G. barrosii presenting amphistomatic leaves with a uniseriate epidermis and G. polymorpha showing hypostomatic leaves and a multiple epidermis or hypodermis on the adaxial surface. Moreover, the G. barrosii leaves had lower values in tissue thickness (with the exception of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Gas exchange; Leaf anatomy; Stomata. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062012000400014 |
| |
|
| |
|
|
| Silva, Fabiola França; Mendes, Bruna Silva; Rocha, Maria Socorro; Brito Neto, José Félix; Beltrão, Napoleão Macêdo; Sofiatti, Valdinei. |
| The castor bean plant, a Euphorbiaceae oil seed C3-metabolism rustic and drought-resistant plant, is cultivated in a wide range of environments due to its good adaptive capacity. However, given the current environmental changes, many biochemical and physiological impacts may affect the productivity of important crops, such as castor bean. This work aimed to evaluate the impacts of the castor bean gas exchange in response to high temperature and increased CO2concentration.Our experiment was conducted in a phytotron located at Embrapa Algodão in 2010. We adopted a completely randomized design, with four treatments in a factorial combination of two temperatures (30/20 and 37/30°C) and two CO2 levels (400 and 800 mmol L-1); four replications were performed,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 5.01.03.00-8 castor bean; Climate change; Gas exchange; Photosynthesis; Chlorophyllssíntese clorofila 5.01.03.06-7. |
| Ano: 2015 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/19075 |
| |
|
|
| Souza,Claudia Rita de; Mota,Renata Vieira da; Dias,Frederico Alcântara Novelli; Melo,Evaldo Tadeu de; Pimentel,Rodrigo Meirelles de Azevedo; Souza,Laís Cristina de; Regina,Murillo de Albuquerque. |
| The performance of Syrah grapevine under protected cultivation with different plastic films was evaluated during 2012 and 2013 seasons in South of Minas Gerais State. Agronomical and physiological measurements were done on eight years old grapevines, grafted onto ‘1103 Paulsen’ rootstock cultivated under uncovered conditions, covered with transparent and with diffuse plastic films. Both plastic covers induced the highest shoot growth rate and specific leaf area. The diffuse plastic induced greater differences on leaf area, pruning weight and leaf chlorophyll content as compared to uncovered vines. Grapevines under diffuse plastic also had the lowest rates of photosynthesis, stomatal conductance and transpiration. Leaf starch, glucose and fructose contents... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vitis vinifera; Plastic cover; Vegetative vigor; Water relations; Gas exchange; Wine grape composition. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052015000300270 |
| |
|
|
| 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 |
| |
|
|
| Oliveira,Deborah; Medeiros,Maria; Pereira,Silvia; Oliveira,Marciel; Frosi,Gabriella; Arruda,Emília; Santos,Mauro. |
| ABSTRACT The main goal of this study was to evaluate the performance of two palm species under semi-arid conditions during the rainy and dry periods: the semi-arid native Syagrus coronata and a native to tropical America, Acrocomia aculeata. The leaf water potential, gas exchange, leaf soluble sugars, starch, free amino acids, total soluble protein content and morphological traits were measured. The highest leaf water potential and CO2 assimilation values in both species were achieved during the rainy period. In response to the low soil moisture content during the dry period, gas exchange decreased 72 and 92% in S. coronata and A. aculeata, respectively, when compared with values from rainy period. As evergreen plants, both species maintained intact leaf... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acrocomia aculeata; Evergreen species; Gas exchange; Syagrus coronata; Water deficit. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052016000200128 |
| |
|
|
| Cacique,Isaias Severino; Bispo,Wilka Messner Silva; Araujo,Leonardo; Aucique-Pérez,Carlos Eduardo; Rios,Jonas Alberto; Silva,Leandro Castro; Rodrigues,Fabrício Ávila. |
| ABSTRACT Mango wilt, caused by the fungus Ceratocystis fimbriata, is an important disease affecting mango production. In view of the beneficial effects of potassium (K) in other profitable crops and the lack of information about the effect of macronutrients on mango wilt development, the present study aimed to evaluate how mango plants supplied with K respond physiologically when infected by C. fimbriata. Mango plants (» 3 years old) from cultivar Ubá were grown in plastic pots containing 58 mg of K·dm−3 (original K level based on the chemical analysis of the substrate) or in plastic pots with substrate amended with a solution of 0.5 M potassium chloride (KCl) to achieve the rate of 240 mg K·dm−3. Disease symptoms were more pronounced in inoculated plants... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mangifera indica; Gas exchange; Host defense; Mango wilt; Plant nutrition; Vascular disease. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052017000400521 |
| |
|
|
| Bueno,Adeney de Freitas; Bueno,Regiane Cristina Oliveira de Freitas; Nabity,Paul David; Higley,Leon George; Fernandes,Odair Aparecido. |
| The twospotted spider mite Tetranychus urticae Koch is a common pest on soybean plants. To clarify plant-arthropod interaction on mite-soybean system, leaf fluorescence, photosynthetic responses to variable carbon dioxide levels, and chlorophyll content were evaluated. Significant photosynthetic rate reduction was observed due to stomatal limitation. Stomatal closure was the major plant physiological response. As a consequence, there was reduction in photosynthetic rates. Surprisingly, plants did not show chlorophyll content reduction associated with photosynthetic impairment. No differences in fluorescence data indicate that T. urticae injury did not impair the function of light harvesting and photoelectron transport. These results showed that T. urticae... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tetranychus urticae; Insect-plant relationship; Fluorescence; Gas exchange; Photosynthesis. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000400005 |
| |
|
| |
|
|
| Sperandio,E.F.; Arantes,R.L.; Matheus,A.C.; Silva,R.P.; Lauria,V.T.; Romiti,M.; Gagliardi,A.R.T.; Dourado,V.Z.. |
| The 6-minute walk test (6MWT) is a simple field test that is widely used in clinical settings to assess functional exercise capacity. However, studies with healthy subjects are scarce. We hypothesized that the 6MWT might be useful to assess exercise capacity in healthy subjects. The purpose of this study was to evaluate 6MWT intensity in middle-aged and older adults, as well as to develop a simple equation to predict oxygen uptake ( V ˙ O 2) from the 6-min walk distance (6MWD). Eighty-six participants, 40 men and 46 women, 40-74 years of age and with a mean body mass index of 28±6 kg/m2, performed the 6MWT according to American Thoracic Society guidelines. Physiological responses were evaluated during the 6MWT using a K4b2 Cosmed telemetry gas... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Exercise; Walking; Gas exchange. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000400349 |
| |
|
| |
|
|
| Rocha,Andréa C.; Canal,Emerson C.; Campostrini,Eliemar; Reis,Fabrício O.; Cuzzuol,Geraldo Rogério F.. |
| Most studies of chromium have been realized in the sediments and in mangrove trees. However, little is known about its effect on growth and metabolism in this vegetation. L. racemosa plants were grown in solution with 20% of ionic strength of Hoagland and Arnon containing 100 mM NaCl and supplemented with 0.00, 0.05 and 0.50 mg L-1 of Cr+3. The growth, the pigments and gas exchange measurements showed no changes in response to doses of chromium. After 30 days the initiation of treatments, plants of L. racemosa had average 0.559 g of total dry weight, 1.34 mg L-1 of total chlorophyll and 7.9 µmol m-2 s-1 of A (CO2 photosynthetic assimilation). The photochemical potential efficiency was affected by the intermediate dose of 0.05 mg L-1 of Cr+3 (Fv/Fm=0.73)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carbohydrates; Fluorescence; Gas exchange; Growth; Heavy metal; Mangrove. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200001 |
| |
|
|
| Pimentel,Carlos; Bernacchi,Carl; Long,Steve. |
| The response of CO2 assimilation rate (A) to the intercellular partial pressure of CO2 (Ci) was measured on intact lemon leaves over a range of temperatures (10 to 40ºC). The A/Ci response shows how change in the leaf temperature alters the activity of ribulose-1,5-bisphosphate (RuBP) carboxylase-oxygenase (Rubisco) and RuBP regeneration via electron transport. The rate of A reached a maximum of 7.9 to 8.9 µmol m-2 s-1 between 25 and 30ºC, while dark respiration (Rd) increased with temperature from 0.4 µmol m-2 s-1 at 10ºC to 1.4 µmol m-2 s-1 at 40ºC. The maximum rates of carboxylation (Vc,max) and the maximum rates of electron transport (Jmax) both increased over this temperature range from 7.5 to 142 µmol m-2 s-1 and from 23.5 to 152 µmol m-2 s-1,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: A/Ci curves; Gas exchange; Lemon. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200006 |
| |
|
| |
|
|
| Habermann,Gustavo; Machado,Silvia R.; Guimarães,Vandeir F.; Rodrigues,João D.. |
| Styrax camporum is a common shrub species from the cerrado regions of São Paulo State, Brazil. Although its leaves do not have a morphologically delimited pulvinus, the apical leaves are oriented parallel to the sun (paraheliotropic leaves), most notably around noon. Horizontal leaves at the base of shoots are oriented perpendicular to the sun's rays (diaheliotropic leaves). The ecophysiological significance of this is not fully understood. We investigated how paraheliotropism influences daily CO2 assimilation (A) and other gas exchange rates, water relations, leaf temperature (Tl), and how these relate to leaf structure as assessed by anatomical leaf descriptions. Paraheliotropic leaves had greater A and stomatal conductance (g s), which led to greater... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brazilian savanna; Ecophysiology; Gas exchange; Leaf movements; Leaf temperature; Photosynthesis; Styracaceae. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100008 |
| |
|
|
| 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 |
| |
|
|
| Yao,Xiaoqin; Liu,Qing; Han,Chao. |
| Ultraviolet-B (UV-B) radiation and nitrogen are expected to increase simultaneously with future changes in global climate. In this study, growth and photosynthetic responses of Picea asperata seedlings to enhanced UV-B and to nitrogen supply were studied. The experimental design included two levels of UV-B treatments (ambient UV-B, 11.02 kJ m-2 d-1; enhanced UV-B, 14.33 kJ m-2 d-1) and two nitrogen levels (0; 20 g N m-2) to determine whether nitrogen can alleviate the negative impacts of enhanced UV-B on seedling growth and photosynthesis. Enhanced UV-B significantly inhibited plant growth and impaired net photosynthetic rate, stomatal conductance, transpiration rate, the light-saturated assimilation rate, assimilation capacity, light compensation point,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Growth; Gas exchange; Nitrogen; Picea asperata; Photosynthesis; UV-B. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100002 |
| |
| Registros recuperados: 68 | |
|
|
|
