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| Registros recuperados: 34 | |
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| MARENCO,Ricardo A.; VIEIRA,Gil; GONÇALVES,José F. de C.. |
| In the Brazilian Amazon, large areas of abandoned lands may revert to secondary forest. In the process, pioneer tree species have an important role to restore productivity in old fields and improve environmental conditions. To determine potential photosynthesis (Apot), stomatal conductance (g), transpiration (E), and leaf micronutrient concentrations in Ochroma pyramidale (Cav. ex Lam.) Urban a study was carried out in the Brazilian Amazon (01o 51' S; 60o 04' W). Photosynthetic parameters were measured at increasing [CO2], saturating light intensity (1 mmol (photons) m-2 s-1), and ambient temperature. The rate of electron-transport (J), Apot,and water-use efficiency (WUE) increased consistently at increasing internal CO2 concentration (Ci). Conversely,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Balsa wood; Electron-transport rate; Reforestation; Stomatal conductance; Transpiration; Water-use efficiency. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672003000100023 |
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| Mielke,Marcelo S.; Matos,Elyabe M.; Couto,Virginia B.; Almeida,Alex-Alan F. de; Gomes,Fábio P.; Mangabeira,Pedro Antonio Oliveira. |
| An experiment was conducted with the aim to analyze the effects of soil flooding and leaf position on net primary productivity and whole plant carbon balance of Annona glabra L. (Annonaceae) seedlings, a highly flood-tolerant tree, native to the tropical Americas. All seedlings survived a period of 56 days of flooding without symptoms of stress. Flooding induced significant increments in root, stem and whole-plant biomass (P <0.01), and in the root:shoot mass ratio (P <0.05). Measurements of leaf gas exchange were conducted at days four, 11, 18 and 56 after flooding, on the first (L1), fourth (L4) and seventh (L7) fully expanded leaves from the apex of each seedling. The mean values of stomatal conductance to water vapour (g s) and net photosynthetic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Annonaceae; Stomatal conductance; Brazilian Atlantic rainforest; Net photosynthetic rate; Flood tolerance. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062005000400025 |
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| Alam,Amirul; Juraimi,Abdul Shukor; Yusop,Mohd Rafii; Hamid,Azizah Abdul; Hakim,Abdul. |
| This study was carried out to determine, evaluation and characterization of the morphological, physiological as well as mineral nutrient vitiations among all forty five purslane accessions collected from different locations of West Peninsular, Malaysia. Significant differences (p<0.05) were observed for all those traits measured regarding morphological, physiological and mineral composition. Morphological traits viz. plant height varied between 20.06-40.8 cm; number of main branch, 1.4-4.4; number of nodes, 8.4-31; internode distance, 2.1-3.43 cm; stem diameter, 2.12-3.8 mm; number of leaves, 97-1019; leaf area, 1.03-2.21 cm², number of flowers, 14-826.8; root length, 5.09-11.7 cm; fresh weight, 40-280 g; and dry weight varied between 2.71-29.16 g.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Purslane; Total chlorophyll; Photosynthesis; Stomatal conductance; Transpiration; Mineral composition. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052014000400011 |
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| Silva,Marcelo de Almeida; Jifon,John Lonfover; Santos,Claudiana Moura dos; Jadoski,Cleber Junior; Silva,Jorge Alberto Gonçalves da. |
| The objective of this study was to compare the gas exchange, photosynthetic capacity and water potential of sugarcane genotypes cultivated under water deficit conditions imposed during the initial growth phase. Experiments were performed in a greenhouse using two sugarcane genotypes namely: HoCP93-776 (drought susceptible) and TCP02-4587 (drought tolerant). Sixty days after planting, two different water treatments were applied (i.e., with or without water deficit). At 0,30 and 60 days after the treatment, gas exchange variables were evaluated for their relationship with water use, intrinsic instantaneous water use efficiency and instantaneous carboxylation efficiency. The SPAD index, photosynthetic pigments, water potential and relative water content in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Saccharum spp.; Photosynthesis; Stomatal conductance; Chlorophyll; Drought tolerance; Water potential. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000500004 |
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| Dalmolin,Ândrea Carla; Dalmagro,Higo José; Lobo,Francisco de Almeida; Antunes Junior,Mario Zortéa; Ortíz,Carmen Eugenia Rogríguez; Vourlitis,George Louis. |
| Vochysia divergens Pohl (commonly known as cambara) is a pioneer tree species that is native to the Amazon Basin but has been invading the seasonally flooded wetlands of the Brazilian Pantanal, forming monospecific communities. The physiological aspects associated with cambara invasion, including the effects of flooding and shading on growth and leaf gas exchange, are unknown but may shed light on why cambara is able to invade this novel habitat so rapidly. Thus, we conducted a manipulative experiment to quantify the effects of shading and flooding on the growth, gas exchange and leaf nutrient content of V. divergens saplings. Based on previous research we hypothesized that (1) experimental flooding would have no effect on the growth and gas exchange of V.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cambara; Physiological stress; Photosynthesis; Plant ecophysiology; Stomatal conductance; Tropical wetlands. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200001 |
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| Dias,Ana S.; Lidon,Fernando C.; Ramalho,José C.. |
| In heat stressed genotypes of Triticum aestivum L. (Sever and Golia) and Triticum turgidum subsp. durum (Acalou and TE 9306), chosen according to its genetic background diversity, Ca and Mg accumulations were correlated with its photosynthetic performance. It was found that with high temperatures the concentrations of Ca increased in the shoots, whereas the accumulation of Mg augmented only in bread wheat genotypes. Under heat stress, the pattern of electrolytes release in Golia and Acalou remained similar, but the extrusion rates became higher in Sever. During grain filling, the levels of total chlorophylls decreased in the heat stressed genotypes (excepting in Sever). In all the Triticum genotypes, stomatal conductance and the net carboxilation rate... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum L.; Triticum turgidum subsp. durum; Net photosynthesis; Nutrients uptake and translocation; Stomatal conductance. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200005 |
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| Zanella,Fábio; Watanabe,Tania Misae; Lima,Ana Lúcia da Silva; Schiavinato,Marlene Aparecida. |
| The effects of drought and rehydration on Canavalia ensiformis (L.) D.C. (jack bean) plants were evaluated using the following gas exchange parameters: net carbon assimilation rate (A), stomatal conductance (g s), Ci/Ca ratio and transpiration rate (E); chlorophyll a fluorescence: Fv/Fm and Fv/F0 ratio. The plants were cultivated under greenhouse conditions and after 30 days from the emergence, irrigation was suspended in the plants submitted to drought, to obtain the following predawn leaf water potential (psipd): -0.40 MPa (control), -1.00 MPa (moderate drought) and -2.30 Mpa (severe drought). Afterwards, the gas exchange and fluorescence analysis were initiated , and 24 h after rehydration the same analyses were repeated. The A, E, g s and Ci/Ca values... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Fluorescence; Moderate drought; Photosynthesis; Severe drought; Stomatal conductance. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300008 |
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| Scambato,Agustina A.; Echeverria,Mariela; Sansberro,Pedro; Ruiz,Oscar A.; Menéndez,Ana Bernardina. |
| The present work was aimed at testing the hypothesis that mycorrhizal Prosopis alba, an economically important tree species worldwide, presents increased salt-tolerance compared with non-mycorrhizal ones and at gaining insight into the possible mechanisms underlying that improvement. For this purpose, a randomized complete block experiment with two factors: mycorrhizal treatments with or without the arbuscular fungus Glomus intraradices and two salinity levels, 0 and 200 mM NaCl was performed. Plant growth in P. alba plants colonized by G. intraradices was less affected by salinity than that in non-arbuscular mycorrhizal (AM) plants, indicating that mycorrhizal colonization turned P. alba more tolerant to salinity. Photosynthesis was reduced by salinity in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Salinity; Stomatal conductance; Transpiration ratio; Proline. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400008 |
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| Prado,Carlos Henrique Britto de Assis; Wenhui,Zhang; Cardoza Rojas,Manuel Humberto; Souza,Gustavo Maia. |
| Predawn leaf water potential (psipd) and morning values of leaf gas exchange, as net photosynthesis (A), stomatal conductance (gs), transpiration (E), and morning leaf water potential (psimn) were determined seasonally in 22 woody cerrado species growing under natural conditions. Despite the lower mean values of psipd in the dry season (-0.35 ± 0.23 MPa) compared to the wet season (-0.08 ± 0.03 MPa), the lowest psipd in the dry season (-0.90 ± 0.00 MPa) still showed a good nocturnal leaf water status recovery for all species studied through out the year. Mean gs values dropped 78 % in the dry season, when the vapor pressure of the air was 80% greater than in the wet season. This reduction in gs led to an average reduction of 33% in both A and E, enabling... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Deciduousness; Network connectance; Stomatal conductance; Photosynthesis. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100002 |
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| Silveira,Helbert Rezende de Oliveira; Souza,Kamila Rezende Dázio de; Alves,Jose Donizeti; Santos,Meline de Oliveira; Andrade,Cínthia Aparecida; Bomfim,Sandro Costa. |
| Irrigation has enhanced coffee production in several regions of Brazil. However, with the increase in irrigated crop areas, problems related to the frequent and poorly planned usage of irrigation may arise. Since there are few studies related to the physiological alterations in coffee plants exposed to water excess, we evaluated the effects of waterlogging on metabolism and partitioning of carbohydrates, levels of photosynthetic pigments and gas exchange in seedlings of two commercial coffee cultivars (Mundo Novo and Catuaí). After acclimation, seedlings with eight pairs of fully expanded leaves were cultivated under three water availability conditions: field capacity, intermittent waterlogging and continuous waterlogging. Gas exchange and the levels of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water excess; Photosynthesis; Reducing sugars; Stomatal conductance; Water efficiency use.. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542015000200138 |
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| Streck,Nereu Augusto. |
| The reduction of crop growth and yield in dry areas is largely due to stomatal closure in response to dry soil, which decreases photosynthesis. However, the mechanism that causes stomatal closure in a drying soil is a controversial issue. Experienced and respected plant physiologists around the world have different views about the primary sensor of soil water shortage in plants. The goal of this review is to present a chronological synthesis about the evidence of the possible candidates for the mechanism by which plants sense a drying soil. Hydraulic signals in the leaves as the mechanism that causes stomatal closure dominated the view on how plants sense a drying soil during the 70s and the early 80s. In the middle 80s, studies suggested that stomatal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil water; Plant water; Water stress; Stomatal conductance. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782004000200039 |
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| Zheng,Ming; Bai,Yungang; Zhang,Jianghui; Liu,Hongbo; Ding,Ping. |
| ABSTRACT In grape, high temperatures and low humidity prolong midday depression of foliar photosynthesis and dramatically reduce fruit yield. In this study, we explored the effects of various mist micro-spray treatments on grape photosynthesis at a test site in Shanshan County (N, 42.91°; E, 90.30°), Turpan, Xinjiang, China. We tested four different mist micro-spray durations including 1 h (WP1), 2 h (WP2), 3 h (WP3), and 0 h (CK). WP1, WP2, and WP3 affected canopy air temperature and humidity for 5 h, 7 h, and 9 h, respectively. At 12:30, WP1, WP2, and WP3 had the strongest cooling effect and altered temperature by −5.12 °C, −5.09 °C, and −5.17 °C respectively. The relative chlorophyll content was higher in the upper than the lower canopy leaves. There... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Air temperature; Chlorophyll; Photosynthesis; Stomatal conductance; Transpiration rate. |
| Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162021000100039 |
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| Verryckt, Lore T.; Van Langenhove, Leandro; Ciais, Philippe; Courtois, Elodie A.; Vicca, Sara; Peñuelas, Josep; Stahl, Clément; Coste, Sabrina; Ellsworth, David S.; Posada, Juan M.; Obersteiner, Michael; Chave, Jérôme; Janssens, Ivan A.. |
| Measuring leaf gas exchange from canopy leaves is fundamental for our understanding of photosynthesis and for a realistic representation of carbon uptake in vegetation models. Since canopy leaves are often difficult to reach, especially in tropical forests with emergent trees up to 60 m at remote places, canopy access techniques such as canopy cranes or towers have facilitated photosynthetic measurements. These structures are expensive and therefore not very common. As an alternative, branches are often cut to enable leaf gas exchange measurements. The effect of branch excision on leaf gas exchange rates should be minimized and quantified to evaluate possible bias. We compared light‐saturated leaf net photosynthetic rates measured on excised and intact... |
| Tipo: Text |
Palavras-chave: Branch cutting; Canopy physiology; French Guiana; Gas exchange; Photosynthesis; Rainforest; Stomatal conductance. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72466/71949.pdf |
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| Registros recuperados: 34 | |
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