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Registros recuperados: 220 | |
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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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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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Lacerda,Claudivan F.; Assis Júnior,José O.; Lemos Filho,Luiz C. A.; Oliveira,Teógenes S. de; Guimarães,Francisco V.A.; Gomes-Filho,Enéas; Prisco,José T.; Bezerra,Marlos A.. |
The effect of salt stress of known intensity and duration on morpho-physiological changes in leaves of different ages from cowpea [Vigna unguiculata (L.) Walp.] plants was studied, aiming for a better understanding of the acclimation process of the whole-plant. Seeds were sown in vermiculite and seedlings were transferred to plastic trays containing aerated nutrient solution, and kept in a greenhouse. When the first trifoliate leaf emerged the seedlings were transplanted into 3 L plastic pots containing aerated nutrient solution. Salt additions started 5 d later, and the salt-treated plants received 25 mmol L-1 per day until reaching a final concentration of 75 mmol L-1. During the experimental period primary leaves and the 1st, 2nd, and 3rd trifoliate... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ion concentration; Photosynthate partitioning; Photosynthesis; Salinity; Stress acclimation. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400003 |
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Gomes,Mara de Menezes de Assis; Lagôa,Ana Maria Magalhães Andrade; Machado,Eduardo Caruso; Medina,Camilo Lázaro; Machado,Marcos Antônio. |
Gas exchanges, sucrose, starch and reducing sugar contents were analyzed in leaves of orange trees with and without Citrus Variegated Chlorosis (CVC), a disease caused by the bacteria Xylella fastidiosa. Healthy plants (HP) and diseased plants (DP) were evaluated 20 and 26 months after bacterial inoculation, in October 1998 and April 1999, respectively. On the first evaluation date, CO2 assimilation rates for HP were greater than DP in the early morning and midday, but on the second date they were greater in HP all along the day. On the first date, there was an increase in the sucrose content of DP at 15:00 h and 17:00 h in relation to HP. On the second evaluation date, DP presented greater reducing sugar content only in the early morning while sucrose... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Citrus sinensis L.; Photosynthesis; Reducing sugars; Starch; Sucrose; Xylella fastidiosa. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100004 |
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Vieira,Antonio José Dias; Oliveira,Dario Alves de; Soares,Taís Cristina Bastos; Schuster,Ivan; Piovesan,Newton Deniz; Martínez,Carlos Alberto; Barros,Everaldo Gonçalves de; Moreira,Maurílio Alves. |
This work aimed to identify the quantitative trait loci (QTL) associated with photosynthesis and growth and productivity traits of soybean and to study possible associations between these traits by the analysis of coincidence of QTL in linkage groups (LGs). Thus, populations of recombinant inbred lines (RILs) of the F7 and F8 generations derived from the cross between the varieties BARC-8 and Garimpo were used. The traits evaluated were net assimilation rate of CO2 under saturating light (Asat), potential photosynthesis rate (Pmax), leaf area (A), specific leaf area (SLA), specific leaf nitrogen (N); root (W R), nodule (W N), stem (W ST), leaf (W L), pod (W P) and plant dry mass (W T); nodule (nN), seed (n s), and pod number (nP); seed fresh mass per plant... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Correlation; Genes; Photosynthesis; Quantitative trait loci. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200004 |
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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 |
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Clebsch,Cláudia C.; Divan Junior,Armando M.; Oliveira,Paulo L.; Nicolau,Márcio. |
Bean seedlings of Fepagro 26, Guapo Brilhante, Iraí, Macotaço and US Pinto 111 cultivars were submitted to treatments with or without addition of ozone to the ambient air, in order to evaluate the effects of exposure on photosynthesis, relative electrolyte leakage, foliar abscission and biomass of the seedlings. Exposure to ozone caused significant decreases in the net assimilation of all cultivars except Iraí. It also caused a significant increase in electrolyte leakage from the Pinto cultivar, but only when AOT40 was the highest. It also produced significant anticipation in the time of foliar abscission in the Pinto, Fepagro and Guapo cultivars. The variability observed in the biomass measurements reflected the limitations to perform long-term... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Relative electrolyte leakage; Foliar abscission; Biomass. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400008 |
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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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Hasan,Syed Aiman; Hayat,Shamsul; Wani,Arif Shafi; Ahmad,Aqil. |
Cobalt (Co) affords both beneficial as well as toxic effects to plants. The present study was performed with an aim to find out the varietal differences among five tomato cultivars against the Co induced changes in growth, photosynthesis, nitrate reductase (E.C.1.6.6.1), carbonic anhydrase (E.C.4.2.1.1), antioxidative enzymes i.e. peroxidase (E.C.1.11.1.7), catalase (E.C.1.11.1.6), superoxide dismutase (E.C.1.15.1.1) and that of proline content. Seeds of tomato (varieties, K-25, NTS-9, NBR-Uday, Sarvodya, and Malti) were soaked in 0, 100, 200 or 300 µM CoCl2 for 0, 4, 8, 12 h (shotgun approach) and sampled at 30 days after sowing. All the varieties showed significantly different response to different treatment combinations. Despite substantial varietal... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidative enzyme; Carbonic anhydrase; Cobalt; Nitrate reductase; Photosynthesis; Tomato. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300001 |
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de Carvalho,Leonardo Bianco; Aguiar Alves,Pedro Luis da Costa; Bianco,Silvano; De Prado,Rafael. |
Glyphosate is the main herbicide used in coffee (Coffea arabica L.) plantations in Brazil. Problems with herbicide drift commonly occur in orchard fields due to non-adequate spraying conditions. A series of experiments was carried out aiming to evaluate physiological dose-response of C. arabica plants submitted to exposure to simulated glyphosate drift in two distinct plant growth stages. Glyphosate was applied at 0, 180, 360, and 720 g acid equivalent (AE) ha-1 directly on coffee plants with 10 and 45 d after transplanting (DAT). Glyphosate doses in a range of 180-360 g AE ha-1 increased photosynthesis, transpiration and stomatal conductance in 10 DAT-plants up to 14 d after application (DAA) while, in 45 DAT-plants, an increase was observed only up to 2... |
Tipo: Journal article |
Palavras-chave: N-(phosphonomethyl) glycine; Herbicide drift; Photosynthesis; Plant nutrition. |
Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000200003 |
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Jara-Rojas,Francisco; Ortega-Farías,Samuel; Valdés-Gómez,Héctor; Poblete,Carlos; del Pozo,Alejandro. |
The coupled model of assimilation and stomatal conductance (A-g s) was evaluated to estimate leaf stomatal conductance of a drip-irrigated vineyard (Vitis vinifera L. cv. Cabernet Sauvignon) located in the Pencahue Valley (35º22 S, 71°47 W, 150 m.a.s.l.), Maule Region, Chile, during the 2003-2004 and the 2004-2005 growing seasons. Additionally, a calibration of the three parameters mesophyll conductance (g m), maximum specific humidity (Dmax) and coupled factor (f0) was applied on vines growing in 35 L pots. An infrared gas analyzer was used to calibrate and evaluate the A-g s which allowed simultaneous measuring of the leaf net CO2 assimilation (A) and stomatal conductance (g s) in 2 to 3 h intervals of time. The calibration indicated that the g m,,... |
Tipo: Journal article |
Palavras-chave: A-g s model; Photosynthesis; Mesophyll conductance; Stem water potential; Sensitivity analysis. |
Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000100011 |
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Bastías,Richard M; Manfrini,Luigi; Corelli Grappadelli,Luca. |
The effect of shading (i.e. reduction of sunlight availability) on fruit growth physiology has been widely studied in apple (Malus domestica Borkh.), but little knowledge exist about fruit growth responses to changes in the light spectrum. The aim of the present research was to study the effect of use of colored nets with differential sunlight transmission in the blue (B, 400-500 nm), red (R, 600-700 nm) and far-red (FR, 700-800 nm) spectra on apple fruit growth and physiological associated responses. Three year old 'Fuji' apple trees were covered with 40% photo-selective blue and red shade nets, 40% neutral grey shade net, and 20% neutral white net as control. Red and blue net reduced in the same proportion (27%) the photosynthetically active radiation... |
Tipo: Journal article |
Palavras-chave: Sunlight spectrum management; Fruit size; Photosynthesis; Morphogenesis. |
Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000200010 |
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Registros recuperados: 220 | |
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