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| Registros recuperados: 220 | |
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| Neves,Ademir D.; Oliveira,Ricardo F.; Parra,José R.P.. |
| The objective of this study was to determine the damage levels caused by Orthezia praelonga Douglas, 1891 and Leucoptera coffeella (Guérin-Mèneville 1842), on rangpur lime and Obatã coffee leaves, respectively. Measurements were based on a new concept for the evaluation of the following plant physiological parameters: photosynthesis, stomatal conductance, leaf temperature and transpiration, and internal concentration of CO2 (by infrared analyzer). A negative correlation between infestation level and photosynthesis was found, where the negative inflexion point of the curve was considered as a reference for damage levels. The control level for O. praelonga is below the 7-13% limit for damaged leaf area (40 to 70 scales per leaf), while for L. coffeella it is... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Economic level injury; Citrus; Coffee; Plant-insect interactions. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652006000400015 |
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| SCHWALBERT,RAISSA; SILVA,LINCON O.S.; SCHWALBERT,RAI A.; TAROUCO,CAMILA P.; FERNANDES,GILLIAN S.; MARQUES,ANDERSON C.R.; COSTA,CAMILA C.; HAMMERSCHMITT,RODRIGO K.; BRUNETTO,GUSTAVO; NICOLOSO,FERNANDO T.. |
| Abstract Abstract: Successive applications of copper fungicides on vines have resulted in increased copper content in vineyard soils over the years. This high copper content has affected the growth of young vines in eradicated vineyards. Thus, the cultivation of annual species for a few years is an alternative to copper phytostabilization, because it would be a good way to decrease copper availability to plants. The aim of this study was to evaluate the physiological responses of different soybean cultivars to copper concentration increase. Four different soybean cultivars were grown under three copper concentrations: 0.5, 20 and 40 μM in nutrient solution. The main outcomes of this study were: i) Cultivar M 6410 IPRO recorded the highest photosynthetic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant system; Cash crops; Heavy metal phytostabilization; Photosynthesis. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000700618 |
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| ROSA,DEREK B.C.J.; SCALON,SILVANA P.Q.; CREMON,THAIS; CECCON,FELIPE; DRESCH,DAIANE M.. |
| ABSTRACT The aim of this study was to evaluate gas exchange, efficiency of the photosynthetic apparatus, and antioxidant activity in Copaifera langsdorffii Desf. The seedlings were cultivated under different conditions of water availability, in order to improve the utilization efficiency of available water resources. The seedlings were cultivated in four different water retention capacities (WRC- 25%, 50%, 75%, and 100%), and evaluated at four different time (T- 30, 60, 90, and 120 days). During the experimental period, seedlings presented the highest values for carboxylation efficiency of Rubisco (A/Ci), intrinsic water use efficiency (IWUE = A/gs), chlorophyll index, and stomatal opening, when grown in the substrate with 75% WRC, but the stomatal index... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant enzymes; Chlorophyll a fluorescence; Photosynthesis; Water stress.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000603039 |
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| Buckeridge,Marcos S.; Aidar,Marcos P.M.. |
| As carbon dioxide increases on Earth atmosphere, the rise in average temperatures may provoke changes in the environment that could damage civilisation as we know it. As a result, the need to sequester carbon becomes urgent, and one of the options we have is to use the potential of the forests to do it by enhancing assimilation of CO2 through photosynthesis. However, if we consider the use of plants to increase carbon sequestration, a problem that looms is that species often acclimate and actually reduce CO2 assimilation through feedback mechanisms of the sugars that are the product. In the present article, we propose that some biochemical pathways, such as those in control of photosynthesis, carbohydrate metabolism and assimilation, and cellulose and... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Global change; Carbon Sequestration; Photosynthesis; Rain Forest; Sugar Sensing; Cellulose synthesis; Gene therapy. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032002000100002 |
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| Rocha,Humberto R. da; Freitas,Helber C.; Rosolem,Rafael; Juárez,Robinson I.N.; Tannus,Rafael N.; Ligo,Marcos A.; Cabral,Osvaldo M. R.; Dias,Maria A.F. Silva. |
| The technique of eddy correlation was used to measure the net ecosystem exchange over a woodland savanna (Cerrado Sensu stricto) site (Gleba Pé de Gigante) in southeast Brazil. The data set included measurements of climatological variables and soil respiration using static soil chambers. Data were collected during the period from 10 October 2000 to 30 March 2002. Measured soil respiration showed average values of 4.8 molCO2 m-2s-1 year round. Its seasonal differences varied from 2 to 8 molCO2 m-2s-1 (Q10 = 4.9) during the dry (April to August) and wet season, respectively, and was concurrent with soil temperature and moisture variability. The net ecosystem CO2 flux (NEE) variability is controlled by solar radiation, temperature and air humidity on diel... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Savanna; Photosynthesis; Soil respiration; Carbon sequestration; Eddy correlation. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032002000100009 |
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| Aidar,M.P.M.; Martinez,C.A.; Costa,A.C.; Costa,P.M.F.; Dietrich,S.M.C.; Buckeridge,M.S.. |
| Plants grown in elevated CO2 environments may exhibit photosynthetic acclimation or down regulation, which is characterised by reduced rates of photosynthesis. In most cases of CO2-induced photosynthetic acclimation, the reduced rates of photosynthesis were still higher than those detected in plants growing at ambient CO2 concentrations. In this work we present a study on the behaviour of seedlings of Hymenaea courbaril, a late secondary/climax species that is one of the most important trees in mature tropical forests of the Americas. After germination, the seedling of H. courbaril increases its rate of growth due to the mobilisation of massive amounts of a storage cell wall polysaccharide (xyloglucan) from its cotyledons. In our experiments, germinated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; CO2 enrichment; Hymenaea courbaril; Storage mobilisation; Root:shoot ratio; Seedling growth; Cotyledons; Open top chamber; Xyloglucan; Biodiversity. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032002000100008 |
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| Silva,Alexandre José da; Magalhães Filho,José Rodrigues; Sales,Cristina Rodrigues Gabriel; Pires,Regina Célia de Matos; Machado,Eduardo Caruso. |
| Abstract Water deficit is a major factor limiting crop yield in rainfed areas. We hypothesized that under water deficit the decrease of photosynthetic production stimulates: carbohydrate remobilization from leaves, stems and roots to reproductive organs; and decreasing flowering intensity and pod development. The present work aims to study the effect of water deficit during bloom and grain pod-filling stages in two indeterminate soybean cultivar, Vtop and Nidera. The following physiological parameters were evaluated by means of daily CO2 assimilation rate (Ai), dynamic of carbohydrates in tissues, plant growth, grain yield and yield components. The study was conducted in a greenhouse with plants sown in tanks of 0.5 m3. Regardless of the phenological... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max L. Merrill; Photosynthesis; Carbohydrate; Pod growth; Seed growth. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000100023 |
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| Marcos,Fernanda Castro Correia; Iório,Raquel de Paula Freitas; Silveira,Adriana Parada Dias da; Ribeiro,Rafael Vasconcelos; Machado,Eduardo Caruso; Lagôa,Ana Maria Magalhães de Andrade. |
| ABSTRACT The aim of this study was to evaluate if endophytic bacteria inoculants would be beneficial to the sugarcane varieties IACSP94-2094 and IACSP95-5000, promoting changes in photosynthesis and plant growth. The plants, obtained from mini stalks with one bud, were treated with two bacteria mixtures (inoculum I or II) or did not receive any inoculum (control plants). The inocula did not affect shoot and root dry matter accumulation as compared to the control condition (plants with native endophytic bacteria). However, photosynthesis and electron transport rate (ETR) increased in IACSP94-2094 treated with the inoculum II, whereas the inoculum I enhanced photosynthesis and stomatal conductance in IACSP95-5000. The inoculum II caused increase in leaf... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Saccharum spp.; Plant-bacteria interaction; Photosynthesis; Nitrogen; Mini stalks with one bud. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052016000100001 |
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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,Diecson Ruy Orsolin da; Vargas,Leandro; Agostinetto,Dirceu; Mariani,Franciele. |
| Weed competition in the soybean causes changes in morphological and physiological characteristics that reduce the competitive ability of the crop. The objective of this study was to determine the control periods and coexistence of glyphosate-resistant hairy fleabane and its interference in morphological and photosynthetic variables and RR soybean yield. A field experiment was conducted during the 2011/2012 growing season, the treatments consisted of weed interference and weed free periods of the glyphosate-resistant hairy fleabane with soybean (BRS Estância RR). The periods were 0, 7, 14, 21, 28, 35, 42 and 154 days after the soybean emergence. The results sugested no differences between the control periods for the variables evaluated. The increase... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Weed interference; Photosynthesis. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052014000400014 |
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| 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 |
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| In the beginning of the spring Aristotelia chilensis sheds the old cohort, forms a new one and flowers. Fifteen days before the flowering and the fall we measured net photosynthesis (A), transpiration (E), water use efficiency (WUE), specific leaf mass (SLM) and area and mass of leaves per branch in old and new cohorts. Under low irradiance the old cohort exhibited higher mean values of A and WUE on area bases (P<0.05). Under high irradiance A and WUE on mass bases were higher in new cohort due to its lower SLM (42.10 gm-2) in relation to old cohort (79.53 gm-2). Because old cohort showed 3.7 times more dry mass per branch it was able to counterbalance its lower performance on mass bases. It was concluded that old cohort was an important source of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aristotelia chilensis; Foliar cohorts; Photosynthesis; Specific leaf mass. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132001000300009 |
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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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| Islam,Mohammad Aminul; Boyce,Amru Nasrulhaq; Rahman,Md Motior; Azirun,Mohd Sofian; Ashraf,Muhammad Aqeel. |
| ABSTRACT VC (20%), TC (20%) and N:P:K fertilizer (farmer's practice) were used to determine the growth and yield attributes of bush bean (Phaseolus vulgaris), winged bean (Psophocarpus tetragonolobus) and yard long bean (Vigna unguiculata). Plants grown with VC (20%) produced the highest fresh biomass for bush bean (527.55 g m-2), winged bean (1168.61 g m-2) and yard long bean (409.84 g m-2). In all the tested legumes the highest pod weight, pod number, pod dry weight and pod length were found in the VC (20%) treatment. Photosynthetic rates in the three legumes peaked at pod formation stage in all treatments, with the highest photosynthetic rate observed in winged bean (56.17 µmol m-2s-1) grown with VC (20%). The highest yield for bush bean (2.98 ton... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vermicompost; Compost; Phaseolus vulgaris; Psophocarpus tetragonolobus and Vigna unguiculata; Photosynthesis; Protein content. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132016000200205 |
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| Jiang,Zhongyang; Peiyong,Guo; Chang,Cheinchi; Gao,Lili; Li,Shixiong; Wan,Jinjin. |
| This study was performed in order to isolate and identify unknown allelochemicals from Ficus microcarpa, and to investigate the inhibitory to bloom-forming of green alga Chlorella pyrenoidosa. Through gradient elution, fraction C2, whose inhibition of alga growth in diverse extracts was the strongest was shown to cause significant reductions of maximum quantum yield, as well as electron transport rates of C. pyrenoidosa. The study data also showed that the increase of fraction C2 concentration decreased the activity of total superoxide dismutase (SOD), but increased the activities of catalase (CAT) and malondialdehyde (MDA) content. These results demonstrate that the active fraction C2 not only induced the photoinhibition or photodamage of PSII reaction... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allelochemical; Phenols; Photosynthesis; Ficus microcarpa; Chlorella pyrenoidosa. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000400595 |
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| Dias,Jaqueline; Pimenta,José Antonio; Medri,Moacyr Eurípedes; Boeger,Maria Regina Torres; Freitas,Claudinei Toledo de. |
| The aim of this work was to compare the physiological parameters of sun and shade leaves of a specimen of L. molleoides. The higher-positional leaves, classified as sun leaves, presented similar photosynthetic rate, lower chlorophyill contents (a, b and total), same a chlorophyll /b chlrorophyll rate, lower transpiratory rate, same stomatal conductance and intercellular concentration of CO2 as the lower-positional leaves, classified as shade leaves. Nutrient concentration, except for Ca and Mg, was the same for both sun and shade leaves.The physiological parameter responses indicated that although receiving lower light intensity, the shade leaves had the same capacity to grow and develop as the sun leaves. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Sun leaves; Shade leaves; Light intensity; Chlorophyll; Lithraea molleoides. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000100011 |
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| Registros recuperados: 220 | |
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