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| Registros recuperados: 360 | |
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| Scholz,Fabian G.; Bucci,Sandra J.; Goldstein,Guillermo; Meinzer,Frederick C.; Franco,Augusto C.; Salazar,Ana. |
| The objective of this study was to characterize and understand morphological and physiological variation in traits related to water economy, at the plant and stand level, along a gradient of tree density in a Neotropical savanna (Cerrado). Cerrado plots subjected to long-term fertilization and gallery forests were also included in the analysis to expand the axes of ecosystem variation. Consistent changes in stand level biophysical traits observed along the gradient of increasing tree density included a decrease in weighted-average wood density, and increases in leaf surface area per plant, leaf specific hydraulic conductivity, specific leaf area and stomatal conductance. A conceptual model of biophysical, morphological and physiological trait interactions... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gallery forest; Hydraulic architecture; Nutrients; Savannas; Specific leaf area; Wood density. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300006 |
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| Bernini,Elaine; Silva,Maria A. B. da; Carmo,Tania M. S. do; Cuzzuol,Geraldo R. F.. |
| Spatial and temporal variation of the nutrient concentrations in leaves and sediment between the roots of Laguncularia racemosa (L.) Gaertn. f and Rhizophora mangle L. was analyzed in the mangrove forest of the estuary of São Mateus River, Espírito Santo, Brazil. In leaves, the nutrients followed the sequence: N> Ca> K> Mg> S> P> Fe> Mn> Zn> Cu, and there were significant differences between species and sites studied. In general, the levels of K were higher in the dry season compared to the rainy season for both species analyzed while Ca and Cu showed higher concentrations in the rainy season for Laguncularia racemosa. In the sediment, the nutrients followed the sequence: Mg> Ca> Fe> K> Mn> P> Zn> Cu, in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Concentration factor; Macronutrients; Micronutrients; Metals. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300005 |
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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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| Benkeblia,Noureddine. |
| The respiration rate (RR) (CO2 production), activation energy (Ea) and Q10 of maleic hydrazide-treated onion bulbs (Allium cepa, cv. Rouge Amposta) at 20.10-6 mol.L-1 (MH1) and 45.10-6 mol.L-1 (MH2) were measured at 4, 10 and 20ºC. Immediately after treatment, the Q10 of MH-treated and control bulbs were not significantly different. After 8 weeks of storage, Q10 of control and both MH-treated bulbs increased and ranged from 2.34 and 2.89. Respiration rate of onions increased during storage, and after 24 weeks, RR values of control, MH1 and MH2 were 0.43, 0.32 and 0.26 mmol CO2.kg-1.h-1 at 20ºC respectively; and 0.26, 0.20 and 0.17 mmol CO2.kg-1.h-1 at 10ºC respectively. At 4ºC, no significant difference was observed between control and MH-treated bulbs.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Activation energy; MH; Onion; Q10; Respiration rate; Sprouting; Storage. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100007 |
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| Marchese,José Abramo; Broetto,Fernando; Ming,Lin Chau; Ducatti,Carlos; Rodella,Roberto Antonio; Ventrella,Marília Contin; Gomes,Greice Daiane Rodrigues; Franceschi,Lúcia de. |
| Leaves of Artemisia annua L. are a plentiful source of artemisinin, a drug with proven effectiveness against malaria. The aim of this study was to classify the photosynthetic mechanism of A. annua through studies of the carbon isotope composition (delta 13C) and the leaf anatomy. A. annua presented a delta 13C value of - 31.76 ± 0.07, which characterizes the plants as a typical species of the C3 photosynthethic mechanism, considering that the average delta 13C values for C3 and C4 species are -28 and -14, respectively. The leaf anatomy studies were consistent with the delta 13C results, where, in spite of the existence of parenchymatic cells forming a sheath surrounding the vascular tissue, the cells do not contain chloroplasts or starch. This... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: C3 and C4 plants; Isotope discrimination; Kranz anatomy; Photosynthesis. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100016 |
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| Faria,José M.R.; Davide,Lisete C.; Silva,Edvaldo A. A. da; Davide,Antonio C.; Pereira,Roselaine C.; van Lammeren,André A.M.; Hilhorst,Henk W.M.. |
| The remarkably short storability of recalcitrant seeds has prevented their inclusion in programs of ex situ conservation. The causes of their desiccation sensitivity and rapid decline in viability during storage are not fully elucidated yet. In this study the highly recalcitrant, fully viable embryos of the tree species Inga vera subsp. affinis were stored under various conditions and analyzed physiologically and cytologically at intervals, in order to obtain more insights in their loss of viability during storage. Embryos stored fully hydrated at 5ºC fully lost viability in 18 d. Sealed storage of partially dehydrated embryos slightly prolonged their viability, with 95% germination being attained after 14 d of storage. However, after 30 d of storage,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Abscisic acid; Polyethylene glycol; Recalcitrant seeds; Seed conservation. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400008 |
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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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| Choudhary,Sikander P.; Bhardwaj,Renu; Gupta,Bishan D.; Dutt,Prabhu; Gupta,Rajinder K.; Kanwar,Mukesh; Dutt,Pitamber. |
| The present study determined the effects of copper and chromium metals on the endogenous titers of polyamines, auxins, abscisic acid and antioxidative enzyme activities in Raphanus sativus L. cv. Pusa chetki seedlings. Among polyamines, putrescine and spermidine contents were enhanced by Cu2+ metal to 62.44 and 402.8 µg g-1 f.w. respectively over control. Spermine which was not observed in control was recorded in highest concentration (1287.9 µg g-1 f.w.) in Cu2+ metal stressed seedlings. On the other hand Cr6+ metal treated seedlings showed reduced contents of putrescine (1.43 µg g-1 f.w.), cadaverine (0.09 µg g-1 f.w.), spermidine (277.99 µg g-1 f.w.) and spermine (2.29 µg g-1 f.w.) when compared to control and Cu2+ metal treated seedlings. Significant... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Catalase; Chromium; Copper; Guaiacol peroxidase; Polyamines (PAs); Superoxide dismutase. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400006 |
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| Agarwal,Sheela; Shaheen,Robina. |
| The purpose of the present work was to evaluate both the antioxidant response system and oxidative stress in leaves from bitter gourd (Momordica charantia L) subjected to NaCl, UV-B and water stresses at three different stages of plant growth: pre-flowering, flowering and post-flowering. Except for peroxidase (POX), all enzyme activities including superoxide dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), glutathione reductase (GR), as well as concentrations of ascorbate (ASA), hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS) exhibited maximum values at the flowering stage under all three stresses. All the enzyme activities, SOD, CAT, POX, PPO, GR and the concentrations of ASA, H2O2 and TBARS were elevated under NaCl... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidative enzymes; Environmental stresses; H2O2; Ion concentration; Thiobarbituric acid-reactive substances. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200007 |
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| Almeida,Alex-Alan F. de; Valle,Raúl R.. |
| Cacao, one of the world's most important perennial crops, is almost exclusively explored for chocolate manufacturing. Most cacao varieties belong to three groups: Criollo, Forastero and Trinitario that vary according to morphology, genetic and geographical origins. It is cropped under the shade of forest trees or as a monocrop without shade. Seedlings initially show an orthotropic growth with leaf emission relatively independent of climate. The maturity phase begins with the emission of plagiotropic branches that form the tree crown. At this stage environmental factors exert a large influence on plant development. Growth and development of cacao are highly dependent on temperature, which mainly affects vegetative growth, flowering and fruit development.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Root growth; Flowering; Pod set; Flushing; Mineral nutrition. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400011 |
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| Heinemann,Alexandre B.; Stone,Luís Fernando; Fageria,Nand K.; Castro,Lucas M. de. |
| In the cerrado region of Brazil, no-tillage is an alternative management practice to conserve soil and reduce cost of crop production. However, many studies have been showed that there is a decrease in the yield when upland rice is cropped in this system. Therefore, there is a need that new breeding initiatives introgress favorable traits into upland rice for no-tillage adaptation. Key traits include faster emergence, ability to germinate when deep seeded, faster root development, and early canopy closure during the vegetative stages. All those traits can be summarized as "early vigor". So, the objective of this study was to evaluate physiological traits of four contrasting parental upland rice cultivars to verify their adaptation to no-tillage system. A... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Leaf area; Leaf expansion; Oryza sativa L; Shoot dry weight. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200004 |
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| Chudasama,Rita S.; Thaker,Vrinda S.. |
| Changes in endogenous gibberellic acid (GA) levels were determined in developing seeds and pods of pigeon pea (Cajanus cajan). Antibodies against GA3 were raised in rabbits and indirect ELISA developed to estimate GA level. Two varieties, black seeded variety (V1) and B.D.N2 (V2), were selected on the basis of their seed index value. The pod length and number of seeds per pod were significantly different for the two varieties. Dry weight, water content (WC), rate of water accumulation, rate of dry matter accumulation (DMA), and GA content in pod and seed were all larger in V1 than in V2. In both varieties, higher GA content was observed during cell elongation and DMA phases, respective to their varietal differences in growth traits. Relationships between... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cajanus cajan; Dry matter accumulation; Endogenous gibberellic acid; Seed development; Water content. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100005 |
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| Patel,Prakash R.; Kajal,Sushil S.; Patel,Vinay R.; Patel,Vimal J.; Khristi,Sunil M.. |
| Soil salinity is a major limitation to crops production in many areas of the world. The present study reports the impact of salt stress on seeds germination, plant growth parameters and leaf ions accumulation in three cowpea Vigna unguiculata (L.) Walp Indian cultivars: Akshay102, Gomti vu-89 and Pusa Falguni. The electrical conductivity (EC) of the soil was 0.75 dS m−1 and the NaCl treatments increased it to 2, 4, 6, 8 and 10 dS m−1. Germination percentage was recorded 10 days after sowing, while shoot and root dry weights were measured in 45 days old plants. Leaf ion concentrations for Na+, K+, Ca2+, Cl− and proline content were determined. The results showed that the germination percentage of seeds was highly affected by salinity in all cultivars in all... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Salt stress; Germination; Proline; Potassium/sodium ratio. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100005 |
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| Maiti,Saborni; Ghosh,Nirmalia; Mandal,Chiranjib; Das,Kingsuk; Dey,Narottam; Adak,Malay Kumar. |
| Two maize varieties, viz. Sartaj and Deccan, have been evaluated according to their responses to chromium (Cr) in terms of specific physiological and biochemical attributes. During the exposure to Cr concentration (0, 50, 100, 200 and 300 µM) of potassium dichromate (K2Cr2O7) for seven days, significant changes of oxidative stress in terms of lipid peroxidation and protein oxidation were recorded along with other antioxidative pathways. It is revealed that irrespective of varieties, Sartaj was more prone to oxidative stress since the amount of superoxide due to Cr exposure was found to be significant, unlike the second variety, Deccan. In addition, for Sartaj the activity of NAD(P)H oxidase recorded a significant linear increase in a dose response... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidative enzymes; MDA; Protein oxidation; ROS. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300007 |
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| Registros recuperados: 360 | |
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