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| Registros recuperados: 360 | |
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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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| Ribas,Alessandra Ferreira; Pereira,Luiz Filipe Protasio; Vieira,Luiz Gonzaga E.. |
| In the last 15 years, considerable advances were made in coffee genetic transformation. Different research groups in the world have been able to transform coffee with genes for insect resistance, decaffeinated coffee, herbicide resistance and control of fruit maturation. Although the majority of the research is still limited to laboratory and greenhouse studies, initial field tests with transformed coffee are beginning to appear in the literature. In this review we provide an update on the state of coffee genetic transformation, presenting technical aspects related to tissue culture systems, strategies for selection and transformation with particle bombardment, as well as the use of Agrobacterium tumefaciens. We also discuss the potential applications of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agrobacterium; Coffea; Biolistic; Genetic engineering; Transgenic. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100007 |
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| Leroy,Thierry; Ribeyre,Fabienne; Bertrand,Benóit; Charmetant,Pierre; Dufour,Magali; Montagnon,Christophe; Marraccini,Pierre; Pot,David. |
| Coffee quality, in the present context of overproduction worldwide, has to be considered as a main selection criterion for coffee improvement. After a definition of quality, and an overview of the non genetic factors affecting its variation, this review focuses on the genetic factors involved in the control of coffee quality variation. Regarding the complexity of this trait, the different types of quality are first presented. Then, the great variation within and between coffee species is underlined, mainly for biochemical compounds related to quality (caffeine, sugars, chlorogenic acids, lipids). The ways for breeding quality traits for cultivated species, Coffea arabica and Coffea canephora are discussed, with specific challenges for each species. For C.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffea spp.; Biochemical compounds; Candidate genes; ESTs; Genetic breeding; Marker-assisted selection; Quality. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100016 |
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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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| Meloni,Diego A.; Martínez,Carlos A.. |
| Glycinebetaine (GB) is a very important organic osmolyte that accumulates in a number of diverse groups of plants in response to environmental stress. In some plants, increased resistance to drought, salinity and low temperature has been achieved through exogenous application of GB. In this study, the effect of exogenously applied GB (8 mM) on the ability of vinal (Prosopis ruscifolia G.) plants to withstand NaCl stress was investigated. The dry biomass of vinal showed a decrease under salt stress, but in GB-treated plants exposed to the same stress, this reduction was mitigated. Sodium accumulated in the leaves of plants grown under saline conditions, but the addition of GB to salt-grown plants reduced Na+ content by 40%. Salinity significantly reduced... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lipid peroxidation; Salt stress; Superoxide dismutase. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300007 |
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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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| Viégas,Ricardo Almeida; Fausto,Maria José Martins; Queiroz,José Elenildo; Rocha,Iza Marineves Almeida; Silveira,Joaquim Albenísio Gomes; Viégas,Pedro Roberto Almeida. |
| In this study the early effects of salinity on growth, total N and ion accumulation and partitioning in Prosopis juliflora (common name algaroba) were studied with 30-day-old plants grown for 8 days in aerated nutrient solution (NS) free of (control) or supplied with 25, 50, 75 and 100 mmol.L-1 NaCl. Plants grown in 25 and 50 mmol.L-1 NaCl accumulated a total dry mass (DM) and shoot N content greater than the control. However, at 75 and 100 mmol.L-1 NaCl such parameters were diminished. Whole plant transpiration rates were higher with 25 and 50 mmol.L-1 NaCl and lower with 75 and 100 mmol.L-1 NaCl. Salinity did not influence shoot (80%) and root (70%) water content (WC) but reduced the K+ content of shoot while that of root was not affected. Increasing... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ion partitioning; Nitrogen; Salinity stress. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100009 |
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| Silva,Elizamar Ciríaco da; Silva,Marcos F. A.; Nogueira,Rejane J. M. C.; Albuquerque,Manoel B.. |
| Erythrina velutina Willd. (common name: mulungu) is a deciduous, heliophyte found in the semi-arid region of northeastern Brazil. To evaluate the growth and water relations of mulungu seedlings in soils with different degrees of moisture content, an experiment was carried out under greenhouse conditions using four water treatments (100%, 75%, 50% and 25% of the field capacity- FC). Predawn (Ψpdw) and midday leaf water potential (Ψmdw), relative water content (RWC), plant height, number of leaves, stem diameter, leaf area (LA), specific leaf area (SLA), leaf area ratio (LAR), dry matter in different organs, biomass partitioning and root:shoot ratio were evaluated. No differences were detected between treatments for Ψpdw after 30 days; however, at midday,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biomass allocation; Dry matter; Leaf area; Root to shoot ratio; Relative water content; Water potential. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400002 |
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| Gonçalves,José Francisco de Carvalho; Barreto,Denize Caranhas de Sousa; Santos Junior,Ulysses Moreira dos; Fernandes,Andreia Varmes; Sampaio,Paulo de Tarso Barbosa; Buckeridge,Marcos Silveira. |
| Aniba rosaeodora is an Amazonian tree species that belongs to the family Lauraceae. Due to intense exploitation for extraction of essential oils (mainly linalol), A. rosaeodora is now considered an endangered species. On the other hand, there is little information about its ecophysiology which would be useful to support future forest planting programs. Hence, the effect of different light intensities on the growth and photosynthetic characteristics of young plants of A. rosaeodora was studied. Nine-month-old plants were subjected to four light treatments (T1= 10 a 250 µmol.m-2.s-1 / control; T2=500 to 800, T3=700 to 1000 and T4=1300 to 1800 µmol.m-2.s-1 / full sunlight). Allometric variables, gas exchange, contents of pigments and chlorophyll a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a fluorescence; Chloroplast pigment contents; Gas exchanges; Photochemical efficiency of photosystem II; Relative growth rate; Tropical species. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300007 |
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| Garg,Neera; Singla,Ranju. |
| Four cultivars of chickpea, two of them of Mediterranean origin (kabuli), CSG 9651, BG 267 and two Indian (desi) types, CSG 8962, DCP 92-3, differing in their salt sensitivities were identified after screening ten genotypes in saline soils. The cultivars CSG 9651 and CSG 8962 were salt tolerant while BG 267 and DCP 92-3 were salt sensitive, respectively. The seeds of different cultivars were inoculated with Mesorhizobium ciceri, strain F: 75 and the plants were grown in the greenhouse. After the establishment of symbiosis, 15-day-old seedlings were administered doses of saline at varying concentrations (0, 4, 6, 8 dSm-1 NaCl, Na2SO4, CaCl2). Plants were harvested at 40, 70 and 100 days after sowing, for analyses. The main aim was to compare the relative... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll pigments; Nitrogenase activity; Nodule; PEPCase; Rubisco. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300003 |
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| Pandey,Nalini; Pathak,Girish C.; Pandey,Dharmendra K.; Pandey,Ritu. |
| Exposure of 10-d-old spinach (Spinacea oleracea L.) plants to excess (500 µM) concentrations of Co, Ni, Cu, Zn and Cd in sand culture inhibited growth, induced toxicity symptoms, oxidative damage and changes in the antioxidant defense system. The severity of the metal-induced effects varied with the metals and the duration of exposure to excess supply of the metals. Each metal induced chlorosis. In addition, excess Co, Ni and Cd also produced metal specific toxic effects. Excess supply of each metal caused lipid peroxidation (TBARS). Their effectiveness in producing oxidative damage was in the order: Ni > Co > Cd > Cu >Zn. Of all the metals, Ni was also most effective in lowering the concentration of the chloroplast pigments (Chl, Car). While... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ascorbate-glutathione cycle; Heavy metal exposure; Spinacia oleracea L. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200003 |
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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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| Registros recuperados: 360 | |
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