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| Registros recuperados: 17 | |
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| Martins,Alexandre Cristante; Marchioretto,Rafaella Migliavacca; Vieira,Ariane Tonetto; Stiehl-Alves,Eudes Maria; Santos,Eliane Kaltchuk dos; Souza-Chies,Tatiana Teixeira de. |
| ABSTRACT South Brazilian grasslands are among the most species-rich grasslands worldwide yet they have been suffering ongoing degradation due to land-use. Little is known about the reproductive ecology of the native species of these grasslands. Thus, our goal was to characterize seed traits and germination requirements of three native species of the tribe Tigridieae (Iridaceae, Iridoideae) due to its richness in the Pampa biome and the contrasting morphology, cytogenetics, and geographic distributions of its representatives. We tested if closely related species possess similar seed traits and whether species with wider distributions have broader germination requirements. Seed production and mass were estimated, and morphological analyses, germination... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dormancy; Functional traits; Germination; Grasslands; Iridaceae; Photoinhibition; Regeneration niche; Reproductive ecology; Seed morphology; Time-to-event analysis. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062020000400730 |
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| Hiendlmeyer,Rosane; Randi,Aurea Maria. |
| Light is a limiting factor for fern stablishment because it controls germination of light sensitive spores. The aim of this work was to study the effect of light levels on spore germination in two ornamental ferns native to the Atlantic forest, under natural conditions. Cyathea delgadii is a tree fern and Blechnum brasiliense, a subarborescent fern. The effect of light levels was analyzed in April and July/2003, in Florianópolis, Santa Catarina state, Brazil. Sterilized spores were sown in Erlenmeyer flasks containing mineral culture medium with macronutrients, iron, and benomyl 0.01%. The Erlenmeyer flasks were kept in 50 cm³ boxes covered with black shade netting, which gave 5, 22, 42, and 62% natural light. Irradiance and temperature were scored daily... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ferns; Germination; Light levels; Photoinhibition; Spores. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062007000400015 |
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| Araújo, Saulo Alberto do Carmo; UFVJM; Vasquez, Hernan Maldonado; UENF; Campostrini, Eliemar; UENF; Netto, Alena Torres; UENF; Deminicis, Bruno Borges; UENF; Lima, Érico da Silva; UENF. |
| O experimento foi realizado com o objetivo de avaliar as trocas gasosas de genótipos de capim-elefante anão, em diferentes condições hídricas. O delineamento experimental foi inteiramente casualizado com três repetições. Foram avaliados três genótipos de capim-elefante anão (Mott, CNPGL 94-34-3 e CNPGL 92-198-7) em duas condições de umidade do solo: irrigado (I) e não-irrigado (NI). Foi observada diferença entre os tratamentos I e NI para todos os genótipos em relação à taxa fotossintética, condutância estomática, transpiração e déficit de pressão de vapor. O genótipo CNPGL 94-34-3 apresentou maior tolerância ao estresse hídrico, seguido pelos genótipos Mott e CNPGL 92-198-7. Todos os genótipos avaliados apresentaram, em condições ideais de umidade do... |
| Tipo: Pesquisa de campo |
Palavras-chave: Ciências Agrárias condutância estomática; Déficit de pressão de vapor; Fotoinibição; Fotossíntese; Transpiração Zootecnia stomatal conductance; Vapor pressure deficit; Photoinhibition; Photosynthesis; Transpiration. |
| Ano: 2009 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/8961 |
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| Lage-Pinto,Frederico; Bernini,Elaine; Oliveira,Jurandi Gonçalves de; Vitória,Angela Pierre. |
| Gas exchange, chlorophyll afluorescence, and photosynthetic pigments of Xylopia sericeaA. St.-Hil. and Siparuna guianensis Aubl. were evaluated during the rainy season and the dry season (2009-2010) in three understories with different ecological conditions (irradiance, water availability, and temperature) located in the União Biological Reserve (known as REBIO União), at Rio de Janeiro State, a natural forest understory, eucalyptus understory under regeneration, and understory of eucalyptus plantation with 18-year-old trees that were removed 1 year before. The lowest values of Fv/Fm e Fm/Fo were observed in the exposed understory for both seasons, with lower values in the dry season, suggesting that reduced water availability potentializes the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Corymbia citriodora; Dehydration; Photoinhibition; Siparuna guianensis; Xylopia sericea. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200003 |
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| Mengarda,Liana Hilda Golin; Milanez,Camilla Rozindo Dias; Silva,Diolina Moura; Aguilar,Marco Antonio Galeas; Cuzzuol,Geraldo Rogério Faustini. |
| This study aimed to characterize the alarm and resistance phases of stress of Caesalpinia echinata under intense irradiance in order to better define its position on forest succession. The alarm phase was identified by rapid reduction in the maximum quantum yield of PSII primary photochemical reactions (ΦP0 = FV/FM) and Performance Index (PIABS) followed by total leaf abscission in the first week of exposure to direct sunlight. The new leaves grown showed recovery of chlorophyll a parameters, increase in blade thickness, elongation of the palisade and spongy parenchymas, higher water content, and reduction of specific leaf area. These changes were associated with the osmoprotector of sucrose and antioxidative of raffinose effects, which indicate an... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Forest succession; Light stress; Photoinhibition; Leaf anatomy; Soluble carbohydrates. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300003 |
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| Berti,Maritza; Pinto,Manuel. |
| Early light induced proteins (ELIP) are a type of proteins which are expressed before than other chloroplast proteins in the presence of light. These proteins have been studied in a large number of annual species such as pea (Pisum sativum L.), barley (Hordeum vulgare L.) and Arabidopsis sp. In perennials plants the studies about ELIPs are very scarce. The possible photoprotective function of the ELIPs has motivated the interest in investigating the presence of this type of proteins in a perennial plant such as grapevine (Vitis vinifera L.) and if their characteristics differ from those found in annual plants. In this paper a comparative study was conducted on the ELIPs expression in grapevine and pea to investigate whether there are differences regarding... |
| Tipo: Journal article |
Palavras-chave: Photoinhibition; ELIPs induction; Abiotic stress; Vitis vinifera; Pisum sativum. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000300011 |
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| Chilian,Javier; Verdugo,Isabel; Poblete,Fernando; Ruiz-Lara,Simón; Casaretto,José A; González,Enrique. |
| Simultaneous exposition to low temperature and high light radiation cause photoinhibition of photosynthetic apparatus, affecting the productivity and geographical distribution of agricultural crops. In several Solanaceous species, tolerance to low temperature stress in combination with high light has been associated with some stimulation in non-photochemical quenching (NPQ), which involved reorganization in light-harvesting complex (LHC) proteins. To study photosynthetic performance in Solanum lycopersicum L. and S. chilense (Dunal) Reiche, and to investigate transcriptional regulation of genes encoding LHC proteins and their involvement in the NPQ, plants of both species were exposed to low temperature (4 °C) and high light radiation (1300 /<mol m-2... |
| Tipo: Journal article |
Palavras-chave: Lipid-peroxidation; Photoinhibition; Photochemical quenching; Zeaxanthin. |
| Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392011000400002 |
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| Martinez, Carlos; Mairet, Francis; Bernard, Olivier. |
| Microalgae can be cultivated in closed or open photobioreactors (PBR). In these systems, light rapidly decreases as it passes through the culture due to the turbidity of the medium. Thus, microalgae experiment different light intensities depending on their position in the medium. In this paper, we study theoretically how the growth rate of microalgae is affected by different factors; incident light intensity, form of the PBR, microalgae population density, turbidity of non-microalgae components, and light path-length of the reactor. We show that for different types of PBR the average growth rate is completely determined by the incident light intensity and the optical depth. In the case of vertical cylindrical PBRs illuminated from above (e.g. race-way or... |
| Tipo: Text |
Palavras-chave: Photobioreactor; Optical depth; Photoinhibition; Light limitation; Turbidity; Modelling. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56133/57675.pdf |
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| Long, Marc; Tallec, Kevin; Soudant, Philippe; Le Grand, Fabienne; Donval, Anne; Lambert, Christophe; Sarthou, Geraldine; Jolley, Dianne F.; Hegaret, Helene. |
| Allelochemical interactions are likely to be a contributing factor explaining the success of large blooms of the harmful marine dinoflagellate Alexandrium, however, the physiological mechanisms of allelochemical interactions remain poorly described. Here we investigated the sub-lethal effects (on an hourly scale) of a filtrate containing allelochemicals from Alexandrium minutum on the physiology of the common diatom Chaetoceros muelleri. The filtrate induced deleterious effects to the diatom physiology within only 30 min of exposure. Esterase activity and photosynthesis were drastically inhibited, with up to 34% of the population being metabolically inactive and up to 30% reduction in photosystem II quantum yield when exposed to the filtrate. In addition,... |
| Tipo: Text |
Palavras-chave: Allelopathy; Alexandrium; Metabolism; Photoinhibition; Lipids; Pigments. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00460/57133/59748.pdf |
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| LIMA,G.R.; MACEDO,D.C.; BARROS,R.L.N.; MACHADO,A.F.L.; PIMENTEL,C.. |
| ABSTRACT: The objective of this study was to evaluate the effects of the application of contact herbicides recommended for common bean crops, as for chlorophyll a fluorescence parameters, leaf soluble proteins content (LSPC) and productivity. The experiment was conducted on the field with five treatments, which were the application of the following herbicides: bentazon (720 g ha-1), fluazifop-p-butil (187.5 g ha-1), fomesafen (250 g ha-1) fluazifop-p-butil + fomesafen (187.5 + 250 g ha-1), and a manually weeded control treatment without herbicide application, in a randomized block design with four replications. Bentazon was the only herbicide causing significant reductions, but only until the first day after herbicide application (DAA), on the following... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phaseolus vulgaris L.; Chlorophyll a fluorescence; Photosystems; Photoinhibition. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100291 |
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| STANCATO,GIULIO C.; MAZZAFERA,PAULO; BUCKERIDGE,MARCOS S.. |
| Considering the performance of CAM epiphytes under high levels of radiation or in shaded environments, with growth rate proportional to light intensity, the objective of this work was to evaluate the effects of long-term light stress on the growth of a Brazilian epiphytic orchid, Cattleya forbesii Lindl. X Laelia tenebrosa Rolfe. Two groups of plants were used in the first experiment, one under 90% (<FONT FACE=Symbol>@</FONT> 1,650 µmol.m-2.s-1) of Photosynthetically Active Radiation (PAR) and the other maintained under 22.5% (<FONT FACE=Symbol>@</FONT> 400 µmol.m-2.s-1). In the second experiment the diffusive resistance, transpiration rate and fluorescence levels were monitored for plants that were under 22.5% of PAR, under 90% and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photoinhibition; Storage; Orchids; Pseudobulb. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042002000200011 |
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| LEMOS FILHO,JOSÉ PIRES DE. |
| O objetivo deste estudo foi verificar a performance fotossintética e a ocorrência de fotoinibição em três espécies do cerrado, na estação seca e estação chuvosa. Os valores do rendimento quântico potencial do fotossistema II (Fv/Fm) após 1 hora de adaptação ao escuro, ao meio dia, foram inferiores a 0,8 para todas as espécies nas duas estações, caracterizando a presença da fotoinibição. Na estação seca, apesar das reduções observadas na condutância estomática, no rendimento quântico efetivo(DF/F`m) e na taxa aparente de transporte de elétrons (ETR), a saturação da fotossíntese foi similar à observada na estação chuvosa, para todas as espécies estudadas, aproximadamente 1500 mmol.m-2.s-1. Nesse nível de luz, o excesso relativo do fluxo de fótons de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Photoinhibition; "cerrado" plants. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042000000100005 |
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| Gonçalves,Marcos C.; Vega,Jorge; Oliveira,Jurandi G.; Gomes,Mara M. A.. |
| Infection by Sugarcane yellow leaf virus (ScYLV) causes severe leaf symptoms in sugarcane (Saccharum spp.) hybrids, which indicate alterations in its photosynthetic apparatus. To gain an overview of the physiological status of infected plants, we evaluated chlorophyll a fluorescence and gas exchange assays, correlating the results with leaf metabolic surveys, i.e., photosynthetic pigments and carbohydrate contents. When compared to healthy plants, infected plants showed a reduction in potential quantum efficiency for photochemistry of photosystem (PSII) and alterations in the filling up of the plastoquinone (PQ) pool. They also showed reduction in the CO2 net exchange rates, probably as a consequence of impaired quantum yield. In addition, reductions were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Luteoviridae; Carbon metabolism; Photoinhibition; Virus symptoms. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582005000100002 |
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| Registros recuperados: 17 | |
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