Leaf Gas Exchanges
Mostrando 13-24 de 25 artigos, teses e dissertações.
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13. A aplicação exógena foliar de ácido abscísico desencadeia mecanismos de tolerância à deficiência hídrica em seringueira
Resumo O ácido abscísico (ABA) é conhecido como o hormônio mais influente em desencadear mecanismos de tolerância a estresse em plantas, inclusive à deficiência hídrica. No entanto, o efeito da aplicação exógena como indutora de tolerância pré-estresse é pouco estudado em plantas de interesse agronômico. O objetivo deste trabalho foi avaliar o
Ciênc. Florest.. Publicado em: 30/05/2019
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14. The chlorophyll a fluorescence as an indicator of the temperature stress in the leaves of Prunus persica
Plants growing in temperate regions are often exposed to stress conditions caused by high temperatures. Photosynthesis is one of the metabolic processes most sensitive to high temperature stress, and it is often inhibited before other cellular functions. Using peach leaf disks, we studied the transient chlorophyll a fluorescence along with the gas exchanges
Braz. J. Plant Physiol.. Publicado em: 25/02/2013
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15. Physiological limitations in two sugarcane varieties under water suppression and after recovering
Increasing water scarcity and depleted water productivity in irrigated soils are inducing farmers to adopt improved varieties, such as those with high-capacity tolerance. The use of tolerant varieties of sugarcane might substantially avoid the decline of productivity under water deficit. This research aimed to evaluate the harmful effects of drought on the p
Theor. Exp. Plant Physiol.. Publicado em: 2013
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16. The level of environmental noise affects the physiological performance of Glycine max under water deficit
Plants in natural environments are subjected to a multitude of environmental cues. However, studies addressing physiological analyzes are usually focused on the isolation of a stress factor, making it difficult to understand plants behavior in their extremely complex natural environments. Herein, we analyzed how environmental variability (noise) may influenc
Theor. Exp. Plant Physiol.. Publicado em: 2013
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17. GerminaÃÃo e desenvolvimento inicial de plÃntulas de cajueiro anÃo precoce sob irrigaÃÃo salina / Germination and early development of dwarf cashew seedlings under saline irrigation
Considering the socio-economic importance of cashew to the Brazilian northeast and the northeastern problems with water scarcity and quality of irrigation water, the objective of this work was set to study the development of dwarf cashew clones at different stages of development under irrigation with saline water. The first experiment was aimed at evaluating
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/03/2011
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18. Fósforo como atenuador dos efeitos da deficiência hídrica em diferentes espécies de gramíneas forrageiras / Phosphorus as attenuation of the effects of water stress on growth and photosynthetic capacity of different species of grasses
A deficiência hídrica provocada pela seca estacional influencia a relação entre a água e as trocas gasosas nas gramíneas forrageiras tropicais, reduzindo seu potencial produtivo. Paralelamente, a ampla deficiência de fósforo dos solos brasileiros soma-se ao conjunto de fatores limitantes da produção vegetal. Nesse contexto, o objetivo deste trabalh
Publicado em: 2010
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19. Fotossíntese, osmorregulação e crescimento inicial de quatro variedades de cana-de-açúcar submetidas à deficiência hídrica. / Photosynthesis, osmorregulation and initial growth of four sugarcane varieties submitted to water deficiency.
The water deficiency of soil is a problem that affects good part of the areas cultivated in the world, over all, to those situated ones in the half-barren regions. The sugarcane is a culture in expansion in the Northeast of Brazil, where the limitation in the water availability for the plant affects the growth and the development of the plant, causing, exces
Publicado em: 2008
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20. Variações diurnas da fotossíntese e efeitos do anelamento de ramos sobre a fotossíntese e o metabolismo do carbono em café arábica / Diurnal changes in photosynthesis and effects of branch girdling on photosynthesis and carbon metabolism in arabica coffee
This study was carried out in order to examine (i) the diurnal changes in photosynthesis rates under low atmospheric evaporative demand, and (ii) the relationship between the rate of net photosynthesis (A) and carbon (C) metabolism in experimentally-manipulated branches through girdling. Two experiments were separately conducted and so analyzed. In both expe
Publicado em: 2008
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21. Crescimento, fotossíntese e mecanismos de fotoproteção em mudas de café (Coffea arabica L.) formadas a pleno sol e à sombra / Growth, photosynthesis and mechanisms of photoprotection in coffee (Coffea arabica L.) seedlings grown under full sunlight and shade
Coffee seedlings have been traditionally grown in shaded nurseries. However, some coffee growers, with the aim of improving acclimation after moving the seedlings from the nursery to the field, are growing the seedlings under full sun. Nonetheless, most information associated with cultivation of coffee seedlings under varying light is restricted to simple mo
Publicado em: 2008
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22. Morphology, relations water and photosyntheses in two cultivate of Coffea canephora submitted the of water déficit / Morfologia, relações hídricas e fotossíntese em duas cultivares de Coffea canephora submetidas ao déficit hídrico
In this study we aimed to expand our earlier understanding on the mechanisms associated with drought tolerance within Coffea canephora. Two cultivars of C. canephora, robusta (drought-sensitive) and kouillou (drought-tolerant) were grown in 24-L pots until 12-month old, when an irrigation and a drought treatment were applied. Plants were droughted until pred
Publicado em: 2007
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23. Tolerância à dessecação em Pleurostima purpurea (Velloziaceae): trocas gasosas, pigmentos fotossintéticos e conteúdo relativo de água foliar / Desiccation tolerance in Pleurostima purpurea (Velloziaceae): gas exchanges, photosynthetic pigments and leaf relative water content
Pleurostima purpurea (Velloziaceae) é uma espécie rupícola encontrada em afloramentos rochosos do estado do Rio de Janeiro, sudeste do Brasil. Por apresentar notável capacidade de tolerar a dessecação vegetativa, este estudo teve o intuito de esclarecer detalhes sobre a estratégia ecofisiológica utilizada por tais plantas frente à desidratação do
Publicado em: 2005
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24. Effect of Errors in Measuring Leaf Temperature and Ambient Gas Concentration on Calculated Resistances to CO2 and Water Vapor Exchanges in Plant Leaves
Errors as small as 1 C in the measurement of leaf temperature (Tleaf) are shown to cause significant changes in the estimated value of the stomatal resistance (expressed in terms of total resistance to water vapor transfer, ∑rH2O). The effect increases as Tleaf increases and as ambient relative humidity increases, if other conditions are maintained constan