Fluorescence, reflectance, and physiological response to water stress in Gmelina arborea Roxb seedlings

 

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Autores: Valverde, Juan Carlos, Arias-Aguilar, Dagoberto, Montero-Zeledón, Ernesto, Gutierrez-Fallas, Dionisio
Formato: artículo original
Estado:Versión publicada
Fecha de Publicación:2021
Descripción:Fluorescence, reflectance, and physiological response to water stress were analyzed in Gmelina arborea Roxb seedlings. The experiment was conducted for 31 days with two treatments: control plants (a normal water regime was applied) and plants under water stress conditions (water was completely limited for these plants during the extent of the experiment). For both treatments, G. arborea clones were used and evaluated every seven days until the end of the experiment.  Photosynthesis, stomatal conductance, leaf turgor, relative chlorophyll content, fluorescence, and reflectance were analyzed. Results showed that the biomass in plants under stress was reduced by 26.9%, being the leaf coverage the one with the greatest affectation (29.1% decrease), while photosynthesis was reduced by 60.1% (5.8 µmol m-2 s-1) compared to the control plant (14.6 µmol m-2 s-1). For the variables stomatal conductance, turgor, and relative chlorophyll content, the behavior was to decrease values from 20 to 60% as the stress period increased. With respect to fluorescence, two standards were determined: from 400 to 550 nm, fluorescence increased in stressed plants, while from 600 to 725 nm, control plants showed the highest excitation. In both ranges, maximum values were presented at the points corresponding to chlorophyll a and b. Finally, reflectance showed differences between 460 and 770 nm, being the plants under stress conditions the ones showing the highest reflectance. The physiological degradation pattern obtained in the stressed plants is due to the organism’s water loss resulting in stomatal closure, increased production of abscisic acid, decreased cell wall synthesis, and limitations in protein synthesis.
País:Portal de Revistas UNA
Institución:Universidad Nacional de Costa Rica
Repositorio:Portal de Revistas UNA
Lenguaje:Español
OAI Identifier:oai:ojs.www.una.ac.cr:article/14474
Acceso en línea:https://www.revistas.una.ac.cr/index.php/uniciencia/article/view/14474
Palabra clave:Forest physiology
water stress
Gmelina arborea
physiological degradation
Fisiología forestal
estrés hídrico
degradación fisiológica
fisiologia florestal
estresse hídrico
degradação fisiológica