DAYTIME VARIATIONS OF CHLOROPHYLL A FLUORESCENCE IN PAU D'ALHO SEEDLINGS

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dc.creatorMarcos Antonio Bacarin
dc.creatorEmanuela Garbin Martinazzo
dc.creatorDaniela Cassol
dc.creatorAntelmo Ralph Falqueto
dc.creatorDiolina Moura Silva
dc.date2016
dc.date.accessioned2026-07-07T03:17:57Z
dc.descriptionAnalysis of transient and modulated fluorescence of chlorophyll a were made at one-hour intervals during an eight-hour period starting at 07:30h aiming to study mechanisms of photoprotection against high radiation and temperature in Gallesia integrifolia plants. Seeds were germinated inside plastic pots containing soil as substrate. At 120 days after emergence, chlorophyll fluorescence measurements were performed using Handy-PEA and FMS2 fluorometers. During the course of a day, an increase and a subsequent decrease in temperature and in photosynthetic active radiation were observed until 12:30h. Changes in transient kinetic curves of chlorophyll a fluorescence were identified. This resulted in changes in JIP test parameters. An increase during the period of high radiation and temperature may be stressed in relation to variables related to dissipation flux and appearance of positive -K and -L bands. Considering the modulated fluorescence, high values of nonphotochemical quenching coefficients associated with lower values of effective photochemical efficiency of the photosystem II (FV'/ FM') and current photochemical efficiency of PSII (PSII) could be observed during early morning. This was probably the result of an inhibition of the biochemical phase of photosynthesis. It can be concluded that Gallesia integrifolia decrease its photochemical activity with the increase in the photosynthetic active radiation, demonstrating a photoinhibitory effect under high irradiance conditions, but without irreversible damages to the photosynthetic apparatus.
dc.formatapplication/pdf
dc.identifier0100-6762
dc.identifierhttps://www.redalyc.org/articulo.oa?id=48849820007
dc.identifier.urihttp://hdl.handle.net/123456789/429607
dc.languageen
dc.publisherUniversidade Federal de Viçosa
dc.relationhttp://www.redalyc.org/revista.oa?id=488
dc.rightsRevista Árvore
dc.sourceRevista Árvore (Brasil) Num.6 Vol.40
dc.subjectAgrociencias
dc.titleDAYTIME VARIATIONS OF CHLOROPHYLL A FLUORESCENCE IN PAU D'ALHO SEEDLINGS
dc.typeartículo científico

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Revista Árvore - Universidade Federal de Viçosa