Circadian Timekeeping for the Photoperiodic Control of Budset in Picea abies (Norway Spruce) Seedlings

Autor:	Inger Ekberg, Lennart Norell, Daphne Vince-Prue, David H. Clapham
Rok vydání:	2001
Předmět:	Physiology Picea abies Biology Continuous light biology.organism_classification law.invention Horticulture law Physiology (medical) Botany Darkness Circadian rhythm Hourglass Ecology Evolution Behavior and Systematics
Zdroj:	Biological Rhythm Research. 32:479-487
ISSN:	1744-4179 0929-1016
Popis:	Romanian populations of Norway spruce are induced to set terminal buds by four inductive cycles of 8 h light/16 h darkness. To distinguish between circadian and hourglass timekeeping for the photoperiodic control of budset, seedlings were raised in continuous light at 300 µmol m-2s-1 at 20°C for 10 weeks. They were then exposed to an extended night regime consisting of three cycles of 8 h light/40 h dark with 4-h or 1-h nightbreaks (120 µmol m-2s-1) applied to groups of plants at intervals during the extended night. Following a final cycle of 8 h light/16 h dark to maximize budset, the plants were transferred to continuous light. Budset was delayed when the night-break was applied close to the critical nightlength (CNL) of 6–7 h or about 22–23 h later in the extended night, consistent with circadian rather than hourglass timekeeping. Confidence intervals were calculated for the times to maximum effect of the night-breaks.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f5ebb84aad0c09af3efd6418773583fc https://doi.org/10.1076/brhm.32.4.479.1336 Zobrazit plný text záznamu