Generation of Circadian Flowering Rhythm of Pharbitis nil Choisy in Response to Dark-Light Period
Year: 1993
Type: article
Abstract: The effects of a phasing dark period and an intervening light period on circadian flowering response to an inductive dark period were studied with Pharbitis, cultivar Kidachi, grown in continuous fluorescent light. A single light-on signal by the transition from dark to light period established a circadian rhythm of flowering, which lasted for at least 48 h. The generation of the rhythm and the phase pattern were not affected by exogenous gibberellin A₃ (GA₃), benzyladenine (BA) or indoleacetic acid (IAA), though the two formers stimulated flowering during the inducible phases of the rhythm. The same circadian rhythm was detected when the phasing dark period was longer than 4 h, but the response level of flowering became higher with lenghening duration of the dark period. The circadian rhythm became evident if the light intensity of the intervening light period was less than 5,000lux, though the flower-response level became generally lower with lowering intensity of the light. The flowering was influenced by the phase of the rhythm during which the plants were exposed to the inductive dark period. A significance of the phasing dark period and the intervening light period is discussed in relation to the first dark-light periods in the photoperiodic flowering of short-day plants that require several cycles of dark-light period to flower.
Author: Ogawa, Yukiyoshi
Language: English
Topic: Light effects on plants
Subfield: Plant Science
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7144825637