Premium
Circadian Rhythmicity in Photoperiodic Regulation of Regeneration in Begonia Leaves
Author(s) -
HEIDE OLA M.
Publication year - 1978
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1978.tb02575.x
Subject(s) - photoperiodism , begonia , circadian rhythm , phytochrome , biology , period (music) , botany , red light , rhythm , reversion , endocrinology , medicine , genetics , gene , physics , acoustics , phenotype
The mechanism of photoperiodic regulation of regeneration in Begonia leaves has been studied by the night interruption technique in 24, 48, and 72‐h cycles. The response to 30 min red light interruptions in 48 and 72‐h cycles indicated a circadian rhythm in red light sensitivity with typical photophile and scotophile phases. In 24‐h cycles two types of response patterns were observed. With a main photoperiod of 3 h the usual response pattern with only one light‐sensitive phase near the middle of the dark period was found, whereas with 8‐h photoperiods two light‐sensitive phases were observed as previously reported by Zimmer in Begonia flowering studies (Gartenbauwissenschaft 38: 57, 1973). Reversion studies with FR indicate that the reactions are mediated by phytochrome. The results are discussed in relation to alternative hypotheses for photoperiodic timing.