This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (39) Citing Articles via Google Scholar Google Scholar Articles by Deitzer, G. F. Articles by Jabben, M. Search for Related Content PubMed PubMed Citation Articles by Deitzer, G. F. Articles by Jabben, M. Agricola Articles by Deitzer, G. F. Articles by Jabben, M.

Articles

Kinetics and Time Dependence of the Effect of Far Red Light on the Photoperiodic Induction of Flowering in Wintex Barley ¹

^a Smithsonian Institution, Radiation Biology Laboratory, 12441 Parklawn Drive, Rockville, Maryland 20852

Flowering in the long day plant Hordeum vulgare L. var. Wintex barley was enhanced by the addition of far red light to the main light portion of the photoperiod. Far red energy was provided to produce quantum flux ratios (660/730 nm) and phytochrome photoequilibria (Pfr/total phytochrome) equivalent to those reported both beneath a leaf canopy and outside a canopy at twilight. The photoperiodic requirement for long days can be completely eliminated by the addition of far red light. However, both the effect of extending the photoperiod without far red and the addition of far red to 12-hour photoperiods were suboptimal. Maximal stimulation was achieved only when far red was added to continuous light. The duration of the period of maximal apex elongation rate, as well as the reduction of the time required for floral initiation, were saturated by three inductive cycles. When far red energy was provided intermittently during 3 days of continuous light, the ability to respond varied in a circadian manner. This enhancement of flowering by far red appears to be mediated by the "high irradiance response" of phytochrome.

¹ This work was carried out under partial support of the Department of Energy under Contract EY-76-S-05-4241 and was partially supported by the Deutsche Forschungsgemeinshaft.

This article has been cited by other articles:

				A. C. Wollenberg, B. Strasser, P. D. Cerdan, and R. M. Amasino Acceleration of Flowering during Shade Avoidance in Arabidopsis Alters the Balance between FLOWERING LOCUS C-Mediated Repression and Photoperiodic Induction of Flowering Plant Physiology, November 1, 2008; 148(3): 1681 - 1694. [Abstract] [Full Text] [PDF]

				M. Hanumappa, L. H. Pratt, M.-M. Cordonnier-Pratt, and G. F. Deitzer A Photoperiod-Insensitive Barley Line Contains a Light-Labile Phytochrome B Plant Physiology, March 1, 1999; 119(3): 1033 - 1040. [Abstract] [Full Text]

				D. Somers, A. Webb, M Pearson, and S. Kay The short-period mutant, toc1-1, alters circadian clock regulation of multiple outputs throughout development in Arabidopsis thaliana Development, January 2, 1998; 125(3): 485 - 494. [Abstract] [PDF]