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. 1982 Sep;70(3):898–900. doi: 10.1104/pp.70.3.898

Phytochrome Regulation of Flowering in the Long-Day Plant, Hyoscyamus niger1

Robert J Downs 1, Judith F Thomas 1
PMCID: PMC1065791  PMID: 16662596

Abstract

A daylength extension with incandescent light is more effective in promoting flowering of long-day plants like Hyoscyamus niger than fluorescent light. A low phytochrome photoequilibrium (Pfr/Ptot), attained by a far-red irradiation at the close of long days under fluorescent light, also promotes flowering. Moreover, if flower initiation processes are initiated by several long days, a low phytochrome photoequilibrium at the end of short, postinduction photoperiods also enhances flowering. The initiation phase of flowering requires Pfr to be present whereas the development phase proceeds more rapidly in the absence of Pfr. Spectral dependence studies, therefore, could be misinterpreted if the initiation and development stages are combined into a single audit of flowering.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Deitzer G. F., Hayes R., Jabben M. Kinetics and time dependence of the effect of far red light on the photoperiodic induction of flowering in wintex barley. Plant Physiol. 1979 Dec;64(6):1015–1021. doi: 10.1104/pp.64.6.1015. [DOI] [PMC free article] [PubMed] [Google Scholar]

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