Abstract
1. Flowering of chrysanthemum, Chrysanthemum morifolium Ramat., is prevented by dark-period interruptions of 4 hours, which convert phytochrome to the flower-inhibiting far-red-absorbing form (Pfr) and maintain it in this form throughout the light period. 2. Pfr is also maintained at an effective level by intermittent lighting provided the dark periods between successive periods of light are so short that dark reversion of Pfr to an ineffective level does not occur. If the light is from incandescent-filament lamps, the dark periods between successive light breaks must not greatly exceed 30 minutes. Cycles of light and dark from 30 minutes to 1 minute are equally effective. 3. Effective cycle length depends on the ratio of red to far-red energies in the light. As the relative amount of red increases, the amount of Pfr formed and the time required for its reversion in darkness to a level ineffective for flower inhibition also increase. For these reasons light from ruby-red, incandescent-filament, and fluorescent lamps is about equally effective in 15-minute cycles, but the effectiveness of ruby-red light fails in 30-minute cycles and of incandescent-filament in 60-minute cycles, whereas that of fluorescent light remains high in longer cycles. 4. In chrysanthemum the time required for the flower-inhibiting reactions catalyzed by Pfr is greater than the dark reversion time of Pfr to an inactive form. This fact accounts for the need of prolonged periods each night of continuous or intermittent light, a condition also encountered in control of flowering in certain long-day plants, regulation of growth in woody species, and positioning of the chloroplast in the alga Mesotaenium.
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Claims 10
Claim · model-written summary
Four-hour dark-period interruptions prevented chrysanthemum flowering.
- Taxon
- chrysanthemum
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Chrysanthemume0 - Treatment
- dark-period interruptions of 4 hourse0
- Gene
- phytochromee0
- Outcome
- Floweringe0
- Direction
- preventede0
- Value
- 4 hourse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpeg?width=500)
Verbatim
e0“Flowering of chrysanthemum, Chrysanthemum morifolium Ramat., is prevented by dark-period interruptions of 4 hours, which convert phytochrome to the flower-inhibiting far-red-absorbing form (Pfr) and maintain it in this form throughout the light period.”
Claim · model-written summary
Intermittent lighting kept Pfr effective when dark periods were short enough to prevent reversion.
- Taxon
- chrysanthemumChrysanthemumt0
- Treatment
- intermittent lightinge0
- Gene
- Pfre0
- Outcome
- maintained at an effective levele0
- Qualifier
- dark periods between successive periods of light are so shorte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pfr is also maintained at an effective level by intermittent lighting provided the dark periods between successive periods of light are so short that dark reversion of Pfr to an ineffective level does not occur.”
t0“Chrysanthemum”
Claim · model-written summary
With incandescent light, intervals between breaks could not greatly exceed 30 minutes.
- Taxon
- ChrysanthemumChrysanthemumt0
- Treatment
- incandescent-filament lampse0
- Outcome
- dark periods between successive light breakse0
- Value
- 30 minutese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“If the light is from incandescent-filament lamps, the dark periods between successive light breaks must not greatly exceed 30 minutes.”
t0“Chrysanthemum”
Claim · model-written summary
Light-dark cycles from 30 to 1 minute were equally effective in inhibiting chrysanthemum flowering.
- Taxon
- ChrysanthemumChrysanthemumt0
- Treatment
- Cycles of light and dark from 30 minutes to 1 minutee0
- Outcome
- equally effectivee0
- Direction
- equally effectivee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cycles of light and dark from 30 minutes to 1 minute are equally effective.”
t0“Chrysanthemum”
Claim · model-written summary
Increasing relative red light increased the Pfr formed and its dark reversion time.
- Taxon
- ChrysanthemumChrysanthemumt0
- Treatment
- relative amount of rede0
- Gene
- Pfre0
- Outcome
- amount of Pfr formed and the time required for its reversione0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“As the relative amount of red increases, the amount of Pfr formed and the time required for its reversion in darkness to a level ineffective for flower inhibition also increase.”
t0“Chrysanthemum”
Claim · model-written summary
Ruby-red, incandescent, and fluorescent lamps were about equally effective in 15-minute cycles.
- Taxon
- ChrysanthemumChrysanthemumt0
- Treatment
- ruby-red, incandescent-filament, and fluorescent lampse0
- Outcome
- about equally effectivee0
- Direction
- about equally effectivee0
- Value
- 15-minute cyclese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For these reasons light from ruby-red, incandescent-filament, and fluorescent lamps is about equally effective in 15-minute cycles, but the effectiveness of ruby-red light fails in 30-minute cycles and of incandescent-filament in 60-minute cycles, whereas that of fluorescent light remains high in longer cycles.”
t0“Chrysanthemum”
Claim · model-written summary
Ruby-red light lost effectiveness in 30-minute cycles.
- Taxon
- ChrysanthemumChrysanthemumt0
- Treatment
- ruby-red lighte0
- Outcome
- effectivenesse0
- Direction
- failse0
- Value
- 30-minute cyclese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the effectiveness of ruby-red light fails in 30-minute cycles”
t0“Chrysanthemum”
Claim · model-written summary
Incandescent light lost effectiveness in 60-minute cycles.
- Taxon
- ChrysanthemumChrysanthemumt0
- Treatment
- incandescent-filamente0
- Outcome
- effectivenesse0
- Direction
- failse0
- Value
- 60-minute cyclese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the effectiveness of ruby-red light fails in 30-minute cycles and of incandescent-filament in 60-minute cycles”
t0“Chrysanthemum”
Claim · model-written summary
Fluorescent light retained high effectiveness in longer cycles.
- Taxon
- ChrysanthemumChrysanthemumt0
- Treatment
- fluorescent lighte0
- Outcome
- remains highe0
- Direction
- remains highe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“whereas that of fluorescent light remains high in longer cycles”
t0“Chrysanthemum”
Claim · model-written summary
The flower-inhibiting reaction catalyzed by Pfr takes longer than Pfr dark reversion in chrysanthemum.
- Taxon
- chrysanthemumChrysanthemume0
- Gene
- Pfre0
- Outcome
- time required for the flower-inhibiting reactionse0
- Qualifier
- greater than the dark reversion time of Pfre0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In chrysanthemum the time required for the flower-inhibiting reactions catalyzed by Pfr is greater than the dark reversion time of Pfr to an inactive form.”
The same questions in other papers
light · phenology · ChrysanthemumResults differ
5 papers in the same direction as this paper · 22 in the opposite direction
- positive
- positive
- positive
24 papers more in this group
See all 28 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.