Abstract
The role of light in cold acclimation of Hedera helix L. var. Thorndale appears to differ from that reported for winter annuals. Although light greatly enhances the degree of hardiness attained, cold acclimation is not obligatorily linked to a light requirement. Photoperiods, varying from 8 to 24 hours, received during the cold acclimation period were equally effective in promoting maximum hardiness. Relatively low light intensities and short photoperiods stimulated maximum hardiness, and proportional increases in hardiness in response to increased photoperiods were demonstrated only in stems of prestarved plants. Exclusion of CO(2) and high concentrations of photosynthetic inhibitors decreased hardiness, but in no instance was hardiness reduced to the level of the dark control. The data are only compatible with a photosynthetic role of light if it is assumed that only a small portion of the total photosynthates are required to elicit maximum hardiness. Alternatively, the light stimulation which was elicited by low light intensities, short photoperiods, in the absence of CO(2), and in the presence of photosynthetic inhibitors, may be a light signal similar to a phytochrome response.
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Claims 9
Claim · model-written summary
Light greatly increased cold hardiness.
- Taxon
- Hedera helix L. var. Thorndale
Hedera helixt0 - Treatment
- lighte0
- Outcome
- degree of hardinesse0
- Direction
- enhancese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Although light greatly enhances the degree of hardiness attained, cold acclimation is not obligatorily linked to a light requirement.”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
Cold acclimation could occur without light.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Outcome
- cold acclimation is not obligatorily linked to a light requiremente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cold acclimation is not obligatorily linked to a light requirement.”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
Photoperiods of 8 to 24 hours equally promoted maximum hardiness.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Treatment
- Photoperiods, varying from 8 to 24 hourse0
- Outcome
- maximum hardinesse0
- Direction
- equally effectivee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Photoperiods, varying from 8 to 24 hours, received during the cold acclimation period were equally effective in promoting maximum hardiness.”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
Low light intensities stimulated maximum hardiness.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Treatment
- Relatively low light intensitiese0
- Outcome
- maximum hardinesse0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Relatively low light intensities and short photoperiods stimulated maximum hardiness”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
Short photoperiods stimulated maximum hardiness.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Treatment
- short photoperiodse0
- Outcome
- maximum hardinesse0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“short photoperiods stimulated maximum hardiness”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
Longer photoperiods proportionally increased hardiness only in prestarved stems.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Organ / stage
- stemse0
- Treatment
- increased photoperiodse0
- Outcome
- hardinesse0
- Direction
- increasese0
- Qualifier
- prestarved plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“proportional increases in hardiness in response to increased photoperiods were demonstrated only in stems of prestarved plants.”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
CO(2) exclusion decreased hardiness.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Treatment
- Exclusion of CO(2)e0
- Outcome
- hardinesse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exclusion of CO(2) and high concentrations of photosynthetic inhibitors decreased hardiness”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
High concentrations of photosynthetic inhibitors decreased hardiness.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Treatment
- high concentrations of photosynthetic inhibitorse0
- Outcome
- hardinesse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high concentrations of photosynthetic inhibitors decreased hardiness”
t0“Hedera helix L. var. Thorndale”
Claim · model-written summary
Hardiness under these treatments did not fall to the dark control level.
- Taxon
- Hedera helix L. var. ThorndaleHedera helixt0
- Outcome
- hardinesse0
- Direction
- reducede0
- Comparator
- dark controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in no instance was hardiness reduced to the level of the dark control.”
t0“Hedera helix L. var. Thorndale”
The same questions in other papers
light · tolerance: abiotic · Hedera helix (English ivy)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
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.