Abstract
Experiments with Kalanchoe blossfeldiana are described in which periods of short-day treatment were interrupted by intercalated long days or light breaks during long dark periods. The effects of 24-hour dark periods preceding and following such intercalated long days were also investigated. The results of these experiments have shown that: Single long days intercalated between numbers of short days have a positive inhibitory effect on flower initiation and are not merely ineffective. The inhibitory effect expressed as the number of inductive cycles annulled is approximately additive, provided the long days are interspersed with short days, but not if several long days are given consecutively. On the average 1 long day is capable of annulling the flower-promoting effect of about 1⅓ short days. To a first approximation flower numbers in Kalanchoe increase exponentially with the number of inductive cycles given—up to at least 12 short days; the inhibitory effect of long days interspersed with short days also fits an exponential curve; i.e. the inhibition is roughly proportional to the amount of previous photo-periodic induction. A light break of as little as 30 seconds' duration given in the middle of a long dark period is as inhibitory as a long day. If followed by a long dark period the inhibition of an intercalated long day is almost completely neutralized; a long dark period preceding it has no such effect. These results have been interpreted as due to the interaction of a flowering inhibitor with a reaction leading to flowering. A mechanism involving competitive inhibition of an adaptively formed enzyme has been described as a possible example of the kind of reaction which could account for the results presented.
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Claims 10
Claim · model-written summary
Single long days intercalated between short days inhibit flower initiation.
- Taxon
- Kalanchoe blossfeldiana
_Kalanchoe_blossfeldiana_-_inflorescence.jpg?width=60)
Kalanchoe blossfeldianae0 - Treatment
- Single long days intercalated between numbers of short dayse1
- Outcome
- flower initiatione1
- Direction
- inhibitory effecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Kalanchoe_blossfeldiana_-_inflorescence.jpg?width=500)
Verbatim
e0“Kalanchoe blossfeldiana”
e1“Single long days intercalated between numbers of short days have a positive inhibitory effect on flower initiation and are not merely ineffective”
Claim · model-written summary
The inhibitory effect of dispersed long days was approximately additive, unlike consecutive long days.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Outcome
- number of inductive cycles annullede1
- Qualifier
- long days are interspersed with short dayse1
- Comparator
- several long days are given consecutivelye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“The inhibitory effect expressed as the number of inductive cycles annulled is approximately additive, provided the long days are interspersed with short days, but not if several long days are given consecutively”
Claim · model-written summary
One long day annulled the flowering effect of about 1⅓ short days on average.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Treatment
- 1 long daye1
- Outcome
- flower-promoting effecte1
- Value
- about 1⅓ short dayse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“On the average 1 long day is capable of annulling the flower-promoting effect of about 1⅓ short days”
Claim · model-written summary
Flower numbers increased approximately exponentially with inductive cycles up to at least 12 short days.
- Treatment
- number of inductive cyclese0
- Outcome
- flower numberse0
- Direction
- increase exponentiallye0
- Qualifier
- up to at least 12 short dayse0
KalanchoeOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“flower numbers in Kalanchoe increase exponentially with the number of inductive cycles given—up to at least 12 short days”
Claim · model-written summary
Inhibition by interspersed long days fitted an exponential curve and was roughly proportional to previous induction.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Treatment
- long days interspersed with short dayse1
- Outcome
- inhibitory effecte1
- Qualifier
- roughly proportional to the amount of previous photo-periodic inductione1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“the inhibitory effect of long days interspersed with short days also fits an exponential curve; i.e. the inhibition is roughly proportional to the amount of previous photo-periodic induction”
Claim · model-written summary
A 30 second light break in a long dark period inhibited flowering as much as a long day.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Treatment
- A light break of as little as 30 seconds' duratione1
- Outcome
- as inhibitorye1
- Direction
- as inhibitorye1
- Comparator
- a long daye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“A light break of as little as 30 seconds' duration given in the middle of a long dark period is as inhibitory as a long day”
Claim · model-written summary
A following long dark period almost completely neutralized inhibition by an intercalated long day.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Treatment
- a long dark periode1
- Outcome
- inhibition of an intercalated long daye1
- Direction
- almost completely neutralizede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“If followed by a long dark period the inhibition of an intercalated long day is almost completely neutralized”
Claim · model-written summary
A preceding long dark period did not neutralize inhibition by an intercalated long day.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Treatment
- a long dark period preceding ite1
- Outcome
- no such effecte1
- Direction
- no such effecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“a long dark period preceding it has no such effect”
Claim · model-written summary
The authors interpret the results as interaction of a flowering inhibitor with a flowering reaction.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Outcome
- reaction leading to floweringe1
- Qualifier
- interaction of a flowering inhibitore1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“interaction of a flowering inhibitor with a reaction leading to flowering”
Claim · model-written summary
Competitive inhibition of an adaptively formed enzyme is proposed as a possible mechanism.
- Taxon
- Kalanchoe blossfeldianaKalanchoe blossfeldianae0
- Outcome
- reaction which could account for the results presentede1
- Qualifier
- competitive inhibition of an adaptively formed enzymee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kalanchoe blossfeldiana”
e1“A mechanism involving competitive inhibition of an adaptively formed enzyme has been described as a possible example of the kind of reaction which could account for the results presented”
The same questions in other papers
light · phenology · Kalanchoe blossfeldianaPositive and negative results
2 papers in the same direction as this paper · 3 in the opposite direction
- positive
- positive
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2 papers more in this group
See all 6 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.