Abstract
Phytochrome control of cucumber seed germination is temperature-dependent. A prolonged exposure to radiation from broad spectrum far red sources (Pfr/P = 0.05 to 0.07) prevents germination at temperatures below 20 C. Above 20 C there is no inhibition and it appears as if there is an escape from phytochrome control. However, radiation from a monochromatic, narrow band 730 nanometer source (Pfr/P < 0.02) inhibits germination at temperatures above 20 C. This result supports the idea that, even at high temperatures, Pfr is responsible for the activation of germination. After 4 days of exposure to far red, a short red irradiation is quite effective in promoting germination if temperatures during the dark incubation periods are maintained below 20 C; red becomes effective at temperatures above 20 C. Promotion of germination will take place at a temperature of 25 C or higher without red irradiation. Again, we have an apparent escape from phytochrome control at high temperatures. However, if higher temperatures are used for only short periods, 2 to 6 hours, in combination with short red irradiation, one can demonstrate that activation of germination at high temperatures is still dependent on phytochrome. Phytochrome is probably destroyed during prolonged exposure to far red. Thus, the subsequent short red irradiation establishes levels of Pfr which may not be sufficient to promote germination at low temperatures but are probably adequate at high temperatures.
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Claims 8
Claim · model-written summary
Phytochrome control of cucumber germination depends on temperature.
- Taxon
- cucumber
Cucumis sativuse0 - Treatment
- temperaturee0
- Outcome
- seed germinatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phytochrome control of cucumber seed germination is temperature-dependent”
Claim · model-written summary
Prolonged broad spectrum far red prevents germination below 20 C.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- prolonged exposure to radiation from broad spectrum far red sourcese0
- Outcome
- germinatione0
- Direction
- preventse0
- Qualifier
- temperatures below 20 Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A prolonged exposure to radiation from broad spectrum far red sources (Pfr/P = 0.05 to 0.07) prevents germination at temperatures below 20 C”
e1“Phytochrome control of cucumber seed germination is temperature-dependent”
Claim · model-written summary
Broad spectrum far red did not inhibit germination above 20 C.
- Taxon
- cucumberCucumis sativuse1
- Outcome
- inhibitione0
- Direction
- no inhibitione0
- Qualifier
- Above 20 Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Above 20 C there is no inhibition”
e1“Phytochrome control of cucumber seed germination is temperature-dependent”
Claim · model-written summary
Narrow band 730 nanometer radiation inhibits germination above 20 C.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- radiation from a monochromatic, narrow band 730 nanometer sourcee0
- Outcome
- germinatione0
- Direction
- inhibitse0
- Qualifier
- temperatures above 20 Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radiation from a monochromatic, narrow band 730 nanometer source (Pfr/P < 0.02) inhibits germination at temperatures above 20 C”
e1“Phytochrome control of cucumber seed germination is temperature-dependent”
Claim · model-written summary
After four days of far red, short red irradiation promotes germination with dark incubation below 20 C.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- a short red irradiatione0
- Outcome
- germinatione0
- Direction
- promotinge0
- Qualifier
- temperatures during the dark incubation periods are maintained below 20 Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After 4 days of exposure to far red, a short red irradiation is quite effective in promoting germination if temperatures during the dark incubation periods are maintained below 20 C”
e1“Phytochrome control of cucumber seed germination is temperature-dependent”
Claim · model-written summary
Red irradiation becomes effective above 20 C.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- rede0
- Outcome
- effectivee0
- Qualifier
- temperatures above 20 Ce0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“red becomes effective at temperatures above 20 C”
e1“Phytochrome control of cucumber seed germination is temperature-dependent”
Claim · model-written summary
Germination is promoted at 25 C or above without red irradiation.
- Taxon
- cucumberCucumis sativuse1
- Outcome
- germinatione0
- Direction
- Promotione0
- Qualifier
- without red irradiatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Promotion of germination will take place at a temperature of 25 C or higher without red irradiation”
e1“Phytochrome control of cucumber seed germination is temperature-dependent”
Claim · model-written summary
Short periods of high temperature combined with red irradiation show that high temperature germination activation still depends on phytochrome.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- short red irradiatione0
- Outcome
- activation of germinatione0
- Qualifier
- 2 to 6 hourse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“if higher temperatures are used for only short periods, 2 to 6 hours, in combination with short red irradiation, one can demonstrate that activation of germination at high temperatures is still dependent on phytochrome”
e1“Phytochrome control of cucumber seed germination is temperature-dependent”
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