Abstract
Experiments on the production of two separate crops of lettuce seeds, each in three different temperature environments, and subsequent tests on the seed are described. Low production temperatures (20 °C day, 10 °C night) gave a low yield of large seeds, and high temperatures (30 °C, 20 °C) gave a higher yield of much smaller seed; the highest yield came from medium temperatures (25 °C, 15 °C), which gave medium-sized seed. After-ripening, manifested as an increase in percentage germination at high temperatures with increase in seed age, occurred in seed from all three production environments of the first crop, though there were differences in degree, and in that from the two higher production temperatures, but not the lowest, of the second crop. Measurements of the forces required to penetrate the layers surrounding the embryo showed an inverse relationship with temperature of the production environment for pericarps but not for endosperms, and a gradual reduction during storage for pericarps but not endosperms. Measurements of germination potential showed that embryos from seeds produced in cool conditions were less able to cope with high temperatures than those from warner conditions. These results are discussed in relation to the control of germination in lettuce.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 14
Claim · model-written summary
Cool mother-plant temperatures produced low seed yield.
- Taxon
- Lettuce
Lactuca sativat0 - Treatment
- Low production temperatures (20 °C day, 10 °C night)e0
- Outcome
- yielde0
- Direction
- lowe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Low production temperatures (20 °C day, 10 °C night) gave a low yield of large seeds”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Cool mother-plant temperatures produced large seeds.
- Taxon
- LettuceLactuca sativat0
- Treatment
- Low production temperatures (20 °C day, 10 °C night)e0
- Outcome
- large seedse0
- Direction
- largee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Low production temperatures (20 °C day, 10 °C night) gave a low yield of large seeds”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
High mother-plant temperatures produced higher seed yield.
- Taxon
- LettuceLactuca sativat0
- Treatment
- high temperatures (30 °C, 20 °C)e0
- Outcome
- yielde0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high temperatures (30 °C, 20 °C) gave a higher yield of much smaller seed”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
High mother-plant temperatures produced smaller seeds.
- Taxon
- LettuceLactuca sativat0
- Treatment
- high temperatures (30 °C, 20 °C)e0
- Outcome
- smaller seede0
- Direction
- smallere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high temperatures (30 °C, 20 °C) gave a higher yield of much smaller seed”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Medium mother-plant temperatures produced the highest seed yield.
- Taxon
- LettuceLactuca sativat0
- Treatment
- medium temperatures (25 °C, 15 °C)e0
- Outcome
- yielde0
- Direction
- higheste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the highest yield came from medium temperatures (25 °C, 15 °C), which gave medium-sized seed”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Medium mother-plant temperatures produced medium-sized seed.
- Taxon
- LettuceLactuca sativat0
- Treatment
- medium temperatures (25 °C, 15 °C)e0
- Outcome
- medium-sized seede0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the highest yield came from medium temperatures (25 °C, 15 °C), which gave medium-sized seed”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
High-temperature germination increased with seed age in all three environments of the first crop.
- Taxon
- LettuceLactuca sativat0
- Organ / stage
- seede0
- Outcome
- percentage germination at high temperaturese0
- Direction
- increasee0
- Qualifier
- all three production environments of the first crope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increase in percentage germination at high temperatures with increase in seed age, occurred in seed from all three production environments of the first crop”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
After-ripening occurred in seeds from the two warmer production environments of the second crop.
- Taxon
- LettuceLactuca sativat0
- Outcome
- After-ripeninge1
- Qualifier
- two higher production temperaturese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in that from the two higher production temperatures, but not the lowest, of the second crop”
e1“After-ripening, manifested as an increase in percentage germination at high temperatures”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
After-ripening did not occur in seeds from the lowest temperature of the second crop.
- Taxon
- LettuceLactuca sativat0
- Outcome
- After-ripeninge1
- Qualifier
- lowest, of the second crope0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but not the lowest, of the second crop”
e1“After-ripening, manifested as an increase in percentage germination at high temperatures”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Pericarp penetration force varied inversely with production temperature.
- Taxon
- LettuceLactuca sativat0
- Organ / stage
- pericarpse0
- Treatment
- temperature of the production environmente0
- Outcome
- pericarpse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“inverse relationship with temperature of the production environment for pericarps but not for endosperms”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Endosperm penetration force did not show the temperature relationship found for pericarps.
- Taxon
- LettuceLactuca sativat0
- Organ / stage
- endospermse0
- Treatment
- temperature of the production environmente0
- Outcome
- endospermse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“inverse relationship with temperature of the production environment for pericarps but not for endosperms”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Pericarp penetration force gradually declined during storage.
- Taxon
- LettuceLactuca sativat0
- Organ / stage
- pericarpse0
- Outcome
- pericarpse0
- Direction
- reductione0
- Setting
- storagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a gradual reduction during storage for pericarps but not endosperms”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Endosperm penetration force did not decline during storage.
- Taxon
- LettuceLactuca sativat0
- Organ / stage
- endospermse0
- Outcome
- endospermse0
- Setting
- storagee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a gradual reduction during storage for pericarps but not endosperms”
t0“Lettuce (Lactuca sativa)”
Claim · model-written summary
Embryos from cool production conditions coped less well with high temperatures than those from warmer conditions.
- Taxon
- LettuceLactuca sativat0
- Organ / stage
- embryose0
- Outcome
- able to cope with high temperaturese0
- Direction
- lesse0
- Comparator
- warner conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“embryos from seeds produced in cool conditions were less able to cope with high temperatures than those from warner conditions”
t0“Lettuce (Lactuca sativa)”
The same questions in other papers
heat · yield · Lactuca sativa (garden lettuce)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
2 papers more in this group
See all 6 papers →in vitro · yield · Lactuca sativa (garden lettuce)Positive and negative results
7 papers in the same direction as this paper · 3 in the opposite direction
- negative
- no effect
- no effect
7 papers more in this group
See all 11 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.