Abstract
Effects of heat-shock treatment following irradiation at an extremely low temperature were examined on radiosensitivity, mutation frequency and response to selection of quantitative traits. Seeds of rice variety Gimbozu were irradiated with various doses of γ- or X-rays at about -70°C, followed by immediate soaking into the water of which temperature was adjusted to 0, 30 and 60°C, for 2 sec. to 6 min. Striking decrease of radiation-induced injuries was observed, as measured in survival rate, seedling height and seed fertility in the M1 generation. Within the ranges of temperature and time for shock in this experiment, the radio-protection effect increased as temperature and time increased, LD50 in 60°C-2min. -shock being about 2. 5 times as high as that in irradiation at room temperature. These effects of heat-shock treatment may be resulted Lrom the restricted mobility of free radicals due to extremely low temperature during irradiation, the restricted recombination among long-lived radicals and the accelerated metabolic activity at raised temperature immediately after irradiation at low temperature. Higher dose irradiation followed by the heat-shock treatment brought about a marked increase of the obtainable highest mutation frequency in three quantitative characters, heading date, culm length and panicle length, and also in qualitative characters except seed fertility : the frequencies of mutants per R unit in all these characters did not differ from those in usual irradiation. In contrast with these results, the frequency of mutants in seed fertility was clearly decreased. Both genetic gain and heritability in heading date and culm length were also proved to be significantly increased by the heat-shock treatment. From these results, it may be concluded that the heat-shock treatment is an effective method for enhancing the relative frequency of genic mutations to that of gross chromosomal aberrations.
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 9
Claim · model-written summary
Heat-shock treatment following low-temperature irradiation strikingly decreased radiation-induced injuries (survival rate, seedling height, seed fertility) in the M1 generation of rice.
- Taxon
- Rice
Oryza sativat0 - Treatment
- heat-shock treatment following irradiatione1
- Outcome
- radiation-induced injuriese0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Striking decrease of radiation-induced injuries was observed, as measured in survival rate, seedling height and seed fertility in the M1 generation”
e1“Effects of heat-shock treatment following irradiation at an extremely low temperature”
t0“Rice”
Claim · model-written summary
The radio-protection effect of the heat shock increased as shock temperature and time increased in rice.
- Taxon
- RiceOryza sativat0
- Treatment
- temperature and time for shocke2
- Outcome
- radio-protection effecte2
- Direction
- increasede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Within the ranges of temperature and time for shock in this experiment, the radio-protection effect increased as temperature and time increased”
t0“Rice”
Claim · model-written summary
LD50 with a 60C 2-min heat shock was about 2.5 times as high as with irradiation at room temperature in rice.
- Taxon
- RiceOryza sativat0
- Treatment
- 60°C-2min. -shocke3
- Outcome
- LD50e3
- Direction
- as high ase3
- Value
- about 2. 5 timese3
- Comparator
- irradiation at room temperaturee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“LD50 in 60°C-2min. -shock being about 2. 5 times as high as that in irradiation at room temperature”
t0“Rice”
Claim · model-written summary
Higher-dose irradiation followed by heat shock markedly increased the highest obtainable mutation frequency in heading date, culm length and panicle length in rice.
- Taxon
- RiceOryza sativat0
- Treatment
- Higher dose irradiation followed by the heat-shock treatmente4
- Outcome
- obtainable highest mutation frequencye4
- Direction
- marked increasee4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Higher dose irradiation followed by the heat-shock treatment brought about a marked increase of the obtainable highest mutation frequency in three quantitative characters, heading date, culm length and panicle length”
t0“Rice”
Claim · model-written summary
Frequencies of mutants per R unit in these characters with heat shock did not differ from those in usual irradiation.
- Taxon
- RiceOryza sativat0
- Treatment
- the heat-shock treatmente4
- Outcome
- frequencies of mutants per R unite5
- Direction
- did not differe5
- Comparator
- usual irradiatione5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Higher dose irradiation followed by the heat-shock treatment brought about a marked increase of the obtainable highest mutation frequency in three quantitative characters, heading date, culm length and panicle length”
e5“the frequencies of mutants per R unit in all these characters did not differ from those in usual irradiation”
t0“Rice”
Claim · model-written summary
The frequency of mutants in seed fertility was clearly decreased by heat shock after irradiation in rice.
- Taxon
- RiceOryza sativat0
- Treatment
- the heat-shock treatmente4
- Outcome
- frequency of mutants in seed fertilitye6
- Direction
- decreasede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Higher dose irradiation followed by the heat-shock treatment brought about a marked increase of the obtainable highest mutation frequency in three quantitative characters, heading date, culm length and panicle length”
e6“the frequency of mutants in seed fertility was clearly decreased”
t0“Rice”
Claim · model-written summary
Genetic gain and heritability in heading date and culm length were significantly increased by heat-shock treatment in rice.
- Taxon
- RiceOryza sativat0
- Treatment
- heat-shock treatmente7
- Outcome
- genetic gain and heritabilitye7
- Direction
- increasede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Both genetic gain and heritability in heading date and culm length were also proved to be significantly increased by the heat-shock treatment”
t0“Rice”
Claim · model-written summary
The authors conclude that heat-shock treatment is an effective method for enhancing the relative frequency of genic mutations versus gross chromosomal aberrations in rice.
- Taxon
- RiceOryza sativat0
- Outcome
- effective method for enhancing the relative frequency of genic mutationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the heat-shock treatment is an effective method for enhancing the relative frequency of genic mutations to that of gross chromosomal aberrations”
t0“Rice”
Claim · model-written summary
The authors suggest the protective effects of heat shock may result from restricted mobility of free radicals at extremely low temperature during irradiation.
- Taxon
- RiceOryza sativat0
- Outcome
- effects of heat-shock treatmente1
- Qualifier
- restricted mobility of free radicalse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“These effects of heat-shock treatment may be resulted Lrom the restricted mobility of free radicals due to extremely low temperature during irradiation”
t0“Rice”
The same questions in other papers
heat · crop injury · Oryza sativa (rice)Positive and negative results
1 in the opposite direction
- negative
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.