Abstract
Characteristics of photosynthetic CO2 exchange and 77K chlorophyll fluorescence in attached and detached leaves of rice were used to examine differences between five varieties exposed to a combination of bright light and low temperature. Preliminary studies established that attached leaves of varieties did not differ in the light dependence of photosynthesis at CO2 saturation or fluorescence properties when grown in full sunlight and measured under comparable conditions. All varieties showed a depression in maximum photosynthetic rate, but not in quantum yield or chlorophyll fluorescence when examined in the late afternoon after a period of active photosynthesis in air at 25°C. Attached leaves of all varieties showed depression of the maximum rate of photosynthesis and of quantum yield as well as an increase in Fo and a decrease in Fv/Fm of chlorophyll fluorescence at 77K following horizontal exposure to bright light in air at 25°. Similar results were obtained with detached leaves exposed to bright light while floating on water at 25°C. The rate of photosynthetic CO2 fixation in air as a function of temperature was examined in attached leaves of two representative varieties, Japonica-like cv. Hungarian- 1, and Indica-derived cv. IR-8. The former was capable to rates of photosynthesis at 10°C which were twice those of the latter, although the rates at 25°C were similar in both varieties. When detached leaves of five varieties of rice were floated on water at 10°C while exposed to 700 µmol photons m-2 s-1 of white light, consistent differences in the response of quantum yield, light and CO2 saturated O2 evolion and 77K fluorescence properties were found. Exposure to bright light at low temperature exaggerated the effects of bright light on these parameters, and larger effects were found in the Indica-derived varieties than in Japonica-like cv. Hungarian-1. These treatments at 10°C did not influence the extent of increase in Fo, but led to a greater decline in Fv/Fm of 77K chlorophyll fluorescence compared with treatments at 25°C. Varieties in which there was a larger decline in Fv/Fm showed slower recovery of variable fluorescence in the dark at 25°C, and especially at 10°C. These responses to in vitro treatments seem capable of distinguishing varieties such as cvv. Hungarian-1 and Er Bai Ai, which are believed to be more chilling tolerant by other criteria, from chilling sensitive varieties such as Gui Chao-2 and IR-8. Even though there is potential for application of these methods in screening programs, there is little evidence that the lesions in primary photosynthetic processes indicated by these methods are significant determinants of photosynthesis under field conditions.
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Claims 13
Claim · model-written summary
All rice varieties showed a depression in maximum photosynthetic rate when examined in the late afternoon after active photosynthesis in air at 25 °C.
- Taxon
- rice
Oryza sativae0 - Treatment
- after a period of active photosynthesis in air at 25°Ce1
- Outcome
- maximum photosynthetic ratee1
- Direction
- depressione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e1“All varieties showed a depression in maximum photosynthetic rate, but not in quantum yield or chlorophyll fluorescence when examined in the late afternoon after a period of active photosynthesis in air at 25°C”
Claim · model-written summary
Quantum yield and chlorophyll fluorescence were not depressed in the late afternoon after active photosynthesis in air at 25 °C.
- Taxon
- riceOryza sativae0
- Treatment
- after a period of active photosynthesis in air at 25°Ce1
- Outcome
- quantum yield or chlorophyll fluorescencee1
- Direction
- no_changeinferrede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e1“All varieties showed a depression in maximum photosynthetic rate, but not in quantum yield or chlorophyll fluorescence when examined in the late afternoon after a period of active photosynthesis in air at 25°C”
Claim · model-written summary
Attached leaves of all varieties showed reduced maximum photosynthetic rate and quantum yield after horizontal exposure to bright light in air at 25 °C.
- Taxon
- riceOryza sativae0
- Treatment
- horizontal exposure to bright light in air at 25°e2
- Outcome
- maximum rate of photosynthesis and of quantum yielde2
- Direction
- depressione2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e2“Attached leaves of all varieties showed depression of the maximum rate of photosynthesis and of quantum yield as well as an increase in Fo and a decrease in Fv/Fm of chlorophyll fluorescence at 77K following horizontal exposure to bright light in air at 25°.”
Claim · model-written summary
Fo of 77K chlorophyll fluorescence increased in attached leaves of all varieties after bright-light exposure.
- Taxon
- riceOryza sativae0
- Treatment
- horizontal exposure to bright light in air at 25°e2
- Outcome
- Foe2
- Direction
- increasee2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e2“Attached leaves of all varieties showed depression of the maximum rate of photosynthesis and of quantum yield as well as an increase in Fo and a decrease in Fv/Fm of chlorophyll fluorescence at 77K following horizontal exposure to bright light in air at 25°.”
Claim · model-written summary
Fv/Fm of 77K chlorophyll fluorescence decreased in attached leaves of all varieties after bright-light exposure.
- Taxon
- riceOryza sativae0
- Treatment
- horizontal exposure to bright light in air at 25°e2
- Outcome
- Fv/Fme2
- Direction
- decreasee2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e2“Attached leaves of all varieties showed depression of the maximum rate of photosynthesis and of quantum yield as well as an increase in Fo and a decrease in Fv/Fm of chlorophyll fluorescence at 77K following horizontal exposure to bright light in air at 25°.”
Claim · model-written summary
Bright light at 10 °C caused a greater decline in Fv/Fm of 77K chlorophyll fluorescence than treatments at 25 °C, without changing the extent of the Fo increase.
- Taxon
- riceOryza sativae0
- Treatment
- treatments at 10°Ce3
- Outcome
- Fv/Fm of 77K chlorophyll fluorescencee3
- Direction
- greater declinee3
- Comparator
- treatments at 25°Ce3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e3“These treatments at 10°C did not influence the extent of increase in Fo, but led to a greater decline in Fv/Fm of 77K chlorophyll fluorescence compared with treatments at 25°C.”
Claim · model-written summary
Larger effects of bright light at low temperature were found in Indica-derived rice varieties than in Japonica-like cv. Hungarian-1.
- Taxon
- riceOryza sativae0
- Material
- Indica-derived varietiese4
- Treatment
- Exposure to bright light at low temperaturee4
- Outcome
- effects of bright light on these parameterse4
- Direction
- larger effectse4
- Comparator
- Japonica-like cv. Hungarian-1e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e4“Exposure to bright light at low temperature exaggerated the effects of bright light on these parameters, and larger effects were found in the Indica-derived varieties than in Japonica-like cv. Hungarian-1.”
Claim · model-written summary
Varieties with a larger decline in Fv/Fm showed slower recovery of variable fluorescence in the dark at 25 °C, and especially at 10 °C.
- Taxon
- riceOryza sativae0
- Outcome
- recovery of variable fluorescence in the darke5
- Direction
- slowere5
- Setting
- in the dark at 25°Ce5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e5“Varieties in which there was a larger decline in Fv/Fm showed slower recovery of variable fluorescence in the dark at 25°C, and especially at 10°C.”
Claim · model-written summary
The in vitro responses seem capable of distinguishing chilling-tolerant varieties (cvv. Hungarian-1 and Er Bai Ai) from chilling-sensitive varieties (Gui Chao-2 and IR-8).
- Taxon
- riceOryza sativae0
- Outcome
- distinguishing varietiese6
- Comparator
- chilling sensitive varieties such as Gui Chao-2 and IR-8e6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e6“These responses to in vitro treatments seem capable of distinguishing varieties such as cvv. Hungarian-1 and Er Bai Ai, which are believed to be more chilling tolerant by other criteria, from chilling sensitive varieties such as Gui Chao-2 and IR-8.”
Claim · model-written summary
Rates of photosynthesis at 10 °C were twice as high in Japonica-like cv. Hungarian-1 as in Indica-derived cv. IR-8.
- Taxon
- riceOryza sativae0
- Material
- Japonica-like cv. Hungarian- 1e7
- Treatment
- at 10°Ce6
- Outcome
- rates of photosynthesise6
- Direction
- higherinferrede6
- Comparator
- Indica-derived cv. IR-8e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e7“Japonica-like cv. Hungarian- 1, and Indica-derived cv. IR-8”
e6“The former was capable to rates of photosynthesis at 10°C which were twice those of the latter”
Claim · model-written summary
Rates of photosynthesis at 25 °C were similar in the two varieties.
- Taxon
- riceOryza sativae0
- Treatment
- at 25°Ce6
- Outcome
- the rates at 25°Ce6
- Direction
- no_changeinferrede6
- Comparator
- Indica-derived cv. IR-8e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e7“Japonica-like cv. Hungarian- 1, and Indica-derived cv. IR-8”
e6“although the rates at 25°C were similar in both varieties”
Claim · model-written summary
Consistent differences among the five varieties were found in the response of quantum yield, light- and CO2-saturated O2 evolution and 77K fluorescence properties to detached-leaf treatment at 10 °C.
- Taxon
- riceOryza sativae0
- Outcome
- the response of quantum yield, light and CO2 saturated O2 evolion and 77K fluorescence propertiese6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e6“consistent differences in the response of quantum yield, light and CO2 saturated O2 evolion and 77K fluorescence properties were found”
Claim · model-written summary
Attached leaves of the varieties did not differ in the light dependence of photosynthesis at CO2 saturation when grown in full sunlight.
- Taxon
- riceOryza sativae0
- Outcome
- light dependence of photosynthesis at CO2 saturatione7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attached and detached leaves of rice”
e7“attached leaves of varieties did not differ in the light dependence of photosynthesis at CO2 saturation or fluorescence properties when grown in full sunlight”
The same questions in other papers
light · physiology: photosynthesis · Oryza sativa (rice)Results differ
22 papers in the same direction as this paper · 24 in the opposite direction
- negative
- negative
- positive
43 papers more in this group
See all 47 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.