Paper · 1994 · Australian Journal of Plant Physiology

Photosynthetic and Growth Responses of Variegated Ornamental Species to Elevated CO2

WJS Downton; WJR Grant

16
claims
25
verbatim quotes
27
citations
3
research areas
—
Not open access

Abstract

Variegated and completely green cultivars of oleander (Nerium oleander L.) and willow myrtle (Agonis flexuosa (Willd.) Sweet) were grown in controlled environment cabinets for 3 and 5 months, respectively, under either ambient levels of CO2 or with supplementary CO2 to a partial pressure of 800 μbar. Photosynthesis of entirely green leaves and the green portions of variegated leaves on both species was greatly stimulated by high CO2 and there was no evidence of downward adjustment (acclimation) of photosynthetic rates to high CO2 during the experiment. Dark respiration rates of these leaves were lowered by high CO2. The yellow portions of willow myrtle leaves showed a low level of photosynthetic activity which was stimulated by high CO2; however, dark respiration rates showed little response to elevated CO2. Green and yellow areas on variegated leaves of willow myrtle had much lower dark respiration rates than completely green leaves, but this difference was not evident for oleander. Yellow portions of oleander leaves showed little evidence of photosynthetic capacity. This was also confirmed by a low photochemical efficiency as determined by chlorophyll fluorescence. A major effect of variegation was to slow overall plant growth compared with completely green plants. The respective 3-fold and 6-7-fold differences in biomass between fully green and variegated cultivars of oleander and willow myrtle was closely related to estimated net carbon gain per day by the plant canopy. Variegation for both species averaged close to 50:50, green:yellow areas. Variegated plants developed about twice the leaf area ratio and specific leaf area compared with their completely green counterparts. The relative growth response to high CO2 was significantly greater for the variegated plants compared to the completely green plants.

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Claims 16

Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Photosynthesis of entirely green leaves of oleander was greatly stimulated by high CO2 with no evidence of acclimation

Taxon
oleandere1
Organ / stage
entirely green leavese2
Treatment
high CO2e2
Outcome
Photosynthesise2
Direction
greatly stimulatede2
Qualifier
no evidence of downward adjustment (acclimation)e2
Comparator
ambient levels of CO2e1
Setting
controlled environment cabinetse1

Verbatim

e1

“Variegated and completely green cultivars of oleander (Nerium oleander L.) and willow myrtle (Agonis flexuosa (Willd.) Sweet) were grown in controlled environment cabinets for 3 and 5 months, respectively, under either ambient levels of CO2 or with supplementary CO2 to a partial pressure of 800 μbar”

✓ located verbatim in the source · abstract, characters 0–300 · show in text ↑
e2

“Photosynthesis of entirely green leaves and the green portions of variegated leaves on both species was greatly stimulated by high CO2 and there was no evidence of downward adjustment (acclimation) of photosynthetic rates to high CO2 during the experiment”

✓ located verbatim in the source · abstract, characters 302–557 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Photosynthesis of entirely green leaves of willow myrtle was greatly stimulated by high CO2 with no evidence of acclimation

Taxon
willow myrtlee1
Organ / stage
entirely green leavese2
Treatment
high CO2e2
Outcome
Photosynthesise2
Direction
greatly stimulatede2
Qualifier
no evidence of downward adjustment (acclimation)e2
Comparator
ambient levels of CO2e1
Setting
controlled environment cabinetse1

Verbatim

e1

“Variegated and completely green cultivars of oleander (Nerium oleander L.) and willow myrtle (Agonis flexuosa (Willd.) Sweet) were grown in controlled environment cabinets for 3 and 5 months, respectively, under either ambient levels of CO2 or with supplementary CO2 to a partial pressure of 800 μbar”

✓ located verbatim in the source · abstract, characters 0–300 · show in text ↑
e2

“Photosynthesis of entirely green leaves and the green portions of variegated leaves on both species was greatly stimulated by high CO2 and there was no evidence of downward adjustment (acclimation) of photosynthetic rates to high CO2 during the experiment”

✓ located verbatim in the source · abstract, characters 302–557 · show in text ↑
Intervention effectobservedoriginal resultmeasured

Claim · model-written summary

Dark respiration rates of green oleander leaves were lowered by high CO2

Taxon
oleandere1
Treatment
high CO2e3
Outcome
Dark respiration ratese3
Direction
lowerede3
Comparator
ambient levels of CO2e1

Verbatim

e1

“Variegated and completely green cultivars of oleander (Nerium oleander L.) and willow myrtle (Agonis flexuosa (Willd.) Sweet) were grown in controlled environment cabinets for 3 and 5 months, respectively, under either ambient levels of CO2 or with supplementary CO2 to a partial pressure of 800 μbar”

✓ located verbatim in the source · abstract, characters 0–300 · show in text ↑
e3

“Dark respiration rates of these leaves were lowered by high CO2”

✓ located verbatim in the source · abstract, characters 559–622 · show in text ↑
Intervention effectobservedoriginal resultmeasured

Claim · model-written summary

Dark respiration rates of green willow myrtle leaves were lowered by high CO2

Taxon
willow myrtlee1
Treatment
high CO2e3
Outcome
Dark respiration ratese3
Direction
lowerede3
Comparator
ambient levels of CO2e1

Verbatim

e1

“Variegated and completely green cultivars of oleander (Nerium oleander L.) and willow myrtle (Agonis flexuosa (Willd.) Sweet) were grown in controlled environment cabinets for 3 and 5 months, respectively, under either ambient levels of CO2 or with supplementary CO2 to a partial pressure of 800 μbar”

✓ located verbatim in the source · abstract, characters 0–300 · show in text ↑
e3

“Dark respiration rates of these leaves were lowered by high CO2”

✓ located verbatim in the source · abstract, characters 559–622 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Yellow portions of willow myrtle leaves had low photosynthetic activity that was stimulated by high CO2

Taxon
willow myrtlee1
Organ / stage
yellow portions of willow myrtle leavese4
Treatment
high CO2e4
Outcome
photosynthetic activitye4
Direction
stimulatede4
Qualifier
a low levele4
Comparator
ambient levels of CO2e1

Verbatim

e1

“Variegated and completely green cultivars of oleander (Nerium oleander L.) and willow myrtle (Agonis flexuosa (Willd.) Sweet) were grown in controlled environment cabinets for 3 and 5 months, respectively, under either ambient levels of CO2 or with supplementary CO2 to a partial pressure of 800 μbar”

✓ located verbatim in the source · abstract, characters 0–300 · show in text ↑
e4

“The yellow portions of willow myrtle leaves showed a low level of photosynthetic activity which was stimulated by high CO2; however, dark respiration rates showed little response to elevated CO2”

✓ located verbatim in the source · abstract, characters 624–818 · show in text ↑
Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

Dark respiration of yellow willow myrtle leaf portions showed little response to elevated CO2

Taxon
willow myrtlee1
Organ / stage
yellow portions of willow myrtle leavese4
Treatment
elevated CO2e4
Outcome
dark respiration ratese4
Direction
little responsee4
Comparator
ambient levels of CO2e1

Verbatim

e1

“Variegated and completely green cultivars of oleander (Nerium oleander L.) and willow myrtle (Agonis flexuosa (Willd.) Sweet) were grown in controlled environment cabinets for 3 and 5 months, respectively, under either ambient levels of CO2 or with supplementary CO2 to a partial pressure of 800 μbar”

✓ located verbatim in the source · abstract, characters 0–300 · show in text ↑
e4

“The yellow portions of willow myrtle leaves showed a low level of photosynthetic activity which was stimulated by high CO2; however, dark respiration rates showed little response to elevated CO2”

✓ located verbatim in the source · abstract, characters 624–818 · show in text ↑
Intervention effectobservedoriginal resultmeasured

Claim · model-written summary

Green and yellow areas on variegated willow myrtle leaves had much lower dark respiration rates than completely green leaves

Taxon
willow myrtlee5
Organ / stage
Green and yellow areas on variegated leavese5
Treatment
variegated leavese5
Outcome
dark respiration ratese5
Direction
much lowere5
Comparator
completely green leavese5

Verbatim

e5

“Green and yellow areas on variegated leaves of willow myrtle had much lower dark respiration rates than completely green leaves, but this difference was not evident for oleander”

✓ located verbatim in the source · abstract, characters 820–997 · show in text ↑
Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

The dark respiration difference between variegated and green oleander leaves was not evident

Taxon
oleandere5
Treatment
variegated leavese5
Outcome
dark respiration ratese5
Direction
not evidente5
Comparator
completely green leavese5

Verbatim

e5

“Green and yellow areas on variegated leaves of willow myrtle had much lower dark respiration rates than completely green leaves, but this difference was not evident for oleander”

✓ located verbatim in the source · abstract, characters 820–997 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Yellow portions of oleander leaves showed little evidence of photosynthetic capacity

Taxon
oleandere6
Organ / stage
Yellow portions of oleander leavese6
Outcome
photosynthetic capacitye6
Direction
little evidencee6

Verbatim

e6

“Yellow portions of oleander leaves showed little evidence of photosynthetic capacity”

✓ located verbatim in the source · abstract, characters 999–1083 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Yellow portions of oleander leaves had low photochemical efficiency as determined by chlorophyll fluorescence

Taxon
oleandere6
Outcome
photochemical efficiencye7
Direction
lowe7
Qualifier
as determined by chlorophyll fluorescencee7

Verbatim

e6

“Yellow portions of oleander leaves showed little evidence of photosynthetic capacity”

✓ located verbatim in the source · abstract, characters 999–1083 · show in text ↑
e7

“This was also confirmed by a low photochemical efficiency as determined by chlorophyll fluorescence”

✓ located verbatim in the source · abstract, characters 1085–1184 · show in text ↑
Intervention effectobservedoriginal resultnegativemeasured

Claim · model-written summary

Variegation slowed overall plant growth compared with completely green plants

Taxon
Variegated Ornamental Speciest0
Treatment
variegatione1
Outcome
overall plant growthe1
Direction
slowe1
Comparator
completely green plantse1

Verbatim

t0

“Photosynthetic and Growth Responses of Variegated Ornamental Species to Elevated CO2”

✓ located verbatim in the source · title, characters 0–84 · show in text ↑
e1

“A major effect of variegation was to slow overall plant growth compared with completely green plants”

✓ located verbatim in the source · abstract, characters 1186–1286 · show in text ↑
Associationobservedoriginal resultmeasured

Claim · model-written summary

The 3-fold biomass difference between fully green and variegated oleander was closely related to estimated net carbon gain per day by the canopy

Taxon
oleandere1
Outcome
biomasse1
Value
3-folde1
Qualifier
closely related to estimated net carbon gain per daye1
Comparator
fully greene1

Not reportedDirection

Verbatim

e1

“The respective 3-fold and 6-7-fold differences in biomass between fully green and variegated cultivars of oleander and willow myrtle was closely related to estimated net carbon gain per day by the plant canopy”

✓ located verbatim in the source · abstract, characters 1288–1497 · show in text ↑
Associationobservedoriginal resultmeasured

Claim · model-written summary

The 6-7-fold biomass difference between fully green and variegated willow myrtle was closely related to estimated net carbon gain per day by the canopy

Taxon
willow myrtlee1
Outcome
biomasse1
Value
6-7-folde1
Qualifier
closely related to estimated net carbon gain per daye1
Comparator
fully greene1

Not reportedDirection

Verbatim

e1

“The respective 3-fold and 6-7-fold differences in biomass between fully green and variegated cultivars of oleander and willow myrtle was closely related to estimated net carbon gain per day by the plant canopy”

✓ located verbatim in the source · abstract, characters 1288–1497 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Variegated plants developed about twice the leaf area ratio and specific leaf area of completely green counterparts

Taxon
Variegated plantse1
Outcome
leaf area ratio and specific leaf areae1
Value
about twicee1
Comparator
completely green counterpartse1

Verbatim

e1

“Variegated plants developed about twice the leaf area ratio and specific leaf area compared with their completely green counterparts”

✓ located verbatim in the source · abstract, characters 1573–1705 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

The relative growth response to high CO2 was significantly greater in variegated plants than in completely green plants

Taxon
variegated plantse1
Treatment
high CO2e1
Outcome
relative growth responsee1
Direction
significantly greatere1
Comparator
completely green plantse1

Verbatim

e1

“The relative growth response to high CO2 was significantly greater for the variegated plants compared to the completely green plants”

✓ located verbatim in the source · abstract, characters 1707–1839 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Variegation averaged close to 50:50 green to yellow areas in both species

Taxon
Variegated Ornamental Speciest0
Outcome
green:yellow arease1
Value
50:50e1

Verbatim

t0

“Photosynthetic and Growth Responses of Variegated Ornamental Species to Elevated CO2”

✓ located verbatim in the source · title, characters 0–84 · show in text ↑
e1

“Variegation for both species averaged close to 50:50, green:yellow areas”

✓ located verbatim in the source · abstract, characters 1499–1571 · show in text ↑

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