Abstract
Export studies were made on leaves of Pisum by monitoring the 14CO2-treated source leaf at its surface at frequent intervals. Radiocarbon levels of fresh leaf samples showed a good correlation with results from the more conventional methods of radiocarbon estimation which involve destructive analysis. The rate of export was highest in plants which had been defoliated, except for the source leaf 20 h or more before the start of the export study. Removal of the shoot apex reduced export and progressive reduction in sink capacity was associated with decreased export rates, particularly over short time periods. Export rates were similar in defoliated and non-defoliated plants where the shoot apex and the roots had been excised. This suggested that a decrease in the source resulted in higher export rates from the remaining source only when active sinks were present; this in turn suggests that, at least under these conditions, active removal of photosynthate is more important in controlling export than the photosynthate build-up in the leaf itself. The non-destructive technique enabled comparisons to be made between export curves for individual plants. It was found that in experiments replicated in time, the same relationship between treatments was present on different days and the shape of the export curves was similar but the absolute values for exported radiocarbon sometimes varied considerably.
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Claims 11
Claim · model-written summary
Radiocarbon levels of fresh leaf samples correlated well with conventional destructive radiocarbon estimation.
- Taxon
- Pisum sativum
Lathyrus oleraceust0 - Organ / stage
- fresh leaf samplese1
- Outcome
- Radiocarbon levelse1
- Qualifier
- good correlatione1
- Comparator
- conventional methods of radiocarbon estimatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e1“Radiocarbon levels of fresh leaf samples showed a good correlation with results from the more conventional methods of radiocarbon estimation which involve destructive analysis”
Claim · model-written summary
The rate of export was highest in defoliated plants, except when the source leaf had been defoliated 20 h or more before the export study.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- defoliatede2
- Outcome
- rate of exporte2
- Direction
- higheste2
- Qualifier
- except for the source leaf 20 h or more before the start of the export studye2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e2“The rate of export was highest in plants which had been defoliated, except for the source leaf 20 h or more before the start of the export study”
Claim · model-written summary
Removal of the shoot apex reduced assimilate export.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- Removal of the shoot apexe3
- Outcome
- exporte3
- Direction
- reducede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e3“Removal of the shoot apex reduced export”
Claim · model-written summary
Progressive reduction in sink capacity was associated with decreased export rates, particularly over short time periods.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- progressive reduction in sink capacitye4
- Outcome
- export ratese4
- Direction
- decreasede4
- Qualifier
- particularly over short time periodse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e4“progressive reduction in sink capacity was associated with decreased export rates, particularly over short time periods”
Claim · model-written summary
Export rates were similar in defoliated and non-defoliated plants when the shoot apex and roots had been excised.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- the shoot apex and the roots had been excisede5
- Outcome
- Export ratese5
- Direction
- similare5
- Comparator
- non-defoliated plantse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e5“Export rates were similar in defoliated and non-defoliated plants where the shoot apex and the roots had been excised”
Claim · model-written summary
A decrease in the source resulted in higher export rates from the remaining source, but only when active sinks were present.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- a decrease in the sourcee6
- Outcome
- export rates from the remaining sourcee6
- Direction
- highere6
- Qualifier
- only when active sinks were presente6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e6“a decrease in the source resulted in higher export rates from the remaining source only when active sinks were present”
Claim · model-written summary
Active removal of photosynthate, rather than photosynthate build-up in the leaf, is more important in controlling export.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Compound
- photosynthatee7
- Outcome
- controlling exporte7
- Qualifier
- more important in controlling export than the photosynthate build-up in the leafe7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e7“active removal of photosynthate is more important in controlling export than the photosynthate build-up in the leaf itself”
Claim · model-written summary
The non-destructive technique allowed comparisons between export curves of individual plants, unlike the conventional destructive methods.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- export curves for individual plantse1
- Comparator
- conventional methods of radiocarbon estimatione2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e1“The non-destructive technique enabled comparisons to be made between export curves for individual plants”
e2“more conventional methods of radiocarbon estimation which involve destructive analysis”
Claim · model-written summary
In experiments replicated in time, the same relationship between treatments was present on different days.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- relationship between treatmentse1
- Qualifier
- in experiments replicated in timee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e1“in experiments replicated in time, the same relationship between treatments was present on different days”
Claim · model-written summary
The shape of the export curves was similar between days.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- shape of the export curvese1
- Direction
- similare1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e1“the shape of the export curves was similar”
Claim · model-written summary
Absolute values of exported radiocarbon sometimes varied considerably between experiments.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- absolute values for exported radiocarbone1
- Qualifier
- sometimes varied considerablye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Leaves inPisum sativum”
e1“the absolute values for exported radiocarbon sometimes varied considerably”