Abstract
In some cereal simulation models, canopy leaf area development is calculated using relationships that summarize how leaf size changes with position. The nature and extent to which various environmental factors interact with ontogenetic variations in leaf size, however, is not clearly understood. This study was undertaken, therefore, to evaluate how temperature, photoperiod and nitrogen impact on leaf to leaf relationships in wheat grown under field conditions. Four contrasting genotypes of wheat comprising two spring and two unvernalized winter types were sown on five dates, supplied with one of two levels of nitrogen (150 kg N ha −1 and 0 kg N ha −1 ), and grown under natural and extended photoperiod conditions. For the spring wheats, individual mature leaf area increased along with leaf number up to leaf 5 (a stage that coincided with rapid stem elongation) but varied for subsequent leaves in a manner that was dependent on genotype and environment.In the period prior to the expansion of the fifth leaf, neither nitrogen nor photoperiod significantly influenced the pattern of change in leaf size. Thereafter, leaves under low nitrogen and extended photoperiod progressively became smaller, an effect that was due primarily to changes in length rather than in width. For the winter genotypes, which did not reach the stage of rapid stem elongation, mature leaf dimensions increased along with leaf number during the whole period of study and were not markedly affected by photoperiod but, after leaf 5, were smaller for the low nitrogen level. For all genotypes, the size of the first leaf and the coefficients derived by regressing the area of successive leaves on the area of the previous leaf during the vegetative phase varied among sowing dates due partly to the temperature environment under which the leaves at each node developed. The results, however, indicated that the potential leaf size at any of the lowermost leaf positions can be obtained by using a logarithmic function that relates the potential size of one leaf to its predecessor. Such relationship can be used to calculate actual leaf size if account is taken of environmental and assimilate supply factors that operate during leaf expansion. Key words: Wheat, sowing date, leaf area, temperature, photoperiod
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Claims 11
Claim · model-written summary
Spring wheat mature leaf area increased through leaf 5, then varied with genotype and environment.
TriticumOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For the spring wheats, individual mature leaf area increased along with leaf number up to leaf 5 (a stage that coincided with rapid stem elongation) but varied for subsequent leaves in a manner that was dependent on genotype and environment.”
Claim · model-written summary
Before fifth-leaf expansion, nitrogen and photoperiod did not significantly influence leaf-size patterns.
- Taxon
- wheat
Triticum aestivumt0 - Organ / stage
- fifth leafe0
- Treatment
- nitrogen nor photoperiode0
- Outcome
- pattern of change in leaf sizee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the period prior to the expansion of the fifth leaf, neither nitrogen nor photoperiod significantly influenced the pattern of change in leaf size.”
t0“wheat”
Claim · model-written summary
Later leaves became progressively smaller under low nitrogen, mainly through reduced length.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- low nitrogene0
- Outcome
- leavese0
- Direction
- became smallere0
- Qualifier
- changes in length rather than in widthe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thereafter, leaves under low nitrogen and extended photoperiod progressively became smaller, an effect that was due primarily to changes in length rather than in width.”
t0“wheat”
Claim · model-written summary
Later leaves became progressively smaller under extended photoperiod, mainly through length change.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- extended photoperiode0
- Outcome
- leavese0
- Direction
- became smallere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thereafter, leaves under low nitrogen and extended photoperiod progressively became smaller, an effect that was due primarily to changes in length rather than in width.”
t0“wheat”
Claim · model-written summary
Winter genotype mature leaf dimensions increased with leaf number throughout the study.
- Taxon
- wheatTriticum aestivumt0
- Material
- winter genotypese0
- Outcome
- mature leaf dimensionse0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For the winter genotypes, which did not reach the stage of rapid stem elongation, mature leaf dimensions increased along with leaf number during the whole period of study and were not markedly affected by photoperiod but, after leaf 5, were smaller for the low nitrogen level.”
t0“wheat”
Claim · model-written summary
Winter genotype mature leaf dimensions were not markedly affected by photoperiod.
- Taxon
- wheatTriticum aestivumt0
- Material
- winter genotypest1
- Treatment
- photoperiode0
- Outcome
- mature leaf dimensionse0
- Direction
- not markedly affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“mature leaf dimensions increased along with leaf number during the whole period of study and were not markedly affected by photoperiod”
t0“wheat”
t1“winter genotypes”
Claim · model-written summary
After leaf 5, winter genotype leaves were smaller at low nitrogen.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- low nitrogen levele0
- Outcome
- leaf 5e0
- Direction
- smallere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“after leaf 5, were smaller for the low nitrogen level”
t0“wheat”
Claim · model-written summary
First-leaf size varied among sowing dates, partly owing to temperature.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- sowing datese0
- Outcome
- size of the first leafe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For all genotypes, the size of the first leaf and the coefficients derived by regressing the area of successive leaves on the area of the previous leaf during the vegetative phase varied among sowing dates due partly to the temperature environment under which the leaves at each node developed.”
t0“wheat”
Claim · model-written summary
Successive-leaf regression coefficients varied among sowing dates, partly owing to temperature.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- sowing datese0
- Outcome
- coefficients derived by regressing the area of successive leaves on the area of the previous leafe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For all genotypes, the size of the first leaf and the coefficients derived by regressing the area of successive leaves on the area of the previous leaf during the vegetative phase varied among sowing dates due partly to the temperature environment under which the leaves at each node developed.”
t0“wheat”
Claim · model-written summary
A logarithmic predecessor-leaf function estimated potential size at lowermost leaf positions.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- potential leaf sizee0
- Comparator
- its predecessore0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the potential leaf size at any of the lowermost leaf positions can be obtained by using a logarithmic function that relates the potential size of one leaf to its predecessor.”
t0“wheat”
Claim · model-written summary
That relationship can calculate actual leaf size when environmental and assimilate supply factors are included.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- actual leaf sizee0
- Comparator
- environmental and assimilate supply factorse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Such relationship can be used to calculate actual leaf size if account is taken of environmental and assimilate supply factors that operate during leaf expansion.”
t0“wheat”
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See all 551 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.