Abstract
Growth and development of the shoot apex in seedlings of three barley cultivars was examined in two daylengths (8, 16 h) and at two mineral nutrient levels (× 1, × 0.1). Production of primordia was greater at the higher nutrient level and in the longer days. The rate of production varied with cultivar but in all cases the plastochron shortened with transition to spike formation. Early flowering (cv. Clipper) was associated with a high rate of primordial production and early transition to spike formation, late flowering (cv. Proctor) with a low rate of production and a longer vegetative phase. The cultivar Akka showed intermediate characteristics. The volume of the apical dome increased linearly with increasing numbers of primordia, the rate of increase varying with cultivar and treatment. Enlargement of the dome was due mainly to increase in cell number. The transition of the apex to produce spikelet primordia occurred with widely differing volumes of the apical dome, thus invalidating the hypothesis that transition is dependent upon attainment of a critical dome size. Although both the rate of production of primordia and enlargement of the dome were markedly affected by photoperiod, both were unaffected when the photoperiodic treatment was given directly to the shoot apex. It is considered that the fate of a primordium once initiated is determined by competition for available metabolites between it, other primordia and the apical dome.
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Claims 14
Claim · model-written summary
Primordia production at the barley shoot apex was greater at the higher mineral nutrient level.
- Taxon
- barley
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Hordeum vulgaree0 - Treatment
- higher nutrient levele1
- Outcome
- Production of primordiae1
- Direction
- greatere1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“seedlings of three barley cultivars”
e1“Production of primordia was greater at the higher nutrient level”
Claim · model-written summary
Primordia production at the barley shoot apex was greater in longer days.
- Taxon
- barleyHordeum vulgaree0
- Treatment
- longer dayse1
- Outcome
- Production of primordiae1
- Direction
- greatere1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“Production of primordia was greater at the higher nutrient level and in the longer days”
Claim · model-written summary
The rate of primordia production varied with barley cultivar.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- rate of productione1
- Qualifier
- varied with cultivare1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“The rate of production varied with cultivar”
Claim · model-written summary
In all cultivars the plastochron shortened with transition to spike formation.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- plastochrone1
- Direction
- shortenede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“in all cases the plastochron shortened with transition to spike formation”
Claim · model-written summary
Early flowering in cv. Clipper was associated with a high rate of primordial production and early transition to spike formation.
- Taxon
- barleyHordeum vulgaree0
- Material
- cv. Clippere1
- Outcome
- rate of primordial production and early transition to spike formatione1
- Direction
- highe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“Early flowering (cv. Clipper) was associated with a high rate of primordial production and early transition to spike formation”
Claim · model-written summary
Late flowering in cv. Proctor was associated with a low rate of primordia production and a longer vegetative phase.
- Taxon
- barleyHordeum vulgaree0
- Material
- cv. Proctore1
- Outcome
- rate of production and a longer vegetative phasee1
- Direction
- lowe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“late flowering (cv. Proctor) with a low rate of production and a longer vegetative phase”
Claim · model-written summary
The barley cultivar Akka showed intermediate characteristics between the early and late flowering cultivars.
- Taxon
- barleyHordeum vulgaree0
- Material
- Akkae1
- Outcome
- intermediate characteristicse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“The cultivar Akka showed intermediate characteristics”
Claim · model-written summary
The volume of the apical dome increased linearly with increasing numbers of primordia.
- Taxon
- barleyHordeum vulgaree0
- Organ / stage
- apical domee1
- Outcome
- volume of the apical domee1
- Direction
- increasede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“The volume of the apical dome increased linearly with increasing numbers of primordia”
Claim · model-written summary
The rate of increase of dome volume with primordia number varied with cultivar and treatment.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- rate of increasee1
- Qualifier
- varying with cultivar and treatmente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“the rate of increase varying with cultivar and treatment”
Claim · model-written summary
Enlargement of the apical dome was due mainly to an increase in cell number.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- Enlargement of the domee1
- Qualifier
- increase in cell numbere1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“Enlargement of the dome was due mainly to increase in cell number”
Claim · model-written summary
The transition of the apex to spikelet primordia occurred at widely differing apical dome volumes, invalidating the hypothesis that transition depends on a critical dome size.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- volumes of the apical domee1
- Direction
- widely differinge1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“The transition of the apex to produce spikelet primordia occurred with widely differing volumes of the apical dome”
Claim · model-written summary
Both the rate of primordia production and enlargement of the dome were markedly affected by photoperiod.
- Taxon
- barleyHordeum vulgaree0
- Treatment
- photoperiode1
- Outcome
- rate of production of primordia and enlargement of the domee1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“both the rate of production of primordia and enlargement of the dome were markedly affected by photoperiod”
Claim · model-written summary
Both the rate of primordia production and dome enlargement were unaffected when the photoperiodic treatment was given directly to the shoot apex.
- Taxon
- barleyHordeum vulgaree0
- Treatment
- photoperiodic treatment was given directly to the shoot apexe2
- Outcome
- the rate of production of primordia and enlargement of the domee1
- Direction
- unaffectede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“the rate of production of primordia and enlargement of the dome”
e2“both were unaffected when the photoperiodic treatment was given directly to the shoot apex”
Claim · model-written summary
The authors consider that the fate of an initiated primordium is determined by competition for available metabolites between it, other primordia and the apical dome.
- Taxon
- barleyHordeum vulgaree0
- Compound
- available metabolitese1
- Outcome
- fate of a primordiume1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“seedlings of three barley cultivars”
e1“the fate of a primordium once initiated is determined by competition for available metabolites between it, other primordia and the apical dome”
The same questions in other papers
light · yield · Hordeum vulgare (barley)Positive and negative results
4 papers in the same direction as this paper · 6 in the opposite direction
- positive
- positive
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7 papers more in this group
See all 11 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.