Abstract
Conditions were developed for the sterile culture of shoot tips of Xanthium pensylvanicum Wallr. for use as a bioassay for flower‐controlling chemicals. By using a modified Murashige‐Skoog medium (minus the auxin but including kinetin) and light intensity much higher than usual for plant tissue cultures, fast growth and development of the shoot tips was achieved. Under short‐day conditions (8 hr day: 16 hr night), the cultures from vegetative shoots flowered and fruited; under noninductive conditions (using a 2 hr light‐break in the middle of the dark period), the shoot tips continued vegetative development. Both intact plants and cultured tips could be photoinduced in the first days after germination. Ecdysterone, a potent insect moulting hormone, was tested in the bioassay system. It was without either qualitative or quantitative effect on flowering or vegetative development on either cultured shoot tips or intact plants irrespective of whether they were under inductive or noninductive photoperiodic conditions.
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Claims 5
Claim · model-written summary
Modified medium and high light produced fast shoot-tip growth and development.
- Taxon
- Xanthium pensylvanicum
Xanthium strumariume1 - Treatment
- modified Murashige‐Skoog medium (minus the auxin but including kinetin) and light intensity much higher than usuale0
- Outcome
- fast growth and development of the shoot tipse0
- Direction
- faste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“By using a modified Murashige‐Skoog medium (minus the auxin but including kinetin) and light intensity much higher than usual for plant tissue cultures, fast growth and development of the shoot tips was achieved”
e1“shoot tips of Xanthium pensylvanicum Wallr.”
Claim · model-written summary
Vegetative shoot cultures flowered and fruited under short days.
- Taxon
- Xanthium pensylvanicumXanthium strumariume1
- Treatment
- short‐day conditions (8 hr day: 16 hr night)e0
- Outcome
- flowered and fruitede0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under short‐day conditions (8 hr day: 16 hr night), the cultures from vegetative shoots flowered and fruited”
e1“shoot tips of Xanthium pensylvanicum Wallr.”
Claim · model-written summary
Shoot tips remained vegetative with a light break in the dark period.
- Taxon
- Xanthium pensylvanicumXanthium strumariume1
- Treatment
- 2 hr light‐break in the middle of the dark periode0
- Outcome
- continued vegetative developmente0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“under noninductive conditions (using a 2 hr light‐break in the middle of the dark period), the shoot tips continued vegetative development”
e1“shoot tips of Xanthium pensylvanicum Wallr.”
Claim · model-written summary
Both intact plants and cultured tips were photoinducible soon after germination.
- Taxon
- Xanthium pensylvanicumXanthium strumariume1
- Organ / stage
- first days after germinatione0
- Outcome
- photoinducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both intact plants and cultured tips could be photoinduced in the first days after germination”
e1“shoot tips of Xanthium pensylvanicum Wallr.”
Claim · model-written summary
Ecdysterone had no qualitative or quantitative effect on flowering or vegetative development.
- Taxon
- Xanthium pensylvanicumXanthium strumariume1
- Treatment
- Ecdysteronee0
- Outcome
- flowering or vegetative developmente0
- Direction
- without either qualitative or quantitative effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ecdysterone, a potent insect moulting hormone, was tested in the bioassay system. It was without either qualitative or quantitative effect on flowering or vegetative development on either cultured shoot tips or intact plants irrespective of whether they were under inductive or noninductive photoperiodic conditions”
e1“shoot tips of Xanthium pensylvanicum Wallr.”
The same questions in other papers
light · growth · Xanthium strumarium (cocklebur)Positive and negative results
3 papers in the same direction as this paper · 3 in the opposite direction
- no effect
- negative
- negative
3 papers more in this group
See all 7 papers →class · growth · Xanthium strumarium (cocklebur)Results agree
1 paper in the same direction as this paper
- positive
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.