Abstract
Most assessments of allelopathy involve bioassays. Our objective was to improve the sensitivity of an alfalfa ( Medicago sativa L.) seedling bioassay for evaluating genetic tolerance to autotoxic leaf extracts. In a petri dish assay on imbibed seed, light inhibited hypocotyl elongation of controls and increased root elongation. Root growth was sensitive to the autotoxin in both light and darkness. An agar medium gave better root growth of controls and lower standard errors than did filter paper when petri dishes were placed on edge to encourage downward root growth or were placed flat where roots grew laterally. Hypocotyl growth was not very sensitive to the autotoxic chemical(s) on either agar or paper medium when the plate was flat, because the hypocotyl arched upward to escape contact with the extract. Hypocotyl growth was sensitive in a rolled paper towel treatment held vertically because the hypocotyl remained in continuous contact with the extract. On agar plates placed flat, 50% inhibition of root length occurred at an extract concentration that was about 8% of that needed for 50% inhibition of germination at 36 and 48 h. Root growth was stimulated up to 15% above controls at very low concentrations of leaf extract. Root length at 120 h was the best indicator of autotoxic effects of alfalfa leaf extracts. We evaluated 17 germplasms and three cultivars of alfalfa for root growth response to the autotoxic chemical and found a twofold range ( P < 0.05) in tolerance.
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Claims 11
Claim · model-written summary
Light inhibited hypocotyl elongation in controls.
Verbatim
e0“light inhibited hypocotyl elongation of controls”
Claim · model-written summary
Light increased root elongation.
- Taxon
- alfalfa
Medicago sativae1 - Treatment
- lighte0
- Outcome
- root elongatione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“light inhibited hypocotyl elongation of controls and increased root elongation.”
e1“alfalfa ( Medicago sativa L.) seedling”
Claim · model-written summary
Root growth was sensitive to autotoxin under light and darkness.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- autotoxine0
- Outcome
- Root growth was sensitive to the autotoxine0
- Qualifier
- both light and darknesse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root growth was sensitive to the autotoxin in both light and darkness.”
e1“alfalfa ( Medicago sativa L.) seedling”
Claim · model-written summary
Agar yielded better control root growth than filter paper.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- agar mediume0
- Outcome
- root growth of controlse0
- Direction
- bettere0
- Comparator
- filter papere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An agar medium gave better root growth of controls and lower standard errors than did filter paper”
e1“alfalfa ( Medicago sativa L.) seedling”
Claim · model-written summary
Agar gave lower standard errors than filter paper.
- Taxon
- alfalfaMedicago sativae1
- Outcome
- standard errorse0
- Direction
- lowere0
- Comparator
- filter papere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An agar medium gave better root growth of controls and lower standard errors than did filter paper”
e1“alfalfa ( Medicago sativa L.) seedling”
Claim · model-written summary
Flat plates made hypocotyl growth relatively insensitive to autotoxic chemicals on agar or paper.
Not reportedDirection
Verbatim
e0“Hypocotyl growth was not very sensitive to the autotoxic chemical(s) on either agar or paper medium when the plate was flat”
Claim · model-written summary
Vertical rolled paper towels gave a sensitive hypocotyl response.
- Taxon
- Hypocotyle0
- Outcome
- Hypocotyl growth was sensitivee0
- Comparator
- rolled paper towel treatment held verticallye0
Not reportedDirection
Verbatim
e0“Hypocotyl growth was sensitive in a rolled paper towel treatment held vertically because the hypocotyl remained in continuous contact with the extract.”
Claim · model-written summary
On flat agar, root-length inhibition required about 8% of the extract concentration needed for comparable germination inhibition.
- Taxon
- alfalfaMedicago sativae1
- Outcome
- 50% inhibition of root lengthe0
- Value
- about 8%e0
- Qualifier
- at 36 and 48 he0
- Comparator
- 50% inhibition of germinatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On agar plates placed flat, 50% inhibition of root length occurred at an extract concentration that was about 8% of that needed for 50% inhibition of germination at 36 and 48 h.”
e1“alfalfa ( Medicago sativa L.) seedling”
Claim · model-written summary
Low leaf-extract concentrations stimulated root growth by up to 15% over controls.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- very low concentrations of leaf extracte0
- Outcome
- Root growthe0
- Direction
- stimulatede0
- Value
- 15%e0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root growth was stimulated up to 15% above controls at very low concentrations of leaf extract.”
e1“alfalfa ( Medicago sativa L.) seedling”
Claim · model-written summary
Root length at 120 h was the best indicator of autotoxicity.
- Taxon
- alfalfaMedicago sativae0
- Outcome
- Root length at 120 he0
- Direction
- beste0
- Comparator
- autotoxic effects of alfalfa leaf extractse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root length at 120 h was the best indicator of autotoxic effects of alfalfa leaf extracts.”
Claim · model-written summary
Alfalfa germplasm and cultivars showed a twofold range in autotoxic tolerance.
- Taxon
- alfalfaMedicago sativae0
- Material
- 17 germplasms and three cultivarse0
- Outcome
- tolerancee0
- Value
- twofold rangee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“17 germplasms and three cultivars of alfalfa for root growth response to the autotoxic chemical and found a twofold range ( P < 0.05) in tolerance.”
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See all 28 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.