Abstract
Dose-response curves were obtained in a background of 1/10 strength Hoagland nutrient solution for lettuce seedlings with Ni at different background levels of CaCl2 and for CaCl2 at different background levels of Ni. Nickel showed a toxicity threshold at 20 μeq L−1 of Ni and a 50% reduction in yield at Ni concentrations of about 30 μeq L−1. However, if the available Ca was increased from that in the control 1/10 strength Hoagland solution of 1.0 to 257 meq L−1, most of the reduction in growth due to Ni toxicity at 30 μeq L−1 was reversed, giving a yield of better than 90% of control. This concentration of Ca (CaCl2) was where Ca started to have a salinity effect and further increases of Ca resulted in yield decrease due to salinity, so that any further alleviation of the Ni toxicity was not discernible. When an Ni dose-response curve was run in the presence of high background concentrations of Ca, Ni concentrations close to its toxic threshold level provided some alleviation of the salinity stress. These curves also showed a strong alleviation of Ni toxicity at high Ni concentrations in the presence of high background concentrations of Ca.
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Claims 7
Claim · model-written summary
Nickel toxicity began at 20 μeq L−1 in lettuce seedlings.
- Taxon
- lettuce
Lactuca sativae1 - Outcome
- toxicity thresholde0
- Value
- 20 μeq L−1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nickel showed a toxicity threshold at 20 μeq L−1 of Ni and a 50% reduction in yield at Ni concentrations of about 30 μeq L−1.”
e1“lettuce seedlings”
Claim · model-written summary
Nickel at about 30 μeq L−1 reduced yield by 50%.
- Taxon
- lettuceLactuca sativae1
- Treatment
- Ni concentrations of about 30 μeq L−1e0
- Outcome
- yielde0
- Direction
- reductione0
- Value
- 50%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nickel showed a toxicity threshold at 20 μeq L−1 of Ni and a 50% reduction in yield at Ni concentrations of about 30 μeq L−1.”
e1“lettuce seedlings”
Claim · model-written summary
Increasing calcium to 257 meq L−1 reversed most nickel growth suppression and restored yield above 90% of control.
- Taxon
- lettuceLactuca sativae1
- Treatment
- available Ca was increasede0
- Outcome
- yielde0
- Direction
- reversede0
- Value
- better than 90% of controle0
- Qualifier
- Ni toxicity at 30 μeq L−1e0
- Comparator
- control 1/10 strength Hoagland solutione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“However, if the available Ca was increased from that in the control 1/10 strength Hoagland solution of 1.0 to 257 meq L−1, most of the reduction in growth due to Ni toxicity at 30 μeq L−1 was reversed, giving a yield of better than 90% of control.”
e1“lettuce seedlings”
Claim · model-written summary
Calcium began causing salinity effects at the concentration that reversed nickel toxicity.
- Taxon
- lettuceLactuca sativae1
- Treatment
- Ca (CaCl2)e0
- Outcome
- salinity effecte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This concentration of Ca (CaCl2) was where Ca started to have a salinity effect”
e1“lettuce seedlings”
Claim · model-written summary
Further calcium increases reduced yield through salinity and obscured further nickel-toxicity alleviation.
- Taxon
- lettuceLactuca sativae1
- Treatment
- further increases of Cae0
- Outcome
- yielde0
- Direction
- decreasee0
- Qualifier
- any further alleviation of the Ni toxicity was not discerniblee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“further increases of Ca resulted in yield decrease due to salinity, so that any further alleviation of the Ni toxicity was not discernible.”
e1“lettuce seedlings”
Claim · model-written summary
Nickel near its toxicity threshold alleviated salinity stress under high background calcium.
- Taxon
- lettuceLactuca sativae1
- Treatment
- Ni concentrations close to its toxic threshold levele0
- Outcome
- salinity stresse0
- Direction
- alleviatione0
- Qualifier
- high background concentrations of Cae0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When an Ni dose-response curve was run in the presence of high background concentrations of Ca, Ni concentrations close to its toxic threshold level provided some alleviation of the salinity stress.”
e1“lettuce seedlings”
Claim · model-written summary
High background calcium strongly alleviated toxicity at high nickel concentrations.
- Taxon
- lettuceLactuca sativae1
- Treatment
- high background concentrations of Cae0
- Outcome
- Ni toxicitye0
- Direction
- alleviatione0
- Qualifier
- high Ni concentrationse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These curves also showed a strong alleviation of Ni toxicity at high Ni concentrations in the presence of high background concentrations of Ca.”
e1“lettuce seedlings”
The same questions in other papers
nickel atom · yield · Lactuca sativa (garden lettuce)Results differ
4 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- negative
2 papers more in this group
See all 6 papers →calcium atom · pest · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- positive
calcium atom · yield · Lactuca sativa (garden lettuce)Results agree
5 papers in the same direction as this paper
- positive
- positive
- positive
2 papers more in this group
See all 6 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.