Abstract
Root colonization by vesicular-arbuscular (VA) mycorrhizal fungi is often suppressed by phosphorus (P) additions; however, nitrogen (N) additions have been reported to both stimulate and suppress root colonization. The objective of this research was to examine colonization of Allium cepa L. roots at a range of P and N concentrations in order to clarify the effects of these nutrients on root colonization. In the first experiment, conducted under N-limiting conditions, P addition had no effect on root colonization by Glontus etunicatum Becker & Gerdemann and increased root colonization by Gigaspora margarita Gerdemann and Trappe. In the second experiment, conducted under N-sufficient conditions, P addition suppressed colonization by G. etunicatum. In the third experiment, P and N additions were such that tissue P:N ratios ranged from 0-03 (P limiting) to 017 (N limiting). No relationship was found between P:N ratio and root colonization for two isolates of G. etunicatum. Root colonization was not affected by P addition when plants were deficient in N but, when N was sufficient, P addition suppressed root colonization. These results demonstrate that plant N stress affects the resistance of the host root to colonization by VA mycorrhizal fungi.
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Claims 5
Claim · model-written summary
Under N-limiting conditions, P addition had no effect on root colonization by Glontus etunicatum.
- Taxon
- Allium cepa L.
Allium cepae0 - Treatment
- P additione1
- Interactor
- Glontus etunicatume1symbiont
- Outcome
- root colonizatione1
- Direction
- no effecte1
- Qualifier
- under N-limiting conditionse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“examine colonization of Allium cepa L. roots at a range of P and N concentrations”
e1“In the first experiment, conducted under N-limiting conditions, P addition had no effect on root colonization by Glontus etunicatum Becker & Gerdemann and increased root colonization by Gigaspora margarita Gerdemann and Trappe”
Claim · model-written summary
Under N-limiting conditions, P addition increased root colonization by Gigaspora margarita.
- Taxon
- Allium cepa L.Allium cepae0
- Treatment
- P additione1
- Interactor
- Gigaspora margarita
Gigaspora margaritae1symbiont - Outcome
- root colonizatione1
- Direction
- increasede1
- Qualifier
- under N-limiting conditionse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“examine colonization of Allium cepa L. roots at a range of P and N concentrations”
e1“In the first experiment, conducted under N-limiting conditions, P addition had no effect on root colonization by Glontus etunicatum Becker & Gerdemann and increased root colonization by Gigaspora margarita Gerdemann and Trappe”
Claim · model-written summary
Under N-sufficient conditions, P addition suppressed root colonization by G. etunicatum.
- Taxon
- Allium cepa L.Allium cepae0
- Treatment
- P additione2
- Interactor
- G. etunicatume2symbiont
- Outcome
- colonizatione2
- Direction
- suppressede2
- Qualifier
- under N-sufficient conditionse2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“examine colonization of Allium cepa L. roots at a range of P and N concentrations”
e2“In the second experiment, conducted under N-sufficient conditions, P addition suppressed colonization by G. etunicatum”
Claim · model-written summary
No relationship was found between the P:N ratio and root colonization for two isolates of G. etunicatum.
- Taxon
- Allium cepa L.Allium cepae0
- Treatment
- P:N ratioe3
- Interactor
- G. etunicatume3symbiont
- Outcome
- root colonizatione3
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“examine colonization of Allium cepa L. roots at a range of P and N concentrations”
e3“No relationship was found between P:N ratio and root colonization for two isolates of G. etunicatum”
Claim · model-written summary
Plant N stress affects the resistance of the host root to colonization by VA mycorrhizal fungi.
- Taxon
- Allium cepa L.Allium cepae0
- Treatment
- plant N stresse4
- Outcome
- resistance of the host root to colonizatione4
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“examine colonization of Allium cepa L. roots at a range of P and N concentrations”
e4“plant N stress affects the resistance of the host root to colonization by VA mycorrhizal fungi”
The same questions in other papers
phosphorus · disease · Allium cepa (onion)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- negative
- 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.