Abstract
Sufficient indole acetic acid (IAA) was produced in yeast extract-mannitol (YM) medium by each of two isolates of indigenous Bradyrhizobium sp., to inhibit primary root growth of cowpea. Similar inoculation of cowpea with YM-cultivated strains from a culture collection or with washed cell suspensions of the two IAA-producing isolates had no apparent inhibiting effect on primary root growth. YM-cultivated cultures of each of the two high IAA-producing strains did not prevent nodulation of secondary roots and did not affect plant growth. In tests on agar plates a Bradyrhizobium sp. strain, CB756, frequently used for commercial inoculant production, stimulated root growth of cowpea and wheat seedlings, but when used to inoculate wheat in sand culture, neither strain CB756 nor the IAA-producing isolates measurably affected wheat growth. Production of IAA by the isolates and strains was strongly influenced by growth medium; all required tryptophan to excrete at least 0,5 μg IAA cm−3. Nine 5-methyl-tryptophan-resistant mutants of one of the high IAA-producing isolates were isolated after transposon mutagenesis. Four mutants excreted more IAA than the wild type strain and the nodule mass of plants inoculated with washed cells of the two highest IAA-producing mutants was less than that of plants inoculated with the wild type strain. Primary root growth was unaffected by the mutants. All the mutants were as effective as the wild type strain in their stimulation of cowpea growth.
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Claims 11
Claim · model-written summary
IAA-producing isolates grown in YM medium inhibited cowpea primary root growth.
- Taxon
- cowpea
Vigna unguiculatat0 - Treatment
- two isolates of indigenous Bradyrhizobium sp.e0
- Interactor
- Bradyrhizobium sp.
Bradyrhizobiume0symbiont - Outcome
- primary root growth of cowpeae0
- Direction
- inhibite0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“two isolates of indigenous Bradyrhizobium sp., to inhibit primary root growth of cowpea”
Claim · model-written summary
Collection strains and washed IAA-producing isolates had no apparent inhibitory effect on cowpea primary roots.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- YM-cultivated strains from a culture collection or with washed cell suspensions of the two IAA-producing isolatese0
- Interactor
- IAA-producing isolatese0symbiont
- Outcome
- primary root growthe0
- Direction
- no apparent inhibiting effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“Similar inoculation of cowpea with YM-cultivated strains from a culture collection or with washed cell suspensions of the two IAA-producing isolates had no apparent inhibiting effect on primary root growth”
Claim · model-written summary
High IAA-producing strains did not prevent cowpea secondary root nodulation.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- two high IAA-producing strainse0
- Outcome
- nodulation of secondary rootse0
- Direction
- did not prevente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“two high IAA-producing strains did not prevent nodulation of secondary roots”
Claim · model-written summary
High IAA-producing strains did not affect cowpea growth.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- two high IAA-producing strainse0
- Outcome
- plant growthe0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“two high IAA-producing strains did not prevent nodulation of secondary roots and did not affect plant growth”
Claim · model-written summary
CB756 stimulated cowpea root growth on agar plates.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- CB756e0
- Interactor
- CB756e0symbiont
- Outcome
- root growth of cowpeae0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“CB756, frequently used for commercial inoculant production, stimulated root growth of cowpea and wheat seedlings”
Claim · model-written summary
CB756 stimulated wheat root growth on agar plates.
- Taxon
- wheat
Triticum aestivumt0 - Treatment
- CB756e0
- Interactor
- CB756e0symbiont
- Outcome
- root growth of cowpea and wheat seedlingse0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“CB756, frequently used for commercial inoculant production, stimulated root growth of cowpea and wheat seedlings”
Claim · model-written summary
CB756 did not measurably affect wheat growth in sand culture.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- strain CB756e0
- Interactor
- CB756e0symbiont
- Outcome
- wheat growthe0
- Direction
- neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“when used to inoculate wheat in sand culture, neither strain CB756 nor the IAA-producing isolates measurably affected wheat growth”
Claim · model-written summary
IAA-producing isolates did not measurably affect wheat growth in sand culture.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- IAA-producing isolatese0
- Interactor
- IAA-producing isolatese0symbiont
- Outcome
- wheat growthe0
- Direction
- neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“when used to inoculate wheat in sand culture, neither strain CB756 nor the IAA-producing isolates measurably affected wheat growth”
Claim · model-written summary
Two high IAA-producing mutants yielded less cowpea nodule mass than the wild type strain.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- washed cells of the two highest IAA-producing mutantse0
- Outcome
- nodule masse0
- Direction
- less thane0
- Comparator
- wild type straine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“nodule mass of plants inoculated with washed cells of the two highest IAA-producing mutants was less than that of plants inoculated with the wild type strain”
Claim · model-written summary
The mutants did not affect cowpea primary root growth.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- mutantse0
- Outcome
- Primary root growthe0
- Direction
- unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“Primary root growth was unaffected by the mutants”
Claim · model-written summary
All mutants stimulated cowpea growth as effectively as the wild type strain.
- Taxon
- cowpeaVigna unguiculatat0
- Treatment
- mutantse0
- Outcome
- cowpea growthe0
- Direction
- as effective ase0
- Comparator
- wild type straine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“cowpea and wheat”
e0“All the mutants were as effective as the wild type strain in their stimulation of cowpea growth”
The same questions in other papers
Bradyrhizobium · growth · Vigna unguiculata (cowpea)Positive and negative results
1 paper in the same direction as this paper · 6 in the opposite direction
- positive
- positive
- positive
4 papers more in this group
See all 8 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.