Abstract
Of 102 rhizoplane and endophytic bacteria isolated from rice roots and stems in California, 37% significantly (P < or = 0.05) inhibited the growth in vitro of two pathogens, Achlya klebsiana and Pythium spinosum, causing seedling disease of rice. Four endophytic strains were highly effective against seedling disease in growth pouch assays, and these were identified as Pseudomonas fluorescens (S3), Pseudomonas tolaasii (S20), Pseudomonas veronii (S21), and Sphingomonas trueperi (S12) by sequencing of amplified 16S rRNA genes. Strains S12, S20, and S21 contained the nitrogen fixation gene, nifD, but only S12 was able to reduce acetylene in pure culture. The four strains significantly enhanced plant growth in the absence of pathogens, as evidenced by increases in plant height and dry weight of inoculated rice seedlings relative to noninoculated rice. Three bacterial strains (S3, S20, and S21) were evaluated in pot bioassays and reduced disease incidence by 50%-73%. Strain S3 was as effective at suppressing disease at the lowest inoculum density (106 CFU/mL) as at higher density (10(8) CFU/mL or undiluted suspension). This study indicates that selected endophytic bacterial strains have potential for control of seedling disease of rice and for plant growth promotion.
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Claims 9
Claim · model-written summary
Thirty-seven percent of rice-associated isolates significantly inhibited two pathogens in vitro.
- Taxon
- rice
Oryza sativae0 - Interactor
- Achlya klebsianaAchlya klebsianae0pathogen
- Second interactor
- Pythium spinosumGlobisporangium spinosume0pathogen
- Outcome
- growthe0
- Direction
- inhibitede0
- Value
- 37%e0
- Setting
- Californiae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Of 102 rhizoplane and endophytic bacteria isolated from rice roots and stems in California, 37% significantly (P < or = 0.05) inhibited the growth in vitro of two pathogens, Achlya klebsiana and Pythium spinosum”
Claim · model-written summary
Four endophytic strains effectively suppressed rice seedling disease in growth pouches.
- Treatment
- Four endophytic strainse0
- Outcome
- seedling diseasee0
- Direction
- highly effectivee0
- Setting
- growth pouch assayse0
Not reportedTaxonComparator
Verbatim
e0“Four endophytic strains were highly effective against seedling disease in growth pouch assays”
Claim · model-written summary
S12, S20 and S21 carried nifD.
Not reportedTaxon
Verbatim
e0“Strains S12, S20, and S21 contained the nitrogen fixation gene, nifD”
Claim · model-written summary
Only S12 reduced acetylene in pure culture.
Not reportedTaxon
Verbatim
e0“but only S12 was able to reduce acetylene in pure culture”
Claim · model-written summary
Four strains significantly increased inoculated rice seedling height.
- Taxon
- riceOryza sativae0
- Treatment
- inoculated rice seedlingse0
- Outcome
- plant heighte0
- Direction
- increasese0
- Comparator
- noninoculated ricee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The four strains significantly enhanced plant growth in the absence of pathogens, as evidenced by increases in plant height and dry weight of inoculated rice seedlings relative to noninoculated rice”
Claim · model-written summary
Four strains significantly increased inoculated rice seedling dry weight.
- Taxon
- riceOryza sativae0
- Treatment
- inoculated rice seedlingse0
- Outcome
- dry weighte0
- Direction
- increasese0
- Comparator
- noninoculated ricee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The four strains significantly enhanced plant growth in the absence of pathogens, as evidenced by increases in plant height and dry weight of inoculated rice seedlings relative to noninoculated rice”
Claim · model-written summary
S3, S20 and S21 reduced rice seedling disease incidence by 50%-73% in pot assays.
- Treatment
- S3, S20, and S21e0
- Outcome
- disease incidencee0
- Direction
- reducede0
- Value
- 50%-73%e0
- Setting
- pot bioassayse0
Not reportedTaxonComparator
Verbatim
e0“Three bacterial strains (S3, S20, and S21) were evaluated in pot bioassays and reduced disease incidence by 50%-73%”
Claim · model-written summary
S3 suppressed disease equally at 106 CFU/mL and higher inoculum densities.
- Treatment
- Strain S3e0
- Outcome
- suppressing diseasee0
- Direction
- as effectivee0
- Value
- 106 CFU/mLe0
- Comparator
- higher densitye0
Not reportedTaxon
Verbatim
e0“Strain S3 was as effective at suppressing disease at the lowest inoculum density (106 CFU/mL) as at higher density (10(8) CFU/mL or undiluted suspension)”
Claim · model-written summary
The authors propose selected endophytes for rice seedling disease control and growth promotion.
- Taxon
- riceOryza sativae0
- Interactor
- endophytic bacterial strainse0biocontrol_agent
- Outcome
- control of seedling diseasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“selected endophytic bacterial strains have potential for control of seedling disease of rice and for plant growth promotion”
The same questions in other papers
inoculation · growth · Oryza sativa (rice)Positive and negative results
361 papers in the same direction as this paper · 34 in the opposite direction · 3 reporting no difference from an alternative
- negative
- positive
- no effect
395 papers more in this group
See all 399 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.