Abstract
Nearly 400 microorganism isolates, including bacteria, actinomycetes, and fungi, were collected from watermelon roots growing in soils suppressive and nonsuppressive to Fusarium wilt of watermelon. These isolates were screened for their ability to restore suppressiveness to microwave-treated suppressive soil and to reduce disease incidence in conducive field soil. Specific isolates of nonpathogenic Fusarium oxysporum from suppressive soil were the only organisms consistently effective in reducing disease (35 to 75% reduction) in both microwave-treated and natural field soils. Thus, we concluded that F. oxysporum was the primary antagonist responsible for suppression in this suppressive soil, although other organisms may contribute to suppressiveness. Selected isolates of F. oxysporum were effective in reducing disease when added to field soils at inoculum levels as low as 50 to 100 chlamydospores per g of soil, which was comparable to or below pathogen inoculum levels (100 to 200 CFU/ g of soil). Root colonization data indicated that reduction of disease was not directly related to the ability of the antagonist to colonize roots extensively or to reduce colonization by the pathogen. Effective antagonists were not associated with specific vegetative compatibility groups, indicating antagonists represent diverse isolates. In split-root experiments, in which the antagonist and the pathogen were physically separated from each other, root colonization by selected isolates of E oxysporum reduced disease incidence, verifying the mechanism of action as induced systemic resistance. Several isolates of F. oxysporum from this suppressive soil have potential for development as biocontrol agents.
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Claims 8
Claim · model-written summary
Specific nonpathogenic F. oxysporum isolates were the only organisms consistently effective in reducing Fusarium wilt disease by 35 to 75% in microwave-treated and natural field soils.
- Taxon
- Watermelon
Citrullus lanatust0 - Treatment
- nonpathogenic Fusarium oxysporume1
- Second interactor
- nonpathogenic Fusarium oxysporum
_(Fusarium_oxysporum_f.sp._batatas)_1234227-PPT-Clemson_University.jpg?width=60)
Fusarium oxysporume1biocontrol_agent - Outcome
- diseasee1
- Direction
- reducinge1
- Value
- 35 to 75% reductione1
- Setting
- microwave-treated and natural field soilse1
FusariumNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_(Fusarium_oxysporum_f.sp._batatas)_1234227-PPT-Clemson_University.jpg?width=500)
Verbatim
t0“Fusarium Wilt of Watermelon”
e1“Specific isolates of nonpathogenic Fusarium oxysporum from suppressive soil were the only organisms consistently effective in reducing disease (35 to 75% reduction) in both microwave-treated and natural field soils”
Claim · model-written summary
F. oxysporum was the primary antagonist responsible for suppressiveness of the soil, although other organisms may contribute.
- Taxon
- WatermelonCitrullus lanatust0
- Interactor
- F. oxysporumFusarium oxysporume2biocontrol_agent
- Outcome
- suppressione2
- Qualifier
- primary antagoniste2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fusarium Wilt of Watermelon”
e2“Thus, we concluded that F. oxysporum was the primary antagonist responsible for suppression in this suppressive soil, although other organisms may contribute to suppressiveness”
Claim · model-written summary
Selected F. oxysporum isolates reduced disease when added to field soil at 50 to 100 chlamydospores per g of soil, comparable to or below pathogen inoculum levels.
- Taxon
- WatermelonCitrullus lanatust0
- Treatment
- added to field soils at inoculum levels as low as 50 to 100 chlamydospores per g of soile3
- Interactor
- F. oxysporumFusarium oxysporume3biocontrol_agent
- Outcome
- diseasee3
- Direction
- reducinge3
- Qualifier
- comparable to or below pathogen inoculum levelse3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fusarium Wilt of Watermelon”
e3“Selected isolates of F. oxysporum were effective in reducing disease when added to field soils at inoculum levels as low as 50 to 100 chlamydospores per g of soil, which was comparable to or below pathogen inoculum levels (100 to 200 CFU/ g of soil)”
Claim · model-written summary
Reduction of disease was not directly related to the ability of the antagonist to colonize roots.
- Taxon
- WatermelonCitrullus lanatust0
- Treatment
- the ability of the antagonist to colonize rootse4
- Outcome
- reduction of diseasee4
- Direction
- no_changeinferrede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fusarium Wilt of Watermelon”
e4“Root colonization data indicated that reduction of disease was not directly related to the ability of the antagonist to colonize roots extensively or to reduce colonization by the pathogen”
Claim · model-written summary
Effective antagonists were not associated with specific vegetative compatibility groups.
- Taxon
- WatermelonCitrullus lanatust0
- Material
- specific vegetative compatibility groupse5
- Outcome
- Effective antagonistse5
- Direction
- no_changeinferrede5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fusarium Wilt of Watermelon”
e5“Effective antagonists were not associated with specific vegetative compatibility groups, indicating antagonists represent diverse isolates”
Claim · model-written summary
In split-root experiments, root colonization by selected E oxysporum isolates reduced disease incidence when antagonist and pathogen were physically separated.
- Taxon
- WatermelonCitrullus lanatust0
- Treatment
- root colonization by selected isolates of E oxysporume6
- Interactor
- E oxysporume6biocontrol_agent
- Outcome
- disease incidencee6
- Direction
- reducede6
- Setting
- split-root experimentse6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fusarium Wilt of Watermelon”
e6“In split-root experiments, in which the antagonist and the pathogen were physically separated from each other, root colonization by selected isolates of E oxysporum reduced disease incidence, verifying the mechanism of action as induced systemic resistance”
Claim · model-written summary
Split-root experiments indicate that reduction of disease by the antagonist acts through induced systemic resistance.
- Taxon
- WatermelonCitrullus lanatust0
- Interactor
- E oxysporume6biocontrol_agent
- Outcome
- disease incidencee6
- Qualifier
- induced systemic resistancee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fusarium Wilt of Watermelon”
e6“In split-root experiments, in which the antagonist and the pathogen were physically separated from each other, root colonization by selected isolates of E oxysporum reduced disease incidence, verifying the mechanism of action as induced systemic resistance”
Claim · model-written summary
Several F. oxysporum isolates from this suppressive soil have potential for development as biocontrol agents.
- Taxon
- WatermelonCitrullus lanatust0
- Interactor
- F. oxysporumFusarium oxysporume7biocontrol_agent
- Outcome
- potential for development as biocontrol agentse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fusarium Wilt of Watermelon”
e7“Several isolates of F. oxysporum from this suppressive soil have potential for development as biocontrol agents”
The same questions in other papers
Fusarium oxysporum · disease · Citrullus lanatus (watermelon)Positive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
infection · disease · Citrullus lanatus (watermelon)Positive and negative results
8 in the opposite direction
- negative
- negative
- negative
5 papers more in this group
See all 9 papers →inoculation · Fusarium oxysporum · Citrullus lanatus (watermelon)Results agree
1 paper in the same direction as this paper
- positive
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.