Abstract
The population dynamics of Meloidogyne incognita juveniles (J2) in association with the parasite Pasteuria penetrans was studied in a field in Martinique. Data obtained at three-week intervals for one year were analyzed to study the relationship between J2 density and endospore infestation levels. Six crop sequences were evaluated in five replicates. They were: resistant tomato, okra, fallow, cabbage; susceptible tomato, okra, fallow, cabbage; bean, pepper, fallow, cabbage; eggplant, fallow; cucumber, velvetbean, fallow, cabbage; fallow, pepper, cabbage, fallow, cabbage. The J2 densities showed fluctuating trends, frequently synchronous with fluctuations of endospore infestation. The highest J2 numbers observed ranged between 1 000 and 1 500 nematodes/100 g of soil in the first four crop sequences, and between 150 and 250 J2/100 g of soil in the last two. The highest percentages of nematodes with adhering endospores ranged between 50 and 70%. The resistant tomato crop showed a sharp decrease in the nematode density at the end of the crop sequence, with a similar synchronous decrease of the endospore infestation. This trend was also observed during the fallow periods in the other treatments. Susceptible crops allowed a sharp increase of the J2 densities. During these periods of population growth, the concomitant increase of the endospore infestation levels was interrupted with fast growing J2 densities. In the last two crop sequences, the J2 densities progressively decreased because of the on-host status of velvetbean and of a longer fallow, respectively. When all the pooled data from the six treatments were considered, a significant linear correlation was observed between J2 densities and the corresponding endospore infestation values (P 0.001). This relationship appeared related to the density of females releasing J2 and/or endospores in the soil. All pooled mean densities also followed the Gutenberg-Richter power law distribution, indicating the oc-currence of chaotic effects influencing their dynamics. Although chaos implies non-predictability of J2 numbers and endospore infestation dynamics, it also suggests that large-scale fluctuations may induce local nematode suppression by P. penetrans.
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Claims 13
Claim · model-written summary
J2 density fluctuated synchronously with endospore infestation.
- Taxon
- tomato
Solanum lycopersicume1 - Interactor
- Meloidogyne incognita
_penetrates_a_tomato_root_-_USDA-ARS.jpg?width=60)
Meloidogyne incognitae2pest - Second interactor
- Pasteuria penetransPasteuria penetranse2biocontrol_agent
- Outcome
- J2 densitiese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_penetrates_a_tomato_root_-_USDA-ARS.jpg?width=500)
Verbatim
e0“The J2 densities showed fluctuating trends, frequently synchronous with fluctuations of endospore infestation.”
e1“They were: resistant tomato, okra, fallow, cabbage”
e2“Meloidogyne incognita juveniles (J2) in association with the parasite Pasteuria penetrans”
Claim · model-written summary
The first four crop sequences reached 1 000 to 1 500 nematodes per 100 g soil.
- Taxon
- tomatoSolanum lycopersicume1
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Outcome
- J2 numberse0
- Value
- 1 000 and 1 500 nematodes/100 g of soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest J2 numbers observed ranged between 1 000 and 1 500 nematodes/100 g of soil in the first four crop sequences”
e1“They were: resistant tomato, okra, fallow, cabbage”
e2“Meloidogyne incognita juveniles (J2)”
Claim · model-written summary
The last two crop sequences reached 150 to 250 J2 per 100 g soil.
- Taxon
- tomatoSolanum lycopersicume1
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Outcome
- J2e0
- Value
- 150 and 250 J2/100 g of soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“between 150 and 250 J2/100 g of soil in the last two.”
e1“They were: resistant tomato, okra, fallow, cabbage”
e2“Meloidogyne incognita juveniles (J2)”
Claim · model-written summary
The peak proportion of nematodes bearing endospores ranged from 50 to 70%.
- Taxon
- tomatoSolanum lycopersicume1
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Second interactor
- Pasteuria penetransPasteuria penetranse2biocontrol_agent
- Outcome
- nematodes with adhering endosporese0
- Value
- 50 and 70%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest percentages of nematodes with adhering endospores ranged between 50 and 70%.”
e1“They were: resistant tomato, okra, fallow, cabbage”
e2“Meloidogyne incognita juveniles (J2) in association with the parasite Pasteuria penetrans”
Claim · model-written summary
Resistant tomato reduced nematode density sharply at the end of the sequence.
- Taxon
- tomatoSolanum lycopersicume0
- Material
- resistant tomatoe0
- Treatment
- resistant tomato crope0
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae1pest
- Outcome
- nematode densitye0
- Direction
- sharp decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The resistant tomato crop showed a sharp decrease in the nematode density at the end of the crop sequence”
e1“Meloidogyne incognita juveniles (J2)”
Claim · model-written summary
Endospore infestation also declined synchronously after resistant tomato.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- resistant tomato crope0
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae1pest
- Second interactor
- Pasteuria penetransPasteuria penetranse1biocontrol_agent
- Outcome
- endospore infestatione0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The resistant tomato crop showed a sharp decrease in the nematode density at the end of the crop sequence, with a similar synchronous decrease of the endospore infestation.”
e1“Meloidogyne incognita juveniles (J2) in association with the parasite Pasteuria penetrans”
Claim · model-written summary
Fallow periods showed the same declining nematode and infestation trends.
- Taxon
- tomatoSolanum lycopersicume1
- Treatment
- fallow periodse0
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Outcome
- nematode densitye1
- Direction
- decreasee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This trend was also observed during the fallow periods in the other treatments.”
e1“The resistant tomato crop showed a sharp decrease in the nematode density at the end of the crop sequence, with a similar synchronous decrease of the endospore infestation.”
e2“Meloidogyne incognita juveniles (J2)”
Claim · model-written summary
Susceptible crops permitted a sharp rise in J2 density.
- Taxon
- tomatoSolanum lycopersicume1
- Material
- Susceptible cropse0
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Outcome
- J2 densitiese0
- Direction
- sharp increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Susceptible crops allowed a sharp increase of the J2 densities.”
e1“susceptible tomato”
e2“Meloidogyne incognita juveniles (J2)”
Claim · model-written summary
During rapid J2 population growth, accompanying increases in endospore infestation were interrupted.
- Taxon
- tomatoSolanum lycopersicume1
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Second interactor
- Pasteuria penetransPasteuria penetranse2biocontrol_agent
- Outcome
- endospore infestation levelse0
- Direction
- interruptede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“During these periods of population growth, the concomitant increase of the endospore infestation levels was interrupted with fast growing J2 densities.”
e1“susceptible tomato”
e2“Meloidogyne incognita juveniles (J2) in association with the parasite Pasteuria penetrans”
Claim · model-written summary
J2 density progressively declined in the velvetbean sequence because of its reported host status.
- Taxon
- velvetbean
.jpg?width=60)
Mucuna pruriens var. utilise0 - Interactor
- Meloidogyne incognitaMeloidogyne incognitae1pest
- Outcome
- J2 densitiese0
- Direction
- decreasede0
- Qualifier
- on-host status of velvetbeane0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“In the last two crop sequences, the J2 densities progressively decreased because of the on-host status of velvetbean and of a longer fallow, respectively.”
e1“Meloidogyne incognita juveniles (J2)”
Claim · model-written summary
J2 density progressively declined in the longer-fallow sequence.
- Taxon
- tomatoSolanum lycopersicume1
- Treatment
- longer fallowe0
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Outcome
- J2 densitiese0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the last two crop sequences, the J2 densities progressively decreased because of the on-host status of velvetbean and of a longer fallow, respectively.”
e1“They were: resistant tomato, okra, fallow, cabbage”
e2“Meloidogyne incognita juveniles (J2)”
Claim · model-written summary
Pooled J2 density and endospore infestation had a significant linear correlation.
- Taxon
- tomatoSolanum lycopersicume1
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Second interactor
- Pasteuria penetransPasteuria penetranse2biocontrol_agent
- Outcome
- J2 densities and the corresponding endospore infestation valuese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a significant linear correlation was observed between J2 densities and the corresponding endospore infestation values (P 0.001).”
e1“They were: resistant tomato, okra, fallow, cabbage”
e2“Meloidogyne incognita juveniles (J2) in association with the parasite Pasteuria penetrans”
Claim · model-written summary
Pooled mean densities followed a Gutenberg-Richter power-law distribution.
- Taxon
- tomatoSolanum lycopersicume1
- Interactor
- Meloidogyne incognitaMeloidogyne incognitae2pest
- Outcome
- pooled mean densitiese0
- Qualifier
- Gutenberg-Richter power law distributione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All pooled mean densities also followed the Gutenberg-Richter power law distribution”
e1“They were: resistant tomato, okra, fallow, cabbage”
e2“Meloidogyne incognita juveniles (J2)”