Abstract
In April 2004, there was a serious outbreak of a tomato (Lypersicon esculentum Mill.) leaf spot disease in Mgeta, Mvomero District of Tanzania. The disease was characterized by lesions on green tomato fruits that were small, sunken, and black and were surrounded by darker green haloes. Lesions on ripe tomato fruits were dark brown to black, superficial, and measured approximately 1 to 2 mm in diameter. On the leaves, lesions were small, black, and surrounded by chlorotic (yellow) haloes. In some cases, the specks coalesced to form large lesions on older leaves. Black lesions were also observed on stems and petioles. A disease survey of selected tomato-producing areas in Arusha, Dodoma, Iringa, and Morogoro regions of Tanzania during 2004 and 2005 revealed that the disease was widespread in farmers' fields in all areas surveyed. Disease incidence was approximately 80%, while severity, rated on the scale of Chambers and Merriman (1), ranged from moderate (11 to 40 lesions per plant) to severe (>40 lesions per plant). A bacterium that produced a greenish, diffusible pigment on King's medium B was consistently isolated from lesions on tomato fruits collected from the fields in all the surveyed areas. All 56 isolates obtained were gram negative, oxidase negative, and fluoresced on King's medium B under UV light. None utilized phenylethylamine as the sole carbon source, while three isolates utilized i-erythritol and lactulose. Biolog analysis of the isolates, along with two reference strains of P. syringae pv. tomato (Pst CEP-3 from Sokoine University of Agriculture, Tanzania and Pst BB6 [Race 1] from Göttinger Sammlung Phytopathogener Bakterien, Göttingen, Germany) identified them as P. syringae pv. tomato, with similarity indices of 0.518 to 0.933. They also were positively identified as P. syringae pv. tomato by repetitive sequence-based-PCR (2,3) and fragment length polymorphism analysis. Pathogenicity of the strains was confirmed by spraying 35-day-old tomato seedlings (cv. Tanya) with suspensions of the isolates at a concentration of 10 8 CFU ml -1 of sterile water. After approximately 72 h, small, water-soaked, dark brown lesions similar to those observed on the field plants were observed on leaves of all the inoculated tomato seedlings. There were no symptoms on control plants. The bacterium was reisolated from the infected plants and identified as P. syringae pv. tomato, in accordance with Koch's postulates. To our knowledge, this is the first report of the occurrence of tomato bacterial speck in Tanzania. References: (1). S. C. Chambers and P. R. Merriman. Aust. J. Agric. Res. 26:657, 1975. (2). F. J. Louws et al. Appl. Environ. Microbiol. 60:2286, 1994. (3). M. Zaccardelli et al. Eur. J. Plant Pathol. 111:85, 2005.
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Claims 13
Claim · model-written summary
A serious tomato leaf spot outbreak occurred in Mgeta in April 2004.
- Taxon
- tomato
Solanum lycopersicumt0 - Interactor
- Pseudomonas syringae pv. tomato
Pseudomonas syringae pv. tomatot0pathogen - Outcome
- leaf spot diseasee0
- Setting
- Mgeta, Mvomero District of Tanzaniae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In April 2004, there was a serious outbreak of a tomato (Lypersicon esculentum Mill.) leaf spot disease in Mgeta, Mvomero District of Tanzania.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
The disease produced small sunken black lesions with green haloes on green fruit.
- Taxon
- tomatoSolanum lycopersicumt0
- Organ / stage
- green tomato fruitse0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- lesions on green tomato fruitse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lesions on green tomato fruits that were small, sunken, and black and were surrounded by darker green haloes.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
Lesions on ripe fruit were superficial, dark brown to black, and about 1 to 2 mm across.
- Taxon
- tomatoSolanum lycopersicumt0
- Organ / stage
- ripe tomato fruitse0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- Lesions on ripe tomato fruitse0
- Value
- 1 to 2 mme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lesions on ripe tomato fruits were dark brown to black, superficial, and measured approximately 1 to 2 mm in diameter.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
Leaf lesions were small, black and surrounded by yellow haloes; some merged on older leaves.
- Taxon
- tomatoSolanum lycopersicumt0
- Organ / stage
- leavese0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- lesionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the leaves, lesions were small, black, and surrounded by chlorotic (yellow) haloes. In some cases, the specks coalesced to form large lesions on older leaves.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
Black lesions were present on stems and petioles.
- Taxon
- tomatoSolanum lycopersicumt0
- Organ / stage
- stems and petiolese0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- Black lesionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Black lesions were also observed on stems and petioles.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
The disease was widespread in surveyed Tanzanian tomato fields.
- Taxon
- tomatoSolanum lycopersicumt0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- diseasee0
- Setting
- farmers' fieldse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the disease was widespread in farmers' fields in all areas surveyed.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
Disease incidence was approximately 80%.
- Taxon
- tomatoSolanum lycopersicumt0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- Disease incidencee0
- Value
- 80%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Disease incidence was approximately 80%”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
Disease severity ranged from moderate to severe.
- Taxon
- tomatoSolanum lycopersicumt0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- severitye0
- Value
- 11 to 40 lesions per plante0
- Qualifier
- severe (>40 lesions per plant)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“severity, rated on the scale of Chambers and Merriman (1), ranged from moderate (11 to 40 lesions per plant) to severe (>40 lesions per plant).”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
Phenotypic and Biolog analyses identified the isolates as P. syringae pv. tomato.
- Taxon
- tomatoSolanum lycopersicumt0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- identified them as P. syringae pv. tomatoe0
- Value
- 0.518 to 0.933e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biolog analysis of the isolates, along with two reference strains of P. syringae pv. tomato (Pst CEP-3 from Sokoine University of Agriculture, Tanzania and Pst BB6 [Race 1] from Göttinger Sammlung Phytopathogener Bakterien, Göttingen, Germany) identified them as P. syringae pv. tomato, with similarity indices of 0.518 to 0.933.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
PCR and fragment length polymorphism analyses also identified the isolates as P. syringae pv. tomato.
- Taxon
- tomatoSolanum lycopersicumt0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- positively identified as P. syringae pv. tomatoe0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“They also were positively identified as P. syringae pv. tomato by repetitive sequence-based-PCR (2,3) and fragment length polymorphism analysis.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
Inoculated tomato seedlings developed lesions after about 72 h, while controls had no symptoms.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- inoculated tomato seedlingse0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- lesionse0
- Qualifier
- After approximately 72 he0
- Comparator
- control plantse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After approximately 72 h, small, water-soaked, dark brown lesions similar to those observed on the field plants were observed on leaves of all the inoculated tomato seedlings. There were no symptoms on control plants.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
The bacterium was reisolated from infected tomato plants, supporting its causal identification.
- Taxon
- tomatoSolanum lycopersicumt0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- reisolated from the infected plants and identified as P. syringae pv. tomatoe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The bacterium was reisolated from the infected plants and identified as P. syringae pv. tomato, in accordance with Koch's postulates.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
Claim · model-written summary
The authors report the first occurrence of tomato bacterial speck in Tanzania.
- Taxon
- tomatoSolanum lycopersicumt0
- Interactor
- Pseudomonas syringae pv. tomatoPseudomonas syringae pv. tomatot0pathogen
- Outcome
- occurrence of tomato bacterial specke0
- Setting
- Tanzaniae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this is the first report of the occurrence of tomato bacterial speck in Tanzania.”
t0“Tomato Caused by Pseudomonas syringae pv. tomato”
The same questions in other papers
inoculation · Pseudomonas syringae pv. tomato · Solanum lycopersicum (tomato)Positive and negative results
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See all 14 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.