Abstract
Phytophthora palmivora causes significant economic losses in Colombian cacao crops, yet its population structure and pathogenicity remain poorly characterized. This study tested the hypothesis that the Colombian Andes Mountain complex acts as a geographic barrier limiting gene flow among P. palmivora populations. We analyzed 73 isolates from western, central, and eastern cacao-growing regions using DArTseq genotyping and standardized pathogenicity assays. High genotypic diversity was observed (Simpson's index = 0.99), with corrected association index analysis indicating predominantly clonal reproduction, consistent with all isolates being A2 mating type. Discriminant analysis of principal components identified seven genetic clusters, but these showed no correlation with geographic distribution, contradicting our geographic barrier hypothesis. Mantel tests confirmed no isolation-by-distance (r = 0.004, P = 0.650). Pathogenicity tests on detached CCN51 leaves revealed extensive virulence variation that was independent of genetic clustering or geography. These findings suggest that observed genetic diversity results from multiple pathogen introductions and anthropogenic dispersal rather than geographic barriers. The lack of correlation between genotype and virulence indicates that pathogenicity determinants are independent of neutral molecular markers used for population structure analysis. Management recommendations include stringent phytosanitary measures to prevent further introductions and consideration of pathogen diversity in resistance breeding programs.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Phytophthora palmivora isolates from Colombian cacao showed high genotypic diversity (Simpson index 0.99).
- Taxon
- Cacao
Theobroma cacaot0 - Interactor
- Phytophthora palmivora
.jpg?width=60)
Phytophthora palmivorat0pathogen - Outcome
- genotypic diversitye0
- Value
- 0.99e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“High genotypic diversity was observed (Simpson's index = 0.99)”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
Corrected association index analysis indicated predominantly clonal reproduction of P. palmivora isolates.
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- predominantly clonal reproductione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“corrected association index analysis indicating predominantly clonal reproduction”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
All P. palmivora isolates were of the A2 mating type.
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- A2 mating typee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all isolates being A2 mating type”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
Discriminant analysis of principal components identified seven genetic clusters among the isolates.
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- genetic clusterse0
- Value
- sevene0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Discriminant analysis of principal components identified seven genetic clusters”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
The genetic clusters showed no correlation with geographic distribution.
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- genetic clusterse1
- Direction
- no correlatione0
- Setting
- geographic distributione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but these showed no correlation with geographic distribution”
e1“identified seven genetic clusters”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
Mantel tests found no isolation-by-distance (r = 0.004, P = 0.650).
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- isolation-by-distancee0
- Value
- r = 0.004e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mantel tests confirmed no isolation-by-distance (r = 0.004, P = 0.650)”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
Pathogenicity tests on detached CCN51 leaves showed extensive virulence variation independent of genetic clustering or geography.
- Taxon
- CacaoTheobroma cacaot0
- Material
- CCN51e0
- Organ / stage
- leavese0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- virulence variatione0
- Qualifier
- independent of genetic clustering or geographye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pathogenicity tests on detached CCN51 leaves revealed extensive virulence variation that was independent of genetic clustering or geography”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
The authors conclude that the observed genetic diversity results from multiple pathogen introductions and anthropogenic dispersal rather than geographic barriers.
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- genetic diversitye0
- Qualifier
- multiple pathogen introductions and anthropogenic dispersal rather than geographic barrierse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“observed genetic diversity results from multiple pathogen introductions and anthropogenic dispersal rather than geographic barriers”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
The authors recommend stringent phytosanitary measures to prevent further introductions of the pathogen.
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- stringent phytosanitary measures to prevent further introductionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“stringent phytosanitary measures to prevent further introductions”
t0“Phytophthora palmivora in Colombian Cacao”
Claim · model-written summary
The authors recommend considering pathogen diversity in resistance breeding programs.
- Taxon
- CacaoTheobroma cacaot0
- Interactor
- Phytophthora palmivoraPhytophthora palmivorat0pathogen
- Outcome
- consideration of pathogen diversity in resistance breeding programse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“consideration of pathogen diversity in resistance breeding programs”
t0“Phytophthora palmivora in Colombian Cacao”