Evidence map›Paper›PMID 42590994›Full record

ArticleMolecular ecology2026

Genomic Sampling and Population Structure of Farmer-Maintained Varieties Reveal Previously Uncharacterized Diversity of Theobroma cacao L. in Costa Rica.

Emma M Herrighty, Chelsea D Specht, Michael A Gore, Luis Solano, Joyce Estrada-Gamboa, Carlos Eduardo Hernandez, Hale Ann Tufan, Jacob B Landis

Abstract read
In one paragraph

Article in Molecular ecology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Emma M HerrightySection of Plant Breeding and Genetics, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA.ORCID https://orcid.org/0000-0002-7720-5755
Chelsea D SpechtSection of Plant Biology and the L.H. Bailey Hortorium, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA.ORCID https://orcid.org/0000-0001-7746-512X
Michael A GoreSection of Plant Breeding and Genetics, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA.ORCID https://orcid.org/0000-0001-6896-8024
Luis SolanoTropical Fruits, Agricultural Unit, Agricultural Center for Innovation in the Humid Tropics, National Institute of Innovation and Transfer in Agricultural Technology (INTA), Pococí, Limón, Costa Rica.ORCID https://orcid.org/0009-0002-4555-2346
Joyce Estrada-GamboaMolecular Biology Laboratory, National Institute of Innovation and Transfer in Agricultural Technology (INTA), San José, Costa Rica.ORCID https://orcid.org/0000-0003-0774-3512
Carlos Eduardo HernandezLaboratory of Food Quality Innovation, School of Agricultural Sciences, National University (UNA), Heredia, Costa Rica.ORCID https://orcid.org/0000-0002-0059-8028
Hale Ann TufanSection of Plant Breeding and Genetics, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA.ORCID https://orcid.org/0000-0002-5323-4244
Jacob B LandisSection of Plant Biology and the L.H. Bailey Hortorium, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA.ORCID https://orcid.org/0000-0002-5631-5365

Funding

The Regional Fund of Agricultural Research and Technological Development ATN/RF 20629-RG
6 · The paper itself

Abstract

Understanding crop genetic diversity is essential for conservation and breeding, yet farmer-maintained germplasm remains largely underrepresented in genomic studies. Theobroma cacao L. has a complex domestication history, extensive global diversity, and is currently cultivated in Central America. Costa Rican cacao has been understudied compared to South American and Mexican cultivars despite cultural and historical importance. In this study, we investigate the genetic diversity of cacao from farmer-managed systems across Costa Rica to search for Criollo germplasm while identifying and characterizing unique local genetic groups. Ninety-four trees were sampled for whole genome resequencing from 17 farms across four regions of the country. Farmer materials were analyzed alongside 166 previously characterized reference accessions representing major cacao genetic groups. Population structure analyses, phylogenetic reconstruction, and network approaches revealed that Costa Rican cacao encompasses multiple known genetic groups, including Criollo-derived lineages while also harbouring locally distinct diversity not represented in current global reference collections. Analyses revealed close kinship between many accessions with no clear geographic patterns corresponding to the observed population differentiation, reflecting the influence of farmers in generating the dominant patterns of gene flow through seed-saving, clonal propagation, and sharing of genotypes among farms. Heterozygosity levels varied substantially among individuals, consistent with a mixture of highly inbred Criollo trees and more heterozygous, admixed genotypes. We find that farmer-managed cacao systems are reservoirs of genetic diversity that can include rare or historically important lineages, underscoring the value of these farming systems for effective conservation and management of genomic resources for cacao resilience and improvement.

Indexed as

CacaoGenetics, PopulationGenetic VariationCosta RicaFarmersGenome, PlantPhylogenyadmixtureCentral AmericaconservationCriollogenome resequencingheritage cacaoheterozygosity

Identifiers

PMID42590994
PMCPMC13469988

What Socratic holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.