Phenotypic diversity of wild cacao in Peru's largest germplasm bank: novel insights for breeding and conservation

Arévalo-Gardini E.; Arévalo-Hernández C.O.; Flores-Isuiza G.; Zuñiga-Cernades L.B.; Arévalo-Gardini J.; Tuesta-Hidalgo O.A.; Ruiz-Camus C.E.; Baligar V.; Mehinhard L.; Zhang D. · Beverage Plant Research (2025) · DOI: 10.48130/bpr-0025-0024

Resumen

The Amazon rainforest is a significant center of origin for Theobroma cacao L. (cacao), and understanding the phenotypic diversity of its wild populations is crucial for genetic improvement and conservation strategies. In this study, the phenotypic diversity of 511 wild cacao accessions, collected between 2008 and 2015 from 18 river basins in the Peruvian Amazon and subsequently conserved at the germplasm bank of the Instituto de Cultivos Tropicales in Tarapoto, Peru, was evaluated. Phenotypic diversity was assessed using 27 quantitative traits related to leaves, fruits, seeds, and flowers. The results revealed significant differences in trait expression among river basins, highlighting the influence of environmental conditions on phenotypic variation. Notably, accessions from the Amazonas, Madre de Dios, and Tigre basins exhibited the highest seed index, while the best pod index was recorded in Madre de Dios, demonstrating considerable variability in yield potential. Similar trends were observed in pod weight, seed number per pod, and fruit dimensions, underscoring the role of geographical origin in shaping phenotypic traits. Phenotypic diversity analysis using principal component analysis and hierarchical clustering identified five distinct groups among the wild cacao accessions. These findings offer valuable insights for selecting superior genotypes adapted to specific environmental conditions and lay the groundwork for future breeding programs to enhance cacao productivity and resilience.

Instituciones: Universidad Nacional Autónoma de Alto Amazonas