The Amazonian dissemination routes and genetic diversity of Moniliophthora perniciosa C-biotype in Northern Peru

Ramos-Carrasco T.A.; Iliquin-Inga I.M.; Aime M.C.; Leiva-Espinoza S.T.; Oliva-Cruz S.M.; Díaz-Valderrama J.R. · Tropical Plant Pathology (2025) · DOI: 10.1007/s40858-025-00757-6

Resumen

Moniliophthora perniciosa C-biotype is the causal agent of witches’ broom disease of cacao (WBD), one of the most important diseases of the crop in Peru. Several questions remain unanswered about this disease in the country, such as the incidence levels, the morphological and genetic diversity, and the dissemination routes of the pathogen. We evaluated fifty isolates from districts located in areas of “Difficult Access” deep in the Amazon, and of “Easy Access” close to urban areas on the Western side of the Amazon. We found higher incidence levels of WBD in districts with historical records of high humidity and precipitation. We also found significant differences in the radial growth of isolates and documented nine mycelial colony growth groups with a varying presence of clamp connections. The microsatellite marker genotyping revealed the highest indexes of diversity in areas of “Difficult Access” and identified these Amazonian areas harbored the ancestral population of M. perniciosa from which the pathogen most likely disseminated towards the “Easy Access” areas. This study lays the foundation for future studies to fully understand the morphological and genetic diversity, and epidemiology of M. perniciosa in the northern Peruvian Amazon. © The Author(s), under exclusive license to Sociedade Brasileira de Fitopatologia 2025.

Instituciones: Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas