Title : Antifungal potential of Piper essential oils against Fusarium triseptatum associated with Gulupa crops
Abstract:
Fusarium species are important phytopathogens responsible for vascular and tissue-associated diseases that can substantially reduce crop productivity and quality. In gulupa (Passiflora edulis f. edulis), infections caused by Fusarium represent a relevant phytosanitary constraint, while their management relies largely on synthetic fungicides. The intensive use of these products is associated with the selection of resistant fungal populations, environmental impacts, toxicity concerns, and pesticide residues that may compromise compliance with international market requirements. These limitations encourage the search for alternative antifungal agents with greater environmental compatibility. Essential oils from the genus Piper constitute a chemically diverse source of volatile specialized metabolites with potential antifungal activity, particularly through vapor-phase exposure. This study evaluated the in vitro antifungal potential of 14 essential oils obtained from Piper species collected in Boyacá and Cundinamarca, Colombia, against Fusarium triseptatum isolated from symptomatic gulupa stems. Essential oils were obtained by steam distillation, and their antifungal activity was initially assessed using a vapor-phase assay at 183 μL/L of air by measuring mycelial growth inhibition. Oils producing at least 60% inhibition were selected for concentration–response assays, and half-maximal inhibitory concentrations (IC??) were estimated by nonlinear regression. Bioactive oils were characterized by GC-MS using columns of complementary polarity, with compound identification supported by mass spectral data and linear retention indices. Nine of the 14 essential oils met the established activity criterion, with IC?? values ranging approximately from 27 to 64 ppm. The strongest antifungal responses were observed for oils from Piper divortans, P. marginatum, P. subflavum var. espejuelanum, P. Piper fusagasuganum and P. aduncum, with IC?? values below 40 ppm. Chemical profiling revealed marked compositional diversity among the active oils. Hydrocarbon sesquiterpenes predominated in several samples, whereas phenylpropanoids and oxygenated sesquiterpenes characterized others. Differences in antifungal potency were also observed between oils from the same species collected in different geographic locations, suggesting that provenance-associated chemical variability may influence biological activity. Overall, these findings highlight Colombian Piper essential oils as promising sources of volatile antifungal agents and provide a basis for developing natural phytosanitary alternatives for the management of F. triseptatumin gulupa crops. Further studies should address mechanisms of action, phytotoxicity, ecotoxicological safety, formulation, and efficacy under controlled and field conditions. This study was funded by Colombia’s Sistema General de Regalías under project BPIN 2023000100058. Collection of plant material and access to genetic resources and their derived products were conducted under Genetic Resources Access Contract No. 121 of January 22, 2016, and its Amendment (Otrosí) No. 21, signed between the Ministerio de Ambiente y Desarrollo Sostenible and the Universidad Nacional de Colombia.
