Antifungal Potential of Essential Oils From Native Mexican Species: Chemical Composition and In Vitro Vapor-Phase...

Colletotrichum gloeosporioides and Rhizopus stolonifer are fungal pathogens that cause significant postharvest fruit losses. The continued use of synthetic fungicides raises concerns about toxicity, environmental impacts, and resistance development, leading to increased interest in alternatives such as essential oils (EOs). This study assessed the antifungal activity of 10 EOs extracted from native aromatic plants of the Yucatán Peninsula using vapor-phase assays. EOs from Lippia origanoides, Bursera simaruba, and Piper auritum showed activity against both fungi. Their chemical compositions were dominated by monoterpenes and monoterpenoids, including carvacrol (60%), α-pinene (65.2%), and safrole (55.7%), respectively. L. origanoides EO exhibited minimal inhibitory concentration (MIC) values of 0.01 and 0.006 µL/mL air against the mycelial growth of C. gloeosporioides and R. stolonifer, respectively, and a 0.4 µL/mL air for spore germination in C. gloeosporioides. Furthermore, this research offers deeper insights into the link between EO chemical composition and antifungal activity through multivariate statistical methods, including hierarchical cluster analysis, heat map visualization, and correlation analysis. Scanning electron microscopy revealed notable ultrastructural changes, such as hyphal shrinkage, deformation, and spore collapse, suggesting membrane disruption. These findings, obtained under in vitro conditions, provide additional evidence of antifungal efficacy in vapor-phase systems and encourage additional investigation of L. origanoides EO. Additional studies, including in vivo experiments and assessments under postharvest conditions, are necessary to determine its practical applicability.