Mechanistic and applied insights into antifungal action of essential oils and phytochemical extracts against Colletotrichum gloeosporioides in mangoes: ultrastructural and GC-MS evidence

Introduction Mango anthracnose, caused by Colletotrichum gloeosporioides , is a major pre- and post-harvest disease that reduces fruit quality, shelf life, and market value. Reliance on synthetic chemicals for postharvest disease management necessitates safer and sustainable alternatives due to health and environmental challenges. Methods This study assessed the in vitro antifungal efficacy of six medicinal plants-Anethum graveolens (AG), Ferula assa-foetida (FA), Justicia adhatoda (JA), Macrotyloma uniflorum (MU), Nyctanthes arbor-tristis (NA), and Vitex negundo (VN)-using five solvent extracts and essential oils (EOs) against C. gloeosporioides . Gas Chromatography-Mass Spectrometry (GC-MS) identified bioactive compounds in the most effective phytoextracts, whereas Scanning Electron Microscopy (SEM) examined ultrastructural aberrations in fungal mycelia post-treatment. Statistical analyses (ANOVA and Bonferroni's post hoc test) assessed the effects of plant species, solvent polarity, and exposure duration on antifungal performance. Results The results showed a clear dose-dependent inhibition of mycelial growth and spore production across treatments. EOs demonstrated the highest antifungal activity, achieving up to 100% inhibition at 40–80 μL mL −1 , followed by petroleum ether (PE) extracts, whereas aqueous (AQ) and methanolic (MeOH) extracts were less effective. Among plants, AG showed the most consistent antifungal effect, followed by FA and JA. GC-MS profiling detected 137 compounds (84.6%−97.65% composition), including fatty acids (23.88%), terpenoids, sesquiterpene alcohols (11.48%), epoxides (8.58%), sulfides (7.11%), and terpenes (5.79%) known to disrupt fungal membranes and inhibit mycelial and spore growth. Discussion The findings indicate that plant species are the key determinant of antifungal efficacy, whereas solvent type and exposure duration act as secondary modulators. EOs, particularly from AG and FA, show promise as eco-friendly alternatives to synthetic fungicides and could be integrated into sustainable strategies for managing mango anthracnose.