Nano silver-encapsulation of Thymus daenensis and Anethum graveolens essential oils enhances antifungal potential against strawberry anthracnose

Abstract

Nanotechnology is an eco-friendly strategy in managing plant diseases. In combination with existing practices nanotechnology can enhance the protection of agricultural products and food. For example, essential oils (EOs) of thyme (Thymus daenensis L.) and dill (Anethum graveolens L.) have an antimicrobial potential and this potential may be enhanced by certain nanoparticle systems. Here we demonstrate that encapsulating EOs of thyme and dill in silver nanoparticles increases their fungicidal activity against Colletotrichum nymphaeae, causing anthracnose in many horticultural crops. Using GC-MS analysis, we identified p-cymene, thymol, carvacrol and (E)-caryophyllene as the main EOs of thyme and limonene, cis-dihydrocarvone, cyclohexanon, and carvone as the main EOs of dill. When the EOs of the two sources were encapsulated in silver nanoparticles, synergistic effects against C. nymphaeae were observed, resulting in more than 80% inhibition of mycelium growth of C. nymphaeae. Moreover, conidia germination was suppressed by nano-encapsulated EOs. We also observed considerable morphological changes in the fungal hyphae when nano-encapsulated EOs were applied. Our study demonstrates the potential of encapsulated EOs in controlling pathogens that can be very applicable as antifungal agents.