Essential Oils as an Antifungal Alternative to Control Several Species of Fungi Isolated from Musa paradisiaca: Part III

Abstract

Essential oils (EOs) are widely recognized for their antifungal properties, but their efficacy against specific phytopathogenic fungi associated with banana (Musa paradisiaca) rot remains underexplored. This study aimed to evaluate the antifungal potential of EOs from Origanum vulgare, Salvia rosmarinus, Syzygium aromaticum, Thymus vulgaris, Cinnamomum verum, and Ocimum basilicum against five fungal species isolated from infected banana peels. Fungal isolates were obtained using PDA medium supplemented with chloramphenicol and were purified by weekly subculturing. Morphological and microscopic characterization was complemented by molecular identification based on ITS sequencing and phylogenetic reconstruction using Neighbor-Joining and UPGMA methods in MEGA v11. In vitro and ex vivo antifungal assays were performed at EO concentrations ranging from 200 to 1000 ppm. Thyme oil exhibited the strongest inhibitory effect, with complete growth suppression at 1000 ppm. Cinnamon and oregano also demonstrated effective inhibition at 600 ppm, while clove, rosemary, and basil were markedly less effective. Statistical analysis confirmed significant effects of EO type and concentration on fungal growth (p < 0.001). Molecular results showed strong phylogenetic support for isolate identification, with bootstrap values above 93% in most clades. These findings support the selective use of specific EOs as sustainable alternatives to synthetic fungicides in the postharvest management of banana diseases and provide a molecularly supported basis for their targeted application in integrated control strategies.

Keywords: antifungal alternative; banana; basil; cinnamon; clove; oregano; post-harvest management; rosemary; thyme.

Figure 1

Macroscopy images of (a) Fusarium pseudocircinatum, (b) Colletotrichum tengchongense, (c) Fusarium verticilloides, (d) Fusarium napiforme, (e) Verticillium dahliae considering the appearance of the front side and (f) Fusarium pseudocircinatum, (g) Colletotrichum tengchongense, (h) Fusarium verticilloides, (i) Fusarium napiforme, and (j) Verticillium dahliae of reverse side.

Figure 1

Macroscopy images of (a) Fusarium pseudocircinatum, (b) Colletotrichum tengchongense, (c) Fusarium verticilloides, (d) Fusarium napiforme, (e) Verticillium dahliae considering the appearance of the front side and (f) Fusarium pseudocircinatum, (g) Colletotrichum tengchongense, (h) Fusarium verticilloides, (i) Fusarium napiforme, and (j) Verticillium dahliae of reverse side.

Figure 2

Microscopy images of (a) Fusarium pseudocircinatum, (b) Colletotrichum tengchongense, (c) Fusarium verticilloides, (d) Fusarium napiforme, (e) Verticillium dahliae and (f) Fusarium pseudocircinatum, (g) Colletotrichum tengchongense, (h) Fusarium verticilloides, (i) Fusarium napiforme, and (j) Verticillium dahliae.

Figure 3

Phylogenetic tree based on ITS region sequences of fungal isolates associated with Musa paradisiaca.

Figure 4

Fungal growth (cm) during 6 weeks in 20 banana samples inoculated with Fusarium pseudocircinatum, Colletotrichum tengchongense, Fusarium verticilloides, Fusarium napiforme, and Verticillium dahlia, stored at 13 °C and 95% HR approximately.

Figure 5

In vitro analysis of Fusarium pseudocircinatum in PDA medium supplied with basil, cinnamon, clove, oregano, rosemary, and thyme essential oils at various concentrations of 200, 400, 600, 800, and 1000 ppm (n = 12).

Figure 6

In vitro analysis of Colletotrichum tengchongense in PDA medium supplied with basil, cinnamon, clove, oregano, rosemary, and thyme essential oils at various concentrations of 200, 400, 600, 800, and 1000 ppm (n = 12).

Figure 7

In vitro analysis of Fusarium verticilloides in PDA medium supplied with basil, cinnamon, clove, oregano, rosemary, and thyme essential oils at various concentrations of 200, 400, 600, 800, and 1000 ppm (n = 12).

Figure 8

In vitro analysis of Fusarium napiforme in PDA medium supplied with basil, cinnamon, clove, oregano, rosemary, and thyme essential oils at various concentrations of 200, 400, 600, 800, and 1000 ppm (n = 12).

Figure 9

In vitro analysis of Verticillium dahliae in PDA medium supplied with basil, cinnamon, clove, oregano, rosemary, and thyme essential oils at various concentrations of 200, 400, 600, 800, and 1000 ppm (n = 12).