Antifungal Activity of Three Essential Oils againstColletotrichum acutatum, the Causal Agent of Strawberry Anthracnose

Abstract

The antifungal effects of thyme, cinnamon bark and clove bud essential oils (EOs) were investigated in vitro on Colletotrichum acutatum mycelial growth, conidial germination, appressoria formation, and in vivo on strawberry fruit disease incidence. All tested EOs, incorporated in potato-dextrose agar, inhibited C. acutatum mycelial growth, and had a fungistatic effect at concentration 667 μl/l of medium. Volatiles of cinnamon bark, thyme and clove bud EOs completely prevented conidial germination at the lowest concentrations of 1.53, 15.3 and 76.5 μl/l of air, respectively, and disabled appressoria formation at concentration of 1.53 μl/l of air. On inoculated strawberry fruit, thyme and cinnamon bark EO volatiles reduced anthracnose incidence at concentrations above 15.3 and 76.5 μl/l of air, respectively. GC-FID and GC-MS analysis showed that major components of thyme EO were p-cymene, thymol, α-terpineol, carvacrol; cinnamon bark EO: transcinnameldehyde, trans-cinnamyl acetate; clove bud EO: eugenol and β-caryophyllene. Our results suggest that volatiles of thyme and cinnamon bark EOs are effective against C. acutatum both in vitro and in vivo.

Efficacy and Mechanism of Cinnamon Essential Oil on Inhibition of Colletotrichum acutatum Isolated From ‘Hongyang’ Kiwifruit

“…Results showed that inhibitory activity of CEO was significantly correlated with the concentration of CEO. In present study, the spore germination was more sensitive to CEO treatment than mycelial growth, which was in accordance with previous studies ( Duduk et al, 2015 ). CEO had a fungistatic effect against mycelial growth of C. acutatum isolated from strawberry anthracnose at 0.667 μL/mL.…”

“…CEO had a fungistatic effect against mycelial growth of C. acutatum isolated from strawberry anthracnose at 0.667 μL/mL. Meanwhile, CEO completely prevented the spore germination and appressorium formation at 0.00153 μL/mL ( Duduk et al, 2015 ). In addition, CEO strengthens its merits as a post-harvest fungicide against food-borne pathogens.…”

“…Our previous studies have demonstrated that CEO have good inhibitory effects against Botryosphaeria parva in vitro , and can reduce soft rot on ‘Hongyang’ kiwifruit in vivo ( He et al, 2015 ). Antifungal activity of CEO against C. acutatum isolated from strawberry anthracnose was investigated ( Duduk et al, 2015 ). Cell plasma membrane (PM) is the action site invaded by antifungal substances, such as silicon and chlorine dioxide ( Wei et al, 2008 ; Liu et al, 2010 ).…”

Role of Natural Volatiles and Essential Oils in Extending Shelf Life and Controlling Postharvest Microorganisms of Small Fruits

“…This may contribute to the buildup of food-borne bacteria and may pose a food safety risk to consumers since small fruits are eaten fresh. Also, small fruits have a very short shelf life due to their susceptibility to spoilage pathogens, physiological disorders and mechanical injury [2]. This is partly due to their high nutrient content and water activity, and low pH which make them susceptible to fungal attack.…”

Essential Oils and Their Applications -A Mini Review

“…Astracanicum on some selected gram-negative bacteria and concluded on the antimicrobial activity and its potential usefulness [79]. According to Nataša et al, thyme, cinnamon bark and clove bud essential oils were effective against Colletotrichum acutatum mycelial growth of strawberry [80]. The cell destruction of these pathogens is as a result of the ability of the hydrophobic compounds in the essential oils to disrupt the microorganism's cell membrane, which results in change of cell morphology, alteration of membrane permeability and leakage of electrolytes [81].…”