Inhibitory Effects of Origanum vulgare Essential Oil on Mycogone perniciosa Growth in Agaricus bisporus Cultivation

Mycogone perniciosa is the causative agent of wet bubble disease, which induces significant losses in the production of Agaricus bisporus, indicating the high importance of the development of novel inhibitory agents. The isolation, identification, and molecular characterization of five isolates of M. perniciosa from diseased fruit bodies of A. bisporus was done. Moreover, the study evaluated the in vitro and in situ potential of Origanum vulgare essential oil (EO) to limit M. perniciosa growth and provided chemical characterization of its volatile components. The obtained strains differed phenotypically and according to their molecular characteristics. O. vulgare EO has shown more promising antifungal activity than the commercial fungicide Prochloraz-Mn in the microatmospheric method. In the treatment of experimentally induced wet bubble disease on A. bisporus in the growing chambers with 2% of O. vulgare EO and simultaneous application of spore suspension of mycopathogen, O. vulgare EO totally inhibited the growth of M. perniciosa. Carvacrol, p-cymene, γ-terpinene, and thymol were dominant constituents of O. vulgare EO examined in this study. O. vulgare EO has shown promising potential to limit growth of M. perniciosa and should be further explored as a novel biofungicide.