<i>Trichoderma</i> Volatile Organic Compounds as a Biofumigation Tool against Late Blight Pathogen <i>Phytophthora infestans</i> in Postharvest Potato Tubers

We tested the ability of 14 strains of <i>Trichoderma</i> to emit volatile compounds that decreased or stopped the growth of <i>Phytophthora infestans</i>. Volatile organic compounds (VOCs) emitted from <i>Trichoderma</i> strains designated T41 and T45 inhibited the mycelial growth of <i>P. infestans</i> grown on a laboratory medium by 80 and 81.4%, respectively, and on potato tubers by 93.1 and 94.1%, respectively. Using the DNA sequence analysis of the translation elongation factor region, both <i>Trichoderma</i> strains were identified as <i>Trichoderma atroviride</i>. VOCs emitted by the strains were analyzed, and 39 compounds were identified. The most abundant compounds were 3-methyl-1-butanol, 6-pentyl-2-pyrone, 2-methyl-1-propanol, and acetoin. Electron microscopy of the hyphae treated with <i>T. atroviride</i> VOCs revealed serious morphological and ultrastructural damages, including cell deformation, collapse, and degradation of cytoplasmic organelles. To our knowledge, this is the first report describing the ability of <i>Trichoderma</i> VOCs to suppress the growth of the late blight potato pathogen.