Unveiling two new species of Trichoderma (Hypocreales, Hypocreaceae) that cause green mold disease on Stropharia rugosoannulata from Guizhou Province, China

<i>Strophariarugosoannulata</i> is an important edible mushroom in China, but green mold disease has caused significant production and economic losses. In this study, two new pathogens <i>Trichodermastrophariensis</i> and <i>T.viridistromatis</i> were identified as the causal agents of this disease. During October-November 2023, six strains of the fungal pathogen were isolated from infected fruiting bodies of <i>S.rugosoannulata</i> and identified based on morphological characteristics and molecular phylogenetic analyses of internal transcribed spacer (nrITS), the second largest RNA polymerase II subunit (<i>rpb2</i>) and the partial translation elongation factor 1-alpha (<i>tef1-α</i>) region. The representative isolates of the pathogenic green mold <i>Trichoderma</i> species were used to perform a pathogenicity test with spore suspensions, resulting in symptoms similar to those observed in the cultivated field. The same pathogens were successfully re-isolated, thereby fulfilling Koch's postulates. Detailed morphological descriptions, illustrations, culture characteristics, and comparisons with morphologically similar and closely related species are provided.