Appressoria are specialized structures formed by certain phytopathogenic fungi during the early stages of the infection process. Over the years, significant advancements have been made in understanding the formation, types, and functions of appressoria. Besides being formed primarily by fungal pathogens, many studies have reported their occurrence in other life modes such as endophytes, epiphytes, and saprobes. In this study, we observed the formation of appressoria in fungal genera that have been found associated with leaf spots and, interestingly, by a saprobic species. We used morphological descriptions and illustrations, molecular phylogeny, coalescent-based Poisson tree processes (PTP) model, inter- and intra-species genetic distances based on their respective DNA markers, and Genealogical Concordance Phylogenetic Species Recognition Analysis (GCPSR) to establish a new species (Pseudoplagiostoma jasmini), a Ciliochorella sp., and a new host record (Coniella malaysiana). The Ciliochorella sp. is reported as a saprobe, while Pseudoplagiostoma jasmini and Coniella malaysiana were found to be associated with leaf spots of Jasminum species. All three taxa produce appressoria, and this is the first study that reports the formation of appressoria by a Ciliochorella sp. and a Pseudoplagiostoma sp.
Keywords: Ciliochorella; Coniella; Pseudoplagiostoma; infection pegs; novel taxon; phylogeny; poisson tree processes; taxonomy.