Thyridariella, a novel marine fungal genus from India: morphological characterization and phylogeny inferred from multigene DNA sequence analyses

A novel saprobic fungal genus, Thyridariella (Thyridariaceae), is herein described to include Thyridariella mangrovei, the type species and T. mahakoshae spp. nov. Both species were collected as saprobes on decaying wood of Avicennia marina, a common mangrove species found near Kaveri River Delta, Tamil Nadu, on the east coast of India. Thyridariella is diagnosed by having an exclusive combination of characters, such as ascomata with ostiolar necks thickened laterally, hyaline, and centrally constricted muriform ascospores with a single longitudinal septum in each segment and surrounded by a mucilaginous sheath. These characters demarcate these taxa from morphologically similar genera such as Halojulella and Julella. In addition, the new genus also differs from Parathyridaria and Thyridaria in having hyaline, muriform ascospores with distinct mucilaginous sheaths. The monophyly of Thyridariella is well supported in the phylogenetic analysis based on a concatenated dataset from two proteins and three nuclear gene regions. The phylogeny also depicts a sister group relationship of our new genus to Parathyridaria and Thyridaria and hence confirms its position within Thyridariaceae.