Spirodecosporaceae fam. nov. (Xylariales, Sordariomycetes) and two new species of Spirodecospora

Abstract

The genus Spirodecospora has been placed in Xylariaceae based on morphological similarities. Spirodecospora spp., found on bamboo in Japan, were taxonomically and phylogenetically studied using molecular data for first time. Molecular phylogenetic analyses were based on the DNA sequence data of three regions: the nuclear ribosomal internal transcribed spacer (ITS) region, the large subunit (LSU) of rDNA, and the second largest RNA polymerase II subunit (rpb2) gene. Results showed that Spirodecospora formed an independent lineage from other known families in Xylariales. The new family Spirodecosporaceae is introduced in this study to accommodate this lineage based on the phylogenetic evidence and morphological differences from the other known families. Spirodecospora is characterised by having deeply immersed ascomata with a cylindrical ostiolar neck, unitunicate, cylindrical asci with I+, wedge-shaped apical ring, and broadly ellipsoidal to fusoid, aseptate, brown, verruculose ascospores with spirally or almost straight linear ornamentation. Based on morphological observations and molecular phylogenetic analyses, S. melnikii and two new species of Spirodecospora, S. paramelnikii and S. paulospiralis, are described and illustrated. A key to the four accepted species of Spirodecospora is provided.

Addition of Five Novel Fungal Flora to the Xylariomycetidae (Sordariomycetes, Ascomycota) in Northern Thailand

“…The intragenomic ITS variation among Muscodor species or anthostomella-like taxa needed to be checked to understand the ITS based species demarcation. Nigropunctata and Spirodecospora species are associated with dead bamboo and are similar to inconspicuous stromatic forms [89]. The microscopic morphologies and phylogenetic analyses support accepting them as distinct clades apart from the core Xylariaceae.…”

“…Recent research on those incertae sedis taxa, which were previously known from a single collection, lacking recent collections, having inconsistent morphologies, no sexual-asexual links, and no molecular evidence, has urged the classification of genus to the family level. Families like the Appendicosporaceae [8], Barrmaeliaceae [32], Fasciatisporaceae [55], Gyrothricaceae [35], Oxydothidaceae [90], and Spirodecosporaceae [89] are some of the examples that have primarily been raised through studies on inconspicuous xylarialean taxa. Prior research has most likely focused on stromatic forms like diatrypoid, hypoxyloid, rosellinioid, and xylarioid rather than inconspicuous stromatic forms like anthostomelloid.…”