Taxonomic analysis of Amphisphaeriales in China: discovery of multiple novel taxa

Amphisphaeriales primarily contains saprobes, pathogens, and endophytes. This order of fungi is difficult to identify because of its taxonomic and morphological complexities. However, it has significant ecological and economic value and has recently become a major focus in fungal research. A total of 164 strains, isolated from decaying plant materials, diseased leaves, and healthy leaves, were used to explore the taxonomic diversity of Amphisphaeriales in China based on analyses of its morphology and multi-locus phylogenies (internal transcribed spacer [ITS], large subunit of ribosomal DNA [LSU], translation elongation factor 1-alpha [tef-1α], and beta tubulin [tub2]). The results of these analyses showed that all these collected strains belonged to 71 species, including Apiosporaceae (Apiospora and Nigrospora), Beltraniaceae (Beltraniella), and Sporocadaceae (Neopestalotiopsis, Pestalotiopsis, and Pseudopestalotiopsis). These analyses reveal three major findings: 38 new species, 33 known species (with A. locuta-pollinis (syn. A. fuxianhuensis) included among the known species. Through this study, we confirm a primary association of Apiospora with Poaceae in tropical and subtropical climates and documents multi-species co-infections. Our findings significantly contribute to the understanding of the placement of new taxa in Apiosporaceae, Beltraniaceae, and Sporocadaceae. Moreover, the results of this study contribute to the future taxonomic revisions and systematic studies of Amphisphaeriales.