Insights into the taxonomy and phylogeny of Diatrypaceae

Diatrypaceae is among the most species-rich families within Xylariales, exhibiting a global distribution, a broad host range, and diverse ecological lifestyles. However, its taxonomy remains problematic due to overlapping morphological traits, insufficient diagnostic features in historical classifications, and the frequent absence of type specimens and corresponding multi-locus sequence data in GenBank. These limitations have resulted in poorly resolved generic boundaries and hinder accurate identification and natural classification within the family. In this study, we undertook an integrative taxonomic revision of Diatrypaceae by examining 17 herbarium specimens loaned from major international collections (B, BPI, BRIP, E, G, K, NY, PC, PDD, S), supplemented by redrawn illustrations from original descriptions where type material was unavailable. Additionally, approximately 150 fresh collections from China, Italy, and Thailand were investigated through single spore isolation and morphological examination. Molecular data were generated for multi-gene phylogenetic analysis based on combined ITS, tub2, LSU, and rpb2 sequences. Phylogenetic reconstruction using Maximum likelihood and Bayesian inference supports the recognition of 183 species within 34 genera, including the introduction of ten novel genera: Allantoideospora, Alloperoneutypa, Brunneosepta, Fusiformiascus, Guttuliascospora, Imitatirotula, Lineariascus, Retiticulatihypha, Sessiliascus, and Trichromostroma. The study also describes 29 novel species, 23 previously known species, and proposes 56 new combinations, all of which are illustrated and compared with morphological data and phylogenetically related taxa. Until further investigation using molecular data is proven, several morphologically characterized genera (Dothideovalsa, Echinomyces, Endoxylina, Leptoperidia, and Rostronitschkia) were placed within Diatrypaceae. This comprehensive morpho-molecular framework significantly refines the taxonomy of Diatrypaceae and provides a foundation for future systematic and ecological studies in this complex family.