Exploring the taxonomy and phylogeny of Sordariomycetes taxa emphasizing Xylariomycetidae in Southwestern China
Authors:   Engineering and Research Center for Southwest Bio-Pharmaceutical Resources of National Education Ministry of China, Guizhou University, Guiyang 550025, P.R. China, Dissanayake Lakmali S , Samarakoon Milan C , Maharachchikumbura Sajeewa SN , Hyde Kevin D , Tang Xia , Li QR , Mortimer Peter E , Faraj Turki , Xu Jianchu , Kang Ji-Chuan , Wanasinghe Dhanushka N 
Published: October 2024

Southwestern China has been widely acknowledged as a global biodiversity hotspot, renowned for its high levels of floral, faunal and microbial diversity. However, research on fungi, particularly microfungi, remains limited with comparison to the other kingdoms i.e. Plantae and Animalia. Within the fungal kingdom, the subclass Xylariomycetidae (Sordariomycetes, Ascomycota), presents a vast range of macro- and micro-morphological features, yet our knowledge of their taxonomy, diversity and geographical distribution is still lacking. To fill out this knowledge gap, our study focused on a survey of Xylariomycetidae taxa across diverse habitats in the Southwest of China, encompassing the provinces of Guizhou, Sichuan and Yunnan. The primary objective of this study was to examine fresh collections of terrestrial Xylariomycetidae and to investigate their taxonomy and phylogeny via polyphasic approaches. Employing phylogenetic analysis of targeted DNA loci within specific families and genera, encompassing all accessible ex-type and non-type strains as well as holotypes and additional herbarium material, we elucidated novel taxonomic relationships among Xylariomycetidae in Southwestern China. Our analyses revealed 30 previously unidentified species and confirmed the existence of 20 known species within the Xylariomycetidae. We also validly publish Apiospora koreana as a new species as it was previously invalidly published. Fourteen new species are introduced to Amphisphaeriales viz. Amphisphaeria ailaoshanensis, A. kunmingensis, A. magna, A. shangrilaensis, A. xishuangbannaense (Amphisphaeriaceae), Apiospora arecacearum, A. koreana, A. menglaensis, A. senecionis and A. trachycarpi (Apiosporaceae), Neoamphisphaeria shangrilaensis (Appendicosporaceae), Iodosphaeria sichuanensis (Iodosphaeriaceae), Broomella meilishanguensis and Robillarda sichuanensis (Sporocadaceae). In Xylariales, 14 new species were introduced viz. Barrmaelia yunnanensis, B. shangrilaensis, Entosordaria shangrilana (Barrmaeliaceae), Diatrypella kunmingensis, Peroneutypa hongheensis (Diatrypaceae), Fasciatispora sichuanensis (Fasciatisporaceae), Hypoxylon guiyangense, H. guizhouense (Hypoxylaceae), Requienella shangrilana (Requienellaceae), Vamsapriya sichuanensis (Vamsapriyaceae), Collodiscula yunnanensis, Digitodochium ailaoshanense, D. yunnanensis and Nemania leishanensis (Xylariaceae). We identified three new Distoseptispora species, D. chishuiensis, D. liupanshuiensis and D. sichuanensis, in Sordariomycetidae. These findings greatly enhance our understanding of fungal diversity in the region, highlighting the presence of numerous potentially novel species and providing a compelling opportunity for mycologists to explore further research avenues. Additionally, the comprehensive morphological descriptions and molecular sequences generated by this study serve as valuable resources for future taxonomic studies and contribute to a broader understanding of fungal diversity in Southwestern China.