Unexplored microfungal diversity from dead woody litter in the dry-hot valleys of Honghe (Yunnan, China)

Despite the critical ecological role fungi play across various ecosystems, the mycoflora of dry-hot valleys remains largely underexplored. This study aims to fill this gap by documenting the diversity and taxonomy of microfungal species in this unique environment. Employing a combination of field sampling, morphological analysis, and molecular techniques, the study conducted a comprehensive survey of microfungi in selected dry-hot valleys of the Honghe region in Yunnan (China). The findings reveal a rich and previously undocumented diversity of <italic>Dothideomycetes</italic> (<italic>Ascomycota</italic>). Among the collected samples, 34.9% of the <italic>Dothideomycetes</italic> isolates were identified as new species described in this study. The identified microfungi belong to six orders encompassing 18 families and 26 genera. A total of 34 microfungal taxa are documented, including two new families, two new genera, 15 new species, and 15 existing records. During this study, <italic>Mangifericomitaceae</italic> (<italic>Pleosporales</italic>) and <italic>Mucomycosphaerellaceae</italic> (<italic>Mycosphaerellales</italic>) are introduced as new families. <italic>Gruyteromyces</italic> and <italic>Longiascospora</italic> are introduced as new genera in <italic>Didymellaceae</italic> (<italic>Pleosporales</italic>) and <italic>Pleurotremataceae</italic> (<italic>Dyfrolomycetales</italic>), respectively. The study also introduces new species: <italic>Anteaglonium hongheense</italic>, <italic>Anthosulcatispora hongheensis</italic>, <italic>Chromolaenicola hongheensis</italic>, <italic>Gruyteromyces hongheensis</italic>, <italic>Helminthosporium hongheense</italic>, <italic>Longiascospora hongheensis</italic>, <italic>Magnibotryascoma hongheense</italic>, <italic>Mangifericomes yunnanensis</italic>, <italic>Mucomycosphaerella hongheensis</italic>, <italic>Neomultiseptospora hongheensis</italic>, <italic>Paulkirkia hongheensis</italic>, <italic>Pseudocapulatispora hongheensis</italic>, <italic>Pseudochaetosphaeronema hongheense</italic>, <italic>P. punithalingamii,</italic> and <italic>Pseudostaurosphaeria hongheensis</italic>. <italic>Aplosporella artocarpi</italic>, <italic>A. hesperidica</italic>, <italic>Chromolaenicola clematidis</italic>, <italic>Dendryphion hydei</italic>, <italic>Leptospora phraeana</italic>, <italic>Murichromolaenicola thailandensis</italic>, <italic>Neomultiseptospora yunnanensis</italic>, <italic>Neoroussoella bambusae</italic>, <italic>Neovaginatispora fuckelii</italic>, <italic>Paraphaeosphaeria jaguarinae</italic>, <italic>Patellaria microspora</italic>, <italic>Pseudocapulatispora longiappendiculata</italic>, <italic>Rhytidhysteron neorufulum</italic>, <italic>Tremateia guiyangensis</italic>, and <italic>Xenoroussoella triseptata</italic>, reported as new records. These results highlight the significance of dry-hot valleys as reservoirs of fungal biodiversity and highlight the importance of including these ecosystems in conservation strategies. This study contributes to the expanding knowledge on fungal diversity in extreme environments and calls attention to the need for further research into the ecological roles and potential applications of these neglected mycoflora.