Taxonomy and Diversity of Woody Litter Microfungi Associated with Six Phylogenetically Related Host Species in Doi Tung National Park, Chiang Rai, Thailand

Woody litter contributes to the high microbiological diversity of tropical forests, providing both habitat and nutrients. In forest environments, fungi are the most abundant microbial communities associated with woody litter, playing vital roles in the decomposition process. Diversity and abundance of fungal community are influenced by various factors, i.e., the decomposition stage, wood type, moisture content, and substrate size. This paper elaborates the study of morphology, phylogeny, host-recurrence, and diversity patterns across two seasons and three decomposition stages in saprobic microfungi associated with woody litter of Nayariophyton zizyphifolium, Microcos paniculata (Malvaceae), Dipterocarpus alatus (Dipterocarpaceae), Afzelia xylocarpa, Dalbergia cana, and D. cultrata (Fabaceae) at Doi Tung national park, Chiang Rai, Thailand. Fungal communities of woody litter from these host species have not been well-investigated. Furthermore, the relationship of host phylogeny to wood-dwelling microfungal communities has not been established. Fungal isolates were obtained through single spore isolation, and their morphologies were characterized. Multilocus phylogenetic analyses using Maximum Likelihood (ML) and Bayesian Inference (BI), based on different gene regions specific to each taxon, were conducted to confirm species identify and taxonomic classifications. Host-recurrence of the identified fungi based on morphological and molecular data, and fungal diversity across seasons and decomposition stages were analyzed to evaluate fungal community composition. A total of 125 fungal collections were identified, representing three classes, 24 orders, 45 families, 63 genera, and 91 species (Table S1). Among these taxa, this study provides detailed taxonomic information and phylogenetic analyses for one new family, two new genera, 11 new species, five first reports of sexual or asexual morph connections, and 20 new host fungal records, additional fungal collections, habitat, and new geographical records. The newly introduced taxa are: Chromolaenicola doitungensis, Colletotrichum nayariophyti, Corynespora chiangraiensis, Cylindroconidiis doitungensis, Dictyoarthrinium doitungensis, Nemania doitungensis, Oxydothis dalbergiae, Palmiascoma chiangraiense, Pisorisporium nayariophyti, Striaticonidium chiangraiense, and Xylochrysis chiangraiensis. of these, Novolignincolaceae (Novolignincola doitungensis) is introduced as a new family, and Doitungomyces (Doitungomyces dipterocarpi) and Sporicula (Sporicula chiangraiensis) as new genera. In addition, new sexual or asexual records for Colletotrichum gigasporum, Cytospora heveae, Misturatosphaeria viridibrunnea, Paraconiothyrium archidendri, and Pseudofusicoccum kimberleyense are described. In addition, fungal host-recurrence was also investigated. Hierarchical clustering revealed minor differences in fungal community composition across phylogenetically related hosts, with the highest specificity at the genus level. The early decomposition stage exhibited the highest diversity with distinct dominant genera. Additionally, fungal genus diversity showed distinct seasonal patterns, with more genera displaying high abundance during the dry season.