Two novel species of Sympoventuriaceae from palms in China

Palm plants (Arecaceae) are widely distributed ornamental hosts in southern China. However, most of these plants are introduced species, and their associated microfungal diversity remains poorly understood. In this study, four strains with morphological affinities to Scolecobasidium and Yunnanomyces (Sympoventuriaceae) were isolated from palm plants in Yunnan Province, China. Two novel species, Scolecobasidium yunnanense and Yunnanomyces didymosporus, are proposed based on morphological observations and separate multi-locus phylogenetic analyses: the phylogeny of Scolecobasidium was constructed from a concatenated ITS + nLSU + tub2 + tef1-α dataset, while analyses for Yunnanomyces within Sympoventuriaceae relied on a combined ITS + nLSU + nrSSU + RPB2 dataset. Scolecobasidium yunnanense is characterized by its branched, septate, thick-walled pale hyphae, erect, unbranched and septate conidiophores often reduced to denticulate conidiogenous cells, and smooth, mostly 2-septate, ellipsoidal to fusiform conidia, measuring 8.3-12.6 × 2.0-3.5 μm. Yunnanomyces didymosporus is characterized by its monilioid mature hyphae, intercalary conidiogenous cells, and chain-forming mostly 1-septate conidia with a dark hilum on one or both ends, measuring 6.1-11.9 × 2.0-4.2 μm. The study confirms their distinctiveness from extant species within each genus and enhances the understanding of microfungal diversity associated with palms.