Taxonomy and phylogeny of Pseudochaetosphaeronema associated with rubber trees from Yunnan Province, China

Approximately 77% of <i>Pseudochaetosphaeronema</i> species have been reported from China and Thailand in terrestrial habitats. We collected and isolated fruiting bodies of ascomycetous fungi in Yunnan Province, China, from dead branches of <i>Hevea brasiliensis</i>. Integrating morphology with phylogenetic analyses of combined ITS, LSU, SSU, and <i>tef</i>1-α sequence data, the strains were identified as a new species (<i>Pseudochaetosphaeronema heveae</i>), two new host records (<i>P. baoshanense</i> and <i>P. chiangraiense</i>), and a new collection (<i>P. xishuangbannaense</i>). Descriptions, illustrations, phylogenetic analysis results, and morphological comparisons with allied taxa of the four <i>Pseudochaetosphaeronema</i> species are provided. These findings expand the known diversity and host associations of <i>Pseudochaetosphaeronema</i>. In addition, based on morphological characteristics and molecular phylogenetic data, <i>P. hongheense</i> is synonymized under <i>P. baoshanense</i>.