Morphology and Phylogeny Reveal New Species and Records of Diplodia, Dothiorella, and Phaeobotryon Associated with Tree Cankers in Xizang, China

The fungal family Botryosphaeriaceae, which includes genera such as <i>Diplodia</i>, <i>Dothiorella</i>, and <i>Phaeobotryon</i>, comprises species commonly associated with woody plants such as endophytes, pathogens, and saprophytes. The Xizang Autonomous Region of China, known for its rich forest resources, harbors significant fungal diversity. However, limited research has been conducted on plant-disease-associated fungi in this region. In this study, we employed morphological characteristics and molecular phylogenetic analyses of the internal transcribed spacer region of rDNA (ITS), the ribosomal large subunit (LSU), the translation elongation factor 1-alpha (<i>tef1</i>) gene, and the partial beta-tubulin (<i>tub2</i>) gene to identify fungal species. As a result, two new species, <i>Diplodia salicicola</i> sp. nov. and <i>Phaeobotryon xizangense</i> sp. nov., are proposed and described herein. Additionally, <i>Di</i>. <i>corticola</i>, <i>Di</i>. <i>mutila</i>, <i>Do</i>. <i>acericola</i>, <i>Do</i>. <i>magnoliae</i>, <i>Do</i>. <i>vidmadera</i>, <i>Do</i>. <i>yunnana</i> comb. nov., and <i>Do</i>. <i>zanthoxyli</i> are reported for the first time in Xizang. Our findings contribute to advancing the knowledge of fungal biodiversity in Xizang's high-altitude ecosystems.