Phylogenomic, Morphological, and Phylogenetic Evidence Reveals Five New Species and Two New Host Records of <i>Nectriaceae</i> (<i>Hypocreales</i>) from China

Fusarioid fungi, members of the <i>Nectriaceae</i> within the <i>Hypocreales</i> (<i>Ascomycota</i>), exhibit diverse ecological roles and possess complex phylogenetic relationships, including endophytic, saprophytic, and pathogenic lifestyles. Among them, the genera <i>Fusarium</i> and <i>Neocosmospora</i> are particularly significant in agriculture and medicine. However, the boundaries between their species remain taxonomically contentious. In this study, 22 representative isolates from plant, fungal, and insect hosts were subjected to a polyphasic taxonomic approach that integrated morphological characterization, multilocus phylogenetic analyses, and phylogenomic analysis based on 4,941 single-copy orthologous genes. Consequently, five new species (<i>F. dracaenophilum</i>, <i>F. puerense</i>, <i>F. wenshanense</i>, <i>N. alboflava</i>, and <i>N. fungicola</i>) were described, and <i>F. qiannanense</i> and <i>N. solani</i> were recorded from new host species. The resulting phylogenomic tree topology was highly congruent with the multilocus phylogeny, providing robust support for the taxonomic distinction between <i>Fusarium</i> and <i>Neocosmospora.</i> This study provides new insights into the taxonomy of fusarioid fungi and has important implications for plant disease management, biodiversity conservation, and the study of fungal evolution.