Whole-Genome Characterization of Inonotus hispidus from Ulmus macrocarpa and Its Comparative Genomics with Strains from Morus alba and Acer truncatum

<i>Inonotus hispidus</i> growing on <i>Morus alba</i> is traditionally regarded as the authentic source of the medicinal fungus. However, this species is also found on other host trees, such as <i>Ulmus macrocarpa</i> and <i>Acer truncatum</i>; yet, whether these strains share comparable genomic and functional traits with <i>Morus</i>-derived strains remains unknown. Here, we performed whole-genome sequencing of a strain isolated from <i>U. macrocarpa</i> (UMI) using Illumina and PacBio platforms and conducted comparative genomic analysis with strains from <i>M. alba</i> (MAI) and <i>A. truncatum</i> (AMI). Antagonistic interactions were also evaluated via dual-culture confrontation assays. The UMI genome was 36.44 Mb in size, comprising 9097 predicted genes, of which 6991 and 1672 were annotated in the KEGG and COG databases, respectively. SNP analysis revealed 623,498 and 335,343 variants in AMI and MAI, with AMI showing greater genomic variation. Core-pan genome analysis identified 2651 core genes and 1046, 1424, and 1217 strain-specific genes in UMI, AMI, and MAI, respectively. Phenotypic assays demonstrated distinct mycelial growth dynamics and antagonistic behaviors, which likely reflect host-related environmental adaptation. Overall, <i>I. hispidus</i> strains from non-<i>Morus</i> hosts exhibit unique genomic and phenotypic features, providing a valuable basis for resource evaluation, artificial domestication, and the medicinal development of wild Sanghuang strains beyond traditional sources.