Phylogenetic Relationships of Five Phallales Species Based on Mitochondrial Genome Analysis

Fungi of the Phallales order are globally distributed and are important in forest ecosystems, and many species have medicinal and edible value. However, despite the rich diversity, the information on this order is limited, and its taxonomic classification remains contentious. In this study, the mitogenomes of five species from the Phallales order were sequenced, assembled, annotated, and compared. All five assembled mitogenomes were circular, ranging in size from 41,465 bp to 99,150 bp. Introns and intergenic regions were the key factors for mitogenome size variation in the Phallales order. The arrangement of 15 protein-coding genes, 2 rRNA genes, and 24 tRNA genes was highly conserved among the Phallales species. The only variation observed was the presence of an additional copy of trnI, trnT, trnD, and trnF in some mitogenomes. Specifically, the mitogenomes of P. rugulosus, P. hadriani, P. rigidiindusiatus, and P. dongsun had an additional copy of trnI, trnT, trnD, and trnF, respectively. A phylogenetic analysis produced well-supported phylogenetic tree, indicating that the mitogenome was an effective molecular marker for inferring evolutionary relationships. The phylogenetic analysis showed that the Phallales and Gomphales species share a closer evolutionary relationship. Our results contribute to a better understanding of the evolutionary dynamics, genetic constitution, and systematic classification of this important fungal community.