Tolypocladium guangdongense is a high-value edible fungus with various medicinal and food safety properties. However, its evolutionary and genetic information is still limited. Mitochondrial genomes are potential models for molecular evolution and phylogenetic studies. In this study, we sequenced the complete mitogenome of T. guangdongense, demonstrating circular sequence of 46,102 bp, containing 14 standard protein-coding genes (PCGs), 2 ribosomal RNA subunit genes, and 28 tRNA genes. Phylogenetic analysis based on mitochondrial genes indicated that T. guangdongense was clustered into the Tolypocladium genus with high support value, based on the core PCG dataset. In addition, rps3 is also a suitable marker in the phylogenetic analysis in Hypocreales. Gene rearrangement analysis indicated that the gene order of PCGs was highly consistent in Hypocreales, and tRNA rearrangement events occurred in most species of Hypocreales; however, the rearrangement rates were not taxonomically correlated. Divergence time estimation based on the old fossil record and previous reports revealed that T. guangdongense originated approximately in the middle Cenozoic (42 Mya, 95% highest posterior density interval: 43-116) with the Tolypocladium genus differentiation. Our results provided more mitogenomic information of T. guangdongense and shed new insights into evolution of the Tolypocladium genus. KEY POINTS: • The general and unique features of T. guangdongense mitogenome are firstly reported. • Phylogenetic analysis further verified the taxonomic status of T. guangdongense. • Divergence time estimation provides more evolutionary information of T. guangdongense.
Keywords: Comparative genomics; Cordyceps; Divergence time; Gene rearrangement; Mitochondrial genome; Phylogenetic analysis.