Complete mitochondrial genome sequencing and phylogenetic analysis of Phellinus igniarius.

The mitochondrial whole genome of Phellinus igniarius was sequenced with the objective of examining the evolutionary relationships amongst related species. The entire mitochondrial genome was assembled using Illumina sequencing technology. The structural annotation and bioinformatics analysis were performed. The mitochondrial genome is a double-stranded circular DNA molecule with a total length of 172,449 bp and 86 genes, comprising 51 protein-coding genes (PCGs), 33 transport RNA (tRNA) genes, and 2 ribosomal RNA genes. Almost all protein coding genes utilise the ATG start codon, mainly TAA and TAG as the stop codon. 51 PCGs were predominantly affected by purification selection, among which giy-3, giy-6, rps3, lagli-3, lagli-5, lagli-11 and lagli-17 genes contained positive selection sites. Insertions, deletions and mutations were observed in the tRNA gene. With the exception of trnS2, which lacks dihydrouracil arm, the secondary structure of all tRNAs shows a typical clover structure. According to the phylogenetic study, Inonotus obliquus and the Phellius igniarius were closely related, belong to Hymenochaetaceae.