Characterization of the complete chloroplast genome of Sphagnum multifibrosum (Sphagnaceae), a unique moss

Sphagnum (Sphagnaceae) plays key roles in southwestern China’s wetland water conservation and carbon sequestration. This study reports the first complete chloroplast genome (plastome) of Sphagnum multifibrosum X. J. Li & M. Zang, an endangered alpine wetland species. The circular cp genome has a total length of 140,417 bp, comprising a large single-copy (LSC) region of 98,305 bp, a small single-copy (SSC) region of 21,340 bp, and two inverted repeat (IR) regions, each 10,386 bp in length. The genome encodes a total of 129 functional genes, including 84 protein-coding genes, 8 ribosomal RNA (rRNA) genes, and 37 transfer RNA (tRNA) genes. The overall GC content was determined to be 36.83%. Among the genes, eleven were identified as containing introns. Nine of these possess a single intron, while the clpP and ycf3 genes are unique in containing two introns each. The IR regions were found to contain duplicates of eight protein-coding genes, two tRNA genes, and all four rRNA genes. Maximum likelihood phylogenetic analysis (based on Sphagnales plastomes) strongly supports a close relationship between S. multifibrosum and S. palustre, clarifying its subgenus placement. This plastome resource aids Sphagnaceae taxonomy, evolutionary research, and conservation of this endangered species.