Characterization of the complete chloroplast genome of Liparis gigantea (Orchidaceae).

Liparis gigantea is a Chinese traditional medicinal herb in the Orchidaceae family. It is a rare and special Liparis species that exhibits relatively large flowers. To illuminate its phylogenetic status and augment genomic resources, the complete chloroplast (cp) genome of L. gigantea was first sequenced and assembled using whole genome next-generation sequencing in this study. The cp genome size is 158,462 bp with a total GC content of 36.9%. Characterized by a quadripartite structure, the genome consists of a large single-copy (LSC) region of 86,032 bp, a small single-copy (SSC) region of 18,322 bp, which is separated by a pair of 27,054 bp inverted repeat regions (IRs). A total of 133 genes were annotated, including 87 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis strongly supported L. gigantea as the sister to two closely related terrestrial species, Liparis nervosa and L. vivipara. The results of this study provide genomic information for future research and application of this medicinal herb.