The complete plastome sequence of the endangered orchid Cymbidium macrorhizon (Orchidaceae)

In this study, we determined the complete chloroplast sequence of Cymbidium macrorhizon Lindl. (Orchidaceae) (NCBI acc. no. KY354040), an endangered plant species protected by the national law of Korea. The gene order and number in the C. macrorhizon plastome were similar to a typical Orchid plastome. The complete plastome was 149,859 bp in length and consisted of a large single copy region of 85,187 bp and a small single copy region of 13,766 bp; these were separated by two inverted repeats of 25,453 bp. The plastome contained 103 genes of which 69 were protein-coding genes, 30 were tRNA genes and four were rRNA genes. Fourteen genes contained one intron and two genes (clpP, and ycf3) had two introns. The AT content of the C. macrorhizon plastome was 60.0% and a total of 62 simple sequence repeat regions were identified in the plastome. Phylogenetic analysis also identified C. lancifolium as a closely related sister to C. macrorhizon, suggesting that the hemisaprophytic nature of C. macrorhizon is derived recently from a common leafy ancestor.