The chloroplast genome sequence of an important medicinal plant Dioscorea nipponica

Dioscorea nipponica is an important medicinal plant belonging to Dioscoreaceae, a family which is vital for the evolution of monocotyledon. In the present study, the nucleotide sequence of the D. nipponica chloroplast genome was determined. It was an AT-rich (63.3%) chloroplast genome with 152,946 bp in length, containing a pair of 23,113 bp inverted repeats, which were separated by a large and a small single copy region of 83,557 bp and 23,064 bp in length, respectively. It encodes 120 unique genes, including 89 protein-coding genes, 27 tRNA genes and 4 rRNA genes. The predicted gene-coding regions covered 58.7% of the genome sequences. Ten genes contained one intron, while two genes had two introns. Phylogenetic analyses showed the present chloroplast genome can be used as a potential supper barcode to distinguish D. nipponica from its closely related species. Furthermore, the chloroplast genome provides a molecular base for the next investigation on this important medicinal species.