Characterization and phylogenetic analysis of the complete chloroplast genome of Curcuma longa (Zingiberaceae)

Curcuma longa, a well-known traditional medicinal plant in China, belongs to the genus Curcuma family Zingiberaceae. In this study, we firstly assembled the complete chloroplast genome of C. longa based on sequences from Illumina and PacBio sequencing platforms. We obtained the complete chloroplast genome with the total length of 162,176 bp. It consisted of a large single-copy region (LSC, 86,984 bp), a small single-copy region (SSC, 15,694 bp), and a pair of inverted repeats (IRs, 29,749 bp each). Sequence analyses indicated that the chloroplast genome contained 111 distinct genes including 79 protein-coding genes, 28 tRNA genes, and four rRNA genes. The nucleotide composition was asymmetric (31.62% A, 18.42% C, 17.79% G, 32.18% T) with an overall AT content of 63.80%. The AT contents of the LSC, SSC and IR regions were 66.00%, 70.35% and 58.85%, respectively. Sixteen genes owned a single intron, while another two genes had two introns. The phylogenetic analysis indicated that C. longa was closely related to species Curcuma roscoeana within the genus Curcuma in family Zingiberaceae.