Characterization of the complete chloroplast genome of Dioscorea polystachya Turcz.

Dioscorea polystachya Turcz. is an important Chinese herbal medicine and the raw material of the medicine ingrediente (Chinese yam polysaccharide). It belongs to Dioscorea, which has 60 species and distribute in middle and southeast of China. In this study, we sequenced the sample of D. polystachya based on Jiaozuo, Henan and determined its complete chloroplast genome. The length of cp genome was 152,958 bp, includes two invert repeats (IR) regions of 25,492 bp, a large single-copy (LSC) region of 83,152 bp, and a short single-copy (SSC) region of 18,822 bp. There were 131 genes, which included 85 protein coding genes, 8 rRNA, and 38 tRNA, and overall GC content covered by 37.1%. Each of trnK-UUU, rps16, trnG-UCC, atpF, rpoC1, trnL-UAA, trnV-UAC, petB, petD, rpl16, rpl2, ndhB, trnI-GAU, trnA-UGC, and ndhA genes contained an intron, clpP and ycf3 contained 2 introns. The phylogenetic position showed that D. Polystachya had the closest relationship with Dioscorea alata (MG267382) and Dioscorea aspersa (NC039807).