Characterization of the complete chloroplast genome of Biondia chinensis (Apocynaceae: Asclepiadoideae: Asclepiadeae), a rare and threatened liana endemic to China

The complete chloroplast genome of Biondia chinensis, a rare liana of the Asclepiadoideae endemic to China, was determined in this study. It is classified as Vulnerable species because of the sharp decline in its population size due to the habitat destruction. The whole chloroplast genome was 160,308 bp long, comprising of a large single copy (LSC) region of 91,335 bp and a small single copy (SSC) region of 19,185 bp, which were separated by a pair of 24,894 bp long inverted repeat (IR) regions. It encoded a total of 131 genes, including 86 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Most of the gene species appeared as a single copy, while 22 gene species appeared in double copies. The overall A + T content was 62.2%, while the corresponding values of the LSC, SSC, and IR regions were 63.9, 68.1, and 56.7%, respectively. Phylogenetic analysis suggested that, among all the species which have been analyzed B. chinensis was relatively close to Vincetoxicum rossisum.