Characterization of the complete chloroplast genome of Xanthoceras sorbifolium, an endangered oil tree

Xanthoceras sorbifolium is an important biodiesel tree in northern China, but its natural population is now very fragmented and in decline. Here we assembled and characterized the complete chloroplast (cp) genome of X. sorbifolium using Illumina pair-end sequencing data. The X. sorbifolium cp genome was 161,231 bp in size, containing a large single copy region (LSC) of 85,299 bp and a small single copy region (SSC) of 18,692 bp separated by a pair of inverted repeats (IRs) of 28,620 bp. The genome had 132 genes, including 86 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. The overall GC content of the X. sorbifolium cp genome was 37.7%, with the corresponding values of LSC, SSC and IR regions being 36.0, 31.7 and 42.3%, respectively. The phylogenomic analysis strongly supported that X. sorbifolium diverged firstly in Sapindaceae. This complete cp genome will be useful for further studies of this endangered plant.