The complete chloroplast genome of Cycas Szechuanensis, an extremely endangered species

In this study, we determined the complete chloroplast genome of Cycas szechuanensis (Cycadaceae, Cycas) using the Illumina sequencing data. The genome is 162,083 bp in length, including a pair of inverted repeats (IRs) of 25,003 bp each, which are separated by a large single-copy region (LSC) and a small single-copy region (SSC) with the size of 88,970 and 23,108 bp, respectively. The genome comprises 131 encoded genes in total, including 86 protein-coding genes (82 PCG species), 8 ribosomal RNA genes (4 rRNA species), and 37 transfer RNA genes (30 tRNA species). The overall GC content of the C. szechuanensis chloroplast genome is 39.42%, while the LSC, SSC, and IRs occupy 38.70, 42.03 and 36.52%, respectively. Based on complete chloroplast genome sequences from 13 species, we reconstructed the phylogenetic relationship of the 13 species and found that C. szechuanensis is closely related to C. debaoensis.