Abstract
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.