Data availability statement
All the chloroplast genome sequences used in this study are derived from the GenBank database at http://www.ncbi.nlm.nih.gov/genbank, and the reference numbers are DQ898156.1, GU456628.1, KU866530.1, KU921430.2, KX352486.1, MG719855.1, MH121055.1, MH180258.1, MN275034, MN539269.1, MN970215, MT501096, NC029392.1, NC029470.1, NC033343.1, NC033345.1, NC034645.1, NC042242.1, respectively.