Data sequencing of chloroplasts
DNA was extracted using either a DNeasy kit (Qiagen, Valencia, California, USA) or with a modified 2 CTAB method (Doyle and Doyle 1987). Genomic DNAs were sheared by nebulization at 30 psi for 70 sec, yielding an average shear size of 500bp as measured by a Bioanalyzer High-Sensitivity Chip (Agilent Technologies, Inc., Santa Clara, California, USA). Constructed paired-end sequencing libraries with insert sizes of 300500 bp with Illumina TruSeq Nano DNA Sample Prep Kit and sequenced using the BGISEQ-500 at the Beijing Genomics Institution (BGI; Shenzhen, China).