genome survey sequencing: Apocynum venetum leaves
The extraction of DNA was conducted using the CTAB method. The quality of the extracted genomic DNA was checked by 1% agarose gel electrophoresis, and the concentration was quantified using a Qubit fluorimeter.  For Illunima sequencing, two paired-end libraries with insert sizes of 270 bp were constructed with the standard protocol provided by Illumina (San Diego, CA, USA) and sequenced on an Illumina HiSeq X ten platform. The size-selected library was quality inspected using an Agilent 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA, USA) and quantified using Quantitative Reverse Transcription PCR (qRT-PCR).