Sweet potato gDNA sequencing
The GBS libraries were constructed using the restriction enzyme ApeKI (GCWGC, where W is A or T) following the protocol developed by Elshire et al., (2011). Sixty-six sets of digested DNA samples were combined using a different barcode adapters (5 L each), and purified using a QIAquick PCR Purification Kit (Cat No.28104, Qiagen, Hilden, Germany) according to the manufacturers instructions. The purified DNA library was considered suitable for sequencing if the adaptor dimer (~128 bp in length) was small or absent, and most other DNA fragments were between 170-350 bp. Amplification fragments sequencing was performed on the Illumina Hiseq 2500 platform (Illumina Inc., San Diego, CA, USA).