Total genomic DNA was extracted from frozen leaf tissue on August 24, 2017 using a prewash method (Li et al., 2007) followed by a modified CTAB protocol (Doyle and Doyle, 1987). DNA was sonicated to 200-300 bp range. TruSeq Nano DNA Library Prep Kit (Illumina, San Diego, CA, USA) was used for end-repair, adapter ligation & purification.  Samples were then treated with bisulfite using the EpiTect kit (Qiagen, Hilden, Germany) according to the manufacturer's protocol with one exception in that the bisulfite DNA conversion was performed twice for a total of 10 hours of incubation.