Cpepo resequencing
The extracted DNA was fragmented with a Bioruptor instrument (ThermoFisher Scientific, Waltham, MA, USA) to generate 200300 bp fragments. Libraries were then prepared as follows: first, the DNA fragments were subjected to end-repair and A-tailing; second, the resulting DNA was ligated with bubble-adapters that contained a barcode sequence, and then amplified with PCR.Qualified libraries were pooled together to form single-stranded DNA (ssDNA) circles and then DNA nanoballs were generated with rolling circle replication. The final DNA nanoballs were loaded onto a sequencing chip and were sequenced with a the BGISEQ-500 platform (BGI-Tianjin).