Whole genome sequence of synthesized allopolyploids in Cucumis reveals subgenome dominance, instant genomic changes initiated by hybridization and increased phenotypic plasticity

Fresh young leaves were collected from one single plant for each sample and immediately frozen in liquid nitrogen for 24 h. Genomic DNA for PacBio and Illumina Sequencing was extracted using the CTAB method. The PacBio sequencing library was prepared according to the recommendation of Pacific Biosciences. Genomic DNA was fragmented to an ~20 kb targeted size by g-TUBE centrifuged at 2,000 r.p.m. for 2 min, then treated with end-repair, adapter ligation and exonuclease digestion. DNA fragments with length around 20 kb were collected by BluePippin electrophoresis (Sage Sciences). DNA libraries were sequenced on the PacBio Sequel platform (Pacific Biosciences) with P6-C4 chemistry..