title: WGS of Arabidopsis thaliana: leaf tissue
design: Samples that showed DNA above the 500 bp ladder band were subjected to a short shearing step using a M220 Focused Ultrasonicator (Covaris). Samples lacking DNA above the 500 bp ladder band were processed for library preparation as recommended for ancient samples (no shearing step). To capture short fragments and maximize complexity despite low input concentration we followed a library preparation method that relies on blunt-end ligation of custom adapters (Meyer & Kircher, 2010). One modification was implemented for the non-sheared samples; cleaning steps during the library preparation process were done using first the QIAquickNucleotide Removal Kit (Qiagen) and then the MinElute PCR Purification Kit (Qiagen) instead of AMPure XP/SPRIselect magnetic beads (Beckman Coulter). Final DNA content in the libraries was quantified using a Qubit fluorometer with the Qubit dsDNA high-sensitivity (HS) Assay Kit (ThermoFisher Scientific). Since samples had individual identifying barcodes, a pooled equimolar aliquot was prepared for sequencing.