DNA isolation and genotyping
For total genomic DNA extraction, leaf tissue was collected from plants grown as previously described prior to glyphosate treatment. Samples were immediately frozen in liquid nitrogen and stored at -80°C. Tissue was ground using a TissueLyser II (Qiagen; 30 Hz for 2 min). Genomic DNA was extracted from 100 mg fresh weight tissue following a modified cetyltrimethylammonium bromide (CTAB) extraction protocol (Doyle, 1991). DNA quality and concentration were measured using a NanoDrop spectrophotometer (Thermo Scientific ND-1000). All DNA samples were normalized to 5 ng uL-1 with deionized water.