Chemical Mutagenesis EMS-treated Seeds Chemical Mutagenesis Chemical mutagenesis is a quick way to create mutants that show improved traits, such as tolerance to drought, cold, and heat. EMS, ethylmethane sulfonate, is a chemical mutagen that most commonly causes transitions by methylation of G residues but can yield a wide spectrum of mutations. The EMS-treated seeds can be grown in selection media or in different conditions to select for mutants. Currently we select drought tolerance mutants using 20% PEG and have obtained many mutant plants that will be further tested in the field in collaboration with Ken Moss. Add this page to your favorite Social Networking websites