EMS is used at concentrations that induce multiple point mutations in each plant, such that mutant alleles of a specific locus are found at a rate of ~1 in 2000-5000 M2 plants. This high rate of mutagenesis makes possible the screening of relatively few plants to find those with the phenotype of interest, a particular advantage if the screen is laborious or if only a small number of genes mutate to the required phenotype.