Advances in genome editing technology offer new hope for modifying traits in polyploid plants, especially those which lack whole genome information, such as Chrysanthemum morifolium (chrysanthemum) - a commercially important hexaploid plant that is propagated asexually worldwide. Kishi-Kaboshi et al. performed genome editing of transgenic chrysanthemums containing multiple copies of a fluorescent protein gene. They found that one genome-editing event was able to introduce mutations in several copies of the transgene, with mutations accumulating in vegetatively-propagated shoots and regenerated calli. Through this approach, multi-allelic genes, and thus polyploid plant traits, can be modified successfully.