Ethyl methanesulfonate (EMS) is a chemical mutagen that is known to cause point mutations. The use of EMS for mutation breeding has been effective in developing populations exhibiting variation in quantitative characters such as height. As towns and cities become more densely populated, space for planting trees and shrubs is becoming more limited. Through mutation breeding, new hardy landscape plants with reduced stature can be developed for these smaller spaces. 

The added benefit of EMS mutagenesis is the potential for reducing fertility. Studies evaluating the effects of EMS have demonstrated that fertility is significantly reduced with treatments of increasing EMS concentrations. Many species that are adapted to the challenging growing conditions of urban and suburban areas are horticultural introductions and not always native. While many species do not demonstrate weediness or invasive qualities, it is necessary to consider the potential for future ecological impacts. 

In order to take preemptive action in this regard, the New Plant Development Program at The Morton Arboretum will be conducting EMS mutation experiments on various exotic woody species and assessing effectiveness in the reduction of fertility.