For most of the past century, chemical and physical mutagens have been used in plant genetic research to introduce novel genetic variation. In crop improvement, more than 2000 plant varieties that contain induced mutations have been released for cultivation having faced none of the regulatory restrictions imposed on genetically modified material. In plant science, mutational approaches have found extensive use in forward genetics and for enhancer and suppressor screens - particularly in model organisms where positional cloning is easily achieved. However, new approaches that combine mutagenesis with novel and sensitive methods to detect induced DNA sequence variation are establishing a new niche for mutagenesis in the expanding area of (crop) plant functional genomics and providing a bridge that links discovery in models to application in crops.