Abstract
Many staple food crops, such as banana, cassava, potato, sweet potato, sugarcane, taro, yam, are propagated vegetatively. Crop improvement using vegetative propagules has special challenges compared with breeding of seed propagated species. Genetic variability is a fundamental necessity for crop improvement; this may be available within the germplasm used by breeders, or may be induced. Mutation breeding can provide a rapid and effective means of crop improvement for both seed and vegetatively propagated crops. Most successes in mutation breeding have been with seed crops as seeds are easy to treat and handle. Mutation induction of vegetatively propagated crops has lagged behind, as a more varied range of target plant materials, and thereby methods, are required. Developments in a range of biotechnologies, but especially cell and tissue culture, provide new and efficient tools for the propagation of target materials, mutation induction, mutant population development and selection. Methods developed for vegetatively propagated crops may also be used in crops with a normal fertile system, but have long life cycles (e.g. fruit trees), where the methods can accelerate the production of new cultivars. This review describes new developments and opportunities for plant mutation breeding in vegetatively propagated crops.