Abstract
Life on earth has been successively irradiated by cosmic rays and terrestrial magnetism, and mutated. Mutation breeding is the application of the evolution in nature. Ion beams are expected as new mutagens, because they deposit high energy on a target densely and locally. The efficiency of ion-beam irradiation in obtaining floral mutants was investigated. Leaf segments of carnation plants were irradiated with carbon ions, and cultured till the shoot regeneration. The carbon ion had the higher effect than gamma-rays. The wider mutation spectrum was obtained in plants irradiated with carbon ions than gamma-rays. New carnation varieties developed by ion-beam breeding were commercialized. The results indicate that ion-beam irradiation could induce wide variety of floral mutants, and the combined method of ion-beam irradiation with tissue cultures is useful to obtain the commercial varieties in a short time. The ion-beam breeding is applied to develop a labor-saving chrysanthemum, phytoremediation etc.
