Ray florets color and shape mutants induced by C ion beam irradiation in chrysanthemum

Matsumura, Atsushi*; Nomizu, Toshikazu*; Furutani, Noriyuki*; Hayashi, Ken*; Minamiyama, Yasuhiro*; Hase, Yoshihiro

We investigated the effect of ion beam irradiation on induction of ray florets color/shape mutants from two strains of chrysanthemum to create new flower cultivars. The ray florets and leaf explants of chrysanthemum cultured on MS medium were irradiated with C ion beam at doses of 1, 2, 4 and 8 Gy. The frequency of shoot primordia formation on ray florets explants of cultivar "Shiroyamate" and shoot bud formation on leaf explants of cultivar "H13" was decreased by 8 Gy and 4 Gy irradiation, respectively. The effective dose of ion beam was less than 4 Gy in "Shiroyamate" and less than 2 Gy in "H13". Yellow ray florets mutants from "Shiroyamate", and various ray florets color mutants (dark-red, light red, pink, pink spray) and a flower shape mutant (double-ray florets) from "H13" were induced by ion beam irradiation. Furthermore, a white mutant was obtained from a chimeric mutant. These results suggest that the combination of ion beam irradiation and tissue culture would be an effective means of generation mutants at a high efficiency.