Comparison of chrysanthemum cultivars based on direct shoot regeneration rates in tissue culture

Direct shoot regeneration from leaf or internode or petiole segments was conducted in 33 cultivars of chrysanthemum. Shoot regeneration rates varied according to cultivars, culture media, and explant types. The high shoot regeneration rate of more than 70% in 15 cultivars (‘Pink Pangpang’, ‘Orange Memory’, ‘Relance’, ‘Zinba’, ‘Beakma’, ‘Innocence’, ‘Sunny Pangpang’, ‘Euro Yellow’, ‘Dublin’, ‘Boramae’, ‘Peak’, ‘Euro White’, ‘Vesuvio White’, ‘Linneker Salmon’ and ‘Pink Pride’) and 2 ones (‘Forward’ and ‘Agason’) was obtained from the segments of leaves and internodes, respectively, cultured on MS medium containing 1.0 mg-$L^{-1}$ BAP, 0.5 mg-$L^{-1}$ IAA and 30 g-$L^{-1}$ sucrose. That in 6 cultivars (‘Shuhonochikara’, ‘Hakunosen’, ‘Whitney Pangpang’, ‘Plaisir D’Amour’, ‘Grace’ and ‘Kumsu’) was observed from the segments of leaves or internodes cultured on 1/2 MS medium 1.0 mg-$L^{-1}$ BAP, 0.5 mg-$L^{-1}$ IAA and 15 g-$L^{-1}$ sucrose In case of 3 cultivars (‘Ilweol’, ‘Puma White’ and ‘Sharon’), when internode explants excised from mother plants, which were pre-cultured on MS medium containing 2 g-$L^{-1}$ activated charcoal and 30 g-$L^{-1}$ sucrose for two months in the dark, and cultured on MS medium containing 1.0 mg-$L^{-1}$ BAP, 0.5 mg-$L^{-1}$ IAA and 30 g-$L^{-1}$ sucrose, that was shown. Seven cultivars including ‘Puma Yellow’, ‘Argus’, ‘Yes Morning’, ‘Whiparam’, ‘Hakunohikari’, ‘Charming Eye’ and ‘Moon light’ requires more improved culture conditions. Tissues with the highest shoot regeneration rate were in descending order, leaf, petiole, and internode segments.