Induction of somatic mutation in chrysanthemum through physical mutagen

The rooted cuttings of two chrysanthemum cultivars Purnima and Otomazakura were treated with gamma rays at different doses i.e. 10, 15 and 20 Gy and transplanted in pots along with untreated rooted cutting as control. Each treatment consisted of 30 cuttings. The data were recorded on various parameters i.e. survival, morphological and floral traits. Reduction in various vegetative and floral traits alongwith increase in morphological abnormalities in flowers and leaves were recorded after exposure of cuttings to gamma irradiation. The floral abnormalities like fasciation of flower head, asymmetric development of ray florets were increased at 10 Gy dose of gamma irradiation. The chimera in flower colour was observed in both cultivars in treated population at 10 Gydose of gamma rays. In cultivar ‘Purnima ’, total three somatic mutants were detected i.e. orange (Orange White Group 159 D/4) and white tubular (White Group 155 B/4) at 10 Gy and white with yellow (Yellow Group 2B/1) chimeric flower head at 15 Gy dose. One mutant was detected in cv. Otomazakura (Purple Group 75 A/1) at 10 Gy dose of gamma rays.