Induction of novel flower colour mutations in chrysanthemum (Chrysanthemum morifolium Ramat.)

Terminal rooted cuttings of chrysanthemum cv. Purnima were exposed to 0, 5, 10, 15 and 20 Gy doses of γ-rays and planted in earthen pots (20 cm). Each treatment consists of four replications with 25 cuttings each. LD₅₀ dose was determined at 15 Gy dose. Morphological abnormalities such as fused leaves and lower levels of chlorophyll content was observed at higher exposure (15 and 20 Gy). Marked variations in flower colour were recorded in the irradiated populations. The original flower colour of Purnima is white with creamish yellow center. Two novel flower colour mutants were isolated, one was yellow in colour with deep yellow center (10 Gy) and other was pink with dark pink center (15 Gy). The mutants were multiplied on a large-scale and evaluated for their stability.