Organogenesis and anatomical study of gamma rays induced mutant of chrysanthemum (Chrysanthemum morifolium Ramat.) from ray florets

Abstract

We developed an efficient in vitro regeneration protocol for the isolation, rapid multiplication and field establishment of Pink Incurving novel mutant from ray florets of chrysanthemum. Earliest (8.33 ± 1.17 d) and highest (86.67 ± 2.03%) callogenesis was observed on Murashige and Skoog (MS) medium supplemented with 10 mg l–1 kinetin (KIN) and 2 mg l–1 α-Naphthalene acetic acid (NAA). MS medium supplemented with 10 mg l–1 KIN + 0.1 mg l–1 NAA was found most effective to induce maximum regeneration of micro shoots (96.33 ± 1.95%) while maximum shoot proliferation (98.33 ± 0.88%) was obtained when the medium was supplemented with 5 mg l–1 KIN + 0.01 mg l–1 NAA + 0.2 mg l–1 GA3. Good shoot elongation was noticed after 30 days of transfer onto a medium comprising of 0.50 mg l–1 GA3. The elongated microshoots were best rooted on half-strength MS medium supplemented with 0.5 mg l–1 NAA. The rooted plantlets were successful acclimatized in 3 weeks in glass jar with polypropylene cap filled with peat + Soilrite® (1:1) and transferred to greenhouse for flowering. The plants obtained through this technique produced the true-to-type flowers in υM2 generation. The isolated mutant was found stable for the selected characters. Histological investigations revealed that unorganized callus got organized and turned into meristematic zone to produce shoot primordia and further developed into multiple shoots as the concentration of growth regulators changed.