Callus Induction and Plantlets Regeneration from Mature Ray Floret of Chrysanthemum

Abstract

The in vitro culture of mature ray floret of 5 commercial chrysanthemum cultivars on solid MS medium containing 0, 0.1, 0.5 and 1.0 mg/l 2,4–D in combination with 0, 1, 2 and 3 mg/l BA was performed at 50 μmol/m²/s 16 hr light and 25 ± 2 ^oC for 8 weeks. The results demonstrated that the hormone free medium and the medium containing only 2,4–D or BA were unable to induced callus in all cultivars tested. Meanwhile, medium containing both 2,4–D and BA showed green and compact callus. The calli were then subjected to shoot regeneration on MS solid medium containing 0, 1, 2 and 3 mg/l kinetin. Regenerated shoots were observed at 8 weeks after shoot induction and higher number of shoots observed at 12 weeks. The difference in responses to kinetin concentration of callus was statistically significance as the highest kinetin concentration generated highest number of shoots. The interaction of callus induction medium and shoot regeneration medium also revealed. Different cultivars also demonstrated different response to shoot regeneration as well.