Regeneration of chrysanthemum (Chrysanthemum morifolium) via somatic embryogenesis and screening of clones for agronomic traits

Key messageSomaclonal variation can be used for crop improvement of chrysanthemum instead of induced mutagenesis. Presentstudy showed the substantial improved flower diameter in regenerated plantlets via somatic embryogenesis. Fieldscreening showed increase in the diameter of flowers and variation in flower colour in somaclonal population. Bothfeatures are appealing for the consumers in floriculture industry. Chrysanthemum morifolium propagation through stem cutting produces weak plants that show delayed anthesis above 20 & DEG;C and a reduced flower diameter. Therefore, in this study chrysanthemum plantlets were produced through somatic embryogenic from calli to exploit the somaclonal variation for their improvement. Various explants from variety Dante yellow were cultured on Linsmaier and Skoog (LS) medium with various concentrations of Kinetin (KT) and 2,4-dichlorophenoxyacetic acid (2,4-D) and their combinations for callus induction. Embryogenic calli were proliferated and regenerated by using different plant growth regulators. Regenerated plantlets were acclimatized and evaluated for agronomic characteristics and compared with the mother plant in a replicated field trial. Results revealed that young leaf explants cultured on LS medium containing 9.02 & mu;M 2,4-D and 11.61 & mu;M KT gave calli of greater sizes as compared to other treatments. A combination of 0.44 & mu;M 6-benzylaminopurine (BAP) and 5.37 & mu;M 1-naphthaleneacetic acid (NAA) yielded the highest callus proliferation (0.27 g & PLUSMN; 0.03). A significant number of shootlets (25 & PLUSMN; 0.8) from embryogenic callus was observed on the medium with 0.45 & mu;M 2,4-D. During the field experiment, Clone S84 showed considerable improvement in flower size as compared to the mother plant and was found to be a promising clone for commercialization.