Induction of organogenesis from Chrysanthemum indicum protoplasts

Chrysanthemum, Chrysanthemum indicum (Asteraceae) (2n=6x=54), is globally the second economically most important floricultural crop. A possible alternative to generate new genetic variation is the creation of somatic hybrids. Hereto protocols for protoplast culture need to be available. Today, several authors have reported partial or complete regeneration, though only for a very limited number of genotypes. We have tested four genotypes using a Murashige and Skoog-based medium. Using liquid culture, 17.6 microcalli were obtained per 105 protoplasts for cultivar ‘Yoko Ono’, whereas experiments with the other cultivars yielded no microcalli. Other protoplast sources and protoplast densities could not induce sustained protoplast division in liquid cultures for the other genotypes tested. Calli were readily obtained from ‘Yoko Ono’ microcalli on MS supplemented with 5 mg/L KIN and 1 mg/L NAA. Globular somatic embryos were induced during callus culture on MS supplemented with BA (2 mg/L) and NAA (0.5 mg/L), whereas through further subculturing on IAA-enriched medium (1-10 mg/L), roots were induced.