Cryopreservation of shoot tips of Chrysanthemum morifolium and related species native to Japan

Summary The shoot tips of Chrysanthemum morifolium (syn. Dendranthema grandiflorum) and related species native to Japan were cryopreserved using preculture for 2 days, slow cooling (0.2°C/min) until –40°C with 10% dimethyl sulphoxide and 3% glucose prior to immersion into LN₂ and rapid thawing. High survival rates were observed in 3 cultivars of chrysanthemum, 12 species and 2 interspecific hybrids, and slightly low survival rates in 3 species. The shoot regeneration rates of the frozen shoot tips varied from 9.4 to 100% depending on species. Shoot tips of chrysanthemum showed high viability even after a storage of 8 months in LN₂. The thawed chrysanthemum shoot tips grew and flowered normally in a greenhouse under natural conditions.Abbreviations BA 6-benzylaminopurine - DMSO dimethyl sulphoxide - NAA 1-naphtalenacetic acid