ORGANOGENESIS IN CARNATION

Shoot regeneration in carnation (Dianthus caryophyllus L.) was influenced by genotype, explant source, and plant growth regulator balance. Plants were regenerated from petals, calyxes, nodes, internodes, and leaves, but only petals, calyxes, and nodes were regenerative from all three cultivars examined ('Scania', 'Improved White Sim', 'Sandra'). Maximum proliferation was achieved with petals on Murashige and Skoog medium supplemented with 0.05-mu-M TDZ and 0.5-mu-M NAA. Shoot initiation originated from cells near vascular regions and perhaps from epidermal cells in petals and via organogenic callus from other explants. There was no evidence of chimeral separation from petals or callus, but somaclonal variants (3.3%) were observed involving petal hue and plant dwarfness. Unstable color patterns were observed in tissue-cultured regenerants of 'Scanial and 'Improved White Sim' similar in type and frequency to propagules derived from cuttings; none were observed for tissue-cultured or cutting-derived plants of 'Sandra'. Chemical names used: N-phenyl-N'-1,2,3-thiadiazol-5-ylurea [thidiazuron (TDZ)]; 1-napthaleneacetic acid (NAA).