Effect of Thidiazuron and Benzylaminopurine on In Vitro Shoot Proliferation of Carnation (Dianthus caryophyllus L.)

Carnations (Dianthus caryophyllus L.) are among the most widely used cut flowers in the world. Tissue culture techniques offer an efficient method for the micropropagation of carnations. This study was conducted to test the effect of thidiazuron (TDZ) and benzylaminopurine (BAP), artificial cytokinins, on shoot multiplication of two carnation cultivars, Barlo II Nora and Raggio di Sole. Isolated axillary buds were cultured on Gamborg\u27s (B-5) basal medium supplemented with 30 g/L sucrose and 8 g/L agar. The cultures were maintained at a 10-h photoperiod (40 (mu-Em2s-1) and 23°C±2C°. Number of multiple shoots produced was dependent upon the genotype and was also influenced by the cytokinin type and concentration. Barlo II Nora produced the highest shoot number with 14 shoots per explant on a medium containing 20 mg/L BAP. The cultivar Raggio di Sole cultured on BAP-containing media produced a maximum of 4 shoots per explant. Barlo II Nora cultured on TDZ-containing media produced a maximum of 8 shoots per explant, however, large amounts of calli were associated with these shoots. Increasing the concentration of cytokinin was associated with an increase in shoot number and a decrease inshoot height. Shoots were rooted on Gamborg\u27s medium containing 2 mg/L of 3-indole-butyric acid (IBA) and then transferred to pots. Once acclimatized the carnations were transferred to a greenhouse where they exhibited normal growth. This method could be useful for the rapid propagation of carnations in commercial production