Optimization of In vitro Culture Conditions of Nasrin (Amaryllis) (Hippeastrum × johnsonii)

Nasrin plant (Amaryllis) is considered as a valuable bulbous plant. The propagation rate of this ornamental plant in natural condition is low. Therefore, application of modern techniques such as tissue culture is an appropriate way to increase the propagation rate of this ornamental plant. In order to study the effect of explant kind, type and concentration of cytokinin on scale explant regeneration of amaryllis, afctorial experiment was done based on a completely randomized design with 4 replications. Different explants including twin scale with basal plate, single scale with basal plate and single scale without basal plate was used. Explants were cultured on MS basal medium supplemented with different concentration of BA or TDZ (0, 0.5, 1 and 2 mg/l) and 0.1 mg/l NAA, 30 g/l sucrose and 8 g/l agar. Results showed that twin scale explants with basal plate were the best explants for in vitro propagation of amaryllis and produced thicker bulblets. On the other hand, no bulblets were regenerated from single scale without basal plate and these explants became brown over the time. Also cytokinin type had no significant effect on the diameter of regenerated bulblets but in medium containing BA more bulblets were regenerated in comparison to medium supplemented with TDZ. Medium without any hormones produced less and thicker bulblets compared with other treatments. By considering the diameter and number of bulblets, application of twin scale and use of MS medium containing 0.5 mg/l BA in combination with 0.1 mg/l NAA is recommended for in vitro propagation of amaryllis