Comparison of In vitro Bulblet Production in Two Commercial Lilium Cultivars, Lilium longiflorum cv. Gironde and L. longiflorum cv. Cassandra

Lilium is an ornamental plant which is highly valuable in international flower markets. Due to Iran’s dependency to the importation of lilium bulbs, it is highly desirable to propagate this plant efficiently within the country. One of the most effective techniques for propagation of lilium is tissue culture techniques, preferably through bulblet production. Some experiments were carried out to obtain a practical protocol for mass production of bulblets of two commercial lilium cultivars, Girande, an Asiatic hybrid, and Cassandra, an Oriental hybrid. Effects of sucrose concentrations (30, 60 and 90 gl-1), bulb scale position (external, central and internal) and the best soil mixture were studied. Factorial experiments based on complete randomized design were used. Explants were placed on MS basal medium supplemented with 0.03 mgl-1 NAA and 0.3 mgl-1 BAP and
7 gl-1 agar after surface sterilization. Data of bulblet production parameters including number of bulblets per explant, number of scales per bulblet, mean of diameter, length, weight, number of rooted bulblet per explant and position of bulblet formation were analyzed cv. Cassandra showed better results for most in vitro bulblet production parameters compared to Gironde. Results showed that central scales and 60 gl-1 sucrose in both cultivars were most effective on length and the best position of bulblet to be chosen. Basal parts of the bulb scales produced the most bulblets compared to the lateral and distal parts, in both cultivars. Peat was the best substrate for in vitro bulblet's growth and development for both two cultivars. Generally, lilium cultivars produced different in vitro bulblets in size.