Abstract:

In order to establish Dahlia pinnata efficient genetic transformation system and to solve the problem of breeding of new varieties in the future through genetic engineering. In this paper, the D. pinnata leaf regeneration system was discussed. The leaves of D. pinnata were used as the experimental material. Several factors such as illumination condition, explant condition, hormone concentration and so on were investigated to optimize the regeneration system in vitro. The experimental results showed that leaf situation can greatly affect D. pinnata regeneration frequently. The best explants were those 25 days apical leaves from the cultured plantlets. The high frequency of shoot regeneration was observed when explants were cultured on MS medium supplemented with 7 mg/L KT and 0.05 mg/L NAA. The leaves were cultured in dark for 15 days firstly, and then they were transferred under light and began to directly regenerate adventitious buds in about 20 days. The maximum number of the adventitious buds was observed within 30-35 days. Maximum shoot differentiation frequency was 86%. Shoot site number per explant was 5.0. When the shoots grew to more than 2 cm high, they were cut from and transferred to the root differentiation medium 1/2MS+0.1 mg/L NAA and developed into the whole plants.