Optimal Medium Compositions for Plant Regeneration via Adventitious Shoot Formation Using 'Fuji' Apple Leaf Explants

Plant regeneration protocols for adventitious shoot organogenesis from apple (Malus domestica ‘Fuji’) leaf explants were developed in the present study. The effects of different basal media, types and concentrations of carbon sources, and concentrations of plant growth regulators were evaluated to determine the optimal shoot regeneration conditions for ‘Fuji’ apple leaf explants. On different treatments involving combinations of basal media, LS and N6 media, and different types and concentrations of cytokinins, 6-benzyladenine (BA) and thidiazuron (TDZ), shoot regeneration rates were the highest in the N6 medium combined with BA. Among the plant growth regulator and carbon source combination treatments, 5.0 mg/L BA, and 0.1 mg/L αnaphthalene acetic acid (NAA) with 40 g/L sorbitol was the optimal combination for shoot regeneration. In addition, the optimal sorbitol concentrations for shoot regeneration were 40 g/L and 60 g/L. The highest regeneration (81.8%) was achieved using 40 g/L sorbitol. The regenerated shoots elongated and rooted on rooting medium, consisting of 1/4 MS medium with 0.2 mg/L indole-3-butyric acid (IBA). The plantlets were acclimatized and the regenerated plants exhibited normal phenotypes.