**2.3 Culture medium**

MS culture medium was used [15], adding 30 g/L of sucrose (Bioxon: Cat. No. 217000), cytokinin (BAP) at 0.05 mg/L (Sigma: Cat. No. B3408), and 15 g/L of bacteriological agar (Bioxon: Cat. No. 215000). pH was adjusted to 5.7–5.8, and the medium was sterilized in an autoclave at 120°C at 20 kgf/cm2 for 15 minutes.
