Received: Mar 25, 2024 / Published: Jun 28, 2024
In-vitro regeneration of soybean is a prerequisite for successful genetic transformation. This study aimed to investigate the culturability of three soybean cultivars for in-vitro regeneration, focusing on genotypes, media, explant types, and plant growth regulators. Shoot tips, cotyledons, and hypocotyl segments were excised from 7-day-old in-vitro seedlings as explants for subsequent in-vitro regeneration. All cultivars exhibited good callus formation from all types of explants, with shoot tips and cotyledons being more suitable. Calluses were induced on Gamborg B5 or Murashige and Skoog (MS) media using various concentrations of 6-benzyladenine (BA) and thidiazuron (TDZ) or 2,4-dichlorophenoxyacetic acid (2,4D). The combination of BA and TDZ or BA and 2,4D exerted an inhibitory effect on shoot and root induction. Media supplemented with BA produced calluses at a rate of 100%. Appropriate BA concentrations for shoot induction for ĐT35 and VNUAĐ2 were 1.0-2.0 mg L-1, and 2.0-3.0 mg L-1, respectively. MS + 2 mg L-1 BA for shoot tip explants and MS + 3.0 mg L-1 BA for cotyledon explants were appropriate to induce calluses and shoots. As BA concentrations increased, the root induction rate gradually decreased considerably. For both ĐT35 and VNUAĐ2, MS + 2.0 mg L-1 BA + 0.5 or 1.0 mg L-1 αNAA could be used to multiply calluses. Although shoots induced from calluses of ĐT35 were observed on MS + 1.5 or 2.0 mg L-1 BA + 1 mg L-1 αNAA, no shoots were observed for VNUAĐ2.
