In vitro adventitious organogenesis in Ajania pacifica (Nakai) Bremer et Humphries

This study tested the effects of explant type, medium composition, and cultivar on in vitro regeneration of callus, shoots, and roots in Ajania pacifica (Nakai) Bremer et Humphries. In Experiment 1, “Bea”, “Bess” and “Bengo” ex vitro internodes and ex vitro leaf explants were inoculated on a modified MS (Murashige and Skoog, 1962) medium with 3 mg • dm^-3 benzylaminopurine (BAP) and 0.5 mg • dm^-3 indole-3-acetic acid (IAA). The share of internodes and leaf explants that proliferated callus were 92–96% and 56–100%, respectively. Adventitious shoot regeneration was observed on “Bengo” and “Bea” internodes (1.12 and 0.32 shoots, respectively, per explant inoculated) and on “Bea” leaf explants (0.2 shoots per explant inoculated). In Experiment 2, “Silver and Gold” ex vitro leaf explants were placed on a modified MS medium with the addition of auxin and cytokinin: 0, 0.5, and 1 mg • dm^-3 1-naphthaleneacetic acid (NAA) or thidiazuron (TDZ) or BAP. Callogenesis was not reported only in the medium without plant growth regulators. Adventitious roots were seen to regenerate on media without plant growth regulators and with 0.5 or 1 mg • dm^-3 NAA (0.47, 1.2, and 2.93 roots per explant inoculated, respectively). In Experiment 3, “Bea”, “Bess” and “Bengo” ex vivo internodes were inoculated on a modified MS medium with 0.6 mg • dm^-3 BAP and 2 mg • dm^-3 IAA. All explants produced calli. Shoots regenerated only on “Bengo” internodes (1.3 shoots per explant inoculated). These results confirmed the possibility of in vitro callogenesis and adventitious organogenesis in Ajania pacifica.