A method for plant regeneration via organogenesis from Pelagonium inquinans leaf disc has been developed. Mature leaf explants were collected from field-grown plants and used for the induction of adventitious shoot regeneration on Murashige and Skoog (MS) medium supplemented with 3% (w/v) sucrose plus plant growth regulators. Maximum shoot organogenesis, with 11.8±1.5 shoots (98.6%) per leaf disc, was obtained with 2 mg/l N6-benzyladenine (BA) and 0.5 mg/l α-naphthyleneacetic acid (NAA) in 30 days. For rooting, the in vitro proliferated and elongated shoots were excised into 1.5-2 cm in length microcutting, which were plated individually on an half-strength MS (1/2MS) medium supplemented with 2% (w/v) sucrose plus various concentrations of indole-3-butyric acid (IBA). Shoots rooted with a frequency of 100% following culture on 1/2MS medium containing 0.5 mg/l IBA.
Mature embryo and leaf base segment of Korean oat were used as materials in an experiment to check plant regeneration efficiency. MS media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin, and picloram were used for callus induction from mature embryos and leaf base segments. Three mg/l of 2,4D and 3 mg/l of picloram in callus induction medium showed high frequency for plant regeneration from mature embryos. Leaf base segments were transferred to callus induction medium and incubated at 25~circC in 16/8 hr light/dark cycle for 3 weeks. Callus induction from leaf base segments of Malgwiri showed high efficiency in medium containing 3 mg/l of 2,4-D and 1 mg/l of kinetin (91.8~%) . In case of Samhangwiri, the combinations of phytohormones did not show significant difference. Regeneration from leaf base segments showed high frequency in shoot medium containing 1 mg/l of antiauxin, tri-iodobenzoic acid (TIBA) and 1 mg/l of 6-benzyladenine (BA). Calli induced from leaf base segments of Samhangwiri and Malgwiri in media containing 3 mg/l of 2,4-D and 3 mg/l of picloram showed high regeneration frequency. It appears that the callus initiation medium may be an important factor for subsequent plant regeneration.