Abstract:
Seeds of purple coral tree (Erythrina fusca Lour.) from 4- and 6-week-old pods were surface sterilized with 15 % (v/v) Clorox for 15 min and rinsed with sterile distilled water 2 min before repeating surface disinfestation at the same concentration and rinsing again sterile distilled water 3 times each for 2 min. For the seeds of 6-week-old pod, they had been separated into 2 groups: scarification with sandpaper or non-scarification which required pre-soaking in the water for 10 hr before surface sterilization. Then, seed coats of all aseptic seeds were removed prior to place on Murashige and Skoog (MS) basal medium for 4 weeks. It was found that germination percentages from 3 types of purple coral tree seed: young seed, sandpaper-scarified mature seeds and non-scarified mature seeds were 90, 80 and 20, respectively. Next, the placement direction of nodal explant was investigated by cutting 1-month-old purple coral tree node and horizontal or vertical placing on MS basal medium for 4 weeks. Results revealed that direction of nodal explant position played an important role on shoot regeneration and it gave 10 and 70% shoot formation, respectively. Later, nodal explants were cultured on MS medium supplemented with various plant growth regulators for 4 weeks. Results showed that combination of multiple hormones conferred the highest multi-shoot formation on BAP in combination with Kinetin and TDZ at 1 mg/l each which induced 4.5 shoots per explant. After transfer regenerated shoot onto the rooting medium, it was discovered that MS basal medium provided root and shoot length better than MS medium consisted of 2 mg/l NAA or IBA.