Triploid plant regeneration from mature endosperms of Sapium sebiferum

Sapium sebiferum is a potential bioenergy plant that can be cultivated under various soil, water and climate conditions for both oil-rich seeds and woody biomass. An efficient protocol for regenerating triploid plants of S. sebiferum was established using mature endosperms as explants. Green and compact calli were induced from endosperms within 30 days on Murashige and Skoog medium (MS) containing 1.0–5.0 mg/l 6-benzylaminopurine (BAP) or in combination with 0.2 mg/l α-naphthalene acetic acid (NAA). Within 45 days after endosperm-derived calli were cut into pieces and cultured on media supplemented with 1.0–2.0 mg/l BAP alone or plus 0.1 mg/l NAA, more than 60 % of the callus explants initiated adventitious buds. The buds elongated into shoots after transfer onto a MS medium containing 0.1 mg/l BAP and 1.0 g/l activated charcoal. Approximate 80 % of shoots rooted on a MS medium amended with 1.0 g/l activated charcoal and 1.0 or 2.0 mg/l indole-3-butyric acid within 30 days. The triploidy of the endosperm-derived plantlets was confirmed by flow cytometric analysis, and the triploid plants grew normally after transplantation.