Callus induction, direct and indirect organogenesis of ginger (Zingiber officinale Rosc)

Abstract

The present study aimed to induce callus, direct and indirect organogenesis of ginger (Zingiber officinale Rosc) by using MS medium supplemented with different concentrations and combination of plant growth regulators. Different types of explants (shoot tip, in vitro leaf and root segments) were cultured on MS medium supplemented with different concentrations (0.00 as control, 0.5 , 1.00, 2.00 and 3.00 mg/l) of auxin 2,4-dichloro-phenoxyacetic acid (2,4-D) for callus induction. The sprouting buds (about 1-1.5 cm) were used as explants for direct shoots and roots induction by MS medium fortified with 3.00 and 4.5 mg/l of 6-benzyl amino purine (BAP) and combination of 3.00 mg/l BAP + 1.5 mg/l Naphthalene acetic acid (NAA). Callus induced by 1.00mg/l 2,4-D was subcultured on MS medium supplemented with 0.5mg/l 2,4-D to obtain a green callus, this callus was transferred to MS medium fortified with combination of 4.00 mg/l BAP + 0.5 mg/l NAA for indirect shoots and roots formation. The results revealed that, for callus induction no callus induced when the leaf and root segments were used as explants, whereas the shoot tip explants initiated callus in all concentrations of 2, 4-D. The highest mean of fresh weight of callus was induced by 1.00 mg/l of 2,4-D (1.302+0.09) g followed by 0.5 mg/l (0.601 +0.04) g and 2.00 mg/l (0.370 +0.05) g. The lowest mean of fresh weight of callus was induced by 3.00 mg/l (0.319 +0.01) g. Significant differences (P<0.05) were detected among the effect of different concentrations of 2, 4-D on callus induction. For direct organogenesis, 4.5 mg/l BAP showed the highest number of In vitro shoots and roots, four shoots and 15 roots per explants. Two shoots and 10 roots per explants were initiated by 3.00 mg/l BAP, the lowest number of in vitro shoots and roots per explant were induced by combination of 3.00 mg/l BAP+1.5mg/l NAA. For indirect organogenesis two shootlets and roots were induced by MS medium fortified with combination of 400 mg/l BAP+0.5 mg/l NAA.