High frequency in vitro regeneration of sandalwood (Santalum album Linn.)

Indian sandalwood (Fam. Santalaceae) is one of the important tree species of the tropical forests known for its essential oil used extensively in perfumery. Three explants viz: mature cotyledons, hypocotyls and mature embryos of sandalwood were cultured on different fortifications of MS medium to judge its in vitro response. In vitro morphogenesis (somatic embryogenesis and/or organogenesis) leading to plantlet regeneration was influenced significantly due to different plant growth regulators. Induction media (MS + 2.0 mg l⁻¹ 2, 4-D) proved adequate for callus induction. Culture media (MS + 0.5 mg l⁻¹ 2, 4-D+0.5 mg l⁻¹ BA/MS + 1.0 mg l⁻¹ 2, 4-D+0.5 mg l⁻¹BA) induced direct somatic embryogenesis and average number of somatic embryo per explant in higher frequencies. While, Induction media (MS + 1.0 mg l⁻¹ 2, 4-D+0.5 mg l⁻¹ BA/MS + 2.0 mg l⁻¹ 2, 4-D+0.5 mg l⁻¹ BA) enhanced the frequency of indirect somatic embryogenesis. Nutrient media (MS + 2.0 mg l⁻¹ NAA+0.5 mg l⁻¹ TDZ) promotes direct organogenesis and plantlet regeneration via direct organogenesis and inoculation medium MS + 1.0 mg l⁻¹ NAA+0.5 mg l⁻¹ TDZ) supports indirect organogenesis. Regeneration medium (MS + 2.0 mg l⁻¹ TDZ+1.0 mg l⁻¹ GA₃) regenerated plantlets in higher frequencies obtained from somatic embryos, while plantlet regeneration via indirect organogenic mode was attained in higher ratio on regeneration medium (MS +1.0 mg l⁻¹ TDZ+1.0 mg l⁻¹ GA₃+0.5 NAA) for the most of the explants cultures. The plantlets were transferred to pots and hardened in Environmental Growth Cabinet and Net House during preliminary weaning period and transferred to field successfully.