Somatic Embryogenesis and Plantlet Regeneration in Red Sandalwood (Pterocarpus Santalinus)

Abstract

Abstract Cotyledonary segments from the germinated immature zygotic embryos were used for somatic embryogenesis of red sandalwood (Pterocarpus santalinus). It was established on Murashige and Skoog (MS) medium containing 5% sucrose and amalgamation of 6-benzylaminopurine (BAP), 2,4-Dichlorophenoxyacetic acid (2,4-D), and α-Naphthaleneacetic acid (NAA). All treatments were responsive for callus induction with the frequency range between 36–97%. The maximum embryogenic frequency (69.44%) was obtained when 0.1 mg/l BAP + 2 mg/l 2,4-D and 0.1 mg/l BAP + 4 mg/l 2,4-D combinations were used. When explants were treated individually with growth regulators, the maximum embryogenic frequency (58.33%) was produced by 4 mg/l 2,4-D. BAP was completely ineffective for somatic embryogenesis when used individually. The average number of globular-staged somatic embryos ranged between 1–5 (irrespective of the treatments). The maximum number of the cotyledonary-staged somatic embryos (2.85) were obtained with treatment 0.1 mg/l BAP and 2 mg/l 2,4-D. The maximum plantlets were developed (1.30) when the cotyledonary-staged embryos from 0.1 mg/l BAP and 2 mg/l 2,4-D were transferred to MS basal medium. The plantlets obtained were acclimatized and showed 100% survival in the greenhouse condition. The embryonic cells have been histologically distinguished from non-embryonic cells with dense cytoplasm and a long suspensor. The induction, maturation and germination of somatic embryos were challenging, suggesting the need for molecular approaches through proteomic expression for mass production and understanding the evolution, structure, and genetic organization of the plant species.