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

Abstract

Abstract Cotyledonary segments from the germinated immature zygotic embryo 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 attempts to obtain embryogenesis with 3% sucrose were ineffective since only non-embryonic callus was observed. The maximum frequency of embryogenic induction (69.44%) was obtained in 0.1 mg/l BAP and 2 mg/l 2,4-D; the data was not significantly (p < 0.05) different from the result obtained when 0.1 mg/l BAP and 4 mg/l 2,4-D were used. When explants were treated individually with growth regulators, the maximum (58.33%) frequency was produced by 4 mg/l 2,4-D. The BAP was completely ineffective when used individually. The maximum number of an advanced-stage embryo (2.85) was 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 embryo from 0.1 mg/l BAP and 2 mg/l 2,4-D were transferred to MS basal medium. The 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. The plantlets obtained were acclimatized and survived in green house condition. Histological observation showed that the cells of the globular embryos had a dense cytoplasm and a long suspensor and used to distinguish between embryonic and non-embryonic cells.