Somatic Embryos Encapsulation for Synthetic Seed Production of Sugar Palm (Arenga pinnata Wurmb Merr.)

Abstract

This paper describes a protocol for producing synthetic seeds of sugar palm (Arenga pinnata Wurmb Merr.) using encapsulated somatic embryos (SEs) and secondary somatic embryos (SSEs) at different developmental stages. The study investigates in vitro germination response of the synthetic seeds influenced by different concentrations of encapsulation matrix and its viability at storage temperature of 4 °C and 25 °C. Encapsulation of SEs and SSEs in 3.0% sodium alginate, complexed in 100 mM calcium chloride sterile solution (CaCl₂·2H₂O) and inoculated on basal MS media under dark condition at 25 ± 2 °C, promoted an optimum 30 and 80% germination rate after 4 and 8 weeks, respectively. Germinated synthetic seeds transferred to MS + 1.0 mg/L BAP (6-Benzylaminopurine) + 1.0 g/L NAA (1-Naphtaleneacetic acid) promoted an optimum average number of shoot regeneration at 7.75 ± 1.32 after 12 weeks. Synthetic seeds being cold-stored at 4 °C displayed consistent declination rate of germination at 0–120 days of storage, while the synthetic seeds stored at normal culture condition of 25 °C promoted optimum germination (80%) during 0–45 days of storage. Optimum number of shoot regeneration at 11.00 ± 0.91 and 12.25 ± 1.32 with the average number of roots at 3.00 ± 0.41 was recorded from the non-refrigerated synthetic seeds cultured on MS + 1.0 mg/L BAP + 1.0 mg/L NAA after 8 weeks. Shoots of normal morphology were observed after 12 weeks of transfer on basal MS media.