Somatic Embryogenesis of Oil Palm (Elaeis guineensis Jacq.) from Bud Explants Using Suspension Culture

The propagation of oil palm seeds through tissue culture and somatic embryogenesis is a preferred method due to its ability to produce entire plants without the need for gamete fusion. While somatic embryo proliferation is typically performed on solid media, this approach is less efficient than liquid media, which is both more cost-effective and can lead to better proliferation results. Thus, this study aimed to determine the most effective combination of growth regulators on MS medium through suspension culture propagation. Buds from oil palm plants served as the initial explants, with embryogenic callus utilized for suspension culture. Bud explants were previously planted on solid MS media with a combination of 2,4-D and BAP to initiate the primary callus which was formed from 97^th to 132nd days, with D4B1 (80 mg/L 2,4-D; 2.5 mg/L BAP) media containing the most primary callus. The primary callus was subcultured twice over a 60-day period before embryogenic callus induction. The embryogenic calli formed on D3B1, D3B2, D4B0, and D4B1 medium between the 90^th and 120^th days. The medium, D4B1 again successfully initiated the embryogenic callus growth, hence it was later used for suspension culture. The fresh weight of calli increased during the first and second subcultures and later declined in the third subculture. The culture process was repeated on a solid MS medium to obtain coleoptilar somatic embryos, with most of them being formed between the 88^th and 115^th days (40.7%). Somatic embryogenesis is an efficient and cost-effective way of propagating oil palm seeds and the use of a specific combination of growth regulators on MS medium through suspension culture propagation can result in the formation of embryogenic calli and coleoptilar somatic embryos.