Effect of auxin on somatic embryo induction and plant regeneration of oil palm SUP-PSU

Abstract

Oil palm cv. SUP-PSU is high yield variety that can adapt well in various growing environments. Commercial production is generally carried out by conventional method through seed propagation. However, it is time-consuming, and the number of plants is not enough for demanding of growers. Tissue culture technique is an alternative method to solve those problems. Thus, the objectives of this research was to study effects of auxins and culture media on plantlet regeneration of oil palm in vitro. The embryogenic callus (EC) derived from culturing zygotic embryo was transferred to oil palm culture medium (OPCM) supplemented with different concentrations of 3,6-dichloro-2-methoxybenzoic acid (dicamba) for 4 weeks. The results showed that 0.1 mg/l dicamba could induce the highest percentage of somatic embryo (SE) induction (80%) as well as number of SEs (1.4 embryos/tube) with root-like structure obtaining callus whereas the highest number of shoots (1.14 shoots/tube) was obtained on the medium added with 0.3 mg/l dicamba with yellowish callus. Subculturing shoots to OPCM without plant growth regulators resulted in shoot elongation. Rooting of the shoots was successfully obtained on OPCM augmented with 0.5 mg/l a-naphthalene acetic acid (NAA). On this culture medium, the highest root induction at 100%, average number of roots at 7.38 roots/shoot, root length at 1.5 cm, growth index at 1.22 and number of leaves at 3.75 leaves/plant were noticed at 8 weeks. Therefore, OPCM with 0.3 mg/l dicamba are suitable for SE induction while adding 0.5 mg/l NAA to the medium are optimum for root induction. Both plant growth regulators containing medium can apply for propagation and improvement of oil palm in future.