In Vitro Responses of Oil Palm (Elaeis Guineensis Jacq.) Apical Meristem and Zygotic Embryo to Growth Regulators and Culture Media

The most obvious in vitro plant propagation pathway is by apical meristem and zygotic embryos culture (direct organogenesis system). However, the apical meristem procedure has limited use in oil palm cultivation because excision of explants kills the source plant and produces one plantlet ultimately. Furthermore, generated offsprings from zygotic embryo culture are not true to type. Somatic embryogenesis is the alternative approach for obtaining normal oil palm plantlets but with inconsistencies. Consequently, studies are necessary to resolve such issues and the adoption of the knowledge gathered from direct organogenesis is likely to proffer solution. It was a 2 x 2 x 3 x 9 factorial experiment which involved: light regime, oil palm types, growth media and plant growth regulator concentrations. Explants were incubated in either uninterrupted light or in uninterrupted darkness. For apical meristems, one set each of the three media; (Murashige and Skoog (MS) 1962), modified MS and Eeuweens (1976) were supplemented with either 30, 50, 70 and 90 mg l-1 NAA or with 5, 10, 15 and 20 mg l-1 2,4-D. Control treatments were without plant growth regulator. For zygotic embryos, a set of the three media were supplemented with 35, 70, 105 and 140 mg l-1 NAA (Naphthalene Acetic Acid) and another set with 4, 8, 12 and 16 mg l-1 2,4-D. Control units of the three media were without either NAA) or 2,4-D. The plantlet initiation rates from apical meristems and zygotic embryos were 100 % respectively, but the procedure is of limited use in oil palm because it results in loss of germplasm. In any case, the technique has provided a better understanding of in vitro oil palm culture and has subsequently facilitated the development of somatic embryogenesis, the preferred system for oil palm plantlets production.