In vitro regeneration of Irvingia gabonensis by somatic embryogenesis

Abstract

A productive genotype of Irvingia gabonensis were cultured in vitro for induction embryogenic calli, somatic embryogenesis and regeneration of plantlets. Fragments of young leaves were used as primary explants. Callogenesis was initiated by culture of explants during 30 days on Murashige and Skoog medium half strength (MS/2) supplemented with 1-6 mg L(-1) of 2,4-dichlorophenoxyacetic acid (2,4-D). The highest percentage of explants forming calli is 85.1% at 3 mg L(-1) of 2,4-D. Somatic embryos were obtained after a subculture of embryogenic calli during 60 days on MS/2 supplemented with 1-3 mg L(-1) of BAP. The highest percentage of embryogenic calli which differentiates somatic embryos is 63.8 +/- 2.3% at 1 mg L(-1) of 6-benzylaminopurine (BAP). The highest number of somatic embryos per callus which is 43.6 is obtained with 2 mg L(-1) of this phytohormone. When isolated from calli and sub-cultured during 30 days on MS/2 supplemented with 2 mg L(-1) of BAP, somatic embryos germinate with a highest percentage of 83%. The subculture of germinated somatic embryos on the same Basal Medium (BM) supplemented with 4 mg L(-1) of BAP and 2 mg L(-1) of Naphthalene Acetic Acid (NAA) during 80 days gives rise to the plantlets with 82.7 +/- 4.8% of success. With this combination, each plantlet has average length of 5.6 cm, bears 3.3 leaves and 7.2 roots with 1 or 2 pivoting roots. Plantlets acclimatized on a mixture sterilized soil/vermiculite at equal volume survive at 93%. Results of this study constitute a new way for a production of Irvingia gabonensis seedlings with pivoting root and they permit to arrest the difficulties of natural and horticultural reproduction.