Whole Plants Regeneration of Cassava Cultivars (Manihot esculenta Crantz) Originated from Côte d'Ivoire via Somatic Embryogenesis

Abstract

Aims: To study the capacity of cassava genotypes in Côte d'Ivoire to induce somatic embryos and to regenerate plants from immature leaves Study Design: In-vitro, laboratory-based study. Place and Duration of Study: National Center for Agronomic Research (CNRA), between January 2017 and April 2018. Methodology: An efficient protocol to regenerate somatic embryogenesis (SE) from cassava (Manihot esculenta Crantz) plants cultivated in Côte d'Ivoire was achieved. Immature leaf lobes were used as explants on Murashige and Skoog (MS) basal medium supplemented with different concentrations (16; 33; 50; 66 and 83 μM) of the auxins Picloram (Pic) and 2,4-Dichlorophenoxyacetic acid (2,4-D). Results: The results showed that the frequency of primary somatic embryogenesis (PSE) and the mean number of somatic embryos varied significantly with the genotype, the type of auxin and the tested concentrations. The highest frequencies and numbers of somatic embryos per explant were observed with cv. TMS 60444 (81.66%; 190.8) on 50 μM Pic, followed by Local XX1 (90%; 180) on 66 μM Pic, To (100%; 145.8) on 50 μM Pic, I (80%; 125.6) on 66 μM 2,4D and M (100%; 112) on 50 μM 2,4D. Shoot bud induction from green cotyledons varied across cultivars and benzylaminopurine combined with 1-Naphthalene acetic acid outperformed benzylaminopurine associated with Indole-3-butyric acid regarding induce of organogenesis. Conclusion: Regenerated plants grew easily in the greenhouse with 90 – 100% survival rate and did not display detectable variation in morphology.