Abimbola Esther BANKOLE
Department of Botany, Faculty of Science, University of Lagos, Lagos State, Nigeria
*Corresponding author’s Email: gbolabim@yahoo.com, doi.org/10.55639/607.020100110
ABSTRACT
Efficient in vitro regeneration systems are essential for large-scale clonal propagation and biotechnology improvement of cassava (Manihot esculenta Crantz). Auxin-cytokinin is a critical determinant of callus formation and morphogenic competence; however, responses to concentration dependence remains genotype-specific and require empirical optimization. The present study investigated the effects of different concentrations of 6-benzylaminopurine (BAP: 0.5 – 3.0 mg L⁻¹) combined with and α-naphthaleneacetic acid (NAA: 1.0 – 4.0 mg L⁻¹) on callus induction and growth responses in nodal explants cultured on Murashige and Skoog medium. Explants were arranged in a randomized design with three biological replicates per treatment. After seven weeks of culture, callus induction frequency, fresh and dry biomass, and cellular proliferation indices were assessed. Morphometric parameters including fresh weight, dry weight, callus length, width, cell proliferation, and biomass loss were assessed. Moderate hormone concentrations (0.5–1.0 mg L⁻¹ BAP combined with 1.0-2.0 mg L⁻¹ NAA) significantly enhanced callus induction and biomass accumulation compared with higher concentrations (p < 0.05). Supra-optimal hormone levels resulted in reduced proliferation, compact callus formation, and lower cellular density, indicating possible hormonal imbalance and growth suppression. The findings demonstrate that precise auxin–cytokinin equilibrium is essential for maximizing callogenic response in cassava nodal tissues. The protocol provides a reproducible framework for improving cassava micropropagation and downstream regeneration systems.
KEYWORDS
BAP,
Cassava,
Callus formation,
NAA,
In vitro culture.
.

