Effect of plant growth regulator concentrations on callus induction and shoot regeneration of Andaliman

Abstract

Abstract Andaliman (Zanthoxylum acanthopodium DC.) is an important spice-producing plant native to North Sumatra, particularly valued by the Batak community. However, the limited availability of uniform planting materials remains a constraint to its cultivation and sustainable utilization. This study aimed to determine the effects of NAA × BAP combinations on callus induction and growth characteristics and to evaluate the subsequent response of induced callus to IAA × TDZ treatments for shoot regeneration. A factorial Completely Randomized Design was used to evaluate callus weight, diameter, height, texture, structure, and colour, followed by descriptive assessment of shoot regeneration. Data were analysed using factorial analysis of variance followed by Duncan’s Multiple Range Test at the 5% significance level. NAA × BAP combinations significantly affected callus weight, diameter, and height. The highest callus fresh weight (96 mg) and height (11.33 ± 2.08 mm) were obtained with 5 mg/L NAA + 10 mg/L BAP, whereas the largest diameter (16.33 ± 1.53 mm) occurred with 1 mg/L NAA + 5 mg/L BAP. Shoot formation occurred in only 5 of 27 cultures (18.5%), with a maximum of three shoots per culture; the highest observed shoot response occurred at 1 mg/L IAA + 1.5 mg/L TDZ. These findings demonstrate regeneration potential rather than an efficient propagation protocol and provide a basis for further optimization for conservation and future commercial propagation of Andaliman.