Shoot Regeneration Response in the ‘Colombiano’ Ecotype of Physalis peruviana L. Is Influenced by the Interaction of TDZ, NAA, and Explant Type

Physalis peruviana exhibits highly variable and poorly reproducible morphogenic responses under in vitro conditions, limiting the development of reliable regeneration systems. This study evaluated how the interaction between thidiazuron (TDZ), naphthaleneacetic acid (NAA), and explant type influences shoot regeneration in the Colombiano ecotype of Physalis peruviana. A factorial design (2 × 3 × 2) revealed that morphogenic responses were primarily driven by interaction effects rather than by individual plant growth regulators. Hypocotyl explants cultured in 4.54 µM TDZ combined with 0.6 µM NAA showed the highest shoot production, shoot formation capacity, and elongation. In contrast, TDZ alone induced limited shoot production, did not support efficient and organized shoot development, and was associated with abnormal morphologies. The response to NAA was non-linear, with intermediate concentrations maximizing shoot regeneration response, indicating that morphogenic competence operates within a narrow hormonal range. Overall, regeneration in the Colombiano ecotype of P. peruviana evaluated here was governed by the interaction between hormonal balance and explant type, identifying favorable conditions for shoot regeneration under the conditions tested.