Efficient and cost-effective shoot regeneration in Aguaymanto (Physalis peruviana L.) using meta-Topolin and 6-benzylaminopurine combinations

Physalis peruviana L. (known as aguaymanto or goldenberry) is a high-value Andean fruit crop with growing international demand due to its nutritional and nutraceutical properties. However, the development of advanced biotechnological tools for this species has been limited by the lack of efficient and reproducible in vitro regeneration protocols. Existing systems rely primarily on the use of zeatin, a highly effective but expensive cytokinin, which restricts their applicability in resource-limited laboratories. In this study, the synergistic effect of 6-benzylaminopurine (BAP) and meta-topolin (mT) on adventitious shoot regeneration from cotyledonary explants of P. peruviana was evaluated. An initial cytokinin screening identified BAP + mT as the most promising combination, and subsequent optimization revealed that the combination of 9.12 µM BAP with 2.28 µM mT promoted the highest shoot regeneration rate (62.96 %), outperforming previously reported zeatin-based protocols. This treatment also significantly enhanced shoot elongation and rhizogenesis without inducing morphological abnormalities. These results position the BAP + mT combination as an economically viable alternative to replace the use of zeatin in regeneration protocols, with potential applications in genetic transformation programs, in vitro propagation, and the improvement of species in the genus Physalis.