Effect of sucrose and abscisic acid on potato (Solanum tuberosum) microtuberisation and dormancy

Microtuberisation serves as a vital approach for the rapid propagation and long-term conservation of potato (Solanum tuberosum L.) germplasm. The present study was carried out during 2023–24 at Sardarkrushinagar Dantiwada Agriculture University, Dantiwada, Gujarat to evaluate the interactive effects of abscisic acid (ABA), sucrose concentrations, and genotype on in vitro microtuber formation across four potato cultivars, i.e. Kufri Badshah, Kufri Surya, Lady Rosetta, and Kufri Nilkanth. Nodal explants were cultured in Murashige and Skoog (MS) liquid medium supplemented with ABA (0.0, 0.1, 0.5, and 1.0 mg/L) and sucrose (8% and 10%) to assess their impact on key microtuberisation parameters. Results demonstrated that increased sucrose concentration significantly enhanced higher number of microtubers and microtuber weight, outperforming all treatments involving ABA. The combination of ABA with sucrose did not yield synergistic effects, indicating sucrose as the principal driver of microtuber development. Among the genotype, Kufri Badshah exhibited the highest microtuberisation efficiency, followed by Kufri Surya, Lady Rosetta, and Kufri Nilkanth. While ABA did not directly improve microtuber induction or growth metrics, it played a critical role in dormancy extension and prolongation of storage viability, an essential factor for transportation and germplasm preservation. Differential cultivar responses to ABA, highlighting the need for conservation strategies suited to each genotype. Overall, this study showed that sucrose is a key factor for microtuber formation, while ABA is crucial for dormancy regulation, providing useful information to improve microtuber production and long-term storage of potato germplasm.