Moderate-abiotic stress increase in vitro tuberization and microtuber growth of potato

In vitro tuberization is known to be a very useful tool for large-scale production of potato. Microtubers produced with this method are suitable to grow in greenhouses and fields, thanks to their compact size and storage food supports sprouting. In this research, we report that moderate-abiotic stresses positively influence potato tuberization, microtuber multiplication and growth in vitro. Single-node explants were temporarily exposed to several abiotic stresses namely, cold (4°C, 0-72 h), heat (30-45°C, 1 h), anaerobiosis (0-72 h) and salinity (250-1000 mM NaCl, 0-1 h). After that, they were cultured on modified solid MS medium containing 2 mg L^-1 BA for 12 weeks. Results showed that all stress treatments obviously increased percent of tuberization, number of microtubers and growth and microtuber fresh weight compared to the untreated control. Among all stress treatments, cold treatment at 4°C for 8 h gave the maximal enhancement of tuberization, microtuber multiplication and growth for about 40, 70 and 76%, respectively. These observations indicate that moderate-abiotic stress treatments can be used as novel tools for the induction of potato tuberization in vitro.