Osmotic Regulation and Viability during Storage of Potato Microtubers Obtained in Vitro

Dehydration, viability, proline, sucrose and glucose concentrations were evaluated on green and white microtubers during storage at two different temperatures. After 10 months at 4 °C, the green and white microtubers showed shrinkage with a dry weight loss of 3.91% and 3.15%. Both, the green and white microtubers at 4 °C presented an enhanced sprouting after storage. At 23 °C, the green microtubers lost the lowest quantity in dry weight (0.8%) and white microtubers lost 2.2%. This behavior is possibly related to the increase in the thickness of the peridermis observed in green microtubers or to the osmotic regulation mediated principally by the observed concentrations of proline and glucose but not sucrose. The best storage conditions for potato microtubers obtained in vitro were at 4 °C for green or white microtubers for up to 10 months with little loss of viability.