Effect of carbohydrates on in vitro low-temperature storage of shoot cultures of apricot

Procedures for cold storage of in vitro cultures can delay subculturing, reducing production costs and risks of contamination and somaclonal variation. The present work investigates the effects of media with sorbitol (116.8 mM, medium SO) or sucrose (58.4 mM) alone (medium SU), or the latter in combination with mannitol (58.4 mM, medium M) on 7-month storage at 5 °C of apricot shoots, cv San Castrese and Boreale. Shoots in SO survived in lower percentages and grew less than in the other treatments during storage, and died in large numbers after transfer to standard culture conditions. In comparison to other treatments, survival was 100% in the presence of M and both shoot weight and number of surviving proliferated axillary shoots was increased. Moreover, M improved regrowth compared to SU under standard culture conditions. The SOD and CAT activity confirmed the higher stress of shoots stored in SO than controls, and in contrast, the low stress of shoots in M.

Research highlights▶ Carbohydrates strongly affected low-temperature (5 °C) storage of apricot shoots. ▶ Mannitol plus sucrose allowed 100% shoot explants survival during storage. ▶ Mannitol improved shoot regrowth after storage compared to sucrose alone. ▶ Sorbitol induced the worst shoot performance during and after storage. ▶ The superoxide dismutase and catalase activity proved the shoot stress on sorbitol.