In vitro conservation of chestnut (Castanea sativa) by slow growth

Slow growth storage has been achieved for Castanea sativa (cv. ‘Montemarano’) shoot cultures over a duration of 48 mo at a temperature of 8°C, where 82% of explants survived and were able to resume normal growth after transfer to standard culture conditions at 23°C. The evaluation of the chlorophyll content of leaves also showed no differences between material stored for 48 mo and control material subcultured at 23°C. With a storage temperature of 4°C, the survival of shoots was significantly lower at approximately 56% after 12 mo, and no plants recovered after 24-mo storage. The presence of 6-benzyladenine 0.44 μM in the culture medium proved to be necessary for the recovery of healthy shoots, while pre-treatments with different concentrations of abscisic acid did not significantly influence the survival of shoots following storage conditions. A low level of light during slow growth storage resulted in positive effects on the rate of shoot survival over the longest preservation periods.