No abstract

No abstract

No abstract

Established shoot cultures of three apple genotypes, `Dayton', `McIntosh', and `Golden Delicious' were subcultured into culture tubes containing a modified MS medium and maintained in a dark chamber at 1.0±0.5°C for periods of 3, 6, 9, and 12 months. Following each cold storage period, culture tubes of each of the three genotypes were transferred to a growth room and maintained under 16 h of light (60 uEs-1m-2) and 21°C. The overall morphological condition of each shoot was then recorded. After 4 weeks of growth, both number and length (in cm) of proliferating shoots were recorded. In general, shoots subjected to 3 or 6 months of cold storage remained green however most cultures did not initiate any new shoots. Cultures subjected to 9 or 12 months of cold treatment were etiolated however new axillary shoots were observed. The proliferation rate after 4 weeks of growth under standard growth conditions were variable among the different genotypes. The implications of using long term cold storage of apple shoot cultures will be discussed.