Determination of genetic stability in surviving apple shoots following cryopreservation by vitrification

In vitro-grown apple shoot tips were successfully cryopreserved by vitrification, with an average survival and shoot formation of 80 percent and 76 percent respectively. Surviving shoots showed the same rate and regrowth patterns as those of non-treated controls. No significant differences (P < 0.05) were observed in morphological characteristics, including shoot length, leaf shape, leaf width/length ratio and root length, between the control and cryopreserved shoots. No different microsatellite alleles and ISSR fragments were detected between control and cryopreserved shoots using twelve pairs of microsatellites and eleven ISSR primers. These results show that cryopreservation using vitrification is a practical method for the long-term storage of apple germplasm.