Assessment of genetic variation among regenerants from in vitro apple leaves using molecular markers

The potential significance of adventitious shoot regeneration from in vitro leaves for apple breeding was studied. 0.2 mg/l TDZ in combination with 0.1 mg/l IBA was used to induce shoot regeneration from segments of fully expanded leaves of apple cultivars 'Golden Delicious Bovey' and 'Goldspur' grown in vitro. DNA samples of each cultivar from in vivo and in vitro, 39 regenerants of 'Golden Delicious Bovey' and 38 regenerants of 'Goldspur', were screened with 25 RAPD primers. A total of 139 scorable bands were amplified in 'Golden Delicious Bovey' and its regenerants, although one regenerant lacked the fragment OPM-02/900 and another regenerant lacked both OPA-01/850 and OPA-11/500 fragments. 'Goldspur' and its regenerants produced 133 scorable bands in total. One regenerant of 'Goldspur' showed the presence of an additional band OPX-14/600. The amount of variation detected by a relatively low number of primers shows that adventitious shoot regeneration from in vitro leaves provides a powerful technique for mutation breeding of apples.