SCREENING FOR SCAB RESISTANCE BY RAPD MARKERS IN CULTIVARS OF APPLE (MALUS SPP)

Genetic markers are a much faster and more practical alternative to cl assical methods for the identification of genes for scab resistance pr esent in different apple cultivars. In our study, 28 scab-resistant cu ltivars, four wild sources of the resistance genes and 10 susceptible cultivars were screened for the presence of the RAPD fragments OPM18/9 00, OPD20/600 and OPA15/900, which are reported to be linked to the Vf gene. All three marker fragments were successfully amplified with dif ferent protocols in Vf-resistant cultivars including 'M. floribunda 82 1'. No marker fragments were amplified in susceptible cultivars, three out of four Va-resistant cultivars, three out of four Vr-resistant cu ltivars, two Vm-resistant cultivars, 'Antonovka PI 172612' and 'M. pum ila R 12740-7A'. All three markers were found in the cv. 'Nova Easygro ', reported to possess the Vr gene, and the cv. 'Reglindis', reported to be Va-resistant. M. atrosanguinea of unknown origin showed the pres ence of OPD20/600 and OPA15/900 marker bands. The cvs. 'Nova Easygro', 'Reglindis' and M. atrosanguinea are probably carriers of the Vf gene .