RAPD markers linked to the Vf gene for scab resistance in apple.

Scab (Venturia inaequalis) is one of the most harmful diseases of apple, significantly affecting world apple production. The identification and early selection of resistant genotypes by molecular markers would greatly improve breeding strategies. Bulked segregant analysis was chosen for the identification of RAPD markers linked to the Vf scab resistant gene. Five different RAPD markers, derived from the wild species Malus floribunda. 821, were identified, and their genetic distance from Vf gene was estimated. The markers OPAM192200 and OPAL07580 were found to be very closely linked to the Vf gene. This result was indirectly confirmed by the analysis of resistant genotypes collected from various breeding programmes. Except for cv 'Murray', which carries the Vm gene, all these resistant genotypes showed the markers OPAM192200 and OPAL07580.