Development of a hybrid apple population: MAS-based testing for Vf gene detection and preliminary field evaluation of its scab resistance

The apple scab, caused byVenturia inaequalis, isone ofthe most devastating diseases ofapples because itdrastically affects the aerial parts ofthe tree. Apple breeding programs frequently aim todevelop cultivars exhibiting resistance toscab. Thus, controlled pollinations were performed onapple trees in2021. The experiment was organised into ahybridisation scheme involving six apple cultivars. The scheme consists of: five female genitors (‘Auriu de Bistrița’, ‘Jonathan’, ‘Golden Delicious’, ‘Starkrimson’, and ‘Idared’) and one male genitor (‘Florina’ – donor for the Vf). Toquickly identify the Vf gene inthe early development stage ofprogenies, three pairs ofprimers were used: AM19, AL07, and VFC. The hybrid combinations with the highest percentage ofprogenies inheriting the Vf resistance gene were: ‘Starkrimson’ ‘Florina’ (59.2%), followed by‘Jonathan’ ‘Florina’ (57.1%). The hybrids that inherited the Vf resistance gene have been transferred to the field and are being further examined for their resistance against scab infections in the field, in the proximity of a natural source of the inoculum infection pressure.