S01 - Session P5 - Genetic background of partial resistance to European canker in the apple cultivar `Santana´

Authors: Jonas Skytte af Sätra *, Larisa Garkava-Gustavsson

European canker is currently one of the major pathogens in Swedish apple orchards. Previous work has identified several cultivars with partial resistance. One of the most resistant ones was the Dutch cultivar 'Santana', which is grown commercially in Sweden. While the genetic background for partial resistance to European canker has previously been studied in the local Swedish cultivar 'Aroma', 'Santana' might provide a different source of resistance. The two cultivars are related through one of the parents of 'Aroma', the moderately susceptible cultivar 'Ingrid Marie', being a grandparent of 'Santana'. Though connected through their pedigrees, 'Ingrid Marie' is unlikely to be the main contributor of the resistances in 'Aroma' and 'Santana'. Therefore, 'Santana' and 'Aroma' could present two different resistance sources, and an understanding of the genetic background in 'Santana' would be a valuable resource for future breeding efforts. To identify QTLs underlying resistance we have analyzed a full-sib family from a cross between 'Santana' and the highly susceptible cultivar 'Katja', which is a local cultivar released from the Swedish breeding programme. The family was phenotyped using an artificial inoculation protocol in a glasshouse and genotyped using the 20K apple Infinium® single nucleotide polymorphism (SNP) array. Thus, we hereby present preliminary data on the genetic background for resistance to European canker in 'Santana' and relate it to our previous studies on 'Aroma'.