Békefi, Zs.Tobutt, K. R.Sonneveld, T.2021-06-282021-06-282003-10-20International Journal of Horticultural Science, Vol. 9 No. 3-4 (2003) , 37-42.1585-0404https://hdl.handle.net/2437/314209Sweet cherries (Prunus avium L.) are generally self-incompatible and pollinator cultivars are needed in orchards for reliable yield. In Hungary, choosing the appropriate cross-compatible cultivar pairs has so far been based on traditional test-crosses in the field. In recent years PCR-based methods that allow the identification of the S-alleles responsible for compatibility have been elaborated. We have determined the S-allele constitution of 24 cultivars and four selections important to Hungarian growers and breeders using PCR-based methods developed at Horticulture Research International, East Malling. The 28 accessions had various pairs of 9 alleles including one new allele, S r . They could be assigned to 12 of the existing incompatibility groups or to a new group (S 4 S 12 ) for which the designation 'Group XXVII' is proposed. The cultivars `Krupnoplodnaja' and 'Rita' had novel genotypes, S 5 S 9 and S 5 S x , respectively and can be placed into group 0 that holds universal pollen donors. The genotype of the cultivar ‘Hedelfingeni óriás' grown in Hungary was found to be S 3 S 4 and therefore different from the cultivar `Hedelfingen' that is widespread in Western Europe.application/pdfincompatibilitysweet cherryS-allelesfolyóiratcikkOpen AccessInternational Journal of Horticultural Sciencehttps://doi.org/10.31421/IJHS/9/3-4/403International Journal of Horticultural Science3-49Int. j. hortic. sci.2676-931X