S-GENOTYPING OF SOME SWEET CHERRY CULTIVARS RELEASED WITHIN BREEDING PROGRAMMES IN THE BALKAN REGION

Sweet cherry cultivars generally exhibit S-ribonuclease (S-RNase)-based gametophytic selfincompatibility and require pollination with pollen of compatible genotypes, which are indispensable to stable fruit production. Therefore, the determination of S-genotype provides relevant information for sweet cherry breeders and growers. The aim of this study was to identify the S-allelic constitution and incompatibility group in eight sweet cherry cultivars which were named and released at Fruit Research Institute, Čačak, Republic of Serbia (‘Asenova Rana’ and ‘Čarna’), Research Station for Fruit Growing, Iasi, Romania (ʻAlexusʼ, ʻBuciumʼ and ʻMargoniaʼ) and Fruit Growing Institute, Plovdiv, Republic of Bulgaria (ʻKossaraʼ, ʻRosalinaʼ and ʻRositaʼ). The use of the polymerase chain reaction (PCR) method with consensus primers for the second introns of S-RNase, as well as primers specific for S1S7 and S9 alleles enabled determination of the following S-genotypes in the assessed cultivars: S1S2 (ʻAlexusʼ), S1S4 (ʻČarnaʼ), S2S9 (ʻKossaraʼ and ʻRositaʼ), S3S6 (ʻBuciumʼ), S3S9 (ʻAsenova Ranaʼ and ʻRosalinaʼ) and S5S6 (ʻMargoniaʼ). In addition, the S-genotypes of two parental cultivars were reported in this manuscript for the first time ‘Boambe de Cotnari’ (S2S7) and ‘Ranna Tcherna’ (S1S2). Based on the obtained S-allelic constitutions, the assessed cultivars were assigned to the following incompatibility groups: I, II, VI, IX, XI, XIV, XV, XVI and XLIII. The results generated in this study provide a valuable resource for cross design in developing new cultivars and for orchard management in the efficient high-yielding fruit production