Determination of self-incompatible genotypes in sweet cherry accessions of Czech genetic resources

Sweet cherries are self-incompatible determined by a gametophytic self-incompatibility system (GSI). The self-incompatibility is controlled by a multi-allelic Slocus and includes two genes coding for the synthesis of proteins responsible for the incompatibility response. The knowledge about the S-allele constitution of cultivars is very important for fruit growers and breeders. Recently, molecular methods have been developed to distinguish the S-alleles in sweet cherries and different molecular primers for the PCR-based identification of all S-alleles were designed during the last years. In our work, we analyzed S-locus genotypes by 10 universal and specific PCR primer combinations within 82 current, old and local sweet cherry cultivars from Czech genetic resources of Research and Breeding Institute of Pomology in Holovousy. We confirmed previous S-genotyping for 46 accessions except 'Droganova', 'Hedelfingen', 'Erika Fruhe Meckenheimer', 'Huldra', 'Rivan', 'Vanda' and 'Winkler'. It can be due to mislabeling or mistakes in previous analyses. Newly, S-genotyping was determined for 36 accessions when we found 4 new S-loci combinations. Totally, we detected S-locus combinations in 21 incompatibility groups. The most frequent incompatibility groups were III (S3S4), IV (S2S3), VI (S3S6) and II (S1S3) with 13, 11, 9 and 8 genotypes, respectively.