Abstract：Apple (Malus domestica Borkh) is a typical Rosaceae species that exhibits gametophytic self-incompatibility (GSI). Identifying the S-genotype of apple cultivars has the practical significance for selecting appropriate pollinated varieties and incompatibility parents for hybridization breeding. In this investigation S-allele-specific PCR was conducted using genomic DNA extracted from 46 apple cultivars as templates and S-genotypes of these cultivars were identified. Furthermore, two new genes named S53- and S54-RNase respectively were cloned from apple cultivars 'Darling' and 'Jinshayilamu'. They were deposited in GenBank under the accession numbers of FJ602074 and FJ602075 respectively.
