Abstract: To identify 20 apple germplasms’ S-genotypes by PCR and sequencing，the universal primers and 19 pairs of specific primers of apple S-alleles were designed for‘Fuji’，‘Huarui’，‘Huashuo’，‘Huaxing’and so on，based on the highly conserved amino acid sequences FTQQYQ and anti-1/MIWPNV and the polymorphic sequences of S-alleles. To verify the accuracy of identified S-genotypes，reciprocal crosses-pollination experiments were carried out using‘Huarui’and ‘Huashuo’with‘Meiba’，‘Jinxiuhong’and‘Huaguan’，respectively. PCR results showed that when using the universal primers，two specific S-allele bands were amplified only from‘Fuji’，‘Huarui’，‘Huashuo’，‘Huaxing’，‘Meiba’and‘Hongcuibao’，whose S-genotypes were S1S9，S9S24，S5S9 and S5S24. When 19 pairs of specific primers were used for amplification，two specific bands were obtained from 14 cultivars，whose S-genotypes were S10S19，S2S3，S2S5，S3S10，S2S9，S5S24，S9S10，S3S10 and S5S9. Therefore，the S-genotypes for 20 apple cultivars were：S1S9 for‘Fuji’，S9S24 for‘Huarui’and ‘Huashuo’S5S9 for‘Huaxing’，‘Meiba’and‘Hongzhenzhu’，S5S24 for‘Hongcuibao’，‘Huayu’and‘99-1-29’，S10S19 for ‘Huashuai’，S2S3 for‘Jinyu’，S2S5 for‘Zaohong’，‘Huamei’and‘Gala’，S3S10 for‘Seokwang’，S2S9 for ‘Jinxiuhong’，‘Miyu’and‘Huaguan’，S9S10 for ‘Lüjia’，S3S10 for‘Shinano Red’，respectively. The pollination experiment showed that the fruiting rate of reciprocal crosses-pollination between‘Huarui’and ‘Huashuo’ germplasm was lower than 15.52% in 2015 and 2016. The fruit ratio of reciprocal crosses-pollination between‘Huarui’and‘Huashuo’with‘Meiba’，‘Jinxiuhong’，‘Huaguan’，‘Fuji’were higher than 46.30% in 2015 and 2016. Therefore，in this experiment，the same combination of S-genotypes had a low fruit setting percentage but a higher fruit setting percentage with different S-genotypes，indicating that the results of pollination supported the results of S-genotype identification.

Key words: Malus × domestica, self-incompatibility, S-genotype