Identification of self-incompatibility alleles and pollen incompatibility groups in sweet cherry by PCR based s-allele typing and controlled pollination

A total of 17 pollen incompatibility groups in sweet cherry (Prunus avium L.) were identified among 46 accessions by PCR based S-allele typing analysis and by controlled test pollinations. Two putative S-alleles different from S₁ to S₆, S_z and S_y were identified. Five S-genotypes, S₁S₅, S₁S₆, S₂S₆, S₄S₆, and S₅S₆, combinations of S₁ to S₆ alleles that had not previously been identified from cultivars in NYSAES, were positively confirmed by PCR based S-genotyping analysis. Also, the S-genotypes of cultivars in some pollen incompatibility groups that had previously been incorrectly reported have been clarified. Several popular cultivars, which were previously used as testers for S-allele typing analysis, were found to have been inaccurately genotyped. In addition, the S-genotypes and self-incompatibility groups of some relatively recently introduced cultivars were identified. The molecular typing system of S-genotypes based on PCR is a useful and rapid method for identifying new S-alleles and incompatibility groups in sweet cherry.