The S-genotyping of wild-grown apricots reveals only self-incompatible accessions in the Erzincan region of Turkey

The S-genotypes of 63 wild-growing Turkish apricots (Prunus armeniaca L.) were determined by PCR amplification of the S-RNase intron regions and SFB gene in order to characterise their sexual (in)compatibility phenotype. We determined the complete S-genotype of 63 wild-grown apricot accessions that originated in the Erzincan region. Ten previously described and 2 new S-alleles (provisionally labelled S_X and S_Y) were identified in the genotypes. S_2 was the most frequent S-allele in the tested germplasm (occurred in 19 accessions), followed by S_8 (17), S_{19} (16), S_3 (13), S_{12} (11), S_6 (10), and S_7 (10); while S_{9}-, S_{11}-, and S_{13}-alleles were found in 8 accessions. A total of 36 different S-genotypes were assigned to the tested accessions. The S_{C}-allele responsible for self-compatibility in apricot was not present, indicating that all accessions are self-incompatible. The analysis of S-allele frequencies allowed us to conclude the close relationship of wild-grown and cultivated apricots in Turkey and helped to raise hypotheses to explain high occurrences of S_2- and S_8-alleles.