S-genotype characterization of 13 North Western European pear (Pyrus communis) cultivars

Abstract

Due to the gametophytic self-incompatibility of European pear (Pyrus communis), S-compatible cultivars that flower synchronically are required in commercial pear orchards to ensure effective pollination and fruit production. The gametophytic self-incompatibility is controlled by a single locus (S-locus) encoding a polymorphic stylar ribonuclease (S-RNase) and pollen-specific expressed F-box genes (SFBB). Both the S-RNase and the SFBB genes are multi-allelic and are ideal markers for molecular S-genotyping. In the present study, we genotype the S-locus of thirteen North Western European pear cultivars by sequencing their S-RNases. All the described cultivars diverged by their S-allele combinations and six of them had unique S-genotype so that they are at least semi-compatible with all the 150 previously described cultivars and could be potentially interesting pollinator cultivars for commercial orchards.