Molecular Identification Of The Self-compatible SFB4' In Sweet Cherry (Prunus Avuim L.)

Self-incompatibility (SI) is a widespread mechanism in flowering plants, which prevents self-fertilization and promotes outcrossing. Sweet cherry (Prunus avium L.) displays the S-RNase-based gametophytic self-incompatibility (GSI) similar to other self-incompatible fruit tree species of the family Rosaceae. In sweet cherry, the S4' haplotype characterized by a self-incompatibility defect in pollen is self-compatible, and is derived from self-incompatible S4 haplotype by X-ray mutagenesis. There have been no molecular methods to differentiate between self-incompatible S4 haplotype and self-compatible S4' haplotype, until recently SFBs (5-haplotype specific F-box protein gene) were found to associate with pollen determinant of GSL This report identified the SFB4' of the self-compatible S4' haplotype. The alignment of the sequences of SFB4' and SFB4 by the BLAST program revealed that there is a 4 bp deletion in SFB4' and the 4 bp deletion is TTTA. The sequence polymorphism generated by the 'TTTA' deletion in the SFB4' was exploited to develop the SFB4' gene-specific molecular marker specific for the detection of the S4' haplotype but not S4 haplotype. The SFB4' gene-specific molecular marker can be visualized directly on an agarose gel, so it can be immediately applied to a marker-assistant cherry breeding program. Thus, this work provides a simple and practical molecular marker for cherry breeding.