The most commercially grown peach [Prunus persica (L.) Batsch.]
cultivars do not require cross-pollination for reasonable fruit set;
however, self-incompatibility is a well-known feature within the
Prunoideae subfamily. Isoelectric focusing and native polyacrylamide
gel electrophoresis of S-ribonucleases; PCR analyses of S-RNase and
S-haplotype-specific F-box genes as well as DNA sequencing were carried
out to survey the self- (in)compatibility allele pool and to uncover
the nature of self-compatibility in peach. From 25 cultivars and
hybrids with considerable diversity in phenotype and origin, only two
S-haplotypes were detected. Allele identity could be checked by exact
length determination of the PCR-amplified fragments and/or partial
sequencing of the peach S-1-, S-2-, and Prunus davidiana (Carr.)
Franch. S-1 RNases. S-RNases of peach were detected to possess
ribonuclease activity, and a single nucleotide polymorphism in the
S,-RNase was shown, which represents a synonymous substitution and does
not change the amino acid present at the position in the protein. A
700-bp fragment of the peach SFB gene was PCR-amplified, which is
similar to the fragment size of functional Prunus L. SFBs. All data
obtained in this study may support the contribution of genes outside
the S-locus to the self-compatible phenotype of peaches
