The majority of stone fruit species are self-incompatible, a feature that is determined by a specific recognition mechanism between the S-ribonuclease enzymes residing in the pistils and the F-box proteins expressed in the pollen tubes. Failure in the function of any component of this bipartite system resulted in self-compatibility (SC) in many
... cultivars of Prunus species. Peach (Prunus persica (L.) Batsch.) is the only species in the Prunoideae subfamily that is traditionally known to be self-compatible, but its molecular background is completely unknown. Isoelectric focusing and S-gene specific PCR revealed that SC is not due to functional inability of pistil ribonucleases. We hypothesize that SC may be a consequence of a kind of pollen-part mutation or the action of one or more currently unknown modifier gene(s). Only two S-alleles were identified in a set of peach genotypes of various origin and phenotypes in contrast to the 17–30 alleles described in self-incompatible fruit trees. Most important commercial cultivars carry the same S-allele and are in a homozygote state. This indicates the common origin of these cultivars and also the consequence of self-fertilization. According to the available information, this is the first report to elucidate the role of S-locus in the fertilization process of peach.
The SSR (Simple Sequence Repeat) markers allow the discrimination of the cultivars and determination its specific DNA fingerprints. The aim of this research was to evaluate fifteen apricot (Prunus armeniaca L.) and fifty-one peach (Prunus persica L.) genotypes cultivated in Hungary to obtain their DNA fingerprints in 6 SSR (Simple Sequence Re...peats) loci by allele numbers and sizes.
DNAs were extracted from leaves. PCR was carried out with CY-5 fluorescent labeled Prunus microsatellite markers and the products were separated on polyacrylamide gel with ALF (Automated Laser Flourometer)-Express II.
According to our results, in the case of peach genotypes, all 6 SSRs were able to amplify alleles. UDP 96 005 was the most informative marker and UCDCH 17 was the least due to its monomorphic pattern. Regarding the apricot samples BPPCT 041 did not amplify any allele. In the case of P. armeniaca UDP 96 005 had the highest heterozygosity index as well and the highest number of alleles. The least informative marker was the UCDCH 17. Since the 6 SSR were not enough to discriminate the apricot and peach genotypes, it is suggested to use more SSR primers.