Physical and physiological changes in mume (Prunus mume Sieb. et Zucc.) subjected to a 10-minute hydrostatic high-pressure treatment at 5, 10, 50, 100, 150, and 200 MPa were investigated. Mume fruit exhibited substantial injury at pressures >5 MPa. All treatments induced color changes, which became more apparent at pressures >100 MPa. Fruit subjected to pressures ≥100 MPa deteriorated and were rendered commercially unacceptable. After transfer to atmospheric pressure all treated fruit exhibited lower CO2 evolution rates compared with control fruit. Only fruit subjected to 5 MPa exhibited an increase (27%) in titratable acidity. Ethylene production rate in mume fruit was very high, but consistently and dramatically decreased after treatment, regardless of the pressure applied. The decline in ethylene production was associated with a decrease in ACC oxidase activity. Chemical names used: 1-aminocyclopropane-1-carboxylic acid (ACC).
S4′ is a pollen-part mutant in sweet cherry (Prunus avium L.) that is extensively used to develop self-compatible cultivars. The S4′-haplotype is known to have a functional stylar component and a nonfunctional pollen component. The pollen component in sweet cherry necessary for the specificity of the pollen reaction is believed to be an S-haplotype specific F-box protein gene, called SFB. This study describes two molecular markers that distinguish between SFB4 and SFB4′ by taking advantage of a four base pair deletion in the mutant allele. The resulting polymerase chain reaction (PCR) products can either be separated directly on a polyacrylamide gel or they can be subjected to restriction enzyme digestion and the different sized products can be visualized on an agarose gel. The latter technique utilizes restriction sites created in the PCR products from the SFB4′ allele, but not the SFB4 allele. Because the primer sets created differential restriction sites, these primer sets were termed dCAPS (derived cleaved amplified polymorphism sequence) markers. These molecular assays can be used to verify self-compatibility conferred by the S4′-haplotype.