The sweet cherry plant (Prunus avium L.) is primarily self-incompatible, with so-called S-alleles responsible for the inability of flowers to be pollinated not only by their own pollen grains but also by pollen from other cherries having the same S-alleles. This characteristic has wide-ranging impacts on commercial growing, harvesting, and breeding. However, mutations in S-alleles as well as changes in the expression of M locus-encoded glutathione-S-transferase (MGST) can lead to complete or partial self-compatibility, simplifying orchard management and reducing possible crop losses. Knowledge of S-alleles is important for growers and breeders, but current determination methods are challenging, requiring several PCR runs. Here we present a system for the identification of multiple S-alleles and MGST promoter variants in one-tube PCR, with subsequent fragment analysis on a capillary genetic analyzer. The assay was shown to unequivocally determine three MGST alleles, 14 self-incompatible S-alleles, and all three known self-compatible S-alleles (S3′, S4′, S5′) in 55 combinations tested, and thus it is especially suitable for routine S-allele diagnostics and molecular marker-assisted breeding for self-compatible sweet cherries. In addition, we identified a previously unknown S-allele in the ’Techlovicka´ genotype (S54) and a new variant of the MGST promoter with an 8-bp deletion in the ´Kronio´ cultivar.

This review cites 137 reports from 25 countries. The highest citation numbers originate from the USA (14), China (14), and Italy (14). In contrast, only one reference is from Hungary, Iran, Morocco, and the United Kingdom. The references are d...

The apple tree (Malus domestica Borkh.) is one of the most economically important fruit crops worldwide, and its productivity is increasingly affected by water deficit. Understanding genotype-specific physiological responses to water deficit is important for improving water deficit resilience in apple. This study evaluated the effects of water deficit (14 days) and subsequent rehydration (7 days) on eight apple genotypes (‘Galaval’, ‘Idared’, ‘Rubinstep’, ‘B11’, ‘HL 308’, ‘HL 2010’, ‘HL 2350’, and ‘HL 827’) grown under semi-controlled container conditions. Physiological parameters, including pigment content, gas exchange, chlorophyll fluorescence, water use efficiency, and leaf water status, were assessed. Water deficit affected all measured parameters, with responses differing among genotypes. In most cases, water deficit was associated with reduced gas exchange and chlorophyll fluorescence, as well as changes in pigment content and leaf water status. However, the magnitude and direction of these responses varied depending on genotype. Some genotypes (e.g., ‘HL 2350’ and ‘B11’) showed more stable physiological performance under water deficit conditions, while others (e.g., ‘Idared’ and ‘Rubinstep’) exhibited more pronounced changes. Rehydration resulted in partial recovery of physiological parameters, although values generally did not reach control levels within the experimental period. The results indicate substantial genotypic variability in physiological responses to short-term water deficit under controlled conditions. These findings provide useful information for further research on water deficit responses in apple; however, additional studies under field conditions and including growth and yield parameters are required to assess the agronomic relevance of the observed differences.

Mechanical damage to apples that occurs without visible skin rupture represents a significant issue during handling and harvesting. The aim of this study was to evaluate the potential for detecting initial internal tissue failure using parameters derived from the deformation curve obtained during a quasi-static penetration test. Particular attention was given to the parameter Pa, defined as the pressure at the yield point, which indicates the onset of structural failure in the tissue. The occurrence of Pa was monitored across five apple genotypes, and the results demonstrated the parameter’s sensitivity to latent internal damage. The parameter Pc, characterising resistance in the later phase of penetration, also showed a strong correlation with fruit bulk density. Significant differences in all mechanical characteristics were observed between the genotypes. The results highlight the potential of these parameters for assessing varietal suitability for mechanised harvesting and sorting. The proposed methodology is readily applicable in the selection of new genotypes within breeding programmes as well as in post-harvest situations.

ISHS XII International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems Sweet cherry rootstocks in high density orchards without irrigation in Central Europe