Search Results (453)

Heat-induced softening of apple fruit varies markedly among cultivars; however, the biochemical factors underlying these differences remain incompletely understood. This study investigated the relationship between cell wall modifications and thermal flesh breakdown in three apple cultivars (‘Bramley’s Seedling’, ‘Fuji’, and ‘Toki’). Fruit flesh samples were heated under controlled conditions and analyzed for changes in texture properties, cell structure, cell wall composition, and molar mass distribution. Heating increased water-soluble pectin in all cultivars, with a markedly greater increase in ‘Bramley’s Seedling’, indicating pronounced pectin solubilization during thermal treatment. A pronounced shift from high- to low-molar-weight polymers in the Na₂CO₃-soluble fraction was also observed only in ‘Bramley’s Seedling’, suggesting extensive depolymerization of the Na₂CO₃-soluble pectic polymers. A decrease in hemicellulose and cellulose content following heating was observed exclusively in ‘Bramley’s Seedling’. Consistently, this cultivar exhibited significantly lower gumminess and chewiness compared with the other cultivars. Beyond compositional changes, ‘Bramley’s Seedling’ exhibited severe tissue disintegration and distinctive rheological behavior indicative of extensive cell rupture. In contrast, ‘Fuji’ and ‘Toki’ retained relatively stable cell wall structures and maintained tissue integrity after heating. These findings suggest that cultivar-dependent disassembly of cell wall polysaccharides, particularly pectin depolymerization and solubilization, is strongly associated with heat-induced tissue breakdown. Full article

This study compared the quality and bioactive composition of cloudy apple juices produced from four traditional and four conventional apple cultivars immediately after harvest and following cold storage of the fruit at 4 °C for three and six months. Apples were harvested at the ripening stage at the same criteria, stored as whole fruit, and processed into cloudy juice after harvest, three, and six months of storage. Physicochemical parameters and sugar composition were determined, while phenolic compounds were quantified by HPLC-PDA. Antioxidant activity, total phenolic, and flavonoid content were measured spectrophotometrically. All analyses were performed in technical triplicate. The results revealed notable differences between traditional and conventional cultivars. Juices produced from traditional apple cultivars exhibited significantly higher total polyphenol and flavonoid contents than those from conventional cultivars. Significant variations in catechin, myricetin, quercetin, and epigallocatechin levels were also observed among cultivars. The traditional apple cultivar ‘Mašanka’ showed higher concentrations of quercetin (0.09 ± 0.01 µg/mL), chlorogenic acid (486.58 ± 5.48 µg/mL), catechin (8.76 ± 0.54 µg/mL), epicatechin (20.22 ± 0.20 µg/mL), and phloridzin (13.48 ± 0.19 µg/mL) compared to the other cultivars. In contrast, conventional cultivars showed higher concentrations of myricetin and procyanidin B1. Moreover, the content of TA, sucrose, and glucose decreased, whereas pH, fructose, TSS (except for ‘Fuji’ and ‘Granny Smith’) increased. The TFC decreased in traditional apple cultivars, while it increased in conventional cultivars; however, the TFC in conventional cultivars remained lower than in traditional ones. Overall, these findings demonstrate that the cold storage of apples significantly affects juice composition and highlight the advantages of traditional apple cultivars for producing juices with enhanced phenolic content and antioxidant activity. Full article

Apple firmness, soluble solids content (SSC), and titratable acidity (TTA) were modeled when fruit were kept under cold storage and shelf-life conditions. These attributes are key indicators of fruit quality, storability, and organoleptic properties. Apple fruit of the ‘Irene’ cultivar were stored at 1 °C for 7 months, with quality assessed monthly and after 7 days of shelf life. Models based on the Storage Time Equivalent Value (STEV) were applied to predict firmness, SSC, and TTA as functions of time in cold storage and shelf life. Rates of change were higher during shelf life, with acceleration factors of 5.78 for firmness, 6.50 for SSC, and 5.51 for TTA. Model performance was high (R²_CV = 0.977, RMSE_CV = 1.16 N for firmness; R²_CV = 0.862, RMSE_CV = 0.29 °Brix for SSC; R²_CV = 0.978, RMSE_CV = 0.155 g L⁻¹ for TTA). The proposed approach integrates cold storage and shelf life into a single predictive framework. The unified STEV models, incorporating acceleration factors, show potential for forecasting the shelf life of ‘Irene’ apples. Full article

The apple (Malus domestica Borkh.) is one of the most widely consumed fruits worldwide due to its pleasant sensory properties and rich phytochemical composition. Therefore, the present study aimed to comprehensively investigate the chemical composition, antioxidant activity, anticancer effects, and molecular interactions of peel and pulp extracts of the Hünkar apple cultivar collected from different locations, using a combined experimental and computational strategy. These factors had a big effect on the extracts’ phenolic composition and biological activity. Moreover, the anticancer results were corroborated by molecular docking analyses, which offered further understanding of the interactions between bioactive compounds and cancer-associated target proteins. This integrative approach underscores the impact of both biological and methodological variables on the antioxidant and anticancer properties of apple-derived extracts, reinforcing their potential as natural sources of bioactive compounds. Cytotoxic activity against HT-22 and C6 cell lines was evaluated using the MTT assay, showing dose- and time-dependent antiproliferative effects. Apple extracts exhibited anticancer effects that were dependent on dosage and duration. The activities of chemicals found in extracts of Hünkar apple samples collected from four different locations against brain cancer proteins (PDB ID: 2DME, 6YPE, 1RV1) were examined. ADME/T analysis was then performed on the three molecules with the highest activity. The quantum chemical properties of these three molecules were also examined using the Gaussian package program with B3LYP, HF, M062X level in 6–31g, 6–31++g, and 6–31++g(d,p) basis sets. Full article

The application of dual cytokinins can significantly enhance shoot multiplication rates in specific apple cultivars compared to standard protocols using a single cytokinin. This study presents a comprehensive analysis of shoot multiplication parameters and the underlying transcriptomic response of two distinct apple scion cultivars, cvs. Húsvéti rozmaring and McIntosh, to the simultaneous application of two cytokinins (BA and KIN). Morphological parameters were recorded, followed by comparative RNA-seq analysis and RT-qPCR validation. Our results demonstrate that the BA+KIN treatment induces a unique transcriptomic signature in both cultivars, which cannot be explained by a simple dose–response effect. In cv. McIntosh, 76% of the DEGs were uniquely regulated by the combination, while in cv. Húsvéti rozmaring, although the overlap with single treatments was higher, 17% of the DEGs (representing 1218 genes) were still exclusively activated by the BA+KIN treatment. The fact that the combined treatment recruits specific gene sets and metabolic pathways that remain silent under single BA or KIN applications—regardless of the cultivar—strongly supports a synergistic or non-additive hormonal interaction rather than a response to increased total cytokinin concentration. The dual treatment revealed 3209 DEGs in the inter-cultivar comparison, reflecting distinct strategies: cv. Húsvéti rozmaring achieved high efficiency growth by down-regulating internal hormones, whereas cv. McIntosh exploited intense auxin signaling and hormonal plasticity to maximize bud release. These results prove that distinct molecular pathways can lead to peak performance depending on the apple cultivar. Full article

In apple (Malus × domestica Borkh), temperature during flowering strongly influences ovule viability and reproductive success, particularly under changing climate conditions. Five apple cultivars—‘Red Aroma’, ‘Discovery’, ‘Elstar’, ‘Rubinstep’, and ‘Summerred’—were exposed to constant temperatures (8 °C, 12 °C, and 16 °C) in the days following anthesis to evaluate ovule degeneration. At six time points after anthesis, fluorescence-stained ovules were visually categorized to assess ovule vitality and degeneration stages. Ovule viability decreased in a highly temperature-dependent manner across all cultivars. High percentages of viable ovules were observed at 8 °C and 12 °C, whereas ovule senescence was significantly accelerated at 16 °C, leading to a rapid loss of viability. Based on fluorescence intensity, ovule degeneration is irreversible once initiated and involves both physiological and morphological changes at higher temperatures. The cultivar ‘Elstar’ exhibited the slowest loss of ovule viability, while the other cultivars showed more rapid degeneration. These findings demonstrate that both temperature and genetic background affect ovule viability, making this stage of the reproductive process crucial in the context of future climate change. Full article

Plum pox virus (PPV) is one of the most destructive pathogens affecting stone fruit trees. It causes sharka disease and severe yield losses. The genetically modified plum cultivar ‘HoneySweet’ was developed to provide long-lasting resistance to PPV via RNA interference. Long-term field trials of ‘HoneySweet’ have been conducted in the Czech Republic since 2001, involving the artificial inoculation of the cultivar with PPV alone, and with apple chlorotic leaf spot virus (ACLSV) and prune dwarf virus (PDV) in combination. This study evaluates the impact of viral infection on tree growth after 24 years in the field. Growth parameters—trunk cross-sectional area (TCSA) and canopy volume—were measured and analysed using ANOVA and Tukey’s test. The results show that infected trees exhibit significantly reduced growth compared to non-infected controls, with the strongest inhibition observed in trees inoculated with PPV + PDV + ACLSV. The presence of ACLSV had the most pronounced negative effect on growth, while PDV did not significantly influence tree vigour. These findings emphasise the importance of using virus-free rootstocks and certified planting material to prevent growth suppression in HoneySweet orchards. Full article

The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive pest that increasingly threatens apple production in Europe by causing fruit damage, yield losses, and quality deterioration under commercial orchard conditions. This study investigated seasonal population dynamics, spatial patterns of fruit damage, yield effects, and post-harvest fruit responses of two apple cultivars (‘Cripps Pink’ and ‘Fuji’) in a commercial orchard over two consecutive seasons (2024–2025). Adult and nymphal activity was monitored using pheromone traps, while fruit damage was assessed at harvest across orchard positions and canopy layers. Potential yield losses were estimated based on damage incidence, and selected physicochemical properties of healthy and affected fruits were analysed. Clear cultivar-dependent differences were observed. ‘Fuji’ exhibited typical external feeding damage, with low but consistent damage levels and limited yield losses in both seasons. In contrast, ‘Cripps Pink’ showed substantially higher damage rates and potential yield losses, particularly in 2025; however, classical external feeding damage was not observed. Instead, fruits exposed to H. halys pressure expressed atypical responses, primarily as increased individual fruit mass and size, and atypical skin color patterns, including pronounced striping and uneven pigmentation. Damage in ‘Cripps Pink’ was strongly structured within the orchard, with higher incidence in the upper and middle canopy layers and in areas adjacent to the forest edge, whereas damage in ‘Fuji’ remained low and spatially uniform. Overall, the results demonstrate that the impact of H. halys depends not only on pest pressure but also on cultivar traits and within-orchard spatial heterogeneity. These findings support the development of cultivar-specific and spatially targeted integrated pest management (IPM) strategies that better reflect the uneven distribution and expression of stink bug injury in commercial apple orchards. Full article

Flesh mealiness, a textural disorder in apples, reduces storage quality and consumer acceptance. The ‘Delicious’ and ‘Fuji’, prominent apple cultivars in China, exhibit contrasting susceptibility to mealiness, though the underlying mechanisms remain unclear. This study compared cytological, physiological and cell wall metabolic changes between mealy ‘Oregon Spur II Delicious’ and non-mealy ‘Miyazaki Spur Fuji’ during ambient storage. Toluidine blue staining and scanning electron microscopy revealed that ‘Delicious’ exhibited larger intercellular spaces and cell separation in contrast to ‘Fuji’. This observation aligns with the earlier onset of mealiness in ‘Delicious’: its mealiness degree increased from 3.06% at harvest to 19.62% after 28 d of storage (a 6.4-fold rise), whereas that of ‘Fuji’ only increased from 2.13% to 3.90% (1.8-fold). This pronounced increase in ‘Delicious’ was accompanied by a significant increase in air space volume and a reduction in expressible juice. Furthermore, the occurrence of mealiness in ‘Delicious’ involved a sharp increase in respiration rate and ethylene production, alongside rapid declines in firmness and starch content. Notably, there was a substantial accumulation of water-soluble pectin (WSP) and chelator-soluble pectin (CSP) in ‘Delicious’, whereas the content of Na₂CO₃-soluble pectin (NSP) remained consistently lower. Monosaccharide composition analysis confirmed significantly reduced arabinose and galactose levels across pectin fractions (WSP, CSP, and NSP) in ‘Delicious’. Correspondingly, immunofluorescence labeling showed a pronounced degradation of arabinan and galactan within the side chains of rhamnogalacturonan-I (RG-I). In addition, the activities of pectin methylesterase, α-L-Arabinofuranosidase, and β-D-Galactosidase remained significantly elevated in ‘Delicious’. Collectively, these findings demonstrate that cultivar differences in flesh mealiness are attributable to divergent physiological senescence and cell wall disassembly processes. Full article

Genetic and climatic factors influence the nutritional content of fruit, with vitamin C being a key component. Using HPLC, we quantified the amount of vitamin C in cherries, apricots, plums, and apples from 2022 to 2024. Contents ranged from 1.6 to 24.6 mg/100 g fresh weight basis (FW), with apples and plums displaying the highest coefficient of variation (32.53% and 45.25%). The highest content was consistently found in accession ‘HL827’, which exceeded 20 mg/100 g FW. Cherries reached up to 12.1 mg/100 g FW in 2023 (‘13590′), but decreased to 1.9 mg/100 g FW in 2024 (‘Jacinta’). Apricots showed high fluctuation, with ‘Betinka’, ‘Candela’, and ‘HL08-052’ exceeding the 30% variance coefficient. Accessions that remained stable (‘HL96-266’) maintained a low variance only. Plums were the most sensitive, experiencing low vitamin C content under hot and dry conditions. Regression analysis identified temperature (NTavg-20) as the dominant climatic driver in plums and cherries (R² = 0.999, p < 0.05 and R² = 0.995, p < 0.05) respectively, whereas apples and apricots showed negligible responses (R² ≤ 0.210). These findings underscore the importance of genotype/environment interactions at the local level and highlight the value of stable accessions as valuable resources for breeding cultivars with high and resilient vitamin C content. Full article

This study examines the reproductive biology of five widely cultivated apple cultivars in Norway (‘Discovery’, ‘Rubinstep’, ‘Red Aroma’, ‘Elstar’, and ‘Asfari’), when crossed with the main pollenizers (‘Summerred’, ‘Discovery’, ‘Katja’, ‘Rubinstep’, ‘Red Aroma’, ‘Fryd’, and ‘Eden’, and two crab apples ‘Professor Sprenger’ and ‘Dolgo’), as well as under self-pollination and open pollination. The experiment was conducted over two seasons (2022–2023) in Hardanger, a region in Western Norway. Flowering time and overlap, in vitro pollen germination, pollen tube growth within the styles and ovary, embryo sac viability, fertilization success, and fruit set were analyzed as key reproductive parameters. Under broadly comparable climatic conditions across both seasons, the results showed that both mother cultivar and the pollenizer strongly influenced progamic processes and fruit set. Pollen tube growth through the pistil was generally faster and more successful in 2022 for all pollination combinations, resulting in a higher fruit set. The only exception was ‘Elstar’, which exhibited a higher fruit set in 2023. If a single optimal pollenizer were to be selected for each apple cultivar in Western Norway, it would be ‘Red Aroma’ for ‘Discovery’ and ‘Rubinstep’; ‘Rubinstep’ for ‘Red Aroma’ and ‘Elstar’; and ‘Professor Sprenger’ for ‘Asfari’. Based on pollen tube growth in vivo and the fruit set, cultivars ‘Discovery’, ‘Rubinstep’, ‘Red Aroma’, ‘Elstar’, and ‘Asfari’ showed self-incompatibility. Full article

Background/Objectives: Plants alter metabolites of their fruits during the ripening process, leading to improved nutritional properties and taste. In addition, metabolite compositions continue to change on the shelf after harvest. However, the dynamics of these important processes are species-specific and so this study aimed to contrast the ripening dynamics of ten different fruit species simultaneously. Methods: Plant material was collected from the fruits of apple, banana, blueberry, kiwifruit, pear, plum, peach, strawberry, raspberry, and tomato at three different stages: unripe, fully ripe, and overripe fruits. Comparative metabolome analysis by GCMS was performed to identify differentially abundant metabolites across the species of this study and to examine their dynamics across ripening and post-harvest storage. These results were complemented by elemental compositions derived from a literature search. Results: In a first, this study demonstrated that both baseline metabolite abundances and their dynamics across ripening clustered species vary largely according to their phylogeny. Comparisons across ripe fruit identified differences in nutritional properties, highlighting species such as banana to be of especially high nutritional value and blueberry and peach to be prominent sources of antioxidants. Comparing the ripening dynamics of all species identified common patterns, such as the conversion of organic acids to sugars and cell wall dynamics, although species-specific responses were also acknowledged, in particular, kiwi and the Rosaceae berries, which may explain differences in post-harvest shelf-life. Conclusions: The observed inter- and intra-specific variation in nutritionally relevant metabolites and elements serves as a reference for both producers and consumers and emphasizes that consuming a variety of fruits, not only across species but also across cultivars within a species, can maximize the intake of beneficial phytonutrients, sugars, amino acids, and antioxidants. Full article

Red pigmentation in apple peel significantly contributes to its commercial value, and bagging treatment contributes to enhancing red coloration in fruits. However, the regulatory mechanisms underlying bagging-induced coloration remain largely unexplored. Through bagging treatment, this study aimed to investigate the role of DNA methylation in anthocyanin biosynthesis in the ‘Nagafu No. 2’ cultivar and its bud mutation variant, which has enhanced red coloration. We compared bagging and unbagging treatments in both the bud mutant (Mt-Bagging and Mt-NoBagging) and the wild type (Control-Bagging and Control-NoBagging). Our results demonstrated that bagging significantly promoted anthocyanin accumulation while reducing chlorophyll content. At 30 days post-bag removal, anthocyanin content was highest in the Mt-Bagging group, followed by the Mt-NoBagging, Control-Bagging, and Control-NoBagging groups, and the highest level of redness (a* values) was detected in the Mt-Bagging group. Genome-wide methylation analysis revealed that differentially methylated regions predominantly targeted structural genes within the anthocyanin biosynthesis pathway, including C4H1, C4H3, C4HL, ANS1, and ANS2. Notably, quantitative PCR analysis confirmed that the upregulation of C4HL, C4H3, and ANS1 in the bagged mutant correlated with its intensified red coloration. These findings offer novel insights into the epigenetic regulation of apple peel pigmentation during bagging cultivation. Full article

Apple aroma is an important factor influencing consumers’ preferences. To understand the overall flavor characteristics of apples (Ruixue, Liangzhi, Grystal Fuji, and Guifei), volatile compounds and aroma profiles were investigated by headspace–gas chromatography–ion mobility spectrometry (HS-GC-IMS) combined with stir bar sorptive extraction (SBSE) and gas chromatography–mass spectrometry (GC-MS). The results showed that a total of 56 aroma compounds were identified by SBSE-GC-MS, and 39 aroma-active compounds were screened out using aroma intensity (AI) and odor activity value (OAV). Aroma recombination experiments showed enhanced ‘fruity’ and ‘sweet’ notes, whereas ‘floral’, ‘woody’, and ‘green’ aromas were weaker compared to the Crystal Fuji sample. Additionally, GC-IMS coupled with principal component analysis (PCA) was used to distinguish the apple samples, and partial least squares regression (PLSR) was applied to explore the correlation between sensory attributes and characteristic aroma compounds. The results indicated that Crystal Fuji exhibited the greatest correlation with the “woody” attribute, and Ruixue was highly correlated with “fruity”, “green”, and “sour” attributes, while butanoic acid, β-damascenone, butyl acetate, pentyl acetate, furfuryl alcohol, γ-decalactone, and vanillin had a significant impact on the “flower” and “sweet” attributes of Guifei. This study clarified the characteristic aroma composition of the four apple cultivars, providing data support for apple flavor quality evaluation and cultivar optimization. Full article

This study evaluated the fruit quality of 12 apple cultivars grafted onto the cold-resistant dwarfing interstock SH40 in the arid region of Lingwu, Ningxia, to identify well-adapted varieties for local production. A total of 21 indicators were measured, encompassing three major aspects: external quality (e.g., fruit size, shape index, peel color), internal flavor (e.g., soluble solids, soluble sugars, titratable acids, vitamin C content), and textural attributes (e.g., hardness, crispness, chewiness), and data were analyzed using principal component analysis and membership function methodology. The cultivars exhibited distinct quality profiles under identical management: ‘Red General’ performed well in fruit size, weight, and sugar–acid balance; ‘Yanfu 6’ showed the highest firmness and crispness; ‘Shengli’ had the greatest soluble solids content; and ‘Granny Smith’ was richest in vitamin C. Four principal components were extracted, explaining 80.06% of the total variance and simplifying the quality evaluation system. Based on the comprehensive membership function scores, ‘Red General’, ‘White Winter Pearmain’, and ‘Huashuo’ ranked highest in overall fruit quality. In conclusion, these three cultivars perform excellently on SH40 and are recommended for promotion, whereas ‘Red Delicious’ is not recommended due to poor performance. These findings offer a practical reference for selecting apple cultivars paired with SH40 in similar arid regions. Full article