Search Results (48)

The effects of different rootstocks on the grape quality and volatile aromatic compounds of ‘Shine Muscat’ were investigated. The basic physicochemical parameters of berries from five scion–rootstock combinations (SM-Beta, SM-SO4, SM-5C, SM-Fercal, SM-YN2) and own-rooted ‘Shine Muscat’ grape were measured, and their volatile aromatic compounds were determined using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS). Our results showed that the SM-YN2 combination exhibited the highest berry weight, and increased by 28.13% compared with SM self-rooted seedling. In addition, the ‘5C’ and ‘YN2’ rootstocks could better maintain total soluble solids (TSS), titratable acidity (TA), TSS/TA and pH in the berries, whereas the ‘Beta’, ‘SO4’ and ‘Fercal’ rootstocks impaired TSS. Volatile profiling identified 841 volatile compounds classified into 15 categories, among which terpenoids constituted the predominant contributors to berry aroma. Furthermore, 22 characteristic aroma compounds were screened, and linalool presented the highest concentration among all terpenoids in ‘Shine Muscat’ fruit. Odor activity values (OAVs) and aroma proportion analyses further revealed that linalool is the key compound for the characteristic ‘muscat’ aroma of ‘Shine Muscat’. In addition, the SM-YN2 combination exhibited 31.96% and 4.61% higher concentration and proportion of linalool compared to own-rooted vines. Notably, with the exception of ‘YN2’, ‘Beta’, ‘SO4’, ‘5C’ and ’Fercal’ downregulated the expressions of one or more terpenoid synthesis-related genes. In conclusion, grafting onto rootstock could improve berry quality, particularly the ‘YN2’ rootstock, which yielded ‘Shine Muscat’ grapes with the highest overall quality. As a resource of the East Asian grape group, ‘YN2’ can be utilized as a rootstock in future production. Full article

Accurate determination of endodormancy release is essential for grapevine dormancy management. However, most phenological models are validated only against macroscopic budbreak dates, without physiological verification of predicted release dates. Here, we integrated phenological modeling with biochemical profiling to characterize endodormancy release in two table grape cultivars with contrasting chilling requirements: ‘Muscat Hamburg’ (Vitis vinifera L.) and ‘Shine Muscat’ (Vitis labrusca × V. vinifera). Endodormancy release dates were determined by forced budbreak assays, and chilling and heat requirements were estimated from 5 min temperature records using the Dynamic Model and Growing Degree Hours. ‘Muscat Hamburg’ released endodormancy on December 16 (10.95 Chill Portions), whereas ‘Shine Muscat’ released on January 6 (22.78 CP). Around these dates, coordinated biochemical changes occurred in buds, including starch depletion, hexose accumulation, ABA decline, GA₃ increase, and redox-related changes in H₂O₂ content and CAT activity. These changes were more pronounced in buds than in canes and were not identical across all biochemical indicators. Hydrogen cyanamide treatment induced biochemical changes similar to those observed during natural dormancy release, with cultivar-specific responses consistent across both conditions. These results indicate that experimentally determined endodormancy release dates are associated with population-level physiological changes, supporting the integration of phenological modeling with biochemical characterization in table grape production. Full article

Berry thinning is a fundamental operation in modern vineyard management, and future robotic thinning systems have the potential to reduce labor intensity and improve operational consistency. However, automated berry thinning under field conditions is still constrained by insufficient berry-level segmentation accuracy, difficulty in recognizing occluded berries, and high missed-detection rates for small berries. These limitations mainly arise from dense berry arrangements, severe mutual occlusion, and the subtle visual features of small targets. To address these challenges, this study developed a lightweight grape berry instance segmentation and thinning decision-support method based on YOLOv8n-seg. A two-stage knowledge distillation strategy, using Mask R-CNN and YOLOv8l-seg as teacher models, was combined with 30% backbone pruning to improve the recognition of occluded and small berries while maintaining model efficiency. Subsequently, the DBSCAN clustering algorithm was used to analyze berry centroid coordinates and equivalent diameters extracted from instance segmentation masks, thereby generating preliminary thinning-target recommendations based on local berry density and berry size. The model was trained and evaluated on a self-constructed dataset containing 330 valid grape bunch images collected in 2025 from Yongming Vineyard, Lin’an District, Hangzhou, Zhejiang Province, China. The results showed that the optimized YOLOv8n-seg model achieved a box $mAP50\text{-}95$ of 0.8945 and a mask $mAP50\text{-}95$ of 0.7910, with an inference speed of 119.19 $FPS$ and 3.26 M parameters on an NVIDIA RTX 3060 Laptop GPU. Compared with the original YOLOv8n-seg model, the optimized model improved mask $mAP50\text{-}95$ by 1.20 percentage points, increased inference speed by 71.79 $FPS$, and reduced the number of parameters by 2.38 M. These results indicate that the proposed method improves grape berry instance segmentation performance while achieving a favorable balance among segmentation accuracy, lightweight characteristics, and inference efficiency. The proposed framework provides an offline RGB-based visual perception and preliminary thinning decision-support method for future grape berry thinning robots. However, because the current dataset was collected from Shine Muscat grape bunches at the berry enlargement stage in a single vineyard using the same imaging setup, the results should be interpreted as preliminary evidence under the specific cultivar, growth stage, vineyard, and imaging conditions of this study. Further validation across different grape cultivars, growth stages, vineyards, production seasons, camera systems, embedded platforms, and real robotic thinning operations is still required. Full article

Soil salinization is one of the major abiotic stresses limiting agricultural production. As an economically important fruit tree worldwide, grapevine generally exhibits weak salt tolerance. Therefore, identifying key stress-tolerance genes is of great significance for improving stress resistance in grapevines. In this study, the transcription factor gene VvWRKY57, which is induced by salt stress, was cloned from the grape cultivar Vitis vinifera ‘Shine Muscat’. Its function under salt stress was systematically evaluated via heterologous overexpression in Arabidopsis thaliana. The full-length CDS of the VvWRKY57 gene is 915 bp, encoding a protein of 305 amino acids. The protein contains a typical WRKY conserved domain, belongs to group II of the WRKY family, and is localized in the nucleus and cytoplasm. Expression pattern analysis showed that VvWRKY57 was expressed in roots, stems, and leaves of grapevine. Based on this expression profile, transgenic Arabidopsis thaliana plants overexpressing VvWRKY57 were generated to further investigate its role in salt tolerance. Subsequent salt tolerance assays revealed that, compared with wild-type plants, the overexpression lines exhibited stronger resistance phenotypes under salt stress. This study demonstrates for the first time that grape-derived VvWRKY57 functions in enhancing salt tolerance in model plants, providing a novel genetic resource and theoretical basis for crop salt-tolerance molecular breeding using this gene. Full article

To improve nitrogen (N) fertilizer management in vineyards and support sustainable production, we conducted field experiments in 2021–2022 to evaluate the effects of reduced N fertilization combined with organic fertilizer (OF) on vine growth, fruit quality, soil fertility, and economic returns in Shine Muscat grapes. Six treatments were established: conventional fertilization (CF), four reduced-N treatments combined with OF (0.9N + OF to 0.6N + OF; i.e., 10–40% N reduction), and a blank control (CK). Yield was significantly increased under 0.8N + OF (18.2% in 2021; 96.0% in 2022) and 0.7N + OF (10.8% in 2021; 47.9% in 2022), with 0.8N + OF also delivering the highest economic returns. Fruit quality analysis showed that 0.8N + OF consistently increased total sugar and the sugar–acid ratio, and improved vitamin C content. Substitution ratios >40% led to a decline in economic benefits. Path analysis indicated that vertical diameter and single-berry weight exerted significant positive effects on total yield. OF substitution also improved fruit quality. Soil available nutrients (N, P, and K) and organic matter were primary factors influencing yield; potassium was the key factor regulating sugar accumulation, with the strongest effect on improving flavor coordination. Reducing N by 20–30% combined with OF (particularly the 0.8N + OF treatment) synergistically enhanced photosynthetic efficiency, N utilization, yield and quality, and soil fertility, representing the optimal fertilization strategy. Full article

The aroma quality of grape fruit is a crucial trait for table grapes, yet its relationship with plant disease resistance remains unclear. Using ‘Shine Muscat’ grapes as material, this study employed HS-SPME-GC-MS combined with odor activity value (OAV) and PLS-DA analysis to investigate the regulatory effects of different rootstocks and GA₃/MeJA treatments on volatile aroma compounds. Linalool and α-terpineol were selected as representative compounds for antibacterial experiments and gene expression analysis of terpenoid synthesis. Results indicate that the Lot rootstock and 15.25 mg·L⁻¹ GA₃ treatment significantly promoted the accumulation of terpenoid aroma compounds. Linalool exhibited significant inhibitory effects on the mycelial growth of Colletotrichum fructicola and induced upregulation of DXS, TPS56, and TPS gene expression. This study reveals a potential link between aroma metabolism and defense responses, providing a theoretical basis for synergistic optimization of grape aroma quality improvement and disease-resistant cultivation. Full article

The vigorous growth of new shoots can significantly reduce grape yield and compromise fruit quality. In order to explore the effects of prohexadione calcium (Pro-Ca) and mepiquat chloride (MC) on the control effect of new shoot growth and fruit quality of grape, ‘Shine Muscat’ grapevine (Vitis labruscana × V. vinifera) was used as the test material, and different concentrations of Pro-Ca and a combination of Pro-Ca and MC were sprayed four times before flowering of ‘Shine Muscat’ grapevines, and the effects of the different treatments on the new shoot growth and fruit quality of ‘Shine Muscat’ grape were analyzed and evaluated. The results demonstrated that low concentrations of Pro-Ca had limited efficacy in controlling shoot growth. However, the combined treatment of Pro-Ca 300 mg/L + MC 300 mg/L not only effectively inhibited shoot elongation but also significantly enhanced the chlorophyll content of the leaves opposite to the clusters and increased branch density. Additionally, this treatment improved berry size (single berry weight, vertical and horizontal diameter) and elevated the soluble solids content (SSC). These findings suggest that the combined application of Pro-Ca (300 mg/L) and MC (300 mg/L) is the most effective strategy for balancing vegetative growth and enhancing fruit quality in ‘Shine Muscat’ grapevines. Full article

Grapevine tissues (Vitis spp.) are rich in various phenolic compounds and polysaccharides, which complicates the isolation of dsDNA for molecular analysis. In this study, 25 different DNA extraction buffers were developed and tested using a six-factor matrix method with five levels of variation. An optimized buffer based on 100 mM Tris-HCl (pH 8.0) was developed, containing 1% (m/v) CTAB, 1% (m/v) PVP, 5% (v/v) β-mercaptoethanol, 30 mM Na₂EDTA, 1.0 M NaCl, and 60 min of incubation. The protocol allowed us to obtain high-quality DNA (187–305 ng/µL, OD260/OD280 = 1.80–1.88) suitable for PCR from five grape varieties: ‘Chardonnay’, ‘Kober 5BB’, ‘Shine Muscat’, ‘Selection Oppenheim 4’, and ‘Fercal’, grown in vitro. This universal buffer improves the reproducibility of results in studies of genetic diversity, pathogen detection, and breeding. Full article

Table grapes are widely consumed fruits, and their quality is largely determined by aroma, texture, and the accumulation of health-promoting compounds such as flavonoids. In this study, we systematically compared the edible quality and molecular basis of flavonoid biosynthesis among three major table grape cultivars: Crimson Seedless (CRS), Red Globe (RG), and Shine Muscat (SM). An integrated approach combining physicochemical assays, Gas chromatography–ion mobility spectrometry (GC-IMS)-based volatile profiling, and transcriptome sequencing (RNA-seq) was employed. Among the three cultivars, SM exhibited superior fruit quality, characterized by the highest firmness, total soluble solids, ascorbic acid, total phenolic content, and flavonoid content, whereas CRS showed the highest titratable acidity. Volatile compound analysis revealed distinct aroma profiles among the cultivars. SM was enriched in ethanol and 2-methylbutanal, contributing sweet and fruity notes, while CRS contained higher levels of C6 aldehydes, such as hexanal and (E)-2-hexenal, which are associated with green and leafy aromas. RG exhibited a relatively simpler volatile profile with lower overall abundance. Transcriptome analysis identified 20 differentially expressed genes involved in the flavonoid biosynthetic pathway, including PAL, C4H, 4CL, CHI, F3H, F3′H, and DFR, of which ten were significantly upregulated in SM. Eight of these genes showed strong positive correlations (r > 0.8) with flavonoid content. These results provide a comprehensive understanding of the metabolic and genetic mechanisms underlying cultivar-specific quality traits and identify promising candidate genes for breeding table grapes with enhanced flavor and health-promoting properties. Full article

Background: Dietary guidance for type 2 diabetes mellitus (T2DM) frequently discourages fruit consumption due to intrinsic sugars, despite extensive evidence supporting the anti-diabetic properties of fruit-derived polyphenols. This reductionist, carbohydrate-only model inadequately reflects the complex bioactive matrices of whole fruits. Objective: To develop an integrated analytical framework that quantitatively balances the predicted anti-diabetic bioactivity of fruit polyphenols against their glycemic burden, and to apply this model to fruits commonly consumed in the Korean market. Methods: Nutritional and phytochemical composition data for five fruits sourced from Korea and India were obtained from national food databases to ensure broader phytochemical diversity. Six representative polyphenols were selected based on abundance and reported significance. Molecular docking was conducted against α-glucosidase and peroxisome proliferator-activated receptor gamma (PPAR-γ) to estimate target-specific affinity, and a “Total Predicted Anti-Diabetic Score” (TPAS) was computed by weighting docking potency by compound concentration. A risk–benefit matrix integrating TPAS and sugar content was applied to classify fruits, followed by a cultivar-level comparison of major grape varieties. Results: Hesperidin exhibited the strongest predicted PPAR-γ binding (−9.3 kcal/mol). Among whole fruits, grapes and oranges showed the highest TPAS (593.19 and 448.77, respectively), placing them in the “redemptive choice” category (high benefit/high glycemic risk). Comparative cultivar analysis identified the Campbell Early grape as the most advantageous option, with a Holistic Value Score (HVS) of 9.5, notably higher than Shine Muscat (3.9). Conclusions: This study presents a structured, computation-driven framework capable of integrating phytochemical potency and nutritional risk into a unified metric for dietary evaluation. Despite higher sugar content, fruits rich in potent polyphenols may confer substantial metabolic benefit when consumed judiciously. These findings challenge sugar-centric dietary models and provide an evidence-based tool for consumer-level guidance in T2DM dietary management. Full article

The rapid development of viticulture in subtropical regions represents a significant achievement in China’s table grape industry over the last two decades. However, insufficient winter chilling in these areas often leads to inadequate dormancy, which compromises nutrient translocation and storage in grapevines. Insufficient chilling accumulation results in asynchronous budbreak and reduced cane quality. In this study, ‘Shine Muscat’ grapevines were used to systematically evaluate how different defoliant agents affect budbreak characteristics from the perspective of nutrient translocation and storage. The results indicated that applications of ethephon or urea alone, as well as their combinations with boric acid, yielded unstable effects, often causing primary bud necrosis, decreased flower formation rates, and phytotoxicity. In contrast, the combination of lime sulfur and boric acid exhibited a remarkable synergistic effect, significantly promoting dry matter and starch accumulation in canes while enhancing the budbreak speed, uniformity, and flower cluster formation rate. Further experiments with varying concentrations of lime sulfur combined with 0.2% boric acid revealed that utilizing 2% lime sulfur in this combination produced the most pronounced effects, achieving the highest dormancy-breaking efficacy under conventional cultivation conditions. This treatment was used for the first time to produce a second crop during off-season cultivation. The dual effects of dormancy release and bud promotion achieved via this approach represent a reliable solution in high-quality and efficient grape production in subtropical regions. Full article

Delayed harvesting of grapes can alter fruit quality and plays an important role in alleviating the problem of market saturation during peak seasons, as well as in regulating the supply period of grapes. In this study, by conducting a comparative analysis of fruit quality, metabolomics (aroma compounds) and transcriptome sequencing of ‘Shine Muscat’ grapes harvested at six different on-tree ripening stages after maturity, we found that: (1) delayed harvesting led to dramatic variation in berry color change (light green to yellow) with a significant increase in soluble solids (19.5 to 20.89 Brix); (2) A total of 25 volatile aroma compounds was identified in collected berry samples, while trans-2-hexenal and hexanal exhibited the highest concentrations in all samples, marking them as key volatile compounds in ‘Shine Muscat’ grapes. Notable variation in the concentrations of linalool, n-butanol, benzyl alcohol, phenylethanol, β-citronellol, and propionic anhydride were recorded in selected harvest periods. OAV analysis results show that linalool has the largest OAV among the detected compounds, and its OAV proportion increased from 53% to 95% during the six sampling periods of ‘Shine Muscat’; (3) Transcriptome sequencing of selected samples demonstrated a positive correlation between eight terpene-synthesis-related genes and linalool accumulation. Furthermore, genes within the MEP pathway (specifically VvTPS55, VvTPS59) and several transcription factors were associated with terpenoids metabolism. Based on soluble solids and OAV results, T18–T22 period (18–22 weeks post-flowering) can become good quality on-vine storge berries. The gene expression profile and developmental patterns of metabolites in MEP pathway may helpful in functional characterization of candidate genes related to terpenoid metabolism in future studies. Full article

Gibberellin (GA)-based seedless cultivation is widely used in the skin-edible interspecific table grape (Vitis labruscana × Vitis vinifera) ‘Shine Muscat’, yet when and how GA treatment reshapes fracture-type texture during berry development remains unclear. This study aimed to identify developmental stages and tissue/cell-wall features associated with GA-dependent differences in berry fracture behavior. We integrated intact-berry fracture testing at harvest (DAFB105), quantitative histology of pericarp/mesocarp tissues just before veraison (DAFB39) and at harvest, sequential cell-wall fractionation assays targeting pectin-rich (uronic acid) and hemicellulose/cellulose-related pools at cell division period, cell expansion period and harvest, and stage-resolved RNA-Seq across the same three developmental stages. GA-treated berries had a larger diameter and showed a higher fracture load and a lower fracture strain than non-treated berries at harvest, while toughness did not differ significantly. Histology revealed thicker pericarp tissues and lower mesocarp cell density in GA-treated berries, together with increased cell-size heterogeneity and enhanced radial cell expansion. Cell wall analyses showed stage-dependent decreases in uronic acid contents in water-, EDTA-, and Na₂CO₃-soluble fractions in GA-treated berries. Transcriptome profiling indicated GA-responsive expression of putative cell expansion/primary-wall remodeling genes, EXORDIUM and xyloglucan endotransglucosylase/hydrolases, at DAFB24 and suggested relatively enhanced ethylene-/senescence-associated transcriptional programs together with pectin-modifying related genes, Polygaracturonase/pectate lyase and pectin methylesterase, in non-treated mature berries. Collectively, GA treatment modifies mesocarp cellular architecture and pectin-centered wall status in a stage-dependent manner, providing a tissue- and cell wall–based framework for interpreting fracture-related texture differences under GA-based seedless cultivation in ‘Shine Muscat’. Full article

Grading of table grapes depends on reliable berry-level phenotyping, yet manual inspection is subjective and slow. A wavelet-guided instance segmentation network named WGMG-Net is introduced for automated assessment of post-harvest grape clusters. A multi-scale feature merging module based on discrete wavelet transform is used to preserve edges under dense occlusion, and a bivariate fusion enhanced attention mechanism is used to strengthen channel and spatial cues. Instance masks are produced for all berries, a regression head estimates the total berry count, and a mask-derived compactness index assigns clusters to three tightness grades. On a Shine Muscat dataset with 252 cluster images acquired on a simulated sorting line, the WGMG-Net variant attains a mean average precision at Intersection over Union (IoU) 0.5 of 98.98 percent and at IoU 0.5 to 0.95 of 87.76 percent, outperforming Mask R-CNN, PointRend and YOLO models with fewer parameters. For berry counting, a mean absolute error of 1.10 berries, root mean square error of 1.48 berries, mean absolute percentage error of 2.82 percent, accuracy within two berries of 92.86 percent and Pearson correlation of 0.986 are achieved. Compactness grading reaches Top-1 accuracy of 98.04 percent and Top-2 accuracy of 100 percent, supporting the use of WGMG-Net for grape quality evaluation. Full article

To reveal the mechanism by which exogenous dopamine (Da) regulates Shine Muscat grape (Vitis labrusca L. × Vitis vinifera L.) in response to low-temperature stress, annual Shine Muscat grape plants were used as material. Different concentrations of Da (0.2–1.0 mmol L⁻¹) were set to investigate its synergistic regulatory effects on grape photosynthetic protection, osmotic adjustment, ion homeostasis, antioxidant defense, and cold-responsive gene expression and to identify the optimal concentration and core pathways through correlation analysis. The results showed that low-temperature stress significantly inhibited plant growth, reduced photosynthetic efficiency, disrupted ion balance, induced oxidative damage, and downregulated the expression of cold-responsive genes. Da exhibited a “low-concentration promotion and high-concentration inhibition” effect, with the 0.4 mmol L⁻¹ treatment showing the best performance: growth indicators such as plant height and stem diameter increased by 22.4–52.2% compared with the low-temperature stress group; photosynthetic parameters and photosystem II (PSII) function were significantly improved; proline content increased by 40.3%; the Na⁺/K⁺ ratio decreased by 44.8%; activity of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD) increased by 31.7–49.5%; and the expression of genes in the C-repeat binding factor (CBF) family was upregulated. Correlation analysis confirmed that the activity of SOD and catalase (CAT) showed a highly significant positive correlation with growth indicators (r > 0.8, p < 0.01) and a highly significant negative correlation with malondialdehyde (MDA) content (r < −0.8, p < 0.01), indicating that antioxidant defense is the core pathway. In conclusion, exogenous Da enhances the cold tolerance of Shine Muscat grape through multi-pathway synergy, with 0.4 mmol L⁻¹ the optimal concentration, which can provide a theoretical basis for cold-resistant cultivation of grapes. Full article