Determination of Fertility-Related Traits in Muscadine Grape Population

In this study, fertility-related traits of 90 muscadine grape genotypes were evaluated. Selected genotypes included 21 standard cultivars, 60 breeding lines, and nine Vitis × Muscadinia hybrids (VM hybrids). The first fruiting bud (FFB), bud fertility (BF), bud fertility coefficient (BFC), number of flowers/flower cluster (N.F/FC), fruit-set efficiency (FSE), number of clusters/vine (N.C/V), and yield/vine (Y/V) traits were evaluated. The FFB trait did not show significant differences among genotypes. The muscadine genotype O28-4-2-2 (1.6 ± 0.2) displayed the FFB closest to the base; however, O17-16-2-1, O18-2-1, and VM A12-10-2 genotypes had the most distant FFB (3.6 ± 0.3). All the other fertility-related traits varied widely among the population. The BF, BFC, N.F/FC, FSE, N.C/V, and Y/V exhibited a range estimated at 35.1%, 81.5%, 259.7, 63.3%, 177 C/V, and 22.3 kg/V, respectively. The muscadine genotypes O42-3-1 (36.7% ± 1.3) and Majesty (34% ± 1.2) exhibited the highest BF; however, the VM A12-10-2 (1.6% ± 0.1) recorded the lowest BF. The VM genotype O15-16-1 (82.8% ± 4.1) displayed the highest BFC; however, the VM A12-10-2 (1.3% ± 0.1) showed the lowest BFC. The muscadine genotypes D7-1-1 (280.3 F/FC ± 21.7) and O17-17-1 (20.7 F/FC ± 5.5) showed the highest and lowest N.F/FC, respectively. The maximum and minimum FSE was observed for the Rosa cultivar (65.7% ± 2.4) and muscadine genotype D7-1-1 (2.4% ± 0.2), respectively. The minimum N.C/V was recorded for VM genotype A12-10-2 (6 C/V ± 0.2) and maximum noted for muscadine genotypes B20-18-2 (183 C/V ± 7.5) and O44-14-1 (176 C/V ± 7.3). Muscadine genotype O23-11-2 (22.6 kg ± 1.1) produced the highest Y/V; however, the lowest yield was recorded for O15-17-1, Fry Seedless, Sugargate, and the VM genotypes and A12-10-2, with an average yield among them estimated at 0.4 kg ± 0.2.

Untargeted Metabolomics and Antioxidant Capacities of Muscadine Grape Genotypes during Berry Development

Three muscadine grape genotypes (Muscadinia rotundifolia (Michx.) Small) were evaluated for their metabolite profiling and antioxidant activities at different berry developmental stages. A total of 329 metabolites were identified using UPLC-TOF-MS analysis (Ultimate 3000LC combined with Q Exactive MS and screened with ESI-MS) in muscadine genotypes throughout different developmental stages. Untargeted metabolomics study revealed the dominant chemical groups as amino acids, organic acids, sugars, and phenolics. Principal component analysis indicated that developmental stages rather than genotypes could explain the variations among the metabolic profiles of muscadine berries. For instance, catechin, epicatechin-3-gallate, and gallic acid were more accumulated in ripening seeds (RIP-S). However, tartaric acid and malonic acid were more abundant during the fruit-set (FS) stage, and malic acid was more abundant in the veraison (V) stage. The variable importance in the projection (VIP > 0.5) in partial least-squares–discriminant analysis described 27 biomarker compounds, representing the muscadine berry metabolome profiles. A heatmap of Pearson’s correlation analysis between the 27 biomarker compounds and antioxidant activities was able to identify nine antioxidant determinants; among them, gallic acid, 4-acetamidobutanoic acid, trehalose, catechine, and epicatechin-3-gallate displayed the highest correlations with different types of antioxidant activities. For instance, DPPH and FRAP conferred a similar antioxidant activity pattern and were highly correlated with gallic acid and 4-acetamidobutanoic acid. This comprehensive study of the metabolomics and antioxidant activities of muscadine berries at different developmental stages is of great reference value for the plant, food, pharmaceutical, and nutraceutical sectors.

Muscadine Grape and Wine Polyphenols Alleviated the Severity of Collagen Induced Arthritis in Mice

Objectives The aim of this study was to investigate the effect of concentrated muscadine grape polyphenols (MGP) and muscadine wine polyphenols (MWP) on the onset and progression of collagen induced arthritis (CIA) in mice. Methods MGP and MWP were concentrated using Amberlite XAD16N resin. Polyphenol composition was determined on HPLC. Male DBA/1 mice were divided into four treatment groups as (1) healthy control, (2) CIA control, (3) CIA + MWP, and (4) CIA + MGP. Arthritis was induced by intradermal injection of type II collagen on days 0 and day 21. Mice in groups 3 and 4 were gavaged with MWP and MGP using a dose of 400 mg/kg body weight for a total of 21 days. Severity of CIA was evaluated using clinical arthritic score and inflammation in the hind-paws. Plasma levels of cytokines, proteases, and anti-collagen antibody were measured using ELISA. Results MGP and MWP contained anthocyanin 3, 5-diglucosides, flavonols, and ellagic acid. Mice in the CIA control group had an onset of arthritis on day 18, which was delayed to day 22 and 24 by MWP and MGP, respectively (P < 0.05). Severity of arthritis was much lower in mice gavaged with muscadine polyphenols after the onset. On day 42, the average arthritic score of mice in the CIA control group progressed to 7.75 on a scale of 0–16, while MGP and MWP significantly reduced this score to 3.75 and 4.00, respectively (P < 0.01). In addition, MGP and MWP significantly reduced the plasma concentration of TNF-α, IL-6, anti-collagen antibodies, and matrix metalloproteinase-3 in CIA mice but not to the same level of healthy mice. The plasma concentration of IL-17 was drastically elevated in CIA mice, but it was not affected by MWP or MGP like other cytokines. This suggested that muscadine polyphenols had limited impact on the Th17 cells in the immune system. Mice gavaged with MPG and MWP had comparable plasma cytokine content, suggesting similar anti-inflammation activity. Conclusions Muscadine grape and wine polyphenols blunt the development of arthritis in mice by reducing the levels of key inflammatory cytokines, antibodies, and proteases, and may offer a promising dietary approach to manage arthritic symptoms. Funding Sources Florida Department of Agriculture and Consumer Service and Florida Viticulture Advisory Council.

Biometrics Assessment of Cluster- and Berry-Related Traits of Muscadine Grape Population

In this study, biometrics assessment of flower structure, cluster-, and berry-related traits were evaluated in a population of 90 muscadine grape genotypes for three consecutive years. This population consisted of 21 standard cultivars, 60 breeding lines, and 9 Vitis x Muscadinia hybrids (VM hybrids). Cluster length (CL) and width (CWI) characteristics exhibited slight differences among the population, with a range estimated at 7.1 and 4.6 cm, respectively. However, cluster weight (CWE), number of berries/cluster (N.B/C), and cluster compactness (CC) traits showed more diversity between individuals with a calculated range of 205.6 g, 32.6 B/C, and 24.1, respectively. Interestingly, all berry-related traits greatly varied between individuals, excluding the number of seeds/berry (N.S/B) character. The N.S/B trait displayed a narrow range of 5.6 seeds within the population. However, characters of berry length (BL), width (BWI), weight (BWE), the weight of seeds/berry (W.S/B), firmness (FF), and dry scar pattern (SP) demonstrated a wide estimated range of 21.2 mm, 21.7 mm, 25.4 g, 0.71 g, 0.21 N, and 82%, respectively. Normal distribution analysis for each trait suggested different distribution patterns extended between unimodal to multimodal behavior. Hierarchical mapping analysis was able to classify the population into several clades based on physical cluster- and berry-related attributes. The PCA suggested that hermaphroditic (perfect) flower structure is associated with compact clusters exhibiting small berries in size and weight (i.e., muscadine genotypes suitable for wine production). However, female flower structure is associated with clusters displaying large berries in size and weight (i.e., muscadine genotypes appropriate for fresh consumption). These patterns occurred independently of cluster size and weight characters. This research is the first study evaluating muscadine biometrics characters at a population level, providing valuable information for market demand and muscadine breeding programs.

Evaluation of Biochemical Juice Attributes and Color-Related Traits in Muscadine Grape Population

Biochemical juice attributes and color-related traits of muscadine grape genotypes have been investigated. For this study, 90 muscadine genotypes, including 21 standard cultivars, 60 breeding lines, and 9 Vitis x Muscadinia hybrids (VM), were evaluated. The biochemical properties of total soluble solids (TSS), titratable acidity, and TSS/Acid (T/A) ratio showed modest diversity among genotypes with a range of 10.3 °Brix, 2.1 mg tartaric acid/L, and 4.6, respectively. Nonetheless, the pH trait exhibited a tight range of 0.74 among the population with a minimum and maximum pH of 3.11 ± 0.12 and 3.85 ± 0.12. Color-related traits showed more deviation between individuals. Total anthocyanin content (TAC), luminosity index (L*), hue angle (h°), and chroma index (C*) displayed a range of 398 µg/g DW, 33.2, 352.1, and 24, respectively. The hierarchical clustering map classified the population into two large groups of colored and non-colored grapes based on L* and h°, suggesting the predominance of these two characters among the population. The colored berries genotypes clade was further divided into several sub-clades depending on C*, TAC, and TSS levels. The principal component analysis (PCA) separated the four-color characteristics into two groups with a negative correlation between them, L* and C* versus TAC and h°. Further, PCA suggested the positive influence of acidity in enhancing the different nutraceutical components. Despite the nature of anthocyanins as a member of phenolic compounds, a lack of significant correlation between TAC and nutraceutical-related traits was detected. The dissimilatory matrix analysis highlighted the muscadine individuals C11-2-2, E16-9-1, O21-13-1, and Noble as particular genotypes among the population due to enhanced color characteristics.

Polyphenol-Rich Muscadine Grape Extract Reduces Triple Negative Breast Cancer Metastasis in Mice with Changes in the Gut Microbiome

Background Triple negative breast cancer (TNBC) has a high propensity to metastasize and no treatments are available to slow or prevent metastatic progression. The goal of this study is to determine whether a proprietary high-polyphenol content muscadine grape extract (MGE) inhibits TNBC metastasis. Methods 4T1 TNBC cells were injected into the mammary fat pad of 6-week-old female Balb/c mice. After 2 weeks, tumors were surgically removed and mice were placed into a control (n=8) or treatment group that received 0.1 mg/mL total phenolics MGE in the drinking water (n=8) for 4 weeks. Immunohistochemistry (Ki67, α-SMA) and hemotoxylin and eosin staining were used to quantify metastases. Gut microbial composition was determined by 16S rRNA sequencing and short chain fatty acids (SCFAs) were detected by gas chromatography. MDA-MB-231, BT-549 and 4T1 TNBC cell motility and cytoskeletal organization was assessed in vitr o by scratch wound migration and confocal microscopy, respectively. Data were evaluated by student’s t -test. Results MGE reduced metastatic proliferation in mouse lungs (33.3%) and livers (58.3%) and decreased the number (51.1%) and size (17.4%) of liver metastases, resulting in a 55.7% reduction in metastatic tumor burden ( P < 0.01). Serum IL-6 was reduced 99.6% in MGE-treated mice ( P = 0.06). MGE attenuated migration, altered cytoskeletal organization, and reduced RHAMM expression in TNBC cells ( P < 0.05). The gut microbiota, a mediator of polyphenolic bioactivities, was altered significantly in MGE-treated mice; MGE increased the alpha diversity (7.14%), Firmicutes/Bacteroidetes ratio (2-fold), relative abundance of butyrate-producing genera, and butyrate (3-fold) ( P < 0.05). Butyrate inhibited 4T1 cell proliferation and migration, suggesting butyrate contributes to MGE’s anti-metastatic activities ( P < 0.05). Conclusion Our results indicate that MGE may be an effective adjuvant therapy to reduce TNBC metastatic progression.

Greenhouse Evaluation of Pinewood Biochar Effects on Nutrient Status and Physiological Performance in Muscadine Grape (Vitis rotundifolia L.)

Muscadine grape is a perennial crop that is highly responsive to local environmental factors and viticulture practices. Biochar is a promising soil amendment used to improve soil water and nutrient retention and promote plant growth. The present study aimed to assess the effects of different pinewood biochar rates on nutrient status and vegetative parameters of muscadine grape cv. Alachua grown on a nutrient-poor sandy soil, Ultisols (97.2% sand, 2.4% silt, and 0.4% clay), and mixed with five different rates (0%, 5%, 10%, 15%, and 20%) of biochar based on weight. Variations in soil moisture, temperature, and leaf greenness value [soil plant analysis development (SPAD) reading], net photosynthesis rate, and plant root and shoot dry weights were measured. In addition, the nutrient status of the soil, plant root, and shoot were determined. The results indicated that the higher rate of biochar could significantly (P < 0.05) improve soil moisture. Biochar can also decrease soil temperature, although there were no significant differences among treatments. Regarding the nutrient status, the biochar amendment increased the nutrient content of phosphorus (P), potassium (K), magnesium (Mg), and calcium (Ca), as well as the soil organic matter content and cation exchange capacity. Higher nutrient contents in soil lead to increased P and Mg in both aboveground and belowground muscadine plant tissues and decreased nitrogen (N), iron (Fe), and copper (Cu) in the root part. There were no significant differences observed in SPAD values, net photosynthesis, or dry weights of the root and shoot. This study demonstrates that the addition of biochar may enhance the soil water and nutrient status as well as improve plant P and Mg uptake; however, it showed no significant differences in the physiological performance of muscadine grape plants.