Table Grape Cultivars Research Articles

Processes of assembly of endophytic prokaryotic and rhizosphere fungal communities in table grape are preponderantly deterministic

Understanding the assemblage of microbial communities is important for the health maintenance and post-harvest quality of fruit crops. However, systematic studies on the core microbiomes of table grapes and microbial community assembly of soil-plant continuum are still rare. To address this, samples were collected and analyzed from key microbiome compartments (bulk soil, rhizosphere of new roots and old roots, endosphere of new and old roots, and endosphere of leaves and fruits) of five table grape cultivars (Balado Black, Jingya, Fujimino, Victoria and Kyoho) at the swelling stage and harvest stage in the field plots. Prokaryotic and fungal communities were analyzed using 16S rRNA and ITS rRNA high-throughput sequencing, respectively. The compartment was the major factor attributable to the variations in both prokaryotic (52.5 %) and fungal communities (23.2 %), respectively. The richness and phylogenetic diversity of both prokaryotic and fungal communities decreased significantly along the compartment continuum from soil to fruit endosphere, but did not differ between the five cultivars across all samples. Occupancy-abundance distribution was used to define 97 core bacteria, 29 core fungi for rhizosphere soil and five core bacteria, 172 core fungi for endosphere. Functional annotations of the rhizosphere core bacteria were mostly associated with ureolysis and chemoheterotrophy, while endophytic core bacteria were mostly fermentative and symbiotic. Rhizosphere core fungi were saprophytic and the endophytic fungi were putatively pathogens. From rhizosphere soil to aboveground organs, the relative importance of deterministic processes for prokaryotic community assembly gradually increased but the contribution of stochastic processes increased for fungal community assembly. These findings highlight niche-specific microbial communities and shared core microbiomes in different grapevine cultivars. The deterministic processes contribute more to the assembly of prokaryotic communities in the aboveground than in the belowground while the assembly of fungal communities exhibits opposite trends. Management practices aiming at niche-specific microbiome should be developed for sustainable grape production.

Aloe vera Gel Coating Extends Marketability and Maintains Quality by Reducing Rachis Browning and Preserving Bioactive Compounds of Commercial Table Grape Cultivars

Aloe vera Gel Coating Extends Marketability and Maintains Quality by Reducing Rachis Browning and Preserving Bioactive Compounds of Commercial Table Grape Cultivars

Vitis species for stress tolerance/resistance

AbstractMany wild plant species are actually true treasures of our world. The value of these treasures is better understood today and many wild species are used for different purposes. Also Vitis species are among the most important species with their ancient history. China and North America are the native ranges of many Vitis species that survive to the present day, most of which have survived by natural selection. These species have attracted the attention of plant breeders for many years due to their resistance to various biotic and abiotic stress conditions, and they have used these species to develop new cultivars. In parallel with the developments in the field of biotechnology, interspecific hybrid genotypes obtained in breeding research for resistance to different stress conditions can be obtained in accordance with the targets in a much shorter time. In these investigations, gene regions in Vitis species with resistance genes were transferred to new hybrid genotypes. Additionally, these species have been used as parents in many breeding programs in different countries due to their resistance to biotic stress conditions, especially fungal diseases. Similar breeding research has been carried out on tolerance to abiotic stress conditions, and interspecific cross-breeding have been made to develop hybrid genotypes that are more tolerant to many abiotic stress conditions. In recent years, resistance and high-quality wine and table grape cultivars obtained from rossbreeding have begun to be used in production. As a result, newly developed interspecific hybrid grapes can be grown with much lower production costs in accordance with the sustainable viticulture model.

Transcriptomic and free monoterpene analyses of aroma reveal that isopentenyl diphosphate isomerase inhibits monoterpene biosynthesis in grape (Vitis vinifera L.)

BackgroundMonoterpenes are among the most important volatile aromatic compounds contributing to the flavor and aroma of grapes and wine. However, the molecular basis of monoterpene biosynthesis has not yet been fully elucidated.ResultsIn our study, transcriptomics and gas chromatography-mass spectrometry (GC-MS) were used to mine candidate genes and transcription factors involved in monoterpene biosynthesis between high-monoterpene and zero-monoterpene table grape cultivars. We found that monoterpene biosynthesis was positively correlated by the expression of five genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (VvDXSs), one encoding 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (VvHDR), three hydroxy-3-methylglutaryl-CoA synthases (VvHMGSs) and one mevalonate kinase (VvMVK), whereas the expression of one isopentenyl diphosphate isomerase (VvIDI) and one 3-hydroxy-3-methylglutaryl-CoA reductase (VvHMGR) negatively correlated monoterpene biosynthesis. Of these genes, VvIDI was selected to validate its function in monoterpene accumulation through a transient overexpression experiment, and was shown to inhibit the biosynthesis of grape linalool and α-terpineol. Meanwhile, we found that a 64-amino acid extension sequence at the N-terminus can guide the VvIDI protein to target the chloroplast.ConclusionsThe findings of this study should help to guide future functional analysis of key genes as well as mining the potential regulatory mechanism of monoterpene biosynthesis in grapes and grape products.

Adapting the process based STICS model to simulate phenology and yield of table grapes- a high value fruit crop in a new emerging viticulture zone of South Asia

Plants strongly interact with their environment making phenology a sensitive indicator of climatic variability. Exploring the possibility of early prediction of phenological timings of table grape cultivars has huge socioeconomic benefits for the growers. Various statistical, mechanistic, and theoretical approaches have been used for parameterization of phenology models mainly for wine grapes. The studies on application of process-based models such as STICS (Simulateur mulTIdisciplinaire pour les Cultures Standard) particularly for table grapes and non-traditional viticulture zones are rather limited. The objective of this study was to calibrate the STICS model and evaluate its performance to simulate phenology and yield of four table grape cultivars in Pothwar- a new emerging viticulture zone of south Asia. For this, phenological timings, growth and yield responses were evaluated at two locations (Islamabad and Chakwal) for two consecutive vintages (2019 and 2020). Daily weather data, soil characteristics, genotype and crop specific data were recorded for model calibration. The results indicated a high robustness of the model for simulating table grapes phenology and yield in all cases. The model simulations indicated a satisfactory to high model efficiency (ME) of 0.69 to 0.94 with a prediction variability up to 4 days for growth stages, whereas ME for yield and pruning weight was 0.84 and 0.90, respectively. The model provided an efficient decision support tool (DST) though crucial predictions for viticulture industry. For instance, early maturity (up to 10 days), lesser yield (19–34 %) and pruning weight (19–42 %) for the warmer location (Chakwal) than for the colder Islamabad were simulated by the model with a high skill. The proximity of predicted values to observed values indicates that STICS is powerful tool for predicting vine phenology and yield, thus it provides a valuable insight in timely planning vineyards operations at key growth stages and selecting cultivars with higher yield for sustainable viticulture.

Effect of Calcium, Magnesium Fertigation and Molybdenum Foliar Sprays on Yield and Fruit Quality of Flame Seedless Table Grape Cultivar

Effect of Calcium, Magnesium Fertigation and Molybdenum Foliar Sprays on Yield and Fruit Quality of Flame Seedless Table Grape Cultivar

Developing a simple and efficient modeling solution for predicting key phenological stages of table grapes in a non-traditional viticulture zone in south Asia.

Phenological shifts are one of the most visible signs of climatic variability and change in the biosphere. However, modeling plant phenological responses has always been a key challenge due to climatic variability and plant adaptation. Grapevine is a phenologically sensitive crop and, thus, its developmental stages are affected by the increase in temperature. The goal of this study was to develop a temperature-based grapevine phenology model (GPM) for predicting key developmental stages for different table grape cultivars for a non-traditional viticulture zone in south Asia. Experiments were conducted in two vineyards at two locations (Chakwal and Islamabad) in the Pothawar region of Pakistan during the 2019 and 2020 growing seasons for four cultivars including Perlette, King's Ruby, Sugraone and NARC Black. Detailed phenological observations were obtained starting in January until harvest of the grapes. The Mitscherlich monomolecular equation was used to develop the phenology model for table grapes. There was a strong non-linear correlation between the Eichhorn and Lorenz phenological (ELP) scale and growing degree days (GDD) for all cultivars with coefficient of determinations (R2) ranging from 0.90 to 0.94. The results for model development indicated that GPM was able to predict phenological stages with high skill scores, i.e., a root mean square (RMSE) of 2.14 to 2.78 and mean absolute error (MAE) of 1.86 to 2.26 days. The prediction variability of the model for the onset timings of phenological stages was up to 3 days. The results also reveal that the phenology model based on GDD approach provides an efficient planning tool for viticulture industry in different grape growing regions. The proposed methodology, being a simpler one, can be easily applied to other regions and cultivars as a predictor for grapevine phenology.

Phenolic, Amino Acid, Mineral, and Vitamin Contents during Berry Development in ‘Italia’ and ‘Bronx Seedless’ Grape Cultivars

Understanding the variations in amino acids, phenolic compounds, elements, and vitamins between grape varieties is essential for optimizing grape production, fine-tuning dietary recommendations, and harnessing the health potential of grapes. In this regard, this comprehensive study investigated the compositional diversity of two distinct table grape cultivars, ‘Bronx Seedless’ and ‘Italia’, at various critical phenological stages (BBCH-77, -79, -81, -83, -85, and -89). The research findings demonstrated remarkable differences in the concentrations of key nutritional components. Bronx Seedless consistently exhibited higher levels of several amino acids, including glutamate, phenylalanine, and aspartate with concentrations reaching 49.6, 52.7, and 24.8 pmol μL−1, respectively, in contrast to Italia. Regarding phenolic compounds, Italia emerged as the richer source, with concentrations notably higher for compounds such as vanillic acid (18.2 µg g−1 FW) and gallic acid (37.4 µg g−1 FW). Mineral analysis revealed variable concentrations, with Italia grapes containing higher levels of Fe (91.0 mg/kg) compared to Bronx Seedless (87.1 mg/kg); however, Bronx Seedless had slightly elevated levels of K (31,089 mg/kg) compared to Italia (28,184 mg/kg). Concidering vitamins, Italia grapes showcased superior levels of Vitamin B1 (14.1 mg/100 g FW) and Vitamin A (11.0 mg/100 g FW), while Bronx Seedless had higher concentrations of Vitamin B6 (29.5 mg/kg), C (3.9 mg/100 g FW) and Vitamin B2 (36.9 mg/100 g FW). Principal component analysis (PCA) elucidated complex relationships within these components, offering insights into potential correlations and interactions. The heatmap visualization further indicated the concentration gradients across various samples, unveiling the intricate nutritional profiles of these grape cultivars. This research can aid grape growers and consumers in making informed decisions about grape cultivars and their corresponding health advantages.

Occurrence of grapevine yellow speckle viroid 2 and Australian grapevine viroid in Idaho grapevines.

Grapevine yellow speckle viroid 2 (GYSVd-2; Pospiviroidae, Apscaviroid) causes yellow speckle disease in grapevine (Koltunow et al. 1989) and was found in Australia, Iran, Italy, China, and Nigeria (Koltunow et al. 1989; Habili 2017; Zongoma et al. 2018). In the U.S., GYSVd-2 was found in the State of Washington (Vitis vinifera L. cv. Merlot; Alabi et al., 2012). Australian grapevine viroid (AGVd; Pospiviroidae, Apscaviroid) was reported in Australia, Italy, China, Tunisia, Iran, and in the U.S. wine grapes (V. vinifera) (Habili 2017). In the U.S., AGVd was reported from California (Al Rwahnih et al. 2009), from Washington State (V. vinifera cv. Syrah; GU327604), and from the State of New York (an unknown cv. of V. vinifera; KY081960). In Idaho, two other viroids, hop stunt viroid (HSVd; Pospiviroidae, Hostuviroid) and grapevine yellow speckle viroid 1 (GYSVd-1; Pospiviroidae, Apscaviroid), common in grapevines were previously found in wine grapes (Thompson et al. 2019) but neither GYSVd-2 nor AGVd were identified in the same high-throughput sequencing (HTS) outputs. In September 2020, 16 leaf and petiole samples were collected from six vineyards in Canyon and Nez Perce counties of Idaho, representing six different wine grape cultivars and an unknown table grape cultivar, and subjected to HTS analysis. One of the samples was from a table grape plant at the edge of a declining 'Chardonnay' wine grape block that was grown next to a wine tasting room deck for aesthetic, ornamental purposes; the table grape and 'Chardonnay' plants were own-rooted and planted in 1981. Ribodepleted total RNAs prepared from these samples, as described previously, were subjected to a HTS analysis on a NovaSeq platform (Dahan et al. 2023), producing 15,095,042 to 31,500,611 250-bp paired-end reads per sample. Raw reads were adapter and quality cleaned and mapped against the V. vinifera, reference genome. Unmapped paired-end reads were assembled, and contigs were analyzed using BLASTn and DIAMOND (Buchfink et al. 2021) programs. Fifteen samples were found infected with HSVd and with GYSVd-1, while one was infected with GYSVd-2 and AGVd; in particular, the table grape plant (arbitrarily designated RBTG) was found infected with all four viroid species. The HTS-derived, 490-nt GYSVd-2-specific contig from the table grape sample represented ∼1.35 genome of the Idaho isolate of GYSVd-2 (GYSVd-2-RBTG) and was 100% identical to the GYSVd-2 sequence JQ686716 from Iran. The HTS-derived, 488-nt AGVd-specific contig represented ∼1.32 genome of the Idaho isolate of AGVd (AGVd-RBTG) and was 100% identical to the AGVd sequence KF876037 from Iran. To validate the HTS data and confirm the presence of the four viroids in the original 16 samples, all of them were subjected to RT-PCR using the viroid-specific primers described by Gambino et al. (2014); all 16 samples were found positive for HSVd and GYSVd-1, and one found positive for AGVd. The RBTG sample was confirmed to be infected with HSVd, GYSVd-1, and AGVd by RT-PCR. GYSVd-2 sequence was not amplified, although primers designed by Gambino et al. (2014) matched the HTS-derived GYSVd-2-RBTG sequence; this may be related to a lower concentration of this viroid in the sample and to properties of the primers. The sampled table grape plant was asymptomatic; all four viroids were apparently not associated with any visible abnormalities in this table grape plant, consistent with the findings that viroids found in grapevines typically do not seem to be associated with visible diseases (Habili 2017).

Multi-criteria decision analysis applied to Brazilian grapevine genotype selection

Developing new table grape cultivars that exhibit high yield and superior fruit quality is imperative to meet the escalating demands of the consumer market in the Lower-Middle São Francisco River Valley. The primary objective of Embrapa Semiárido's Active Germplasm Banks (AGB) for grapes is the conservation of Vitis sp. germplasm under semi-arid climatic conditions to make it available for research, particularly for the breeding and development of novel grape cultivars. This study aims to use Multi-Criteria Decision Analysis (MCDA), specifically the Preference Ranking Organization Method for Enrichment Evaluation (Promethee) II, to rank the grape genotypes of the Embrapa Semiárido's AGB, considering multiple criteria to define the primary grape varieties for the breeding program. The decision maker (DM) participated in all process stages, from validating qualitative and quantitative criteria to evaluating the criteria weights, and the decision matrix had 106 seeded and 50 seedless grape genotypes with 14 criteria. For visual analysis, we generated the GAIA Plane using the Visual Promethee Software. In the group of seeded grape cultivars, the three top-ranked genotypes were 'Italia Clone I′, 'Dona Maria', and 'Italia Muscat', while in the seedless group, the best-rated were 'BRS Ísis', 'BRS Linda', and 'BRS Morena'. Our research demonstrated, for the first time, the evaluation of grape genotypes using MCDA method with qualitative and quantitative criteria.

Practical method for table grape selection using multicriteria decision análisis

The São Francisco Valley (Pernambuco-PE, Brazil) is of great importance for the local economy, since the region represents a large portion of Brazilian production and export of fresh grapes. Traditional methods of feasibility analysis involve only cost or productivity analyses, but for the grape growers there must be techniques and methods that assist decision making involving other criteria with characteristics of the grape. Yet, there is a noticeable lack of multi-criteria methods that assist the grower in making decisions for selection of commercial table grape cultivars for the feasibility analysis. Thus, the aim of the present study is to select table grape cultivars through multiple criteria, using a new method for eliciting scale constants: the Flexible and Interactive Tradeoff (FITradeoff), for the purpose of assisting a rural producer to expand production while minimizing inconsistencies in the decision-making process. With the assistance of a decision maker, the Decision Matrix and Consequence Table were constructed on Microsoft Excel® – composed by 11 criteria and 3 alternatives, all closed source grape cultivars (with patents). Then, the data were applied on the FITradeoff software for the ranking problematic. Thus, it was possible to arrive at a ranking of the best alternatives, where the cultivar Timpson (SNFL) (U2) was found to be the optimal solution proposed for the rural producer. The application of FITradeoff provided a satisfactory result with little time and effort spent, leading to a final suggestion for the decision maker. In addition, at the end of the process, it provided graphical visualization of the performance and dominance of each criterion selected, as well as a ranking of the grape cultivars through the Hasse Diagram, with the order of the best alternatives. Ordering the grape genotypes considering Multi-Criteria Decision Analysis methods is crucial to selection of commercial table grape cultivars. The method can be applied to other segments of agriculture that require multi-criteria evaluations.

The effects of glycine betaine application on frost tolerance in three table grape cultivars

The effects of glycine betaine application on frost tolerance in three table grape cultivars

Identification of Novel Quantitative Trait Loci Associated with Table Grape Fruit Quality Characteristics in a Segregating Population and Transferability of Existing Quality Markers

Grape (Vitis) production and fruit quality traits such as cluster size, berry shape, and timing of fruit development are key aspects when selecting cultivars for commercial production. Molecular markers for some, but not all, of these traits have been identified using biparental or association mapping populations. Previously identified markers were tested for transferability using a small (24 individual) test panel of commercially available grape cultivars. Markers had little to no ability to differentiate grape phenotypes based on the expected characteristics, except the marker for seedlessness. Using a biparental interspecific cross, 43 quantitative trait loci (QTLs) (previously identified and new genomic regions) associated with berry shape, number, size, cluster weight, cluster length, time to flower, veraison, and full color were detected. Kompetitive allele-specific polymerase chain reaction markers designed on newly identified QTLs were tested for transferability using the same panel. Transferability was low when use types were combined, but they were varied when use types were evaluated separately. A comparison of a 4-Mb region at the end of chromosome 18 revealed structural differences among grape species and use types. Table grape cultivars had the highest similarity in structure for this region (>75%) compared with other grape species and commodity types.

Studies on the biological and productive potential of some table grape cultivars grown in the pedoclimatic conditions of southern Oltenia

The researches carried out followed the potential of some vine cultivars with table grapes, from the point of view of biology and the grape production of the cultivars, from the ampelographic collection of the Research – Development Station for Plant Culture on Sands Dabuleni. During the three years of the study, the vine cultivars with table grapes cultivars budded between April 12 and May 10, the 'Victoria' and 'Prima Cl. 1022' cultivars budded between the earliest, and the latest 'Moldova' cultivar. The point of view of the average production of grapes, in the analyzed period the cultivars 'Prima Cl. 1022' stood out, 17389 kg/ha with a difference from the witness of 2809 kg/ha and 'Perla de Zala' 15527 kg/ha with a difference from the witness of 947 kg/ha, both statistically uninsured. The values of the content in total sugars, at harvest maturity, fluctuated from one cultivar to another but also from one year to another. From this point of view, the first place was the 'Perla de Zala' cultivar with an average amount of total sugars of 207 g/l and a difference compared to the witness of 73 g/l, statistically assured as significant. In the period 2020-2022, the table grape vine cultivars analyzed behaved differently depending on the climatic conditions of the crop year.

High Growing Season Temperatures Limit Winter Recovery of Grapevines from Xylella fastidiosa Infection - Implications for Epidemiology in Hot Climates.

Management of widespread plant pathogens is challenging as climatic differences among crop-growing regions may alter key aspects of pathogen spread and disease severity. Xylella fastidiosa is a xylem-limited bacterial pathogen that is transmitted by xylem sap-feeding insects. Geographic distribution of X. fastidiosa is limited by winter climate, and vines infected with X. fastidiosa can recover from infection when held at cold temperatures. California has a long history of research on Pierce's disease and significant geographic and climatic diversity among grape-growing regions. This background in combination with experimental disease studies under controlled temperature conditions can inform risk assessment for X. fastidiosa spread and epidemic severity across different regions and under changing climate conditions. California's grape-growing regions have considerable differences in summer and winter climate. In northern and coastal regions, summers are mild and winters are cool, conditions which favor winter recovery of infected vines. In contrast, in inland and southern areas, summers are hot and winters mild, reducing likelihood of winter recovery. Here, winter recovery of three table grape cultivars (Flame, Scarlet Royal, and Thompson Seedless) and three wine grape cultivars (Sauvignon Blanc, Cabernet Sauvignon, and Zinfandel) were evaluated under temperature conditions representative of the San Joaquin Valley, an area with hot summers and mild winters that has been severely impacted by Pierce's disease and contains a large portion of California grape production. Mechanically inoculated vines were held in the greenhouse under one of three warming treatments to represent different seasonal inoculation dates prior to being moved into a cold chamber. Winter recovery under all treatments was generally limited but with some cultivar variation. Given hot summer temperatures of many grape-growing regions worldwide, as well as increasing global temperatures overall, winter recovery of grapevines should not be considered a key factor limiting X. fastidiosa spread and epidemic severity in the majority of cases.

Molecular and Metagenomic Analyses Reveal High Prevalence and Complexity of Viral Infections in French-American Hybrids and North American Grapes.

French-American hybrids and North American grape species play a significant role in Canada's grape and wine industry. Unfortunately, the occurrence of viruses and viral diseases among these locally important non-vinifera grapes remains understudied. We report here the results from a large-scale survey to assess the prevalence of 14 viruses among 533 composite samples representing 2665 vines from seven French-American hybrid wine grape cultivars, two North American juice grape cultivars (Concord and Niagara), and the table grape cultivar Sovereign coronation. Based on reverse transcription polymerase chain reaction (RT-PCR) assays, ten viruses were detected. Grapevine rupestris stem pitting-associated virus, grapevine leafroll-associated virus 3, grapevine Pinot gris virus and grapevine red blotch virus were detected with the highest frequency. As expected, mixed infections were common; 62% of the samples contained two or more viruses. Overall, hybrid wine grapes were infected with more viruses and a higher prevalence of individual viruses than juice and table grapes. To validate these findings and to refine the virome of these non-European grapes, high-throughput sequencing (HTS) analyses of five composite samples representing each category of grapevine cultivars was performed. Results from HTS agreed with those from RT-PCR. Importantly, Vidal, a widely grown white-wine grape with international recognition due to its use in the award-winning icewine, is host to 14 viruses, four of which comprise multiple and distinct genetic variants. This comprehensive survey represents the most extensive examination of viruses among French-American hybrids and North American grapes to date.

Temperature variability during the growing season affects the quality attributes of table grapes in Pothwar-insight from a new emerging viticulture region in South Asia.

Rising air temperature due to climate change has posed a mammoth challenge to global viticulture and key berry quality traits are compromised. Exploring the effects of seasonal temperature variability on berry ripening and quality attributes in different viticulture regions may help in sustainable viticulture industry. The present research was designed to explore the effect of temperature variables on key quality attributes of table grape cultivars in Pothwar region of Pakistan. Key berry quality traits such as total soluble solids (TSS), titratable acidity (TA), maturity indices (MI), ascorbic acid, sugars, total polyphenol contents (TPC) and total anthocyanin contents (TAC) were unlocked for four important table grape cultivars under varying environmental conditions at Chakwal and Islamabad districts for two consecutive vintages of 2019 and 2020. The district Chakwal has up to 0.92 °C, 1.35 °C, 1.12°C and 0.81°C higher Tmin, Tmax, Tmean anddiurnal temperature variation (DTV)respectively, compared to Islamabad particularly for the 2019 vintage. The results of the present study revealed that the warmer site (Chakwal) has significantly (P ≤0.05) higher juice pH, TSS (°brix) and maturity indices (MI) particularly for the relatively hotter vintage of 2019. Interestingly, MI was 33% higher for the relatively warmer vintage of 2019 compared to 2020 with relatively lower acidity (up to 38%). Moreover, higher titratable acidity (11.2%), ascorbic acid (28.5%), polyphenols (20.3%) and anthocyanins (10.6%) were noticed for the colder Islamabad compared to Chakwal. Although elevated temperature for warmer location and vintage favoured berry ripening, however key biochemical attributes such as titratable acidity, ascorbic acid, polyphenols and anthocyanins were negatively affected. The findings of the present research provide useful insight into the impact of growing season temperature on key berry attributes and may help devise adaptation strategies to improve berry quality.

Maturity Assessment of Different Table Grape Cultivars Grown at Six Different Altitudes in Lebanon.

Table grapes are harvested based on well-known maturity indices that must be monitored after fruit veraison. The aim of this study was to assess these indices across multiple locations and environmental conditions, encompassing different table grape cultivars such as Black Pearl, Crimson Seedless, Superior Seedless, and Red Globe. For this reason, grape sampling was conducted across six distinct locations characterized by varying altitudes above sea level (m asl) and environmental conditions over the ripening season. The main maturity indices, including pH, sugar content, titratable acidity, berry firmness, and other parameters were monitored over the growing season. Moreover, the quantification of total polyphenols, total anthocyanins, and antioxidant activity was determined using spectrophotometric assays at harvesting. The study has examined the effect of the vineyard's location on grape quality and its interaction with the cultivar and environment. Crimson Seedless maintained a relatively high level of acidity with altitude near harvesting. Black Pearl exhibited a notable decline in both sugar content and berry firmness as elevation increased, whereas Red Globe demonstrated contrasting outcomes. The optimal maturity of Superior Seedless was observed at an elevation of 1000 m asl. Black Pearl and Crimson Seedless exhibited better adaptability to intermediate elevations (650 and 950 m asl), while Red Globe and Superior Seedless showed better adaptability to higher elevations (1000-1150 m asl). Among the studied cultivars, Black Pearl exhibited significantly higher levels of total polyphenols and anthocyanins, while close values were noticed between red and green cultivars.

Effects of Table Grape Cultivars on Fruit Quality and Aroma Components.

The basic physical and chemical qualities, nutrition, aroma components, and sensory evaluation of 17 varieties of table grapes were studied. The quality evaluation system of different table grape varieties was preliminarily determined. Our results show that the soluble solid content in Ruby Seedless was 21.17%, which was higher than that of other varieties. The black varieties Aishenmeigui and Sweet Sapphire had the highest total phenol content. Aishenmeigui had high levels of tannin and vitamin C. In addition, the aroma contents in Meixiangbao, Ruby Seedless, and Shine-Muscat were higher than those in other varieties. Manicure Finger and Ruby Seedless had higher levels of C6 compounds. Moreover, the "Kyoho" series of grape Meixiangbao, Sunmmer Black, Jumeigui, Hutai 8 hao, and Black Beet were high in ester content, while Muscat varieties, including Zaoheibao, Aishenmeigui, Jumeigui, and Shine-Muscat were rich in terpene substances. Ruby Seedless, Shine-Muscat, and Heibaladuo had higher comprehensive scores in sensory evaluation. Hence, the comprehensive quality of Shine-Muscat, Ruby Seedless, and Aishenmeigui was better. These results may serve as references for determining the quality differences between table grape varieties.

Effects of Selenium Biofortification on Phytochemical Characteristics of Some Table Grape Cultivars

Table grapes, rich in vitamins and minerals, play an important role in human nutrition, thus largely used in daily diets. Selenium (Se) with positive impacts on human health and anticancerogenic effects, has recently become prominent in human nutrition and animal feeding. In this study, selenium fortifications were made at different doses (control, 4 ppm and 8 ppm) to 9 different table grape cultivars (Alphonse Lavallée, Bilecik İrikarası, Cardinal, Sultani Seedless, Tekirdağ Seedless, Italia, Lival, Victoria, Royal) and total phenolics, anthocyanins and flavonoids of the cultivars were determined. While total phenolics of the whole berry was presented, skin and pulp total anthocyanins and total flavonoids were presented separately. The greatest total phenolic amount was obtained from 4 ppm selenium treatment in Bilecik İrikara (157.31 mg/g) cultivar. The greatest total anthocyanin contents were obtained from the skin of with 8 ppm selenium treatment in Alphonse Lavallée (11.22 mg/g). Selenium treatments increased total flavonoids of Bilecik İrikarası, Lival, Royal and Sultani Seedless cultivars. It was concluded based on findings that Se treatments influenced phytochemical characteristics of the table grapes.