Grape Cultivars Research Articles

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.

Approach to assessing the drought resistance of grapes on model intact leaves

On the one hand, water scarcity poses challenges to the growth, development, longevity and resistance of grapes to diseases and low temperatures, on the other hand, however, it is necessary to obtain a high-quality harvest. Under the conditions of increasing continentality of the climate, it is of great importance to breed the cultivars characterised by effective fruiting without damaging the grape plant under drought conditions. Identifying characteristics of drought resistance in grapes is a challenging task, given the size of the plants, the extended development period, the absence of a specific criterion for drought resistance and the labour-intensive and time-consuming nature of the exploratory analysis. This study proposes the use of intact leaves from a specific grape variety placed in controlled environmental conditions as a model system. The paper assesses the applicability of intact grape leaves as a reliable model for evaluating drought resistance in the cultivar. It compares variations in physiological parameters—electrolyte leakage, chlorophyll stability index, and malonyldialdehyde content—observed in intact leaves under the influence of sorbitol and in leaf discs under the influence of polyethylene glycol with different concentrations and exposure times. The variations of physiological parameters in grape leaves subjected to controlled soil drought were used as a reference standard. In two independent experiments in 2022-2023, exposure to simulated intense soil drought for three weeks revealed cultivar differences in the ratio of electrolyte leakage and chlorophyll stability index in the test and control cultivars. Similar results were obtained in an experiment on intact grape leaves placed in a 10 % sorbitol solution for 3 hours. It was established that the cultivars ‘Morozko’, ‘Kutuzovsky’ and ‘Dostoiny’ exhibit higher drought resistance compared to the V. vinifera varieties ‘Cabernet Sauvignon’ and ‘Barkhatny’. This approach can be used as a preliminary method for determining the drought resistance of grape cultivars, independently or in combination with fi eld studies.

Influence of Grapevine Cultivar on Population Levels of Lobesia botrana (Lepidoptera: Tortricidae) and Effectiveness of Insecticides in Controlling This Pest

The European grapevine moth, Lobesia botrana (Denis and Schiffermüller) (Lepidoptera: Tortricidae), is the most critical pest of vineyards. In the present study, pheromone-baited traps were applied in 2021 and 2022 to monitor the moth population dynamics and to determine the number of L. botrana generations. The number of eggs and larvae was also counted in four vineyards with Askari, Yaghooti, Keshmeshi, and Fakhri cultivars. Moreover, the morphological properties of clusters were evaluated in different grape cultivars to find out the susceptible cultivar to L. botrana. In 2022, different insecticides were used in the Askari cultivar vineyard, and larval damage level was assessed. Three generations were recorded in all vineyards each year. The population of males was not affected by the cultivar. In contrast, the population density of eggs and larvae was significantly higher in Yaghooti than in other tested cultivars. It could be attributed to the cluster compactness and thin skin of berries in Yaghooti, which makes it more susceptible to L. botrana infestations. In contrast, the lowest eggs and larval population density was reported in the Fakhri cultivar indicating the tolerance of this cultivar compared to the other tested cultivars. The field trial showed that the application of insecticides in the second and third generations reduced the damage level of L. botrana. The rotation of insecticides with different modes of action in consecutive generations of L. botrana can be used to reduce damage levels.

Dacicus, new grape cultivar for white wines, with genetic resistance to cryptogamic diseases

Dacicus, new grape cultivar for white wines, with genetic resistance to cryptogamic diseases

Potential of production of orange type wines with increased bioactive substance content from new selection grape cultivars from the Republic of Moldova

Potential of production of orange type wines with increased bioactive substance content from new selection grape cultivars from the Republic of Moldova

Optimization of In Vitro Embryo Rescue and Development of a Kompetitive Allele-Specific PCR (KASP) Marker Related to Stenospermocarpic Seedlessness in Grape (Vitis vinifera L.).

Seedlessness is one of the highest valued agronomic traits in grapes. Embryo rescue in combination with marker-assisted selection have been widely applied in seedless grape breeding due to the advantages of increasing the ratio of seedless progenies and shortening the breeding cycle. However, the large number of deformed seedlings produced during embryo rescue and the lack of fast, efficient, and low-cost markers severely inhibit the process of seedless grape breeding. In this study, a total of eighty-three grape cultivars (51 seedless and 32 seeded) with diverse genetic backgrounds and two populations derived from embryo rescue, including 113 F1 hybrid individuals (60 seedless and 53 seeded), were utilized. We screened suitable media for converting malformed seedlings into normal seedlings, analyzed the association between the SNP in VviAGL11 and seeded/seedless phenotype, and developed a KASP marker related to stenospermocarpic seedlessness. Our results indicated that the transformation rate of 37.8% was obtained with MS medium supplemented with 2.0 mg·L-1 of 6-BA and 0.5 mg·L-1 of IBA. The presence of an A nucleotide allele at position chr18:26889437 was further confirmed to be fully associated with the stenospermocarpic seedlessness phenotype. The developed KASP marker, based on the verified SNP locus in VviAGL11, successfully distinguished the seedless and seeded genotypes with high precision and throughput. The results will contribute to enhancing the efficiency of embryo rescue and facilitate parent selection and early selection of seedless offspring with molecular markers, thereby accelerating the breeding process in seedless table grapes.

Studies on Improving the Efficiency of Somatic Embryogenesis in Grapevine (Vitis vinifera L.) and Optimising Ethyl Methanesulfonate Treatment for Mutation Induction.

Somatic embryogenesis (SE) has many applications in grapevine biotechnology including micropropagation, eradicating viral infections from infected cultivars, mass production of hypocotyl explants for micrografting, as a continuous source for haploid and doubled haploid plants, and for germplasm conservation. It is so far the only pathway for the genetic modification of grapevines through transformation. The single-cell origin of somatic embryos makes them an ideal explant for mutation breeding as the resulting mutants will be chimera-free. In the present research, two combinations of plant growth regulators and different explants from flower buds at two stages of maturity were tested in regard to the efficiency of callusing and embryo formation from the callus produced in three white grape cultivars. Also, the treatment of somatic embryos with the chemical mutagen ethyl methanesulfonate (EMS) was optimised. Medium 2339 supplemented with β-naphthoxyacetic acid (5 μM) and 6-benzylaminopurine (BAP-9.0 μM) produced significantly more calluses than medium 2337 supplemented with 2,4-dichlorophenoxyacetic acid (4.5 µM) and BAP (8.9 µM) in all explants. The calluses produced on medium 2337 were harder and more granular and produced more SEs. Although the stage of the maturity of floral bud did not have a significant effect on the callusing of the explants, calluses produced from immature floral bud explants in the premeiotic stage produced significantly more SEs than those from more mature floral buds. Overall, immature ovaries and cut floral buds exposing the cut ends of filaments, style, etc., tested for the first time in grapevine SE, produced the highest percentage of embryogenic calluses. It is much more efficient to cut the floral bud and culture than previously reported explants such as anthers, ovaries, stigmas and styles during the short flowering period when the immature flower buds are available. When the somatic embryos of the three cultivars were incubated for one hour with 0.1% EMS, their germination was reduced by 50%; an ideal treatment considered to obtain a high frequency of mutations for screening. Our research findings will facilitate more efficient SE induction in grapevines and inducing mutations for improving individual traits without altering the genetic background of the cultivar.

Impact of Foliar Spray with Gibberellic Acid GA3 and Nauta Fertilizer on the Some Vital and Mineral Components of Three Cultivars of Grape (Vitis vinifera L.)

The University of Mosul’s Department of Horticulture and Landscape Design / College of Agriculture and Forestry vineyard hosted this study. During the growing season 2022, to study the effects of foliar fertilization with Nauta fertilizer containing amino acids and seaweed extracts in three concentrations (0, 250, and 500 mg l-1) and foliar spraying with gibberellic acid in three concentrations (0, 50, and 100 mg l-1) on three table grape varieties, Halwany Lebanese, Kamali, and Black Khalili, and their interactions and effects on some It is possible to summarize the most important results obtained: According to this study, Halwany surpassed Kamali and Black Khalili in petiole iron concentration and grape variety superiority. Halwany and Kamali were over the Black Khalili variety in the average concentration of potassium in the petioles, just as the grape varieties were over the Halwany variety in the average protein and phosphorus concentrations. The Black Khalili variety also outperformed the Halwany and Kamali varieties in zinc content and carbohydrate percentage. In leaf petioles, nitrogen content increased significantly after foliar application of Nauta organic fertilizer at 250 mg l-1. In addition to the superiority of foliar spraying at 500 mg l-1 of the same fertilizer in main stem carbohydrates, protein, phosphorus, and iron in leaf petioles. Foliar spraying with gibberellic acid, especially at a concentration of 100 mg l-1, led to a significant increase in the average of protein and the concentration of phosphorus, potassium, zinc and iron in the leaf petioles.

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.

Influence of Bio, Nano and Conventional Fertilizers on the Growth Features of a French Black Grape Variety

A French black grape cultivar was tested in a Babylon province/Al-Hamzah Al-Gharbi district private orchard using the Randomized Complete Block Design (RCBD) three-factor factorial configuration. The first is applying biofertilizer, which includes Bacillus megaterium and Mycorrhiza glomus fungus, to the soil at two concentrations (0 and 10 ml L-1), the second is applying liquid organic fertilizer at three concentrations (0, 15, and 30 ml L-1), and the third is applying organic fertilizer via foliar spraying. Nanofluid concentrations will be 0.1 and 3 ml L-1 in 2020 and 2021. Most biofertilization vegetative growth metrics showed that excelled in the leaf area per cluster was 9.42 cm cluster-1 in both seasons, while organic nano-fertilization at 3 ml L-1 boosted most vegetative growth indicators. Most vegetative development metrics responded significantly to bidirectional research parameter interactions, the bi-interaction between organic nano-fertilizer at a concentration of 3 ml L-1 and organic fertilizer at a concentration of 30 ml L-1 significantly affected the leaf area, the total leaf area, and the leaves’ content of total chlorophyll. 10 ml L-1 biofertilizer and 30 ml L-1 organic fertilizer achieved the heist values in leaf area, total leaf area, and leaf content. The interaction between the bio fertilizer at a dosage of 10 ml L-1 and the organic nano fertilizer at a concentration of 3 ml L-1 considerably altered the content of total chlorophyll in leaves.

Impact of pruning severity, chicken manure, and foliar application of kare combi on productivity and quality of zaitouni grape cultivar (Vitis vinifera L.)

Impact of pruning severity, chicken manure, and foliar application of kare combi on productivity and quality of zaitouni grape cultivar (Vitis vinifera L.)

Effect of Bio Fertilizer, Nano Organic Fertilizer and Non-Nano Organic Fertilizer on the Quantitative Traits of French Black Grape Cultivars

A French black grape cultivar was tested in a private orchard in the Al-Hamzah Al-Gharbi region of Babylon province using the three-factor, three-replicate Randomized Complete Block Design (RCBD). Biofertilizers like Bacillus megaterium and Mycorrhiza glomus fungus are applied to the soil at a concentration of 0 and 10 ml L-1; liquid organic fertilizer is applied to the soil at concentrations of 0, 15, and 30 ml L-1; and finally, organic fertilizer is sprayed on the leaves of the plants. The nanofluid in two different concentrations (0.1 and 3 ml L-1) during the entire year (2021). Averages were compared using the statistical program GenStat and the least significant difference (L.S.D.) test at the level of probability 0.05. The experiment included one sector (18) of the cultivar’s vines, with a number of experimental units distributed randomly in three sectors, and the number of vines was (54) vines for the cultivar. Here is a quick rundown of the most relevant findings: The results revealed that biofertilization at a concentration of 10 ml L-1 had a significant influence on most quantitative features of the yield, leading to an increase in the overall yield, which peaked at 36.2 and 38.6 kg. Vine-1., While the average number of clusters increased to 51.6 and 53.9 per vine with the application of organic nano-fertilization at a concentration of 3 ml L-1, the highest value for total yield was attained at 37.0 kg vine-1. The organic fertilization at a concentration of 30 ml L-1 had a significant effect on most of the quantitative indicators, leading to an increase in the total yield as it gave the highest value of 36.6 and 37.5 kg vine-1.

Polyphenolic Compounds in Extracts from Roasted Grapevine Canes: An Investigation for a Circular Approach to Increase Sustainability in the Viticulture Sectors.

In this study, we compared the polyphenolic composition of the roasted grapevine wood chips of four Vitis vinifera cultivars-namely, Sorbara, Grasparossa, Malbo Gentile, and Spergola. These waste byproducts have the potential as infusion chips for the aging of alcoholic beverages and vinegars, contributing to an enriched sensory profile. Roasting amplifies aromatic nuances and triggers the depletion of crucial bioactive compounds, including polyphenols. We investigated the extent of polyphenolic loss in the ethanolic extract of roasted grapevine chips to repurpose this waste byproduct and assess its potential. We assessed the levels of trans-resveratrol, trans-ε-viniferin, trans-piceatannol, and the main resveratrol trimer. Our findings indicated a significant decrease in polyphenol content as the roasting temperature increased, from 16.85-21.12 mg GAE/g for grapevine chips roasted at 120 °C to 3.10-7.77 mg GAE/g for those roasted at 240 °C. This study also highlights notable genotypic differences in polyphenolic content. Among the red grape cultivars analyzed, Sorbara exhibited the highest levels (7.77-21.12 mg/GAEg), whereas the white grape cultivar Spergola showed the lowest polyphenolic content (3.10-16.85 mg/GAEg). These findings not only contribute to the scientific understanding of polyphenol stability but also hold practical implications for the enhancement of aged beverages, as well as advancing sustainable practices in the viticulture industries.

Phenolic Composition of Red and White Wine Byproducts from Different Grapevine Cultivars from La Rioja (Spain) and How This Is Affected by the Winemaking Process.

The recovery of raw materials offers an opportunity for applying the principles of circular bioeconomy. The phenolic composition of three underused wine byproducts (skin, seed, and bunch stem) was analyzed through UHPLC-QqQ-MS/MS to evaluate the intercultivar variability comparing red and white grape cultivars from La Rioja (Spain) and the influence of the winemaking, comparing conventional fermentation and carbonic maceration. We observed that the red skin, especially from Graciano, is rich in anthocyanins, whereas the white skin contains mainly phenolic acids, flavonols, and flavan-3-ols, with Maturana Blanca being the richest variety. Seeds are rich in flavan-3-ols and lignans with Maturana Blanca and Viura, respectively, the richest cultivars. Stems contain high amounts of flavan-3-ols, lignans, and stilbenes, with the red cultivars of Garnacha and Tempranillo being the richest samples. Carbonic maceration has a negative effect on the phenolic amount compared to conventional fermentation. In synthesis, we observed that each type of byproduct from red or white grape cultivars has a particular phenolic composition that can result in obtaining different ingredients with particular phenolic composition for target applications.

Establishment and application of a Multiple nucleotide polymorphism molecular identification system for grape cultivars

Grapes (Vitis L.) are one of the most important and popular fruits in China. However, efficient identification of grapes is important in the protection of domestic grapes and breeders’ rights. Here, we developed a new method called multiple nucleotide polymorphisms (MNP), which combines the advantages of multiple PCR amplification and high-throughput sequencing to improve the efficiency of grape variety identification. We identified 582 universal MNP markers and screened them based on the whole genome sequencing data of 31 representative cultivars. Subsequently, MNP libraries of 60 common cultivars were constructed using multiple PCR amplification and sequencing. The pairing comparison of 60 grape materials revealed a high identification rate (>99 %) of MNP markers. Furthermore, MNP accurately distinguishes diploid and polyploid, which can assist in molecular identification of grapes. Overall, MNP molecular identification technology provides a new way for grape variety identification. Compared with SNP, MNP reduces the cost of identification because it does not need to make expensive gene chips. In addition, MNP can perform the amplification of thousands of primers in a single tube and uses sequencing instead of polyacrylamide gel electrophoresis, which greatly saves experimental consumables and labor compared with SSR. Collectively, the developed technique has the advantages of low cost and high efficiency, which is more competitive than other identification methods at present. The developed technology can assist in resource research and promote plant breeding.

The impact of fruit thinning on size and quality of fresh-market muscadine berries.

Achieving a larger berry size accompanied with even ripening are demanded by producers in growing muscadine cultivars. The current study aimed to evaluate the impact of fruit thinning on berry size and quality in two muscadine grape cultivars, 'Triumph' a bronze-fruited cultivar bearing hermaphrodite flowers, and 'Supreme' a dark black-fruited cultivar bearing female flowers. Thinning was performed before bunch closure and only one cluster per cane was retained. Results indicated a significant interaction of treatments and cultivars on berry weight and berry diameter. In 'Supreme,' berry weight and berry diameter were significantly increased where thinning was performed, and difference in plant yield between thinned and not thinned vines was not significant. For 'Triumph,' thinning had no significant impact on berry weight and diameter, but yield was ultimately reduced. Other physico-chemical characters were not affected by fruit thinning. However, differences were observed between both cultivars for these characters. The values of antioxidant scavenging activity (ASA) and total phenolic content (TPC) were 62.7% and 21.7% higher in 'Supreme' as compared to 'Triumph,' irrespective of the thinning treatments. Being a colored cultivar, 'Supreme' berries have higher anthocyanins than 'Triumph,' which has a negligible amount of anthocyanins. The ASA exhibited a strong positive correlation with TPC and anthocyanin content of muscadine grapes. There was also a significant positive correlation between TPC and anthocyanins. Cluster thinning of some muscadine grape cultivars may improve individual berry size without affecting overall plant yield or the fruit color, firmness, biochemical attributes and bioactive compounds. © 2023 Society of Chemical Industry.

Precision maturation assessment of grape tissues: Hyperspectral bi-directional reconstruction using tomography-like based on multi-block hierarchical principal component analysis

This paper introduces a tomography-like method for assessing grape maturation. It analyses inner tissue spectra through point-of-measurement (POM) sensing. A multi-block hierarchical principal component analysis (MHPCA) algorithm was used for the spectral reconstruction of total grapes (skin, pulp, and seed). Two grape cultivars, Loureiro (white; n = 216) and Vinhão (red; n = 205) were measured at 12 dates after veraison (DAV). The reconstructed spectra showed no significant differences (p < 0.001) from the originals for both grapes. Loureiro had better statistical metrics (Person's correlation coefficient (r) values for: total grape: 0.99, skin: 1; pulp: 1, seed: 0.94) than Vinhão (r values for: total grape: 0.92, skin: 0.92; pulp: 0.95, seed: 0.95). Using self-learning artificial intelligence (SL-AI), the following parameters were predicted for both grapes: soluble solids content (%; MAPE <13%), puncture force (N; MAPE <29%), chlorophyll content (a.u.; MAPE <29%), and anthocyanin content (a.u.; MAPE <17%, Vinhão only). When comparing observed values with predicted skin, pulp, and seed spectra, Vinhão showed no statistical differences for most parameters, except pulp chlorophyll on one DAV in the final maturation stage. The same was done with the Loureiro cultivar. Although Loureiro mostly showed no statistical differences in assessed parameters across tissues and dates, variations were found in pulp and skin chlorophyll content and puncture force. This tomography-like approach based on tissue maturation can help viticulturists to access instant data on grape maturation, supporting informed decision-making and promoting more sustainable agricultural practices.

Evaluation of Grape (Vitis vinifera L.) Genotypes for Growth, Phenological and Yield under North-Eastern Dry Zone of Karnataka, India

Eight grape genotypes were evaluated during 2021-2022 at New orchard, University of Agricultural Sciences, Raichur, Karnataka. The experiment was conducted in Randomized Block Design with three replication. The grape cultivars of five year old vines planted at spacing of 3.0m× 1.5m and trained on Y system of training. The forward pruning was done on 21st October, 2021. There were eight table grape genotypes under the evaluation study, i.e., Thompson Seedless, Manik Chaman, Sharad Seedless, 2A Clone, K.R. White, Manjari Naveen, Fantasy Seedless and Medica. Among genotypes, Medica recorded the maximum pruning weight (1.39 Kg vine-1), number of fruitful canes vine-1(36.00). Thompson Seedless observed maximum shoot length (126.49 cm). Manik Chaman recorded maximum cane diameter (10.31 mm). The genotype Thompson Seedless has recorded earliness in bud sprouting (7.10 days), minimum number of days to anthesis (29.12 days) and fruitset (35.25 days). The early ripening genotypes was Sharad Seedless (98.70 days). The maximum bunch weight was recorded in the genotype 2A Clone (598.87 g). The genotype Medica recorded the maximum number of bunches vine-1(112.00) with highest bunch yield (41.32 kg vine-1)

Productivity and Physicochemical Properties of the BRS Isis Grape on Various Rootstocks under Subtropical Climatic Conditions

Brazil has emerged as a significant producer of seedless grapes due to high consumer demand. This has led to increased production of seedless grapes in non-traditional cultivation regions, such as subtropical areas. To meet this demand, the search for new grape varieties suitable for these conditions, such as the ‘BRS Isis’ variety, has become an option for growers. The interaction between grape cultivars and rootstocks is specific, and their adaptability to climatic conditions can result in uneven performance. Therefore, the choice of rootstock should be considered before making any recommendations. The purpose of this study was to assess the productive performance, physical-chemical, and biochemical properties of the ‘BRS Isis’ vine grafted onto rootstocks (‘IAC 572’, ‘IAC 766’, and ‘Paulsen 1103’) in two production cycles. The experimental design consisted of randomized blocks, with seven blocks and three plants per plot, for a total of 63 vines. Thus, the vine’s income components, physical qualities of bunches and berries, chemical profile, bioactive substances, and antioxidant activity were assessed. The Tukey test (5% probability) was used to compare means between rootstocks. The data on scion cultivar and rootstock pairings were further evaluated using principal component analysis (PCA). There were substantial variations in the rootstocks, with ‘IAC 572’ and ‘IAC 766’ producing more bunches, generating more fresh mass, and having a longer bunch length than ‘Paulsen 1103’. However, phenolic compounds and flavonoids were greater in ‘BRS Isis’ grapes than in ‘Paulsen 1103’. ‘BRS Isis’ shows good adaptation to subtropical environments when employing the IAC 572 and IAC 766 rootstocks due to their higher yield and bioactive component accumulation compared to grapes grafted onto ‘Paulsen 1103’. However, regardless of the rootstock utilized, ‘BRS Isis’ grapes perform well commercially in subtropical environments.

Berry texture QTL and candidate gene analysis in grape (Vitis vinifera L.).

Berry texture is a noteworthy economic trait for grape; however, the genetic bases and the complex gene expression and regulatory mechanism for the diverse changes in berry texture are still poorly understood. In this study, the results suggest that it is difficult to obtain high-mesocarp firmness (MesF) and high-pericarp puncture hardness (PPH) grape cultivars with high pericarp brittleness (PerB). The high-density linkage map was constructed using whole-genome resequencing based on 151 F1 individuals originating from intraspecific hybridization between the firm-flesh cultivar 'Red Globe' and soft-flesh cultivar 'Muscat Hamburg'. The total length of the consensus map was 1613.17cM, with a mean genetic distance between adjacent bin markers of 0.59cM. Twenty-seven quantitative trait loci (QTLs) for berry MesF, PPH, and PerB were identified in linkage groups (LGs) 1, 3, 4, 6, 8, 9, 10, 11, 14, 16, and 17, including twelve QTLs that were firstly detected in LGs 6, 11, and 14. Fourteen promising candidate genes were identified from the stable QTL regions in LGs 10, 11, 14, and 17. In particular, VvWARK2 and VvWARK8 refer to chromosome 17 and are two promising candidate genes for MesF and PPH, as the VvWARK8 gene may increase pectin residue binding with WARK for high berry firmness maintenance and the allele for VvWARK2 carrying the 'CC' and 'GA' genotypes at Chr17:1836764 and Chr17:1836770 may be associated with non-hard texture grape cultivars. In addition, real-time quantitative polymerase chain reaction (RT-qPCR) verification revealed that the promising candidate transcription factor genes VvMYB4-like, VvERF113, VvWRKY31, VvWRKY1, and VvNAC83 may regulate cell wall metabolism candidate gene expression for grape berry texture changes.