Labrusca Research Articles

Preharvest salicylic acid treatments improve phenolic compounds and biogenic amines in ‘Niagara Rosada’ table grape

The ‘Niagara Rosada’ (Vitis labrusca) grape is widely consumed for its nutritional qualities and flavor, in addition to presenting a great diversity of phytochemical compounds, mainly polyphenols. ‘Niagara Rosada’ has a limited shelf life, especially when kept at room temperature, a common form used by markets in Brazil. Salicylic acid (SA) is a low-cost alternative postharvest technique, due to its accessibility (low cost) and potential to mitigate postharvest losses, in addition to maintaining quality. Exogenous application of salicylic acid in the pre-harvest period was studied to improve the postharvest quality of ‘Niagara Rosada’ grapes with the aim of increasing its shelf life. SA was applied in different doses, in two stages during the pre-harvest, in the season of berry growth and during veraison. The results show that 1 and 2 mmol L−1 were efficient in reducing the incidence of berry drop and decay of berries. Treatments with SA provided an increase in phenolic compounds. Among the phenolic acids, there was an increase in chlorogenic acid and gallic acid, related to antifungal action. Regarding polyphenols, rutin, cyanidin-3,5-diglucoside and 3-O-glycosidic delphinidin were the major compounds found in all treatments. Salicylic acid induced an increase in serotonin and melatonin content, as well as in the aminoacids (tryptophan and 5-hydroxytryptophan). During the storage, there was a decrease in histamine and dopamine levels. These alterations may be used as a tool to induce fruit resistance during storage, leading to an increase of crop yields. Thus, exogenous treatment using 1 and 2 mmol L−1 SA increases postharvest life, improves biochemical quality of the musts and induces increased antioxidant compounds.

Transcriptomics Integrated with Free and Bound Terpenoid Aroma Profiling during "Shine Muscat" (Vitis labrusca × V. vinifera) Grape Berry Development Reveals Coordinate Regulation of MEP Pathway and Terpene Synthase Gene Expression.

Terpenes and their derivatives are important biomarkers of grape quality as they contribute to the flavor and aroma of grapes. However, the molecular basis of terpene biosynthesis throughout the grapevine phenological developmental cycle remains elusive. Our current study investigates the free and bound terpene biosynthesis of berries at different phenological stages from preveraison to harvest. Detailed gene expression (transcriptomics) analysis, terpenoid volatile production by gas chromatography-mass spectrometry (GC-MS), and in planta transient expression were employed. Our results show that concentrations of most individual terpenes at different stages are distinctive and increase from preveraison to the veraison stage followed by a decrease from veraison to maturity. The combined transcriptomic analysis and terpene profiling revealed that 22 genes belonging to the MEP pathway and multiple classes of transcription factor family members including bHLH and several hormone biosynthesis- or signaling-related genes likely participate in the regulation of terpenoid biosynthesis according to their specific expression patterns in berries. Quantitative real-time polymerase chain expression analysis of 8 key differentially expressed genes in MEP pathways and further 12 randomly selected genes was performed during 8 sampling stages and validated the RNA-seq-derived expression profiles. To further confirm the function of a subset of the differentially expressed genes, we investigated the effects of combined overexpression of 1-deoxy-d-xylulose-5-phosphate synthase (VvDXS1-LOC100249323), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (VvDXR-LOC100248516), and terpene synthase (VvTPS56-LOC100266449) on the production of terpenes by transient overexpression in Nicotiana benthamiana leaves. The overall developmental patterns of total terpenes and gene expression profiles will help guide the functional analyses of further candidate genes important for terpene biosynthesis of grape as well as identifying the master transcriptional and hormonal regulators of this pathway in the future.

Análisis de la cadena productiva del macerado de uva (Vitis labrusca l.) en la región San Martín

La presente investigación surge como respuesta a la presencia de problemas como la poca disponibilidad para establecer asociaciones entre los transformadores de la uva, así como la incapacidad del gobierno local y regional para gestionar programas de desarrollo. El objetivo general formulado fue el determinar los factores de la cadena productiva que están limitando la oferta del producto macerado de uva (Vitis labrusca l.) en la Región San Martín (2018). En cuanto a lo metodológico, se diseñó una investigación no experimental con un nivel exploratorio - descriptivo y correlacional. Se trabajó con una muestra no probabilística de 15 transformadores de macerado de uva. El resultado principal alcanzado fue que: el proceso de abastecimiento desde la óptica del transformador muestra serias limitantes en cuanto a su componente de control de calidad de la materia prima, tanto para la uva y el aguardiente, además, no se viene realizando el análisis fisicoquímico proximal de aguardiente de caña. La conclusión principal muestra un entorno desfavorable para los proveedores de materia prima, debido a la inexistencia de capacidades para garantizar un producto de calidad; no hay presencia de desarrollo tecnológico debido a que la agricultura se desarrolla de manera empírica; del mismo modo no poseen poder de negociación y muestra un bajo aprovechamiento de sus áreas de cultivo y poco acceso a créditos. Además, por la falta de asociatividad, se ven limitados a acceder a programas de apoyo público.

The complete chloroplast genome sequence of Vitis vinifera × Vitis labrusca ‘Shenhua’

Vitis vinifera × Vitis labrusca ‘Shenhua’ is a tetraploid grape, a Franco-american species. This study first published the complete chloroplast genome of Vitis vinifera × Vitis labrusca ‘Shenhua’ was assembled. The chloroplast genome is 160928 bp in length, including a large single copy region (89,148 bp), a small single-copy region (19,072 bp) and a pair of inverted repeats of 26,354 bp. The chloroplast genome encodes 133 genes, comprising 88 CDSs, 37 tRNA genes and 8 rRNA genes. The phylogenetic tree demonstrated that Vitis vinifera × Vitis labrusca ‘Shenhua’ is different from the other 16 varieties.

Anatomical and biochemical changes in leaves of Vitis labrusca L. cv. Niagara Rosada in response to infection by Elsinoë ampelina Shear

The major grapevine cultivated in Brazil for in natura consumption is Vitis labrusca cv. Niagara Rosada, which it is considered susceptible to anthracnose. It is well-known that the pathogen infects preferentially immature leaves. To investigate quantitatively the anatomical and biochemical changes in leaves of Niagara Rosada cultivar after infection by Elsinoe ampelina Shear, healthy leaves at 4 and 11 days after sprouting (das) and infected leaves 7 days after inoculation with the fungus were analyzed, totaling 11 das. Scanning microscopy was used to compare healthy and symptomatic leaves surface morphology. Quantitative anatomical analyses were performed using light microscopy. The biochemical aspects included indicators of plant defense against anthracnose, such as total phenolic compounds, total flavonoids and enzymatic activities of peroxidase and polyphenoloxidase. The content of chlorophylls a, b, and total was also analyzed to verify the plant response to infection. All anatomical parameters analyzed showed lower values in inoculated leaves than those observed in the healthy leaves. Biochemical analyses indicated that the contents of total flavonoids (mgRE g−1) were similar between healthy leaves at 4 das (0.63 ± 0.01) and 11 das (0.63 ± 0.02), but inoculated leaves showed a higher concentration of flavonoids (0.75 ± 0.05). The polyphenoloxidase activity (U mL−1) varied between healthy and inoculated leaves, exhibiting the lowest activity in healthy leaves at 4 das (1.49 ± 0.10) and increasing in healthy (11.07 ± 0.23) and in inoculated leaves (15.20 ± 0.60) at 11 das. Polyphenoloxidase and peroxidase activity and flavonoids content increased after infection, but these increases were not sufficient to prevent disease advance.

Economic viability of ‘Niágara Rosada’ grape production in the north and northwest regions of Rio de Janeiro

Abstract The ‘Niágara Rosada’ grape (Vitis labrusca) is the main table cultivar produced in the North and Northwest Regions of the Rio de Janeiro State. This cultivar presents greater rusticity and lower production cost than the cultivars of fine grape (Vitis vinifera L.) because it is more resistant to diseases and the absence of some cultural treatments. The research aimed to determine the economic affordability of the production of ‘Niágara Rosada’ grapes in the north and northwest regions of Rio de Janeiro state, by calculating the Net Present Value (NPV) and the Internal Rate of Return (IRR), and to identify the risk of viticulture, through the sensitivity analysis and the use of the Monte Carlo method. To collect the data, questionnaires, and interviews were applied directly to the wine producers on the technical coefficients and respective production costs of the grape in 1 ha. The results highlighted that viticulture could be a good alternative for the regions, with satisfactory profitability. The variables with the most significant effect on profitability were the sale price of the product, the cost of labor, and the price of packaging. The probability of winegrowers to obtain a negative NPV is 33.32%, considering an attractiveness rate of 6% per year.

Direct determination of boscalid in grape samples by differential pulse voltammetry using a carbon paste electrode

A new methodology to determine directly the fungicide boscalid (BSC) was developed and applied in 100% juice, peel extracts, pulp and seeds purple grape (Vitis labrusca L.) with a working carbon paste electrode (CPE) without sample preparation.

Effect of dietary grape pomace on fats digestibility in horses

Effect of dietary grape pomace on fats digestibility in horses

Eco-physiological responses of ‘Campbell Early’ and ‘Jinok’ grape vines of two regions affected by different climatic conditions

This study was performed to evaluate vine performance, physiological disorders of the berries, and disease of two grape (Vitis labrusca) cultivars, ‘Campbell Early’ and ‘Jinok’, in response to climate changes in private vineyards of two different latitudes, the Naju region (35°N) and the Okcheon (36°N) region, between the years 2016 and 2018. The climates from April to August or during the period of berry ripening (July and August in 2016–2018 in the Naju region was warmer than that of the 10-years average, causing approximately a 10-day longer duration of leafing to harvesting than during 2011 and 2012 for ‘Campbell Early’ vines. Total shoot length was the highest for both grape cultivars grown in Naju vineyard, when temperatures ranged between 20 and 25 °C from April to June, resulting in increased yield of ‘Campbell Early’ vines. Severe cracking of up to 59.1% of ‘Campbell Early’ berries occurred in the vineyard in Okcheon in 2017 when a high amount of precipitation occurred during the period of ripening. Also, an incidence of berry blight occurred on up to 30.6% of berries in ‘Campbell Early’ vines in the vineyard in Naju in 2018, which was subjected to a mean daily maximum temperature of 33.6 °C. Mean daily maximum temperature and number of heatwave days during the ripening period were positively related to the occurrence of berry cracking over the three years of this study, with a significant correlation observed between precipitation and mean temperature and berry blight. Downy mildew and powdery mildew occurred on both grape cultivars in the vineyard in Naju over the three years, with severe leaf spot observed on both cultivars in the region.

The Muscadine Grape (Vitis rotundifolia Michx)

The muscadine grape is native to the southeastern United States and was the first native grape species to be cultivated in North America. The natural range of muscadine grapes extends from Delaware to central Florida and occurs in all states along the Gulf Coast to east Texas. It also extends northward along the Mississippi River to Missouri. Muscadine grapes will perform well throughout Florida, although performance is poor in calcareous soils or in soils with very poor drainage. Most scientists divide the Vitis genus into two subgenera: Euvitis (the European, Vitis vinifera L. grapes and the American bunch grapes, Vitis labrusca L.) and the Muscadania grapes (muscadine grapes). There are three species within the Muscadania subgenera (Vitis munsoniana, Vitis popenoei and Vitis rotundifolia). Euvitis and Muscadania have somatic chromosome numbers of 38 and 40, respectively. Vines do best in deep, fertile soils, and they can often be found in beside river beds.
 Wild muscadine grapes are functionally dioecious due to incomplete stamen formation in female vines and incomplete pistil formation in male vines. Male vines account for the majority of the wild muscadine grape population. Muscadine grapes are late in breaking bud in the spring and require 100-120 days to mature fruit. Typically, muscadine grapes in the wild bear dark fruit with usually 4 to 10 fruit per cluster. Bronze-fruited muscadine grapes are also found in the wild, and they are often referred to as scuppernongs. There are hundreds of named muscadine grape cultivars from improved selections, and in fact, one that has been found in the Scuppernong river of North Carolina has been named Scuppernong. There are over 100 improved cultivars of muscadine grapes that vary in size from 1/4 to 1 ½ inches in diameter and 4 to 15 grams in weight. Skin color ranges from light bronze to pink to purple to black. Flesh is clear and translucent for all muscadine grape berries.
 Originally published 1994 by Peter C. Anderson and Timothy E. Crocker. Published on EDIS June 2003. Revised November 2010, October 2013, January 2017. This revision with Sarkhosh and Huff.

The impact of red grape juice (Vitis labrusca)consumption associated with physical training on oxidative stress, inflammatory and epigenetic modulation in healthy elderly women

The imbalance of epigenetic, oxidative stress and inflammatory markers is associated with the aging physiopathology. Then, the influence of bioactive nutritional compounds and physical training on these biomarkers has been studied, although the combination of both strategies has been not investigated. Therefore, our aim was to verify the effect of the association of physical training with red grape juice (Vitis labrusca) consumption on global histone acetylation H3 and H4 levels, oxidative stress markers and interleukin 6 (IL-6) levels in peripheral blood of healthy elderly women. This double-blind randomized clinical study consisted of 29 volunteers, aged 59 years and over, divided into three groups: grape juice group (GJG, n = 9); placebo and exercise group (PLEG, n = 10) and grape juice and exercise group (GJEG, n = 10). During 1 month, GJG consumed 400 ml of grape juice per day (integral and conventional), while the PLEG and GJEG groups, besides consuming juice or placebo were submitted to a concurrent physical training protocol (two times per week, 60 min / session). The volunteers were submitted to blood collections before and after the intervention for the biomarkers analysis, e.g. IL-6, histone acetylation H3 and H4, lipid oxidative damage (TBARS), proteins (Carbonyl), non-enzymatic antioxidant defense (Sulfhydryl groups) and activity of antioxidant enzymes (superoxide dismutase and catalase). There were no statistically significant differences in the global levels of histone acetylation H3 and H4 post intervention compared to the basal period as well and between groups were found. However, PLEG and GJEG showed a remarkable reduction on IL-6 levels after intervention. We also observed an increase in Carbonyl levels, SOD activities and Sulfhydryl levels comparing before and after intervention. Considering the interaction of time and groups, a significant increase in Sulfhydryl levels only in GJG was found. The physical training protocol associated or not with grape juice consumption showed anti-inflammatory effects and an influence in the antioxidant defenses (non enzymatic and enzymatic) in elderly women. However in grape juice group, without exercise, we observed an increase in non enzymatic antioxidant defense, what could be attributed to the polyphenols content. These responses seem not to be involved with histone acetylation status.

Development of a Full-Length Infectious cDNA Clone of the Grapevine Berry Inner Necrosis Virus

Grapevine berry inner necrosis virus (GINV) belongs to the genus Trichovirus in the family Betaflexiviridae. The GINV isolate LN_BETA_RS was obtained from a “Beta” grapevine (Vitis riparia × Vitis labrusca) exhibiting chlorotic mottling and ring spot in Xingcheng, Liaoning Province, China. To verify the correlation between GINV and grapevine chlorotic mottling and ring spot disease, we constructed an infectious cDNA clone of GINV isolate LN_BETA_RS using the seamless assembly approach. Applied treatments of agroinfiltration infectious cDNA confirmed systemic GINV infection of the Nicotiana occidentalis 37B by reverse transcription polymerase chain reaction (RT-PCR) and transmission electron microscopy, exhibiting chlorotic mottling symptoms on leaves. Infectious cDNA was also transmitted to new healthy N. occidentalis plants through rub-inoculation. Moreover, the cDNA clone was agroinfiltrated into “Beta” and “Thompson Seedless” grapevine plantlets, and the inoculated grapevines exhibited leaf chlorotic mottling and ringspot during the two years of observation. GINV-inoculated “Beta” grapevines had serious leaf chlorotic mottling and ringspot symptoms on the whole plant, while relatively few symptoms were observed on the leaves of agroinoculated “Thompson Seedless” grapevines in early spring and only weak ring spot gradually appeared later in the top young leaves. Our experiments fulfilled Koch’s postulates and revealed the causative role of GINV in grapevine chlorotic mottling and ring spot disease.

Protective Effect of Vitis labrusca Leaves Extract on Cardiovascular Dysfunction through HMGB1-TLR4-NFκB Signaling in Spontaneously Hypertensive Rats.

The Vitis labrusca is a grapevine that has antioxidant, neuroprotective, hepatoprotective, and anticarcinogenic activity. However, the effect of Vitis labrusca leaves on the cardiovascular system is yet to be ascertained. The present study was designed to investigate the effects of Vitis labrusca leaves extract (HP1) on cardiovascular remodeling in spontaneously hypertensive rats. Experiments were performed in rats and were randomly divided into the following groups: Wistar Kyoto rat (WKY), normal control group; spontaneously hypertensive rats (SHR), negative control group; SHR + Losa, positive control group (losartan, 10 mg/kg/daily, AT1 receptor blocker) and SHR + HP1 (100 mg/kg/daily). HP1 was orally administered daily for 4 weeks. The HP1 treatment significantly improved blood pressure, electrocardiographic parameters, and echocardiogram parameters compared to hypertensive rats. Additionally, the left ventricular (LV) remodeling and LV dysfunction were significantly improved in HP1-treated hypertensive rats. Furthermore, an increase in fibrotic area has been observed in hypertensive rats compared with WKY. However, administration of HP1 significantly attenuated cardiac fibrosis in hypertensive rats. Moreover, HP1 suppressed the expression of high mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), receptor for advanced glycation end products (RAGE), and extracellular signal-regulated kinases (ERK1/2) induced by hypertensive rats, resulting in improved vascular remodeling. Therefore, these results suggest that HP1 can improve the cardiovascular remodeling in hypertensive rats, and the mechanisms may be related to the suppressive effect of HP1 on HMGB1-TLR4-NFκB signaling in the cardiovascular system. Thus, the protective role of the traditional herbal medicine HP1 may provide new insights into the development of therapeutic drugs on the development of hypertensive cardiovascular dysfunction.

Grape juice attenuates left ventricular hypertrophy in dyslipidemic mice.

ObjectiveWe evaluated the effects of grape juice (Vitis labrusca L.) on dyslipidemia, resistance to insulin, and left ventricular hypertrophy (LVH) in mice homozygous for the absence of the LDL receptor gene (LDLr -/-) under a hyperlipidemic diet.MethodologyWe divided 30 male mice (3 months old) into three groups (n = 10); the HL group was fed a high-fat diet, the HLU group received a high-fat diet and 2 g/kg/day of grape juice, and the HLS group was fed a high-fat diet and simvastatin (20 mg/kg/day). We assessed the blood pressure profile of the mice. We also determined the levels of C-reactive protein (CRP) and lipid profile, glycemic and insulinemic profiles, and calculated the HOMA-IR. Cardiomyocyte hypertrophy, interstitial collagen deposit, and the expression of CD40 ligand (CD40L) and metalloproteinases 2 and 9 were assessed immunohistologically.ResultsAfter 60 days, the mice treated with grape juice showed similar results as those of the group treated with simvastatin. The use of grape fruit attenuated dyslipidemia and insulin resistance and significantly increased the levels of high cholesterol density lipoproteins (HDLc). The antioxidant potential of phenolic compounds associated with the increase in HDLc levels in the mice of the HLU group prevented the development of LVH and arterial hypertension since it inhibited the inflammatory response induced by the CD40 pathway and its ligand CD40L. Consequently, there was a lower expression of MMP-2 and MMP-9 and lower serum levels of CRP.ConclusionGrape juice has a hypolipidemic and cardiac protective potential, presenting a similar effect as that of simvastatin through a direct antioxidant action of phenolic compounds, or indirectly, via antioxidant action and anti-inflammatory activity of the HDLc. These results suggest that grape juice is a functional food possessing a high potential to prevent cardiovascular diseases.

Accumulation of Phenolic Compounds and Antioxidant Capacity during Berry Development in Black 'Isabel' Grape (Vitis vinifera L. x Vitis labrusca L.).

Grapes are one of the most economically important fruits in the world and are of considerable benefit to human health due to their phenolic compounds. The black ‘Isabel’ grape (V. vinifera L. x V. labrusca L.) is widely grown in the Black Sea region of Turkey, where it is attracting increasing interest. The aim of this study was to investigate phenolic compounds and antioxidant capacity (DPPH (2,2-diphenyl-1-picrylhydrazyl) and CUPRAC (CUPric Reducing Antioxidant Capacity)) in the grape during berry development, which has been not reported yet from the region. A trend towards an increase in total phenolic compounds, flavonoid, and anthocyanin contents and antioxidant capacity values was observed from un-ripened to overly ripened berries. In addition, anthocyanins in berries and proanthocyanidins seeds were characterized during berry development. Accordingly, malvidin-3-O-glucoside was the major anthocyanin in skin (1.05–1729 mg/kg fresh weight (fw)) and whole berry (0.23–895 mg/kg fw), followed by the content of peonidin-3-O-glucoside (0.98–799 mg/kg fw and 0.15–202 mg/kg fw, respectively). After veraison (onset of ripening or change of color in the grape berries), all proanthocyanidins showed a gradual decrease through ripening. The results showed that anthocyanins and proanthocyanidins in the grape showed significant stage-dependent changes with positive or negative strong correlations. Considering the phenolic compounds, an optimum harvest date of the grape might be suggested between mid-September and mid-October (263 and 293 DAFBs).

Effect of exercise and grape juice on epigenetic modulation and functional outcomes in PD: A randomized clinical trial

ObjectiveThis study aimed to investigate the impact of an aquatic physical training program associated with grape juice (Vitis labrusca) consumption on functional outcomes, Brain-Derived Neurotrophic Factor (BDNF) and global histone H4 acetylation levels in peripheral blood from individuals with Parkinson's disease. MethodsNineteen participants were randomized to Aquatic Exercise (AQ, n = 9) and Aquatic Exercise + Grape Juice (AQ+GJ, n = 10) groups and performed to 4 weeks of an aquatic intervention (twice a week, approximately 60 min/session). The AQ+GJ groups also consumed 400 mL of grape juice per day during this period. Functional capacity (six-min walk test, 6MWT), mobility (The Timed Up and Go, TUG) and the risk of falls (Berg Balance Scale, BBS) were evaluated before and after intervention. In addition, blood collections were carried out for biomarker analysis (e.g. BDNF and global histone H4). ResultsThe aquatic exercise program induced functional improvement in individuals with Parkinson's disease, specifically ameliorating their mobility and functional capacity. In addition, enhanced levels of BDNF and histone H4 acetylation were found after the intervention. Grape juice consumption did not potentiate these effects, since any significant differences between the AQ and AQ+GJ groups were not found in all analysed variables. ConclusionsThe present study provides important insights about aquatic exercise-modulated BDNF levels in individuals with Parkinson's disease in combination with functional improvements, suggesting that histone acetylation status may interact to dictate the molecular mechanisms involved in this response. Parkinson disease, aquatic exercise, BDNF, epigenetic, grape juice.

Transcriptomic Analysis of Root Restriction Effects on Phenolic Metabolites during Grape Berry Development and Ripening

In the present study, the effects of root restriction (RR) on the main phenolic metabolites and the related gene expression at different developmental stages were studied at the transcriptomic and metabolomic levels in "Summer Black" grape berries (Vitis vinifera × Vitis labrusca). The results were as follows: seven phenolic acid compounds, three stilbene compounds, nine flavonol compounds, 10 anthocyanin compounds, and 24 proanthocyanidin compounds were identified by ultra-performance liquid chromatography-high-resolution mass spectrometry. RR treatment significantly promoted the biosynthesis of phenolic acid, trans-resveratrol, flavonol, and anthocyanin and also affected the proanthocyanidin content, which was elevated in the early developmental stages and then reduced in the late developmental stages. The functional genes for phenylalanine ammonia-lyase, trans-cinnamate 4-monooxygenase, 4-coumarate-CoA ligase, shikimate O-hydroxycinnamoyl transferase, chalcone synthase, chalcone isomerase, stilbene synthase, flavonoid 3',5'-hydroxylase, anthocyanidin 3-O-glucosyltransferase, and the transcription factors MYBA1, MYBA2, MYBA3, and MYBA22 were inferred to play critical roles in the changes regulated by RR treatment.

Colletotrichum species causing grape ripe rot disease in Vitis labrusca and V. vinifera varieties in the highlands of southern Brazil

AbstractRipe rot is one of the most important bunch diseases of grapes in the highlands of southern Brazil and a matter of concern for winegrowers. Sixty‐one strains isolated from berries of Vitis labrusca and V. vinifera varieties with symptoms were classified by phylogenetic analysis of the sequences of β‐tubulin, glyceraldehyde‐3‐phosphate dehydrogenase, D1/D2 domain of 28S rDNA, and rDNA internal transcribed spacer. They were also characterized by morphology, and their pathogenicity was evaluated. The combined molecular data allowed identification of six Colletotrichum species: C. fructicola, C. kahawae and C. viniferum (gloeosporioides complex), C. limitticola, C. nymphaeae (acutatum complex), and C. karstii (boninense complex). This is the first report of C. karstii and C. limitticola associated with the ripe rot of grapes. Morphological characteristics varied within and among species, confirming their separation at the complex level. Pathogenicity tests on V. vinifera berries showed that the most prevalent species, C. viniferum (37.8%) and C. fructicola (36.1%), were more virulent than the less prevalent species C. limitticola and C. karstii. Our findings indicate that there is a high diversity of Colletotrichum species associated with ripe rot disease of grapes in Brazil. There were no clear differences in the distribution of Colletotrichum species between V. labrusca and V. vinifera varieties. The determination of fungal species responsible for grape ripe rot in Brazilian vineyards may contribute to further epidemiological studies and the development of more efficient prophylactic methods for ripe rot management.

The Relationship Between Bud Size and Exotherm Formation in Dormant Buds of Grapevine

This study was conducted to determine the relationship between bud size and low temperature exotherm (LTE) formation in dormant period of grapevines. For this purpose, primary and secondary buds of Karaerik (Vitis vinifera L.) and 53 Pazar 01 (Vitis labrusca) genotypes which are known to have differences between the bud structure and size, were examined separately. In the study carried out in 2016-2017 and 2017-2018 dormant periods, low temperature exotherms were determined by Differential Thermal Analysis (DTA) method in order to determine the freezing point of the buds. Dormant buds of grapevine size were determined by microscopic imaging of the sections taken after histological procedures. It was demonstrated by the DTA test that the buds with different histological structures had different character and number of LTE. In this study, it was determined that bud samples belonging to Vitis vinifera L. form exotherm at lower temperatures than bud samples belonging to Vitis labrusca species. For both genotypes, it was determined by the histological determinations that the primary buds had a larger structure than the secondary buds. In the study, it was found that the buds with an area less than 0.010 mm2 did not produce LTE. As a result of the study, it was found that the bud structure and size were effective on LTE formation of grapevine dormant buds.

Application of tamarind seed starch as edible coating in the post-harvest quality of grapes ‘Isabel’ (Vitis labrusca × Vitis vinifera L.)

The Isabel grape (Vitis labrusca × Vitis vinifera L.) is the most produced grape in Brazil, however, it has a short postharvest period due to rapid degradation during storage. The use of coating has been an alternative to prolong the shelf-life of fruits. The objective of this work was to evaluate the postharvest quality of 'Isabel' grapes coated with tamarind (Tamarindus indica L.) seed starch. The experimental design was completely randomized with five treatments with edible coating based on tamarind seed starch, at concentrations of 0, 0.5, 1, 1.5 and 2% and five replications. The grapes were immersed in the solutions with different concentrations and stored in B.O.D. at 12 ± 2 ° C and 85 ± 5% relative humidity for 12 days. Weight loss, color, pH, soluble solids, total titratable acidity, relationship between soluble solids and acidity, anthocyanins, flavonoids and vitamin C were evaluated. The 2% coating of tamarind seed starch was the most efficient, providing shelf life in 12-day grapes when stored at 12 ± 2 ° C and 85 ± 5% RH, and maintaining the main quality aspects, with higher SS / TA ratio and vitamin C.