Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GRAPES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMed1993

Endothelium-dependent vasorelaxing activity of wine and other grape products.

Current interest in the presumed benefits of wine in protecting against coronary heart disease prompted us to investigate possible effects of various grape products on vascular function in vitro. Certain wines, grape juices, and grape skin extracts relaxed precontracted smooth muscle of intact rat aortic rings but had no effect on aortas in which the endothelium had been removed. Quercitin and tannic acid, compounds known to be present in grape skins, also produced endothelium-dependent relaxation; two other grape skin compounds, resveratrol and malvidin, did not relax the rings. Phenylephrine-induced contractions were attenuated by prior exposure of aortic rings to grape skin extracts. The extracts also increased guanosine 3',5'-cyclic monophosphate (cGMP) levels in intact vascular tissue, and both relaxation and the increase in cGMP were reversed by NG-monomethyl-L-arginine and NG-nitro-L-arginine, competitive inhibitors of the synthesis of the endothelium-derived relaxing factor, nitric oxide (NO). The vasorelaxation induced by grape products therefore appears to be mediated by the NO-cGMP pathway. If such responses occur in vivo, they could conceivably help to maintain a patent coronary artery and thereby possibly contribute to a reduced incidence of coronary heart disease.

Animals↗
PubMed2005

Antihypertensive and cognitive effects of grape polyphenols in estrogen-depleted, female, spontaneously hypertensive rats.

Both endogenous and dietary estrogens reduce hypertension and enhance cognitive abilities in estrogen-depleted female spontaneously hypertensive rats (SHR). Many of the beneficial effects of estrogens/phytoestrogens also appear to be provided by other polyphenols (e.g., proanthocyanidins) in grape seed, which lack appreciable estrogenic receptor binding. The present study tested the hypothesis that similar to phytoestrogens, proanthrocyanidins in grape seed polyphenols reduce salt-sensitive hypertension in young, estrogen-depleted SHR. SHR were ovariectomized at 4 wk of age and placed on phytoestrogen-free diets with or without 0.5% grape seed extract added and with high (8.0%) or basal (0.6%) NaCl. After 10 wk on the diets, grape proanthrocyanidin supplementation significantly reduced arterial pressure in the rats fed the basal (10 mmHg) and high (26 mmHg)-NaCl diet, compared with the nonsupplemented controls. In vitro superoxide production was significantly reduced (23%) by the grape seed polyphenols. Spatial learning (8-arm-radial maze) in the SHR on the basal NaCl diets was improved by dietary grape seed polyphenols. These results indicate that grape seed polyphenols decrease arterial pressure in SHR, probably via an antioxidant mechanism.

Animals↗
PubMed2006

Changes in grape phylloxera abundance in ungrafted vineyards.

To examine seasonal changes in the abundance of grape phylloxera Daktulosphaira vitifoliae (Fitch), several sampling methods were tested at vineyards in Victoria, Australia. At a recently infested site, changes detected by root assessment, trunk trapping, and emergence trapping were closely correlated, although the largest numbers of grape phylloxera were obtained using traps that collected phylloxera emerging from soil. This trapping technique was further used to investigate changes in grape phylloxera numbers across three different sites from southeastern Australia as well as in three consecutive seasons at the same vineyard. Grape phylloxera numbers decreased as vines deteriorated; a single peak of emergence occurred in every summer. Size and timing of emergence peaks varied between sites and also between vine blocks within a site. The number of grape phylloxera trapped was correlated with degree-days. Monitoring soil temperature may provide a way of timing control options against grape phylloxera and a way of identifying peak periods when phylloxera detection surveys should be completed or when grape phylloxera are at the highest risk of spreading among vineyards.

Animals↗
PubMed1999

Dietary tomato and grape pomace in rats: effect on lipids in serum and liver, and on antioxidant status.

Addition of tomato and grape pomace to the cholesterol (0.3%) diet of male Wistar rats produced a dose-dependent effect. During the eight-week experiment, 5% pomace showed no effect; however, 15% pomace reduced serum cholesterol levels from 4.4 mmol/L to 2.5 mmol/L (tomato) and 2.0 mmol/L (grape). At a concentration of 15%, both tomato and grape pomace induced a redistribution of cholesterol in lipoproteins, resulting in a pronounced anti-atherogenic profile: reduced cholesterol concentration in very-low-density lipoprotein (VDL) (24% [tomato], 50% [grape]) and low-density lipoprotein (LDL) (3-fold, 3.6-fold). In addition, grape pomace increased cholesterol concentration in high-density lipoprotein (HDL) by 26%. Both types of pomace reduced the VLDL and LDL contribution to cholesterol transport in favour of HDL. Grape pomace (15%) produced a significant reduction in cholesterol and triacylglycerols in the liver and serum respectively. Diets containing tomato and grape pomace reduced plasma levels of conjugated dienes by 30-50%, and showed a tendency towards higher superoxide dismutase and glutathione peroxidase activity in the liver.

Animals↗
PubMed2005

Effects of plant phenolics and grape extracts from Greek varieties of Vitis vinifera on Mitomycin C and topoisomerase I-induced nicking of DNA.

In recent years, a number of reports have shown the anticancer activity of grape extracts and wine against various types of cancer such as breast, lung and gastric cancer. This property is mainly attributed to the plant polyphenols identified in grapes. The aim of the present study was to investigate the mechanisms by which grape extracts and plant polyphenols found in them exert their chemopreventive and antitumour activities. Thus, aqueous and methanolic extracts from two Greek varieties of Vitis vinifera, fractions enriched in polyphenols of these extracts and polyphenolics (caffeic acid, ferulic acid, gallic acid, protocatechuic acid and rutin) found in grapes were screened using two in vitro assays: i) the topoisomerase I relaxation assay and ii) the mitomycin C-induced DNA strand breakage. The grape extracts, the polyphenol-rich fractions and some of the polyphenolics (caffeic acid and protocatechuic acid) were potent inhibitors of topoisomerase I, indicating that the inhibition of this enzyme may be one of the mechanisms accounting for the anticancer activity of these compounds. Moreover, the grape extracts inhibited the mitomycin C-induced DNA strand breakage suggesting that they could prevent ROS-mediated DNA damage. On the other hand, the polyphenol-rich fractions and the plant polyphenols enhanced the mitomycin C-induced DNA strand breakage indicating prooxidant activity. Thus, it is of interest that whole grape extracts act as chemopreventive agents by inhibiting topo I and mitomycin C-induced DNA damage, while polyphenol enriched fractions and plant polyphenolics exert prooxidant activity leading to enhancement of DNA damage which may account for the cytotoxic and apoptosis-inducing properties of plant polyphenols against cancer cells.

DNA Damage↗
PubMedDate not supplied

Determination of spiroxamine residues in grapes, must, and wine by gas chromatography/ion trap-mass spectrometry.

Analytical methodology was developed and validated for the determination of spiroxamine residues in grapes, must, and wine by gas chromatography/ion trap-mass spectrometry (GC/IT-MS). Two extraction procedures were used: the first involved grapes, must, and wine extraction with alkaline cyclohexane-dichloromethane (9 + 1, v/v) solution, and the second grape extraction with acetone, dichloromethane, and petroleum ether. In both procedures, the extract was centrifuged, evaporated to dryness, and reconstituted in cyclohexane or 2,2,4-trimethylpentane-toluene (9 + 1, v/v), respectively. Spiroxamine diastereomers A and B were determined by GC/IT-MS, and a matrix effect was observed in the case of grapes but not in must and wine. Recovery of spiroxamine from fortified samples at 0.02 to 5.0 mg/kg ranged from 78-102% for grapes and must, with relative standard deviation (RSD) <13%; for red and white wines, recoveries ranged from 90 to 101% with RSD <9%. The limit of quantification was 0.02 mg/kg for grapes, must, and wine or 0.10 mg/kg for grapes, depending on the extraction procedure used.

Acetone↗
PubMed2006

[Anti-dementia effects of grape peel extracts experiment study].

OBJECTIVE: To study anti-dementia effects and mechanism of grape peel extracts on imitative dementia rats modle. METHODS: The imitative dementia rats modle were established using health male Wistar rats by intraperitoneal injection of D-galactose and NaNO2, simultaneity, administer physiological saline solution, Piracetam Tablets, low dose grape peel extracts, middle dose grape peel extracts, high dose grape peel extracts to intervene separately. Using neurobehavioral tests, antioxidation genus, cholinesterase genus and nitric oxide synthase, histopathological and morphological parameters and immunohistochemical methods etc measure index to observe and evaluate. RESULTS: Grape peel extracts can significantly ameliorate learning and memory function of imitative dementia rats modle, and improve SOD enzyme, NOS enzyme, CAT enzyme activity in rats brain, inhibite MDA enzyme, AchE enzyme activity, reduce the expression of beta-APP-positive immunoreactive neurocytes (beta-APP+) and beta-amyloid-positive immunoreactive neurocytes (beta-AP+) in cerebra cortex and Hippocampus. CONCLUSION: Grape peel extracts can inhibite oxygen free radicel to form, ameliorate cholinomimetic neural function, enhance NOS enzyme activity in the hippocampus and cerebra cortex, reduce the development of beta-AP deposited macula, grape peel extracts probability have a preventive action against early-aged dementia.

Animals↗
PubMed1994

A special-purpose computer for molecular dynamics: GRAPE-2A.

Molecular dynamics simulations have been extensively used in research of proteins. Since these simulations are quite computer intensive, their acceleration is of main interest of the research. In molecular dynamics simulations, almost all computing time is consumed in calculating the forces between particles, e.g., Coulomb and van der Waals forces. We have designed and built GRAPE-2A (GRAvity PipE 2A), a special-purpose computer for use in simulations of classical many-body systems. GRAPE-2A calculates forces exerted on a particle from the other particles. GRAPE-2A can calculate force of an arbitrary functional form of a central force. The host computer, which is connected to GRAPE-2A through the VME bus, performs other calculations such as time integration. The peak speed of GRAPE-2A is 180 Mflops. We can also stimulate systems with periodic boundary conditions by the Ewald method, using GRAPE-2A and another special-purpose computer, WINE (Wave space INtegrator for the Ewald method).

Computer Simulation↗
PubMed1996

Mutagenicity of white grape juice in the Ames test.

The mutagenicity of commercially available white grape juice was evaluated in the Ames mutagenicity test. Grape juice elicited a positive mutagenic, response in Salmonella typhimurium strain TA104 and a weaker response in strains TA97, TA98, TA100 and TA1530. The mutagenic response was evident in the absence of an activation system and inclusion of such a system did not influence mutagenicity. The grape juice-mediated mutagenic response was not due to histidine residues in the juice or likely treatment with sulfite. Moreover, freshly prepared grape juice displayed a similar mutagenic response. Three different brands of commercially available white grape juice were investigated in the Ames test; they all provoked a clear positive mutagenic response, but the degree of mutagenicity differed and could not be attributed to differences in the content of solids. It is concluded that grapes contain direct-acting genotoxic component(s).

Beverages↗
PubMed2006

Effect of intra and interspecific interaction on OTA production by A. section Nigri in grapes during dehydration.

The aim of this study was to assess the colonizing capability and OTA production of different populations of Aspergillus section Nigri spp. in grapes, as affected by the interactions with other fungi, during a simulated in vitro sun-drying. Mature white grapes were divided into two lots of healthy and artificially injured grapes and inoculated with A. section Nigri spp. (A. carbonarius OTA producer, A. niger aggregate OTA producer, A. niger aggregate OTA non-producer), Eurotium amstelodami and Penicillium janthinellum, in different combinations. The drying process was simulated adjusting water activity firstly at 0.98 a(w) and gradually decreasing it to 0.76 a(w) for a total of 20 days. Colonizing grape percentages were recorded after 5, 10, 15 and 20 days of dehydration and OTA content was measured after 5, 7, 10, 12, 15, 17 and 20 days. Colonization of grapes increased with time in all treatments. A. niger aggregate OTA-positive showed the highest colonization percentage, followed by A. carbonarius, and finally their mixed inoculum. When the two OTA-producing strains were combined, addition of any other microorganism increased the percentage of infection by A. section Nigri. A. carbonarius was the highest OTA producer in pure culture, followed by A. niger aggregate OTA-positive. In general, when competing fungi were added to A. carbonarius inoculum, the OTA content was reduced. E. amstelodami was the only competing fungus which increased OTA accumulation. The sun-drying process may be conducive to OTA accumulation in dried grapes. The complex fungal interactions which may take place during this process, may act as an additional control factor, given that the higher presence of A. niger aggregate OTA-negative inhibits OTA accumulation by OTA producing species.

Antibiosis↗
PubMed2006

Occurrence of ochratoxin A in wine and ochratoxigenic mycoflora in grapes and dried vine fruits in South America.

Grape and wine production in South America represents about 6.6% and 10% respectively of the world grape and wine production. The available information on the ochratoxigenic mycoflora and ochratoxin A (OTA) presence in wine grapes, wines, grape juices and dried vine fruits is limited. Surveys have been carried out in Argentina and Brazil which showed that Aspergillus niger aggregate are predominant in the Argentinean varieties while from the Brazilian varieties the species A. niger, Aspergillus ochraceus and Aspergillus carbonarius were isolated. A mycobiota survey from wine grapes in Argentina showed that while Alternaria alternata was predominant, Aspergillus section Nigri species were isolated from 60% of samples. About 41% of black Aspergilli isolates produced OTA with levels ranging from 2 to 24.5 ng mL(-1). In another study, about 83% of A. carbonarius isolates from dried vine fruits produced OTA, with levels ranging from 2 to 5200 ng mL(-1). A survey of grape juices and wines of Brazilian, Argentinean and Chilean origin were found to contain very low levels of OTA. Studies are in progress in Latin America on the ecophysiology of ochratoxigenic fungi and OTA occurrence to reduce the impact of this toxin in the food chain.

Aspergillus↗
PubMed2006

Occurrence of ochratoxigenic fungi and ochratoxin A in grapes from a Tunisian vineyard.

The occurrence of ochratoxin A (OTA) and the identification of the ochratoxigenic microbiota in Tunisian grapes were studied for the first time. Black aspergilli were the dominant genus among the filamentous fungi isolated from grapes and were the only potential OTA-producing fungi found. The most abundant species were member of Aspergillus niger aggregate (63%) and Aspergillus carbonarius (36%). Uniseriate aspergilli were rarely present (1%). Of the A. carbonarius isolates, 97% were OTA positive but only 3% of the A. niger aggregate isolates were OTA positive. During grape maturation, the frequency of black aspergilli increased due to increase of the numbers of A. carbonarius. Musts (n=24) obtained from grapes collected at the different sampling times were analyzed for their OTA content. Up to 37% of the musts contained OTA at levels varying between 0.59 and 2.57 microg/l. The amounts of OTA in musts increased as grapes matured. These results indicate that A. carbonarius is the main cause of OTA contamination of Tunisian grapes.

Aspergillus↗
PubMed2006

Effect of in vitro gastric and duodenal digestion on the allergenicity of grape lipid transfer protein.

BACKGROUND: Severe grape allergy has been linked to lipid transfer protein (LTP) sensitization. LTPs are known to be resistant to pepsin digestion, although the effect of gastroduodenal digestion on its allergenicity has not been reported. OBJECTIVE: We sought to investigate the effect of gastric and gastroduodenal digestion on the allergenic activity of grape LTP. METHODS: The proteolytic stability of grape LTP was investigated by using an in vitro model of gastrointestinal digestion. The allergenicity of LTP and its digesta was assessed in vitro by means of IgE immunoblotting, RASTs, and in vivo skin prick tests in the same patients with grape allergy. RESULTS: Grape LTP was resistant to gastric digestion, and yielded a 6000-d relative molecular mass C-terminally trimmed fragment after duodenal digestion. This fragment retained the in vitro IgE reactivity of the intact protein. Inclusion of phosphatidylcholine during gastric digestion protected the LTP to a limited extent against digestion. Digestion did not affect the in vivo (skin prick test) biologic activity of LTP. CONCLUSION: The allergenic activity of grape LTP was highly resistant to in vitro digestion. This property might facilitate sensitization through the gastrointestinal tract and might also potentiate the ability of LTPs to elicit severe allergic reactions in sensitized individuals. CLINICAL IMPLICATIONS: Purified natural allergens will facilitate the development of component-resolved diagnostic approaches, including allergen chips. This study contributes to our understanding of the role digestion plays in symptom elicitation in true food allergy.

Allergens↗
PubMed2005

Rejuvenation of antioxidant system in central nervous system of aged rats by grape seed extract.

Oxidative stress is considered as a major risk factor that contributes to age-related increase in lipid peroxidation and declined antioxidants in the central nervous system during aging. Grape seed extract, one of the bioflavonoid, is widely used for its medicinal properties. In the present study, we evaluated the role of grape seed extract on lipid peroxidation and antioxidant status in discrete regions of the central nervous system of young and aged rats. Male albino rats of Wistar strain were divided into four groups: Group I-control young rats, Group II-young rats treated with grape seed extract (100 mg/kg body weight) for 30 days, Group III-aged control rats and Group IV-aged rats supplemented with grape seed extract (100 mg/kg body weight) for 30 days. Age-associated increase in lipid peroxidation was observed in the spinal cord, cerebral cortex, striatum and the hippocampus regions of aged rats (Group III). Activities of antioxidant enzymes like superoxide dismutase, catalase, glutathione peroxidase and levels of non-enzymic antioxidants like reduced glutathione, Vitamin C and Vitamin E were found to be significantly decreased in all the brain regions studied in aged rats when compared to young rats. However, normalized lipid peroxidation and antioxidant defenses were reported in the grape seed extract-supplemented aged rats. These findings demonstrated that grape seed extract enhanced the antioxidant status and decreased the incidence of free radical-induced lipid peroxidation in the central nervous system of aged rats.

Aging↗
PubMed2005

Mycotoxin-producing and other fungi isolated from grapes for wine production, with particular emphasis on ochratoxin A.

Mycotoxins are toxic secondary metabolites produced by filamentous fungi that have been detected in food commodities, including grapes and wine. A survey was conducted to assess mycotoxin-producing fungi in grapes destined for wine production. The mycotoxigenic capacity of the isolates was tested in culture media. Grapes were analyzed by plating methods from 4 Portuguese wine-growing regions at 3 maturation stages (pea berry, early veraison and ripe berry) between 2001 and 2003. From the 10,602 strains detected and identified, the most frequent genera were Cladosporium (25%), Alternaria (24%), Botrytis (15%), Penicillium (9%) and Aspergillus (8%). Most (92.0%) were non-mycotoxigenic or produced mycotoxins of unknown relevance to health. Potential producers of ochratoxin A (OTA) (Aspergillus niger aggregate, 5.4%, Aspergillus carbonarius, 0.6%) and trichothecenes (Fusarium spp., 0.4%; Trichothecium roseum, 0.8%) were the most frequent mycotoxigenic species isolated from grapes. OTA was detected in all cultures of A. carbonarius and 4% of A. niger aggregate strains. There was potential for OTA and trichothecene production in grapes by A. carbonarius and T. roseum, respectively, prior to harvest time. Data presented herein indicate that A. carbonarius is most likely to occur in vineyards with Mediterranean climates, while T. roseum is more likely to occur in more temperate climates, and is associated with gray rot. The present work emphasizes the need to use grapes under good condition so as to reduce the risk of contamination with mycotoxigenic fungi and subsequent mycotoxin occurrence in wine.

Aspergillus↗
PubMed2000

Inhibition of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse skin ornithine decarboxylase and protein kinase C by polyphenolics from grapes.

Ornithine decarboxylase is the rate-limiting enzyme in the biosynthesis of polyamines, which are believed to play an essential role in diverse biological processes including cell proliferation and differentiation. We have previously reported [J. Bomser, K. Singletary, M. Wallig, M. Smith, Inhibition of TPA-induced tumor promotion in CD-1 mouse epidermis by a polyphenolic fraction from grape seeds, Cancer Letters 135 (1999) 151-157] that pre-application of a grape polyphenolic fraction (GPF) to mouse skin epidermis inhibits 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ornithine decarboxylase (ODC) activity, as well as 7, 12-dimethylbenz[a]anthracene (DMBA)-initiated, TPA-promoted mouse skin tumorigenesis. The present studies were designed to further characterize the effect of time and dose of application of GPF on TPA-induced ODC activity and protein expression, and on protein kinase C activity in mouse skin epidermis. In addition, the effect of GPF on ODC kinetics in vitro was examined. Application of 5, 10, and 20 mg of GPF 20 min prior to treatment with TPA resulted in a significant decrease in epidermal ODC activity of 54, 53, 90%, respectively, compared with controls. Yet, ODC protein levels (Western blot) in the 10 and 20 mg GPF groups were significantly increased by 1.8 and 1.9-fold, respectively, compared with controls. A similar response was observed with the ODC inhibitor 2-difluoromethylornithine (DFMO), which served as a positive control. Application of grape polyphenolics (20 mg) at 60 and 30 min prior to treatment with TPA inhibited ODC activity by 62 and 68%, respectively, compared with controls (P<0.05). In contrast, application of grape polyphenolics (20 mg) at 60, 120 and 240 min after treatment with TPA resulted in no significant changes in ODC activity. A similar increase in epidermal ODC protein was observed in these GPF-treated animals, similar to that observed when GPF application preceded TPA. When applied to mouse skin prior to TPA, GPF was associated with a decrease in subsequent PKC activity compared with controls at 10 and 30 min following TPA treatment. The GPF-associated decrease in PKC activity preceded the decrease in ODC activity. In a separate in vitro study, kinetic analyses indicated that GPF is a competitive inhibitor of ODC activity. Collectively these data suggest that the grape polyphenolic fraction is effective as an inhibitor of ODC activity when applied before TPA, and that the magnitude of inhibition is independent of epidermal ODC protein content. In addition, GPF is a competitive inhibitor of ODC activity in vitro. The decrease in TPA-induced ODC activity due to GPF treatment is preceded by an inhibition of TPA-induced PKC activity. Thus, the polyphenolic fraction from grapes warrants further examination as a skin cancer chemopreventive agent that interferes with cellular events associated with TPA promotion.

Animals↗
PubMed1999

Quantitative determination of free and hydrolytically liberated beta-damascenone in red grapes and wines using a stable isotope dilution assay.

Quantitative analysis of free and hydrolytically liberated beta-damascenone in grapes and wines was developed, using a stable isotope dilution assay. Free beta-damascenone was isolated from grapes and wines by diethyl ether-hexane (1:1, v/v) extraction and the precursor(s) (glycosidic, polyols) of beta-damascenone using Sep-Pak Plus C18 RP cartridges. Hydrolytically liberated beta-damascenone was generated by acid hydrolysis from the precursor(s) extract. Red wines from Bordeaux (Merlot, Cabernet Sauvignon and Cabernet Franc, 1995 and 1996 vintage), Burgundy (Pinot Noir, 1995 and 1996 vintage) regions and Grenache wines from Chateauneuf du Pape and Côtes du Rhône (1995 vintage) were analysed to quantify free beta-damascenone. The wines made from Grenache and Cabernet Sauvignon (1996 vintage) grapes presented the highest mean amounts of free beta-damascenone, 5.4 and 5.5 micrograms l-1, respectively. Merlot, Cabernet Sauvignon and Cabernet Franc grapes of Bordeaux (1996 vintage) and their corresponding wines were analysed for quantification of free and hydrolytically liberated beta-damascenone. The levels of hydrolytically liberated beta-damascenone in grapes could predict closely the levels of free beta-damascenone in the corresponding wines after one year of ageing, i.e., almost half the levels found for the grape samples. The influence of enzyme and heat treatment of Merlot wine samples on their beta-damascenone levels was studied. Heat treatment doubled the levels of this compound, but enzyme treatment generated, in the corresponding wines, half the levels of beta-damascenone found in the non-enzyme treated wines.

Gas Chromatography-Mass Spectrometry↗
PubMed2003

Genetic structure and differentiation in cultivated grape, Vitis vinifera L.

222 cultivated (Vitis vinifera) and 22 wild (V. vinifera ssp. sylvestris) grape accessions were analysed for genetic diversity and differentiation at eight microsatellite loci. A total of 94 alleles were detected, with extensive polymorphism among the accessions. Multivariate relationships among accessions revealed 16 genetic groups structured into three clusters, supporting the classical eco-geographic grouping of grape cultivars: occidentalis, pontica and orientalis. French cultivars appeared to be distinct and showed close affinity to the wild progenitor, ssp. sylvestris from south-western France (Pyrenees) and Tunisia, probably reflecting the origin and domestication history of many of the old wine cultivars from France. There was appreciable level of differentiation between table and wine grape cultivars, and the Muscat types were somewhat distinct within the wine grapes. Contingency chi2 analysis indicated significant heterogeneity in allele frequencies among groups at all loci. The observed heterozygosities for different groups ranged from 0.625 to 0.9 with an overall average of 0.771. Genetic relationships among groups suggested hierarchical differentiation within cultivated grape. The gene diversity analysis indicated narrow divergence among groups and that most variation was found within groups (approximately 85%). Partitioning of diversity suggested that the remaining variation is somewhat structured hierarchically at different levels of differentiation. The overall organization of genetic diversity suggests that the germplasm of cultivated grape represents a single complex gene pool and that its structure is determined by strong artificial selection and a vegetative mode of reproduction.

Genetic Variation↗