3,889 research outputs found

    Effects of the inoculation with arbuscular mycorrhizal (AM) fungus of the genus Glomus on growth and leaf mineral concentrations of grapevine (Vitis vinifera cv. Cabernet Sauvignon)

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    The effects of root inoculation with mycorrhizal fungi (genus Glomus) on growth and leaf mineral concentrations of grapevine (Vitis vinifera cv. Cabernet Sauvignon) were studied under the growth conditions of Central Chile. Inoculation enhanced the uptake of N and K and vegetative growth but decreased the foliar concentration, but not necessarily the uptake of P

    Projected Climate Change Impacts on Grape Growing in the Okanagan Valley, British Columbia, Canada

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    A statistical analysis was conducted on long-term climate records in the Okanagan Valley wine grape growing region of British Columbia, Canada. No observable trends for average annual temperatures were found in the region. Analyses of monthly mean and extreme temperatures show wide spatial and temporal heterogeneity, indicating that future studies using downscaling of global climate models for this region will require resolutions on the order of several kilometers. Mean winter temperatures are increasing throughout the valley, and extreme minimum temperatures are also increasing during the winter at the central and northern sites which have historically presented the most risk of winter damage to grapevines. Only the most southern and northern sub-regions are expected to see significant changes in their heat unit accumulations during the growing season. Over the coming century, the southern end of the valley will likely move from Winkler heat unit region 1 to 2. All regions of the Okanagan will continue to have latitude-temperature indices among the lowest of the world's fine table wine producing regions over the coming century. Growing season and dormant season average temperatures are expected to change by only a modest amount by 2100. Current climate maturity groupings for ripening grape varieties will likely stay constant at cool (central and southern areas) and intermediate (south-central) for all sites except Osoyoos (south). The climate trendings at Osoyoos suggest it will transition from an intermediate to a warm grouping by about 2050. The early to mid-season ripening capacity of the region may improve due to climate changes, but there is a risk of the asymmetric late season increases in minimum daily temperatures lowering the daily temperature range at some sites, possibly leading to difficulties in maintaining a balanced between sugar and sensory profiles as wine grapes approach maturity. The projected warming at the southern end of the valley should favor improved and increased Merlot production, will require Chardonnay production to shift northwards, and will allow growing of warmer climate wine grape varieties currently inaccessible because of low winter temperatures and a lack of growing season heat units. Increasing winter temperatures throughout the region are expected to result in increased risk of pests such as Pierce’s disease

    Control of anthocyanin biosynthesis pathway gene expression by eutypine, a toxin from Eutypa lata, in grape cell tissue cultures

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    Eutypine, 4-hydroxy-3-(3-methyl-3-butene-1-ynyl) benzaldehyde, is a toxin produced by Eutypa lata, the causal agent of Eutypa dieback in grapevine. The effect of the toxin on anthocyanin synthesis has been investigated in Vitis vinifera cv. Gamay cell cultures. At concentrations higher than 200 μmol/L, eutypine reduced anthocyanin accumulation in cells. The reduction in anthocyanin accumulation was proportional to the eutypine concentrations and HPLC analysis showed that eutypine affected the levels of all anthocyanins. The effect of eutypine application on the expression of five genes of the anthocyanin biosynthesis pathway, including chalcone synthase (CHS), flavonone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), leucoanthocyanidin dioxygenase (LDOX), and UDP glucose- flavonoid 3-O-glucosyl transferase (UFGT) was determined. Expression of CHS, F3H, DFR and LDOX was not affected by the addition of eutypine to grapevine cell cultures. In contrast, expression of the UFGT gene was dramatically inhibited by the toxin. These results suggest that in grapevine cell cultures, eutypine strongly affects anthocyanin accumulation by inhibiting UFGT gene expression. The mechanism of action of eutypine is discussed

    Immunodetection of chitinase-like and beta-1,3-glucanase-like proteins secreted in vitro by embryogenic and non-embryogenic cells of grapevines

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    Research NoteEmbryogenic and non-embryogenic cell lines were obtained from the rootstock 41B (Vitis vinifera cv. Chasselas x V. berlandieri). A few extracellular proteins from culture media of embryogenic and non-embryogenic grapevine cell lines during multiplication showed a positive reaction with anti-chitinase antibodies (embryogenic cell lines) and anti-β-1,3-glucanase antibodies (non-embryogenic cell lines)

    Descripción y comparación ampelográfica de cepas de Vitis vinifera L., cv. Albariño adultas (Procedentes de estaquillado de cepas viejas), de propagación in vitro y de semilla, cuando tienen un año

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    Research NoteDescription and ampelographic comparison of mature stock of Vitis vinifera cv. Albarino (from cutting of old stock), in vitro propagation and seeds after one yea

    ANTIOXIDANT POTENTIAL ACTIVITY, IN VITRO, OF THE GRAPE SKIN AND SEEDS OBTAINED AFTER THE FIRST STAGE OF VINIFICATION FROM VITIS VINIFERA CV. TANNAT AND VITIS LABRUSCA CV. BORDEAUX.

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    The analysis of antioxidant potential activity, from skins and seeds of the species Vitis vinifera cv. Tannat and Vitis labrusca cv. Bordeaux, obtained after the first stage of fermentation of their respective wines, performed from crude ethanol extract. Dried skins and seeds of the species Vitis vinifera cv. Tannat and Vitis labrusca cv. Bordeaux, obtained after the first stage of fermentation of their respective wines, analyzed for antioxidant potential. For that, a crude ethanol extract made. First, a Liquid Chromatography High Efficiency (HPLC) method was developed for detection and confirmation of the presence of the compounds responsible for antioxidant potential in grapes The antioxidant potential was verified using three types of tests: DPPH (2,2-diphenyl-1-picrylhydrazyl), phosphomolybdenum complex, and lipid peroxidation (TBARs- thiobarbituric acid). The results showed that even though there is an extraction of phenolic compounds during alcoholic fermentation, the remaining material still possesses various phenolic compounds that maintain their antioxidant characteristics. Antioxidation capabilities were more active with DPPH, then in lipid peroxidation, and the lowest result concerning the standards analyzed with phosphomolybdenum method. Statistical analysis showed no significant difference between the 5% level between the two varieties studied. These results show the presence of compounds with antioxidant activity in the waste from winemaking and for this reason, the analyzed material is promising for use in various pharmaceutical fields such as medicines, cosmetic and food technology. The present study aimed to clarify the existence of antioxidative properties in the wine waste thus adding value to the residue

    Volatile Messenger of Death - Grapevine Fatty Acid Hydroperoxide Lyase Acts in Cell-Death Related Immunity

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    Grapevine is a widespread and valuable agricultural crop, but easily infected by plant pathogens. Oxylipins are fatty acid-derived compounds acting as important signal molecules in plant responses to biotic and abiotic stresses

    Effect of cluster thinning on fruit composition of Vitis vinifera cv. Pinot noir (Vitis vinifera L.)

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    The technique of cluster thinning is being used in aim to reduce the crop load of vine in order to improve the quality of grapes. The aim of the trial was determination the optimal timimg for thinning regarding the results given from chemical analysis of the must immediately after the harvest. The experiment was conducted at the experimental station of the Faculty of Agriculture in Zagreb in 2006 and 2007 years, on cv. Pinot noir according to the random block design system. The cluster thinning was performed with 40 % intensity in three terms; immediately after the flowering period (P1), three weeks after the flowering period (P2) and with the begining of veraison (P3). The results were compared with the results of the control treatement without cluster thinning performance. The analysis of variance of given data has shown a significant difference in must composition between the terms of cluster thinning and a control treatement, and yield per vine has not been reduced with earlyer term of cluster thinning

    Viticulture in Warmer Climates: Mitigating Environmental Stress in Douro Region, Portugal

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    There is evidence that temperatures all over the planet are increasing slowly but steadily. The projections for the Mediterranean basin indicate a strong warming and decreased precipitation, especially in summer, and they are not favorable for agriculture in general and, in particular, for viticulture, which is a very climate-sensitive system. The vineyards of Douro Demarcated Region, located in the northeastern Portugal, are grown in marginal conditions, and the expected daily higher temperatures and decreased rainfall are bound to affect the yield and wine quality. Touriga Nacional and Tinta Roriz are two of the most valuable varieties for high-end wines of Douro, and they were subjected to a number of experiments on mitigation techniques to counteract the worse effects of adverse weather conditions. Irrigation, canopy shading, water nebulization, and kaolin coating can mitigate the losses caused by increasing stressful conditions, but they have detrimental effects on some wine characteristics. They even might not be sufficient to protect the already producing vineyards from aggravated weather conditions
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