•The postharvest quality of berry was maintained by exogenous melatonin.•The accumulation of amino acids was greatly promoted in response to melatonin.•The endogenous melatonin biosynthesis was ...enhanced by exogenous melatonin.•The phenolics-oriented metabolism was accelerated by dose of melatonin.
Melatonin (MLT) has gained increasing attention due to its pleiotropic effects. In present study, ‘Kyoho’ grapes were immersed in 200 μM of MLT to investigate the role of exogenous melatonin in postharvest metabolism response. Results indicated that berry abscission and rotten index was reduced by 37.50% and 58.37%, respectively, by exogenous MLT treatment, while the amino acid accumulation was greatly enhanced. Furthermore, the endogenous MLT biosynthesis was activated, where the transcript expression of genes, encoding tryptophan decarboxylase, tryptophan decarboxylase, N-acetylserotonin methyltransferase and N-acetyltransferae were upregulated significantly (p < 0.05), in accordance with the increase of endogenous MLT. Phenolic biosynthesis related genes were upregulated significantly, accompanied with the significantly higher phenolics content (p < 0.05). On day 15, the expression level of phenylalanine ammonia-lyase in MLT-treated group was twice of that in control. Therefore, this study provides the first evidence pertinent to the contribution of exogenous melatonin to the phenolics metabolism in postharvest table grape.
K
is the most abundant cation in the grape berry. Here we focus on the most recent information in the long distance transport and partitioning of K
within the grapevine and postulate on the potential ...role of K
in berry sugar accumulation, berry water relations, cellular growth, disease resistance, abiotic stress tolerance and mitigating senescence. By integrating information from several different plant systems we have been able to generate new hypotheses on the integral functions of this predominant cation and to improve our understanding of how these functions contribute to grape berry growth and ripening. Valuable contributions to the study of K
in membrane stabilization, turgor maintenance and phloem transport have allowed us to propose a mechanistic model for the role of this cation in grape berry development.
In the face of water stress, plants evolved with different abilities to limit the decrease in leaf water potential, notably in the daytime (ΨM). So-called isohydric species efficiently maintain high ...ΨM, whereas anisohydric species cannot prevent ΨM from dropping as soil water deficit develops. The genetic and physiological origins of these differences in (an)isohydric behaviours remain to be clarified. This is of particular interest within species such as Vitis vinifera L. where continuous variation in the level of isohydry has been observed among cultivars. With this objective, a 2 year experiment was conducted on the pseudo-F1 progeny from a cross between the two widespread cultivars Syrah and Grenache using a phenotyping platform coupled to a controlled-environment chamber. Potted plants of all the progeny were analysed for ΨM, transpiration rate, and soil-to-leaf hydraulic conductance, under both well-watered and water deficit conditions. A high genetic variability was found for all the above traits. Four quantitative trait loci (QTLs) were detected for ΨM under water deficit conditions, and 28 other QTLs were detected for the different traits in either condition. Genetic variation in ΨM maintenance under water deficit weakly correlated with drought-induced reduction in transpiration rate in the progeny, and QTLs for both traits did not completely co-localize. This indicates that genetic variation in the control of ΨM under water deficit was not due simply to variation in transpiration sensitivity to soil drying. Possible origins of the diversity in (an)isohydric behaviours in grapevine are discussed on the basis of concurrent variations in soil-to-leaf hydraulic conductance and stomatal control of transpiration.
This study on a grapevine mapping population shows that isohydric or anisohydric behaviour is under genetic control and is not simply controlled by transpiration response to soil drought.
•The date of occurrence of budburst and flowering phases were modeled using the conception of cumulative distribution function (CDF).•Modelling temperature variability, specially under high variable ...arid and semi-arid climatic conditions.•Site-specific phenology modeling carried out with high spatial resolution.•Simple approach to predict grape cv. Yaghouty phenology under various climatic conditions.
This study aimed to develop a new approach for predicting budburst and flowering with no dependency on GDD coupled with a GDD model to predict veraison with the capability of application for site-specific prediction of phenphases using geospatial functions. The budburst and flowering phases were predicted using probability statistical models based on threshold temperature occurrence and the chill requirement supplement was considered as a Boolean function. The field phenological data were recorded from irrigated vineyards with the same management systems. Based on the climatic conditions, four growing patterns of grapevine were defined over the study area, and phenological models were separately fitted for each growth pattern. The spatial analysis was performed by ArcGIS9x using linear models that fitted between the predicted phenophase and digital elevation model (DEM, grid cell 75 m). The results of the model indicated normalized RMSE and model efficiency of 12.5 %–0.93, 6.3 %–0.95, and 18.9 %–0.79, respectively for budburst, flowering, and veraison phases, with the absolute error of 1.12–1.75, which indicated high accuracy in the phenology estimation. The validated models of phenophase occurrence probability used historical weather data under different climatic conditions. The changes in probability during the days of the year were analyzed using different regression models. The best-fitted model for the budburst probability followed the sigmoid model under climatic conditions with mild (R2=0.98) or cool (R2=0.95) winter whereas the quadratic models (R2=0.98) were best-fitted under cold winter. The flowering model followed the quadratic model (R2=0.97) under all climatic conditions. The maps of phenophase characterized the site-specific time of budburst, flowering, and veraison.
Most modern and traditional grape-growing regions are facing challenging times due to the unpredictability of weather conditions and warming trends. Innovative and sustainable tools such as ...seaweed-based biostimulants may play a key-role in the development of environment-friendly viticultural strategies to improve yields, biotic/abiotic stress tolerance and fruit and wine quality. A sprayable Ascophyllum nodosum extract was tested on grapevines cv. Sangiovese grown under Mediterranean conditions (central Italy) and on grapevines cv. Pinot Noir and Cabernet Franc within a cool-climate viticulture region (Michigan, USA). The product was sprayed on the canopies at label doses (1.5 kg/ha) five times during the season, starting two weeks before veraison. The seaweed extract did not affect leaf gas exchanges, yield or cluster and berry size, but hastened veraison, improved anthocyanins accumulation in all cultivars and increased phenolic content particularly in Sangiovese. Therefore, medium-late application of the seaweed extract can be a simple way to favour chromatic and chemical proprieties of grapes and wines. This is the first report of positive effects of Ascophyllum nodosum extracts on the quality of cultivated wine grapes. The adoption of the technique can be particularly suitable to cool-climate viticulture, especially as it pertains to short growing seasons and genotypes with a limited phenolic profile.
Methyl jasmonate (MeJA) has shown promising applications in mitigating fruit quality deterioration. However, whether pre-harvest spraying of MeJA enhances post-harvest grape antioxidant enzyme ...activities and inhibits membrane lipid degradation by regulating energy metabolism has not been reported. In this study, the effect of 50 μmol L–1 MeJA treatment on energy metabolism was investigated in “crystal” grapes stored for 32 d. Its roles in the antioxidant properties and membrane lipids were also investigated. The results showed that MeJA treatment reduced the decay, weight loss, and browning index, inhibited the accumulation of soluble solids, improved the appearance of the fruit, and had a protective effect on crystal grapes. Compared with the fruit, MeJA-treated fruit stalks had higher adenosine triphosphate and adenosine diphosphate content and energy charge, as well as higher hydrogen ion ATPase, calcium ion ATPase, cytochrome C oxidase, and succinate dehydrogenase activities. During storage, MeJA stimulated glutathione production by activating dehydroascorbate reductase and monodehydroascorbate reductase activities, thereby maintaining total antioxidant capacity, free radical scavenging ability, ferrous reducing ability in the fruit. In addition, MeJA treatment inhibited the increase of phospholipase D, lipoxygenase, palmitic acid, and stearic acid; promoted the accumulation of phosphatidylcholine, linoleic acid, and arachidonic acid; and increased the unsaturated fatty acid/saturated fatty acid ratio. Therefore, MeJA maintained a higher energy charge level in grape stalks to varying degrees, slowed down the energy deficit, and inhibited oxidative stress and membrane lipid peroxidation processes in grapes, thereby reducing fruit deterioration and maintaining better fruit quality during storage.
•Grapevine fruit stalks provide energy to the fruit, thus maintaining high quality.•MeJA inhibited the degradation of grape linoleic acid and arachidonic acid.•MeJA enabled a high unsaturated/saturated fatty acid ratio to be maintained.•MeJA has good application prospects in the preservation of grapes after harvest.
BACKGROUND AND AIMS: Rotundone, a potent aroma compound responsible for peppery aroma and flavour in Shiraz, was detected recently in Vitis vinifera L. cv. Duras wines. In 2011 and 2012, two separate ...experiments were carried out to determine the effect of ripeness and viticultural techniques on rotundone concentration in Duras wine. METHODS AND RESULTS: Rotundone was measured in wines prepared by microvinification techniques (1 L Erlenmeyer). Accumulation of this compound in wines depended on vintage conditions and the degree of ripening, such that a higher concentration of rotundone was reached 44 days after mid‐veraison. Application of exogenous jasmonic acid and grape thinning did not significantly affect rotundone concentration, whereas leaf removal strongly reduced rotundone concentration. Wine from the irrigated treatment had a higher concentration of rotundone, and in most cases, vine water status over the veraison–harvest period was identified as a key variable that was well correlated with observed intraplot variability. CONCLUSIONS: These findings confirm that some common viticultural practices can be used to manipulate the peppery character in red wine. SIGNIFICANCE OF THE STUDY: Our results may assist grape growers to produce Duras, Shiraz and other cultivars where rotundone makes an important contribution to wine aroma.
The grapevine trunk-disease complex limits vineyard longevity in all major grape-growing regions. Although trunk diseases have been distinguished based on etiologies (e.g., Botryosphaeria-, Eutypa-, ...and Phomopsis dieback, Esca) and causal agents, mixed infections of trunk pathogens and other wood-colonizing fungi are frequent in grapevines. These diverse fungal communities in grapevine span four classes in the Pezizomycotina (Ascomycota) and 10 genera in the Hymenochaetales (Basidiomycota). Traditional identification based on morphology is largely untenable because of overlap in colony characteristics or spore dimensions, or lack of sporulation in culture. When based on DNA sequencing, searches of uncurated, public molecular databases can lead to misidentifications. The new molecular database TrunkDiseaseID.org is populated with accurate rDNA ITS sequences from 250 + isolates (pathogens and saprobes) and secondary DNA barcodes for delineating closely related species. Currently, no such comprehensive database exists for grapevine wood-colonizing fungi. In addition to ITS and secondary barcode sequences, this database provides a scientific reference, origin, and ecological status for each isolate, to aid diagnosticians in communicating results and recommendations to growers. Outreach through the National Plant Diagnostic Network and the US Department of Agriculture's Identification Technology Program will connect diagnosticians to this new database for grape.
•Grapevine trunk diseases are caused by diverse fungal communities.•Mixed infections confound culture-based identification.•Searches of uncurated, public molecular databases can lead to misidentifications.•To aid diagnosticians, we developed a molecular database, TrunkDiseaseID.org.•The ecological status of each species conveys level of disease risk to growers.
Grape skin color is among the most important qualitative traits on which selection is based in wine and table grape breeding programmes. Skin color is determined by the quantity and composition of ...anthocyanins. In prior work on cultivated forms, it was shown that polymorphisms in the grape transcription factor family VvMYBA are responsible for anthocyanin content variation in the berries of cultivated grapevine (Vitis vinifera subsp. vinifera). Wild grapevine (V. vinifera subsp. sylvestris) is the ancestor of the cultivated V. vinifera subsp. sativa and has black-colored berries. The purpose of this study was to determine how the VvmybA1 and VvmybA2 polymorphisms emerged and affected the genetic diversity of wild grapevines in the Mediterranean basin by examining samples from the Iberian Peninsula, Italian Peninsula and Caucasian region. Our observations provide evidence that variation in the two transcriptional regulators generated a novel allele series via length polymorphisms in VvmybA1 and a point mutation in VvmybA2, which is lacking in cultivated grapevine. Further, correlation was detected between allele composition and anthocyanin contents. According to polymorphisms in both VvMYBA genes at the color locus, we were able to identify several haplotypes. The most ancestral haplotype (HapN) was found in wild grapevine in the western Mediterranean region and corresponded to wine grape cultivars, whereas recent haplotypes were detected in eastern regions. These eastern zones showed the most diverse haplotypes, which appeared in table cultivars where intense breeding practices may have replaced the original haplotype diversity. These findings provide information about the evolution of grapes since their domestication and have direct implications for wine quality.
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