Elimination of stem pitting and corky bark diseases from grapevine by fragmented shoot apex culture

Fragmented shoot apex culture of grapevine has been shown to regenerate plants free from the graft-transmissible diseases stem pitting (legno riccio) and corky bark. The efficiency of elimination of the disease agents following 2 years of indexing based on 66 plants of three varieties was 100%.     

Grapevine (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.): Old Varieties are Reflected in Works of Art

Grapevine (Vitis vinifera L.): Old Varieties Are Reflected in Works of Art. The northwest of the Iberian Peninsula is home to a number of ancient grapevine varieties now in danger of extinction, regarding which the literature contains only a few references, dating from the 19th century. In this region, baroque religious art, which is commonly ornamented with grapevine motifs, achieved great importance. This work reports the ampelographic comparison of the leaves of 19 old grapevine varieties from this region with those represented on 42 baroque altarpieces. Many of the latter were found to be ampelographically correct representations of grapevine leaves; in some cases they showed such similarity to these old varieties that their cultivation at the time when the corresponding sculptures were made can be confirmed. A larger study may therefore help determine when other varieties were cultivated in the past.     

Grapevine Phenological Quantitative Trait SSR Genotyping Using High-Throughput HRM-PCR Analysis

Discrimination among grapevine varieties based on quantitative traits, such as flowering, veraison and ripening dates is crucial for variety selection in the context of climate change and in breeding programs. These traits are under complex genetic control for which 6 linked SSR loci (VVS2, VVIn16, VMC7G3, VrZAG29, VMC5G7, and VVIB23) have been identified. Using these markers in HRM-PCR analysis, we assessed genetic diversity among a large collection of 192 grapevine varieties. The grapevine germplasm used encompasses the majority of Greek vineyard with 181 varieties, 3 prominent foreign varieties and 11 varieties of Palestinian origin. The SSR markers used were highly polymorphic, displaying unique melting curves for unusually higher number of samples than generally observed in SSR analysis. This prompted us to examine sequence composition for selected samples and found that variation present as SNPs in the flanking sequences of SSR motifs was responsible for the observed polymorphism. Hence, HRM-PCR proved to be a tool of higher analytical power to distinguish genotypes surpassing the discrimination power of conventional gel-based SSR analysis. The study provides a better understanding of genetic variation of SSR marker loci associated to phenological traits in grapevine varieties, signifying an analytical methodology that may be of higher discrimination power in detection of polymorphism for utilization in breeding programs.     

Breakdown of resistance to grapevine downy mildew upon limited deployment of a resistant variety

Background  

Natural disease resistance is a cost-effective and environmentally friendly way of controlling plant disease. Breeding programmes need to make sure that the resistance deployed is effective and durable. Grapevine downy mildew, caused by the Oomycete Plasmopara viticola, affects viticulture and it is controlled with pesticides. Downy mildew resistant grapevine varieties are a promising strategy to control the disease, but their use is currently restricted to very limited acreages. The arising of resistance-breaking isolates under such restricted deployment of resistant varieties would provide valuable information to design breeding strategies for the deployment of resistance genes over large acreages whilst reducing the risks of the resistance being defeated. The observation of heavy downy mildew symptoms on a plant of the resistant variety Bianca, whose resistance is conferred by a major gene, provided us with a putative example of emergence of a resistance-breaking isolate in the interaction between grapevine and P. viticola.     

Comparison of a retrotransposon-based marker with microsatellite markers for discriminating accessions of Vitis vinifera

Identification and knowledge concerning genetic diversity are fundamental for efficient management and use of grapevine germplasm. Recently, new types of molecular markers have been developed, such as retrotransposon-based markers. Because of their multilocus pattern, retrotransposon-based markers might be able to differentiate grapevine accessions with just one pair of primers. In order to evaluate the efficiency of this type of marker, we compared retrotransposon marker Tvv1 with seven microsatellite markers frequently used for genotyping of the genus Vitis (VVMD7, VVMD25, VVMD5, VVMD27, VVMD31, VVS2, and VZAG62). The reference population that we used consisted of 26 accessions of Vitis, including seven European varieties of Vitis vinifera, four North American varieties and hybrids of Vitis labrusca, and 15 rootstock hybrids obtained from crosses of several Vitis species. Individually, the Tvv1 and the group of seven SSR markers were capable of distinguishing all accessions except 'White Niagara' compared to 'Red Niagara'. Using the Structure software, the retrotransposon marker Tvv1 generated two clusters: one with V. vinifera plus North American varieties and the other comprising rootstocks. The seven SSR markers generated five clusters: V. vinifera, the North American varieties, and three groups of rootstock hybrids. The percentages of variation explained by the first two components in the principal coordinate analysis were 65.21 (Tvv1) and 50.42 (SSR markers) while the Mantel correlation between the distance matrixes generated by the two types of markers was 42.5%. We conclude that the Tvv1 marker is useful for DNA fingerprinting, but it lacks efficiency for discrimination of structured groups.     

葡萄卷叶病毒的纯化,血清学研究及其在脱毒组培苗检测中的应用

将具有典型葡萄卷叶病(Grapevine leafroll diseas,GLRD)症状的葡萄组织,经差速和硫酸铯—蔗糖密度梯度离心,提纯了GLRV,并制备了兔抗血清。电镜下可观察到长度从600～2000nm的线形病毒颗粒,其中以1400nm左右为主。免疫电镜结果表明线形病毒颗粒能被美国的NY-1分离株抗血清(Ⅲ型)所修饰。在间接ELISA中提纯制品与GLRV的Ⅲ、Ⅳ、Ⅱ型抗血清均能产生免疫反应。与Ⅲ型抗血清产生较强的免疫反应,Ⅳ型次之,Ⅱ型最弱。在SDS-免疫双扩散实验中病组织韧皮部粗提液与GLRV的Ⅲ,Ⅳ、Ⅱ型抗血清均产生免疫沉淀线。从而推测我国葡萄园内的葡萄卷叶病很可能由2种或3种卷叶病毒感染所致.采用A蛋白夹心酶联免疫吸附试验(PAS-ELISA)检测葡萄试管苗,Ⅲ型抗血清和自制抗血清的平行测试结果基本相符,共获得11个生食葡萄和10个山葡萄品种的脱葡萄卷叶病毒和扇叶病毒的组培苗,扩繁后田间试种表现出良好的农艺性状。     

From the cradle of grapevine domestication: molecular overview and description of Georgian grapevine (Vitis vinifera L.) germplasm

Historical information and archaeological and palaeobotanical findings point Georgia, in the South Caucasus, as a cradle for grapevine (Vitis vinifera L.) domestication from its wild form (V. vinifera silvestris Beck.) and subsequent selection and development of varieties with characters suitable for human consumption. The hypothesis of Georgia being a center of domestication, combined with its distance from western countries and the importance of its viticulture and wine production, make Georgian grape germplasm particularly interesting to be investigated under the genetic point of view. Twenty nuclear microsatellite loci were used to genotype 112 Georgian grapevine accessions (V. vinifera sativa Beck.) from germplasm collections and 18 from spontaneous growing plants (V. vinifera silvestris Beck.) found in wild conditions and to compare them to a large international cultivar collection in France. Data analysis shows that Georgian grapevine germplasm has maintained distinctive traits despite arrival of international, foreign varieties and still conserve characteristics of local breeding linked to traditional wine production regions of the country. Results have identified alleles, overall loci, well represented in the Georgian germplasm (cultivated and wild) and absent or poorly represented in other countries, highlighting uniqueness and originality of traits of this viticulture. Moreover, the search for relationships between Georgian and foreign viticulture has evidenced few interesting cases linking the Georgian varieties with Western European ones and with neighboring Caucasian countries, helping to identify the real place of origin in some doubtful cases. In addition, populations or sparse individuals of wild grapevine still preserved in the Georgian natural environments present smaller genetic distances with local cultivars than in other European regions. Principal component analysis (PCA) has also identified special overlapping of the wild compartment with some cultivated varieties. This work provides a highly significant new contribution to applied aspects of Georgian grapevine genetic resources management and use. Uniqueness of the Georgian cultivated grapevine gene pool together with its close relatedness with the wild compartment makes this country a good candidate to address questions regarding domestication and grapevine genetic resource conservation.     

Mixed spatial models for data analysis of yield on large grapevine selection field trials

In large field trials, it may be desirable to adjust for spatial correlation due to variation in soil fertility and in other environmental factors. Spatial correlation within a field trial can mask differences in the genotypic values of clones, consequently reducing the possibility of identifying superior genotypes. This paper describes a strategy to improve the precision of statistical data analysis of grapevine selection trials through the use of mixed spatial models. The efficiency of mixed spatial models was compared with that of a classical randomized complete block model (with independent and identically distributed errors). The comparisons were based on yield data from three large experimental populations of clones of the Arinto, Aragonez (Tempranillo) and Viosinho grapevine varieties. The fit of the spatial mixed models applied to yield data was significantly better than that of the classical approach, resulting in a positive impact on selection decisions and increasing the accuracy of genetic gain prediction.     

单氰胺对葡萄休眠过程中冬芽水分和碳水化合物的影响

以酿酒葡萄品种'赤霞珠'和'霞多丽'为材料,对其冬芽休眠进程和休眠过程中冬芽水分和碳水化合物含量的变化进行分析.结果表明,(1)在陕西杨陵地区气候条件下,'霞多丽'、'赤霞珠'分别在12月20日和1月9日达到深度休眠,随后开始休眠解除阶段.(2)在芽休眠过程中,两个品种冬芽的总水分含量、自由水含量和淀粉含量均随休眠的加深而降低,随休眠的解除而增加,而冬芽的束缚水含量、束缚水/自由水比值、可溶性糖含量均在休眠加深阶段持续上升,在休眠解除阶段逐渐降低.(3)单氰胺处理后,两品种冬芽中自由水含量显著增加,束缚水的比例同时显著降低,且'赤霞珠'的变化幅度大于'霞多丽',但其总水分、可溶性糖和淀粉等含量在休眠过程中无显著变化.(4)葡萄冬芽中的水分含量及存在状态、可溶性糖含量和淀粉含量的变化与其休眠进程密切相关;单氰胺处理能够增加冬芽自由水含量,降低其束缚水含量,从而有效打破葡萄休眠.     

Characterization of Plasmopara-resistance in grapevine using in vitro plants

Although the exact mechanisms by which grapevine cells operate to reduce disease incidence caused by the downy mildew fungus Plasmopara viticola are not fully elucidated, our cytological results obtained from infected in vitro-plants confirm that enhanced disease resistance is associated with an expression of distinct reactions in a chronological order. An increased production of reactive oxygen species (superoxide radicals, 4-6 hours post infection, hpi) was followed by a hypersensitive response (6-8 hpi), an increased activity of peroxidase in cells flanking the infection area and in the vascular tissue (10-12 hpi) and an increased production, accumulation or conversion of phenolic compounds (12-15 hpi). These mechanisms seem also to be present in susceptible varieties as shown after an inoculation with non-host oomycetic pathogens on the basis of peroxidase activity, but they do not become activated after P. viticola infection. The investigation of the peroxidase activity in leaves at several time points after an infection with P. viticola indicated that there is a strong correlation between the POX activity in leaves of in vitro-plants and the resistance of grapevine plants to P. viticola in the field.     

Virus-derived gene expression and RNA interference vector for grapevine

The improvement of the agricultural and wine-making qualities of the grapevine (Vitis vinifera) is hampered by adherence to traditional varieties, the recalcitrance of this plant to genetic modifications, and public resistance to genetically modified organism (GMO) technologies. To address these challenges, we developed an RNA virus-based vector for the introduction of desired traits into grapevine without heritable modifications to the genome. This vector expresses recombinant proteins in the phloem tissue that is involved in sugar transport throughout the plant, from leaves to roots to berries. Furthermore, the vector provides a powerful RNA interference (RNAi) capability of regulating the expression of endogenous genes via virus-induced gene-silencing (VIGS) technology. Additional advantages of this vector include superb genetic capacity and stability, as well as the swiftness of technology implementation. The most significant applications of the viral vector include functional genomics of the grapevine and disease control via RNAi-enabled vaccination against pathogens or invertebrate pests.     

A functional EDS1 ortholog is differentially regulated in powdery mildew resistant and susceptible grapevines and complements an Arabidopsis eds1 mutant

Vitis vinifera (grapevine) is the most economically important deciduous fruit crop, but cultivated grapevine varieties lack adequate innate immunity to a range of devastating diseases. To identify genetic resources for grapevine innate immunity and understand pathogen defense pathways in a woody perennial plant, we focus in this study on orthologs of the central Arabidopsis thaliana defense regulator ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1). The family of EDS1-like genes is expanded in grapevine, and members of this family were previously found to be constitutively upregulated in the resistant variety ‘Norton’ of the North American grapevine species Vitis aestivalis, while they were induced by Erysiphe necator, the causal agent of grapevine powdery mildew (PM), in the susceptible V. vinifera variety ‘Cabernet Sauvignon’. Here, we determine the responsiveness of individual EDS1-like genes in grapevine to PM and salicylic acid, and find that EDS1-like paralogs are differentially regulated in ‘Cabernet Sauvignon’, while two are constitutively upregulated in ‘Norton’. Sequencing of VvEDS1 and VaEDS1 cDNA and genomic clones revealed high conservation in the protein-encoding sequence and some divergence of the promoter sequence in the two grapevine varieties. Complementation of the Arabidopsis eds1-1 mutant showed that the EDS1-like gene with highest predicted amino acid sequence similarity to AtEDS1 from either grapevine varieties is a functional ortholog of AtEDS1. Together, our analyses show that differential susceptibility to PM is correlated with differences in EDS1 expression, not differences in EDS1 function, between resistant ‘Norton’ and susceptible ‘Cabernet Sauvignon’.     

Gene pool variation and phylogenetic relationships of an indigenous northeast Italian grapevine collection revealed by nuclear and chloroplast SSRs

A germplasm safeguard programme was set up with 19 grapevine varieties considered as indigenous to northeastern Italy. To better estimate how genetic structure can be used to obtain a conservation perspective of local varieties, genetic variability was examined at 30 nuclear and 3 chloroplast polymorphic microsatellite loci in the native varieties plus 7 European cultivars taken as reference. The genetic profiles of all the cultivars were searched for possible parentage relationships and several suspected cases of the same variety having different names were investigated. The alleles shared at the loci suggest a parent-offspring relationship between Merlot and Cabernet Franc, 'Gruaja' and 'Negrara Veronese', and Marzemina Nera and Marzemina Bianca. Alleles at the 30 nuclear loci are consistent with Raboso Veronese being the progeny of Marzemina Bianca and Raboso Piave. Chloroplast-specific haplotypes were singled out for the first time in this indigenous germplasm and should be considered typical of the region. It is hypothesized that there are many specific haplotypes for the local varieties due to a past contribution of wild grapevine to the cultivated gene pool. The majority of investigated cultivars were demonstrated to constitute an independent source of genetic variation, and therefore a possible valuable resource of genetic traits for breeders.     

Future scenarios for viticultural zoning in Europe: ensemble projections and uncertainties

Optimum climate conditions for grapevine growth are limited geographically and may be further challenged by a changing climate. Due to the importance of the winemaking sector in Europe, the assessment of future scenarios for European viticulture is of foremost relevance. A 16-member ensemble of model transient experiments (generated by the ENSEMBLES project) under a greenhouse gas emission scenario and for two future periods (2011–2040 and 2041–2070) is used in assessing climate change projections for six viticultural zoning indices. After model data calibration/validation using an observational gridded daily dataset, changes in their ensemble means and inter-annual variability are discussed, also taking into account the model uncertainties. Over southern Europe, the projected warming combined with severe dryness in the growing season is expected to have detrimental impacts on the grapevine development and wine quality, requiring measures to cope with heat and water stress. Furthermore, the expected warming and the maintenance of moderately wet growing seasons over most of the central European winemaking regions may require a selection of new grapevine varieties, as well as an enhancement of pest/disease control. New winemaking regions may arise over northern Europe and high altitude areas, when considering climatic factors only. An enhanced inter-annual variability is also projected over most of Europe. All these future changes pose new challenges for the European winemaking sector.     

Evidence of a secondary grapevine domestication centre detected by SSR analysis

The origin of the grapevine was investigated with archaeobotanical, cultural and historical data. A primary domestication centre was located in the Near East region but there is no agreement on the existence or role of secondary domestication centres. In this work, PCR-based microsatellite analysis has been applied to study the origin of some Italian cultivated grapevines from in situ direct domestication of the wild autoctonous grapevine. Three different Italian locations in Grosseto, Cosenza and Nuoro were identified for this study, and domesticated grapevine as well as wild local accessions growing in these location, were analysed by SSR markers. Cluster analysis performed on Cosenza and Grosseto samples showed a high value of genetic distance between domesticated and wild accessions. On the contrary two cultivars (Bovale Murru and Bovale Muristellu) recovered in Nuoro (in the Sardinia island) were very close to some wild varieties. This suggests that the latter two cultivars may have originated from wild grapevines and consequently that in this location a secondary grapevine domestication event occurred. Six Lambrusco varieties were also included in this analysis as ancient putative ancestors of the cultivated grapevines. The molecular analysis excluded this hypothesis and suggest Lambrusco as an independent Vitis taxon.The first two authors contributed equally to this research     

Transporters expressed during grape berry (Vitis vinifera L.) development are associated with an increase in berry size and berry potassium accumulation

Potassium accumulation is essential for grapevine (Vitis vinifera L.) growth and development, but excessive levels in berries at harvest may reduce wine quality particularly for red wines. In addition to decreasing the free acid levels, potassium also combines with tartaric acid to form largely insoluble potassium bitartrate. This precipitates during winemaking and storage, resulting in an increase in wine pH that is associated with negative impacts on wine colour, flavour, and microbiological stability. For these reasons, a better understanding of potassium transport and accumulation within the vine and berries is important for producing fruit with improved winemaking characteristics. Here two genes encoding KUP/KT/HAK-type potassium transporters that are expressed in grape berries are described. Their function as potassium transporters was demonstrated by complementation of an Escherichia coli mutant. The two transporters are expressed most highly in the berry skin during the first phase of berry development (pre-veraison), with similar patterns in two grapevine varieties. The timing and location of expression of these transporters are consistent with an involvement in potassium accumulation in grape berries.     

The utilization of unreplicated trials for conservation and quantification of intravarietal genetic diversity of rarely grown ancient grapevine varieties

The conservation of the genetic diversity within ancient grapevine varieties, which are rarely grown nowadays and are subject to genetic erosion, is extremely important in guaranteeing future utilization. This article studies the use of unreplicated trials as a way of preserving the genetic variability of those varieties and quantifying their intravarietal diversity as the raw material for future selections. Through simulation, several experimental situations were generated, varying the numbers of test and check treatments and the type of experimental design associated with the check treatments (augmented randomized complete block design and alpha–alpha design). The quality of the estimates of genotypic variance increased with the increase of the number of genotypes in the conservation collection and with the frequencies of plots with check genotypes. A greater precision was achieved in the quantification of the genetic diversity of ancient grapevine varieties when collections of over 250 genotypes and a minimum of 33 % of plots containing check genotypes were used.     

西南干热河谷地区葡萄休眠规律的研究

在西南干热河谷地区南亚热带气候条件下,4个酿酒葡萄品种梅尔诺 Merlot 、黑虎香 Fox 、霞多丽Chardonnay 和佳美 Gamay 分别在10月初、10月中旬、11月初和11月中旬进入生理性内休眠;约在12月初、12月中旬、1月初和12月中旬进入生态休眠阶段 萌芽率>5 0 % .休眠期葡萄新梢淀粉和总糖含量的变化趋势为:随着休眠程度的加深,淀粉含量上升,总糖含量下降;随着内休眠解除,总糖上升,淀粉下降,二者呈相反的变化趋势.研究结果为在该地区打破葡萄休眠,实现葡萄避雨栽培提供了理论基础.     

Support Vector Machine and Artificial Neural Network Models for the Classification of Grapevine Varieties Using a Portable NIR Spectrophotometer

The identification of different grapevine varieties, currently attended using visual ampelometry, DNA analysis and very recently, by hyperspectral analysis under laboratory conditions, is an issue of great importance in the wine industry. This work presents support vector machine and artificial neural network’s modelling for grapevine varietal classification from in-field leaf spectroscopy. Modelling was attempted at two scales: site-specific and a global scale. Spectral measurements were obtained on the near-infrared (NIR) spectral range between 1600 to 2400 nm under field conditions in a non-destructive way using a portable spectrophotometer. For the site specific approach, spectra were collected from the adaxial side of 400 individual leaves of 20 grapevine (Vitis vinifera L.) varieties one week after veraison. For the global model, two additional sets of spectra were collected one week before harvest from two different vineyards in another vintage, each one consisting on 48 measurement from individual leaves of six varieties. Several combinations of spectra scatter correction and smoothing filtering were studied. For the training of the models, support vector machines and artificial neural networks were employed using the pre-processed spectra as input and the varieties as the classes of the models. The results from the pre-processing study showed that there was no influence whether using scatter correction or not. Also, a second-degree derivative with a window size of 5 Savitzky-Golay filtering yielded the highest outcomes. For the site-specific model, with 20 classes, the best results from the classifiers thrown an overall score of 87.25% of correctly classified samples. These results were compared under the same conditions with a model trained using partial least squares discriminant analysis, which showed a worse performance in every case. For the global model, a 6-class dataset involving samples from three different vineyards, two years and leaves monitored at post-veraison and harvest was also built up, reaching a 77.08% of correctly classified samples. The outcomes obtained demonstrate the capability of using a reliable method for fast, in-field, non-destructive grapevine varietal classification that could be very useful in viticulture and wine industry, either global or site-specific.