Quantitative trait loci affecting pathogen resistance and ripening of grapevines

Grapevines (Vitis vinifera L.) form the basis of viticulture, and are susceptible to diseases such as downy mildew (Plasmopara viticola) and powdery mildew (Erysiphe necator). Therefore, successful viticulture programs require the use of pesticides. Breeding for resistance is the only eco-friendly solution. Marker-assisted selection is currently widely used for grapevine breeding. Consequently, traits of interest must be tagged with molecular markers linked to quantitative trait loci (QTL). We herein present our findings regarding genetic mapping and QTL analysis of resistance to downy and powdery mildew diseases in the progenies of the GF.GA-47-42 (‘Bacchus’ × ‘Seyval’) × ‘Villard blanc’ cross. Simple sequence repeats and single nucleotide polymorphisms of 151 individuals were analyzed. A map consisting of 543 loci was screened for QTL analyses based on phenotypic variations observed in plants grown in the field or under controlled conditions. A major QTL for downy mildew resistance was detected on chromosome 18. For powdery mildew resistance, a QTL was identified on chromosome 15. This QTL was replaced by a novel QTL on chromosome 18 in 2003 (abnormally high temperatures) and 2004. Subsequently, both QTLs functioned together. Additionally, variations in the timing of the onset of veraison, which is a crucial step during grape ripening, were studied to identify genomic regions affecting this trait. A major QTL was detected on linkage group 16, which was supplemented by a minor QTL on linkage group 18. This study provides useful information regarding novel QTL-linked markers relevant for the breeding of disease-resistant grapevines adapted to current climatic conditions

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Linking monoterpenes and abiotic stress resistance in grapevines

Rising temperatures and ozone levels are among the most striking stressful phenomena of global climate changes, and they threaten plants that are unable to react rapidly and efficiently. Generic responses of plants to stresses include the production of excess reactive oxygen species (ROS). Excessive ROS accumulation can lead to extensive oxidation of important components such as nucleic acids, proteins and lipids which can further exacerbate ROS accumulation leading to programmed cell death. Although most studies on plant antioxidants have focused on non-volatile compounds, volatiles belonging to the isoprenoid family have been implicated in the protection against abiotic stresses, in particular thermal and oxidative stress whose frequency and extent is being exacerbated by ongoing global change and anthropogenic pollution. Historically, research has focused on isoprene, demonstrating that isoprene-emitting plants are more tolerant to ozone exposure and heat stress, reducing ROS accumulation. Yet, evidence is being compiled that shows other volatile isoprenoids may be involved in plant responses against abiotic stresses. Grapevines are not isoprene emitters but some varieties produce other volatile isoprenoids such as monoterpenes. We investigated photosynthesis and emission of volatile organic compounds upon heat stress in two Vitis vinifera cv. ‘Chardonnay’ clones differing only for a mutation in the DXS gene (2-C-methyl-D-erythritol 4-phosphate (MEP) pathway), regulating volatile isoprenoid biosynthesis. We showed that the mutation led to a strong increase in monoterpene emission upon heat stress. At the same time, maximum photochemical quantum yield (Fv/Fm ratio) of PSII was affected by the stress in the non-emitting clone while the monoterpene emitter showed a significant resilience, thus indicating a possible antioxidant role of monoterpenes in grapevine. Future mechanistic studies should focus on unveiling the actual mechanism responsible for such findings

Induction of terpene biosynthesis in berries of microvine transformed with VvDXS1 alleles

Terpenoids, especially monoterpenes, are major aroma-impact compounds in grape and wine. Previous studies highlighted a key regulatory role for grapevine 1-deoxy-D-xylulose 5-phosphate synthase 1 (VvDXS1), the first enzyme of the methylerythritol phosphate pathway for isoprenoid precursor biosynthesis. Here, the parallel analysis of VvDXS1 genotype and terpene concentration in a germplasm collection demonstrated that VvDXS1 sequence has a very high predictive value for the accumulation of monoterpenes and also has an influence on sesquiterpene levels. A metabolic engineering approach was applied by expressing distinct VvDXS1 alleles in the grapevine model system “microvine” and assessing the effects on downstream pathways at transcriptional and metabolic level in different organs and fruit developmental stages. The underlying goal was to investigate two potential perturbation mechanisms, the former based on a significant over-expression of the wild-type (neutral) VvDXS1 allele and the latter on the ex-novo expression of an enzyme with increased catalytic efficiency from the mutated (muscat) VvDXS1 allele. The integration of the two VvDXS1 alleles in distinct microvine lines was found to alter the expression of several terpenoid biosynthetic genes, as assayed through an ad hoc developed TaqMan array based on cDNA libraries of four aromatic cultivars. In particular, enhanced transcription of monoterpene, sesquiterpene and carotenoid pathway genes was observed. The accumulation of monoterpenes in ripe berries was higher in the transformed microvines compared to control plants. This effect is predominantly attributed to the improved activity of the VvDXS1 enzyme coded by the muscat allele, whereas the up-regulation of VvDXS1 plays a secondary role in the increase of monoterpene

Molecular identification of the grapevine "Goethe" from Urussanga (Sc) with microsatellite markers

‘Goethe’ grape is a symbol of the viticulture of Urussanga region, south of the state of Santa Catarina, which is currently claiming the geographical indication of the grape and wine Goethe. Microsatellite markers are the biotechnological tool most used for molecular identification of grapevine varieties worldwide. These markers have the potential of generate unique DNA profiles for all the diverse grape genotypes. The aim of this work was to characterize two selections of the grapevine ‘Goethe’ from Urussanga, using microsatellite markers. Genomic DNA was extracted from young leaves and branches of nine accessions of each selection “Goethe Clássica and ‘Goethe Primo’ maintained at one public and eight private collections of Urussanga. Ten microsatellite loci VVS2, VVMD5, VVMD7, VVMD27, VrZAG62, VrZAG79, VVMD25, VVMD28, VVMD31 and VVMD32 were genotyped by capillary electrophoresis. Results showed that the two variants of ‘Goethe’ have an identical molecular profile which doesn’t match any other DNA profile of grapevines previously described in literature or available in databases. The phenotypic differences observed are probably due to somatic mutations in functional regions of the genome, a phenomenon which leads to the creation of clones in grape

Biodiversity and characterization of twenty-two Vitis vinifera L. cultivars in the Northwestern Iberian Peninsula

Modern viticulture practices with vineyards planted to only one cultivar can contribute to the loss of grapevine diversity. The special geographic conditions in the northern and northwestern Iberian Peninsula make this region a refuge area where grapevine diversity is still high. The preservation of older traditional cultivars reduces the genetic erosion and allows the production of unique wines. A total of 22 older grapevine cultivars growing since 1993 at the grapevine collection located at the Misión Biológica de Galicia research station, Spain, are described in this work. The phenotypic and genetic variability have been evaluated through the ampelographic characteristics of the adult leaves and analysis of 10 microsatellite markers (VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD28, VVMD31, VVMD32, VrZAG62, and VrZAG79). Describing these older cultivars, some of which have not been described to date, and resolving the problem of synonyms and homonyms are necessary steps in their recovery. Copyright © 2009 by the American Society for Enology and Viticulture.Peer Reviewe

A dense single-nucleotide polymorphism-based genetic linkage map of grapevine (Vitis vinifera L.) anchoring pinot noir bacterial artificial chromosome contigs

12nonenoneM. TROGGIO; G. MALACARNE; G. COPPOLA; C. SEGALA; D.A. CARTWRIGHT; M. PINDO; M. STEFANINI; R. MANK; M. MOROLDO; MORGANTE M; M.S. GRANDO; R. VELASCOM., Troggio; G., Malacarne; G., Coppola; C., Segala; D. A., Cartwright; M., Pindo; M., Stefanini; R., Mank; M., Moroldo; Morgante, Michele; M. S., Grando; R., Velasc

Genetic characterization and relationships of traditional grape cultivars from Transcaucasia and Anatolia

We present here the first large-scale genetic characterization of grape cultivars from Transcau-casia and Anatolia. These regions where wild grapes still grow in nature have been cultivating wine and table grapes for thousands of years and are considered the cradles of viticulture. Using 12 nuclear microsatellite markers, we genotyped 116 accessions of traditional grape cul-tivars from Armenia, Georgia and Turkey and we detected 17 identical genotypes and six homonymy cases, mainly within each national germplasm. Neighbour-joining analysis of gen-etic distance showed that each germplasm could have multiple origins and although they are now separated, they might have some common ancestors. In addition, four varieties from Wes-tern Europe included as outgroups turned out to be more related to Georgian cultivars than other germplasms, suggesting a possible ancient origin in Georgia. This work represents a first step towards germplasm management of this rich ampelographic heritage