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The wine industry is facing critical issues due to climate changes since production is established on very tight Genotype × Environment interaction bases. While, some cultivation practices may reduce adverse effects of abiotic stresses on the vines, e.g., the use of irrigation to mitigate drought, the deleterious impacts of warming on fruit development are difficult to manage. Elevated temperature alters grapevine fruit growth and composition, with a critical increase of the sugars/organic acids ratio. Select grapes with improved metabolite balances to offset high temperature effects is a valuable option to sustain viticulture. Unfortunately, the lack of knowledge about the genetic diversity for fruit traits impacted by temperature impairs the design of breeding programs. This study aimed to assess the variation in berry volume, main sugars and organic acids amounts in genetic resources. Fruit phenotyping focused on two critical stages of development: the end of green lag phase when organic acidity reaches its maximum, and the ripe stage when sugar unloading and water uptake stop. For that purpose, we studied a panel of 33 genotypes, including 12 grapevine varieties and 21 microvine offspring. To determine the date of sampling for each critical stage, fruit texture and growth were carefully monitored. Analyses at both stages revealed large phenotypic variation for malic and tartaric acids, as well as for sugars and berry size. At ripe stage, fruit fresh weight ranged from 1.04 to 5.25 g and sugar concentration from 751 to 1353 mmol.L-1. The content in organic acids varied both in quantity (from 80 to 361 meq.L-1) and in composition, with malic to tartaric acid ratio ranging from 0.13 to 3.62. At the inter-genotypic level, data showed no link between berry growth and osmoticum accumulation per fruit unit, suggesting that berry water uptake is not dependent only on fruit osmotic potential. Diversity among varieties for berry size, sugar accumulation and malic to tartaric acid ratio could be exploited through cross-breeding. This provides interesting prospects for improving grapevine to mitigate some adverse effects of climate warming on grapevine fruit volume and quality.

Grapevine is a very important crop species that is mainly cultivated worldwide for fruits, wine and juice. Identification of the genetic bases of performance traits through association mapping studies requires a precise knowledge of the available diversity and how this diversity is structured and varies across the whole genome. An 18k SNP genotyping array was evaluated on a panel of Vitis vinifera cultivars and we obtained a data set with no missing values for a total of 10207 SNPs and 783 different genotypes. The average inter-SNP spacing was ~47 kbp, the mean minor allele frequency (MAF) was 0.23 and the genetic diversity in the sample was high (He = 0.32). Fourteen SNPs, chosen from those with the highest MAF values, were sufficient to identify each genotype in the sample. Parentage analysis revealed 118 full parentages and 490 parent-offspring duos, thus confirming the close pedigree relationships within the cultivated grapevine. Structure analyses also confirmed the main divisions due to an eastern-western gradient and human usage (table vs. wine). Using a multivariate approach, we refined the structure and identified a total of eight clusters. Both the genetic diversity (He, 0.26-0.32) and linkage disequilibrium (LD, 28.8-58.2 kbp) varied between clusters. Despite the short span LD, we also identified some non-recombining haplotype blocks that may complicate association mapping. Finally, we performed a genome-wide association study that confirmed previous works and also identified new regions for important performance traits such as acidity. Taken together, all the results contribute to a better knowledge of the genetics of the cultivated grapevine.

Aims: This study aims to characterize the SODEA ampelographic collection in Meknès, the only germplasm repository in Morocco. To assess the usefulness of this germplasm, a study was conducted to verify the trueness to type of the genotypes and to provide the first database for a reference collection in Morocco. A core collection was then established to define a small sample easier to handel further characterization. Methods and results: Ninety-four grapevine samples from the collection were analyzed using 20 nuclear SSR markers. From these samples, we identified 67 grapevine genotypes. The nuclear SSRs revealed a high diversity within the SODEA collection: 202 alleles were detected with a mean of 10.1 alleles per locus. Analysis of molecular data with the software DARwin was used to classify the genotypes into six groups according to their origin or their genetic relatedness. The 18 autochthonous cultivars were differentiated according to geographical origin (North vs. South). We established a core collection among this germplasm using MSTRAT: the complete diversity present in the collection was captured with only 34 individuals. Nevertheless, an optimal core collection representing 89% of the diversity was constituted by only 17 cultivars. Among these 17 individuals, 5 are autochthonous. Conclusion: The collection of SODEA represents a unique resources of grapevines for Morocco. It contains several important autochthonous cultivars in terms of diversity and agronomic utilisation. Significance and impact of the study: The study showed potential and interest of the cultivars present in the collection of SODEA, suggesting that their utilisation may be important for the farmers.

Electrophoresis was employed as the method of study for the characterisation of Vitis vinifera varieties cultivated in Galicia (Spain). Mature dormant shoots were used for the study. The enzymatic system glucose- phosphate isomerase (GPI) was analysed using the method of PARFITT and ARULSEKAR (1989). Seventeen varieties (Albariño, Dona Blanca, Godello, Loureira, Treixadura, Torrontés, Albillo, Palomino, Verdejo Blanco, Macabeo, Jerez Fina, Asal Galego, Moscatel Galego, Galego Dourado, Galego de Montemor, Brancellao, and Caiño Bravo) were studied. Eight groups of phenotypes were obtained. Each one of which had clearly differentiated characteristics from more than one varity, except in the case of Garnacha.

Application of philometric methods in the differentiation between clones of the varieties of grapevines that are traditionally cultivated in Galicia (NW Spain) has been studied. Our aims is to work whith a number of leafparameters as large as possible to ensure differences among clones. Experimental measurements have been obtained using Computer Techniques (ROMANI et al., 1993). They have been analyzed by commercial statistic package using of Discrimination Analysis (SAS Statistical Programme). We have to establish separation at clone level for each variety, by means of using certain discrimination parameters which allow us to elaborate determination keys. The parameters which best explain the differences between the clones would be the shape and size of the dentation, leaf bosoms and the whole leaf in general

61 tunisian autochton grapevine varieties have been collected for biochemical identification. Isozymes analysis with starch gel electrophoresis technique was used to confirn or to cancel random denominations awarded to the majority of these local varieties. In our conditions, concentrated plant extracts were obtained from vigorous donnant canes newly cut off from selected mother plants during automn. These allowed us to dispose of rigorously interpretable isozyme banding patterns of GPI and PGM systems and to overcome difficulties often related to the use of PGM system. The study of GPII and PGM enzyme systems allowed us to classify the autochton accessions into 16 different groups from which 5 groups containing only 2 or 3 varieties. On the other hand, the study of AAT and peroxydase enzyme systems has shown stable and legible isozyme banding patterns allowing to discriminate between equivalent accessions such as Sakasly and Kahli (two black local vines very similar), 3 varieties of Bidh Hamem (Bidh Hamem, Bidh Hamem Rafraf and Bidh Hamem Sfax), and 2 varieties of Bezzoul Kelba Bidha (Sfax and Gabes). In addition, certain varieties having for longtime the same denominations were characterized. A case of point the 4 varieties Khalt meaning mixture (Bouchemma, Abiedh, Mdaouer and Souche 1) and the 3 varieties of Arich (Ahmar, Dressée, and Jerba) were proved to be completely different from each other. In the same way, Bezzoul Khadem has been differed from Hemri variety. The complementary use of berry colour allowed to discriminate between Saouadi, Khdhiri and Jebbi varieties and to subdivise the remainig groups into sub-groups. The study of GPI, PGM, AAT and peroxydase isozyme banding patterns in combination with berry colour has led to establish a classification of the 61 autochton varieties into 37 groups including 26 varieties definitely differentiated through the results of this biochemical study.

Through multiple vegetative propagation cycles, clones accumulate mutations in somatic cells that are at the origin of clonal phenotypic diversity in grape. Clonal diversity provided clones such as Cabernet-Sauvignon N°470, Chardonnay N° 548 and Pinot noir N° 777 which all produce wines of superior quality. The economic impact of clonal selection is therefore very high: since approx. 95% of the grapevines produced in French nurseries originate from the French clonal selection. In this study we provide the first broad description of polymorphism in different clones of a single grapevine cultivar, Pinot noir, in the context of vegetative propagation. Genome sequencing was performed using 454 GS-FLX methodology without a priori, in order to identify and quantify for the first time molecular polymorphisms responsible for clonal variability in grapevine. New generation sequencing (NGS) was used to compare a large portion of the genome of three Pinot noir clones selected for their phenotypic differences. Reads obtained with NGS and the sequence of Pinot noir ENTAV-INRA® 115 sequenced by Velasco et al., were aligned on the PN40024 reference sequence. We then searched for molecular polymorphism between clones. Three types of polymorphism (SNPs, Indels, mobile elements) were found but insertion polymorphism generated by mobile elements of many families displayed the highest mutational event with respect to clonal variation. Mobile elements inducing insertion polymorphism in the genome of Pinot noir were identified and classified and a list is presented in this study as potential markers for the study of clonal variation. Among these, the dynamic of four mobile elements with a high polymorphism level were analyzed and insertion polymorphism was confirmed in all the Pinot clones registered in France.

On a réalisé une étude des caractères qui différencient le mieux les cépages autochtones de la Galice (NW Espagne) et on a élaboré une clé de détermination. Pour cela on a utilisé comme méthode l'ampélométrie, basée uniquement sur des caractères mesurables. A l'aide d'un système informatique on a mesuré 150 paramètres par feuille, 14 feuilles par cépage et on a étudié au total 17 cépages.

RNASeq or double-stranded RNA based approaches allowed the reconstruction of a total of 9 full-length or near full-length genomes of the recently discovered grapevine virus T (GVT). In addition, datamining of publicly available grapevine RNASeq transcriptome data allowed the reconstruction of a further 14 GVT genomes from five grapevine sources. Together with four GVT sequences available in Genbank, these novel sequences were used to analyse GVT diversity. GVT shows a very limited amount of indels variation but a high level of nucleotide and aminoacid polymorphism. This level is comparable to that shown in the closely related grapevine rupestris stem pitting-associated virus (GRSPaV). Further analyses showed that GVT mostly evolves under conservative selection pressure and that recombination has contributed to its evolutionary history. Phylogenetic analyses allow to identify at least seven clearly separated groups of GVT isolates. Analysis of the only reported PCR GVT-specific detection primer pair indicates that it is likely to fail to amplify some GVT isolates. Taken together these results point at the distinctiveness of GVT but also at the many points it shares with GRSPaV. They constitute the first pan-genomic analysis of the diversity of this novel virus.