F. Martínez de Toda

Application of AFLPs to the characterization of grapevine Vitis vinifera L. genetic resources. A case study with accessions from Rioja (Spain)

Abstractu2002AFLPs were used to characterize 67 different grapevine accessions from a collection of D.O.Ca. Rioja in Spain. A correct selection of primers and selective nucleotides allowed us to maximize the number of amplified fragments analyzed per reaction yielding an average of 100 per reaction, 49% of which were polymorphic. Based on the presence or absence of amplified fragments for each genotype resulting from a reaction with two primer combinations, we have established the genetic similarity between the different accessions in the collection. These results allowed us to resolve different genotypes maintained under the same name (homonyms) and to identify the same genotype under different names (synonyms) thus permitting the elimination of redundant germplasm. Furthermore, by providing information on more than 50 polymorphic loci per reaction, a few reactions were sufficient to identify distinct AFLP patterns characteristic of specific clones, with different agronomic and organoleptic features, belonging to the same cultivar. The possibility for clonal identification, shown here for grapevines, can have important implications in the protection and management of clonal selections.

Use of molecular markers in detection of synonymies and homonymies in grapevines (Vitis vinifera L.)

Abstract RAPD and microsatellites are used in the present study as molecular markers for characterisation of grapevine germplasm material. The studied varieties were located in two germplasm banks in Spain. Thirty nine accessions were included in the study, including some presumed synonymies and homonymies. Sixty six primers were used for the RAPD study. Twenty were selected for the multivariate analysis and grouping of the varieties. Seven varieties had a monotypic pattern. Twenty three accessions were also analysed with microsatellites with the VVMD7, VVS2, VVS5 and VVS29 loci, obtaining eight different patterns. The high discriminating ability of the RAPD analysis allowed all the studied varieties to be distinguished. A good concordance was obtained for both RAPD and microsatellites when the two analysis were carried out. The following synonymies were confirmed: Moristell and one of the accessions of Monastel; Maturana and Ribadavia; Concejon and one of the accessions of Monastrell; and most of the studied muscat varieties. Homonymies were detected for Miguel de Arco, Monastel, Monastrell and Turruntes. Both RAPD and microsatellites are considered as adequate molecular markers for characterisation of germplasm banks with the use of one or the other depending on the objectives of the study. When results are intended to compare with other laboratories or germplasm banks, microsatellites give simple and more comparable results.

Reducing the sugar and pH of the grape (vitis vinifera l. Cvs. 'Grenache' and 'tempranillo') through a single shoot trimming

Many vineyards all over the world can easily produce high potential alcohol levels, but the importance of the sugar content in berries has been changing over the past few years. The objective of this work was to reduce the sugar and pH of the grapes, delay berry ripening by decreasing the ratio between the leaf area and yield, perform an intense trimming treatment after berry set and establish the consequences for grapevine productivity in the following year. Severe shoot trimming was done over a three-year period (2010 to 2012). Phenological, vegetative and productive parameters were examined. The date of veraison was delayed by about 20 days. On the same harvesting date, the trim treatment had lower soluble solids (12% to 15 % reduction), lower pH (0.1 to 0.3) and a lower total anthocyanin content (10% reduction). The trim effect was also reflected in berry weight; as a consequence, bunch size and yield were also reduced by around 10%. If the trim treatment does not reduce the leaf area to fruit ratio below 0.50 m2/kg, there is no negative impact on vine capacity in the next year.

Does full exposure of clusters have any negative effects on Tempranillo (Vitis vinifera L.) Grape Quality in La Rioja, Spain? The use of severe Cluster-zone Leaf Removal after Berry Set

A three-year experiment comprising severe leaf removal (LR) was carried out on Tempranillo grapes in Logrono, North-central Spain. For the LR treatment, six basal leaves, along with the basal lateral shoots, were removed two weeks after fruit set. Berry total soluble solids (TSS) were examined when the colour began to appear. Grapes from both the LR and control (C) vines were analysed at the same TSS level (≈ 22°Brix). LR advanced the onset of anthocyanin synthesis slightly but significantly. Yield components were not affected by LR and no symptoms of sunburn were observed. Both treatments showed similar juice pH and titratable acidity, although tartaric acid increased with LR while malic acid decreased with it. In spite of failing to increase the final anthocyanin concentration of the grape juice, LR enhanced the colour and body of the wine. These results indicate that a relatively early LR could be a viable way to improve the quality of grapes and wine under the climatic conditions of the Rioja wine region.

Vineyard zonal management for grape quality assessment by combining airborne remote sensed imagery and soil sensors

Vineyard variability within the fields is well known by grape growers, producing different plant responses and fruit characteristics. Many technologies have been developed in last recent decades in order to assess this spatial variability, including remote sensing and soil sensors. In this paper we study the possibility of creating a stable classification system that better provides useful information for the grower, especially in terms of grape batch quality sorting. The work was carried out during 4 years in a rain-fed Tempranillo vineyard located in Rioja (Spain). NDVI was extracted from airborne imagery, and soil conductivity (EC) data was acquired by an EM38 sensor. Fifty-four vines were sampled at véraison for vegetative parameters and before harvest for yield and grape analysis. An Isocluster unsupervised classification in two classes was performed in 5 different ways, combining NDVI maps individually, collectively and combined with EC. The target vines were assigned in different zones depending on the clustering combination. Analysis of variance was performed in order to verify the ability of the combinations to provide the most accurate information. All combinations showed a similar behaviour concerning vegetative parameters. Yield parameters classify better by the EC-based clustering, whilst maturity grape parameters seemed to give more accuracy by combining all NDVIs and EC. Quality grape parameters (anthocyanins and phenolics), presented similar results for all combinations except for the NDVI map of the individual year, where the results were poorer. This results reveal that stable parameters (EC or/and NDVI all-together) clustering outcomes in better information for a vineyard zonal management strategy.

Grape quality assessment by airborne remote sensing over three years

The prediction of grape composition is becoming more important due to the need to reduce current levels of alcohol and pH of wines, a problem that is exacerbated by climate change. This work presents a 3-year study of the spatial variability of grape composition in a rain-fed Tempranillo vineyard located in Rioja (Spain). It is based on the acquisition of multispectral imagery at veraison (start of the ripening process); and zoning based on normalised difference vegetation index (NDVI) to assess its performance for zonal management. The results reveal a high spatial variability within the plot, with a stable pattern over the years, even with very different climate conditions. NDVI was a good predictor of vegetative growth parameters. However, the prediction of grape composition was more complex. Unexpectedly, anthocyanins were found to be higher in the highest vigour zone, which is particularly discussed in the article. Since vigour is not the only factor affecting grape quality, the delineation of management zones should be done considering other input information together with NDVI.