Juan Carlos Sancha

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

Abstract AFLPs 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.

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.

Characterization and Identification of Minority Red Grape Varieties Recovered in Rioja, Spain

A research project to recover the minority varieties of Rioja was started in 1988 as grapevine biodiversity accumulated during the past centuries was diminishing. The selected vines were preserved within a germplasm bank. Ampelographic description according to 44 Internationale Organisation de la Vigne et du Vin (OIV) characters and genetic characterization using 11 nuclear microsatellites markers were performed on each of the 45 red accessions at the germplasm bank in Logroño, Spain. In total, 26 different varieties were found by the ampelographic and genetic analysis and 24 of them were identified. The remaining two varieties did not match any other genetic profile in the Spanish or European microsatellite databases. The origin of the identified varieties is very diverse, indicating the importance of grape variety exchange that occurred during the last centuries. Minority varieties could play an important role in the future, considering their capacity to adapt to new climatic conditions and their specific wine profiles.