Contribution to the sensory and volatile characterization of four traditional Galician red varieties

AIM: The diversity and complexity of the fermentation ecosystem during wine making limits the successful prediction of wine characteristics. The use of selected starter cultures has allowed a better control of the fermentation process and the production of wines with established characteristics. Among them, the use of mixed fermentations with Starmerella bacillaris and Saccharomyces cerevisiae yeasts has gained attention in recent years due to the fructophylic nature of the first and the ability of this inoculation protocol to reduce the acetic acid and ethanol content of the wines.

Somatic embryogenesis (SE) has been used in a variety of biotechnology applications such as virus elimination, cryopreservation, induced mutagenesis and genetic transformation. The SE induction process may cause DNA alterations and ploidy changes, which may provide a source of genetic variability useful for the improvement of agronomic characteristics of plants. This research aims at investigating the spontaneous alterations of the genome in grapevine plants regenerated through SE. Regenerants obtained from different embryogenic events from three different grapevine genotypes (Catarratto, Frappato and Nero d’Avola) were analysed.

Grapevines are grown grafted in most viticultural regions. Grapevine rootstocks are either hybrids or pure species of different American Vitis spp. (particularly V. berlandieri, V. rupestris and V. riparia), which were primarily used to provide root resistance to the insect pest Phylloxera. In addition to Phylloxera resistance, grapevine rootstocks were also selected in relation their resistance to various abiotic stress conditions. Future rootstocks should have the potential to adapt viticulture to climate change without changing the characteristics of the harvested product. However, high grafting success rates are an essential prerequisite to be able to use them with all the varieties. The objective of this work is to develop quantitative techniques to characterize graft union formation in grapevine.

Climate, especially temperature, plays a major role in grapevine development. Several bioclimaticindices have been created to relate temperature to grapevine phenology (e.g. Winkler Index, Huglin Index, Grapevine Flowering Véraison model [GFV]).

Grapevines are continually wounded throughout their cultivation especially during winter pruning. Grapevines respond to wounding by occluding xylem vessels with gels or tyloses to limit pathogen attack and dehydration of the tissues. Although the production of xylem vessel occlusions has been studied in grapevine, to date we have no knowledge of whether different genotypes respond differently. The objective of this study was to characterize the genetic variation in xylem vessel occulsions in five different scion genotypes pruned at different dates.