Optimization of in vitro establishment of grapevine varieties for fast micropropagation 

The Valpolicella area (Veneto Region, Italy) is famous for its high quality wines: Amarone and Recioto, both obtained from partial post-harvest dehydrated red grapes.

Rachis browning is a common abiotic stress that occurs during postharvest storage, leading to a decrease in commercial value of table grapes and resulting in significant economic losses. Its early detection could enable the implementation of preventive strategies. In this report, we show the feasibility of a non-destructive early detection of browning based on Hyper Spectral Imaging (HSI). Furthermore, rachis samples were subjected to transcriptomic analysis to understand putative pathways causing differences in browning within varieties.

This experiment tries to characterize the role of soil, climate and harvest date on the composition of grape-derivated thiols, 3-mercapto-hexanol (3MH) and 3-mercapto-hexile acetate (A3MH), in the white wines from Colombard varieties in Gascony (South-West of France). A network of 6 plots has been observed since 1999 on different pedologic units. The plots have common agronomical characteristics, plantation spacing (2,900 to 3,500 vines per ha), plantation aging (1985-1990), strength conferred by rootstock (SO4, RSB), soil management (grass covered 1 by 2) and training system (vertical shoot positionning pruned in single Guyot). Meteorological stations are located near the plots.

It was at the end of the second world war that professor Branas laid the foundations of french vine selection. He was also behind the creation of domaine de vassal (1949) and antav (1962), which were to become the bridgeheads of the french strategy for the conservation, selection and multiplication of viticultural diversity. Initially based on visually virus-symptom-free massal selections, with the main aim of providing healthy, clearly-identified plant material, the process evolved as knowledge gained towards clonal selection.

Contribution Sparkling wines elaborated following the traditional method undergo a second fermentation in closed bottles of base wines, followed by aging of wines with lees for at least 9 months. Most of the sparkling wines elaborated are white and rosé ones, although the production of red ones is highly increasing. One of the initial problems in red sparkling wine processing is to obtain suitable base wines that should have moderate alcohol content and astringency and adequate color intensity; which is difficult to obtain when grapes must be harvested at low phenolic and industrial maturity stage. The low phenolic maturity degree in the red grapes makes essential to choose an adequate winemaking methodology to obtain the base wines because the extracted polyphenols will vary according the winemaking technique: carbonic maceration or destemmed-crushed grapes.