Optimizing protocol for a rapid and cost effective DNA isolation for Marker Assisted Selection pipeline

In France, the definition of appellations of origins is entrusted to the Institut National des Appellations d’Origine. (‘NAO). With the increase in price of appellations of origin vine­yards and considering the interests at stake, Institut National des Appellations d’Origine and the Institut National de Recherche Agronomique (INRA) established a work group in 1993 in order to study the “terroir-wine” relationship as precisely as possible, taking into account the knowledge acquired by researchers of the INRA and the experience in the field of the agents of the INAO.

The oenological potential of grapes at harvest depends on a combination of the major components of Terroir: the climate, the soil, the plant material, the training system and the crop management.

During red wine ageing or conservation, color and taste change and astringency tends to reduce. These changes result from reactions of flavan-3-ols and/or anthocyanins among which condensation reactions with acetaldehyde are particularly important. The full characterization of these reactions has not been fully achieved because of difficulties in extracting and separating the newly formed compounds directly from wine. Model solutions mimicking food products constitute a simplified medium for their exploration, allowing the detection of the newly formed compounds, their isolation, and their structure elucidation.

Due to varietal factors, the formation of undesirable deposits of flavonols, especially quercetin (Q), occurs in several red wines.

Recent studies have demonstrated the role of certain lactones, particularly 2-nonen-4-olide, and volatile thiols (3-sulfanylhexan-1-ol) in the over ripped aromas of noble rot sweet wines (Stamatopoulos et al. 2014ab). These compounds are partly formed during the maturation and under the activity of B. cinerea on grapes. This research was carried out in the vineyard of Sauternes with aim to better understand their genesis depending on the grape over-ripening on two different soil types during 3 vintages. Thus, the study was conducted, with the Sémillon grape, during vintages 2012, 2014 & 2015, at 4 stages of over-maturation of the grapes (healthy, pourri plein, pourri roti, pourri roti + 15 days) considering two vineyard plots with different soil characteristics (calcosol & peyrosol) planted with the 315 Sémillon clone and grafted on 101-14 rootstock respectively in 1981 and 1980 and cultivated with the same vineyard management. Volatile lactones were assayed by liquid-liquid extraction followed by GC/MS analysis and the precursors of 3-sulfanylhexanol by an adaptation of the method by Capone et al. 2010 (SPE-
UPLC/FTMS).