Correlation between agronomic performance and resistance gene in PIWi varieties in the field

Climate change scenarios predict increases in the frequency and severity of droughts in arid zones. Under these conditions some plants can rapidly acclimate to stress and further fortify their defenses by retaining memories of stress which enable stronger or more rapid responses if an environmental perturbation recurs.

The sequential activity of miR156 and miR172 controls the juvenile to adult phase transition in many plant species, where miR156 abundance decreases while miR172 increases along plant development. Very little is known about phase transition in horticultural woody species, which show substantially long vegetative phases. In grapevine, phase transition seems to be dissociated, displaying a first transition from juvenile to adult vegetative state in the first year, coincident with tendril differentiation and a subsequent induction of inflorescences in place of some of tendrils in later years under flowering inductive environmental conditions. Since grapevine is a highly heterozygous species, the generation of genetically homogeneous material for replicated transcriptomic analyses from seed-derived plants was a main challenge.

Downy mildew caused by Plasmopara viticola remains a central challenge in grapevine production, particularly under conditions aiming at reduced fungicide input.

Cognac vineyard is mainly dedicated to brandy production. Within the vineyard restructuring context, one part is turned over wine varieties for wine production (about 1,500 ha planted from 1999 to 2005). Today, the new wine producers need technical references about qualitative potential of the « Charentes Terroir », varieties and adapted vineyard management.
In order to answer to this professional request, an observatory of 18 plots of Merlot and 12 plots of Sauvignon have been laid out since 2003 and 2004 on various kinds of pedoclimate.

Significant wine aroma can be formed from non-volatile precursors that are linked to sugars, including but not limited to grape-derived monoterpene and C13-norisoprenoid glycosides.