Response to powdery and downy mildew of varieties with disease resistance genes (PIWI)

Wine quality depends largely on berry ripening conditions in relation to soil and climat. The influence of the soil has been studied in Bordeaux since the early Seventies (SEGUIN, 1970; DUTEAU et al., 1981; VAN LEEUWEN, 1991; VAN LEEUWEN et SEGUIN, 1994) and, more recently, in the Val de Loire (MORLAT, 1989), the Alsace (LEBON, 1993) and the Costières de Nîmes regions (MARTIN, 1995).

Les effets de l’état hydrique et de l’alimentation en azote sur le potentiel aromatique des raisins de Sauvignon blanc ont été mesurés sur des vignobles du Bordelais. Les déficits hydriques ont été caractérisés par le potentiel tige déterminé en milieu de journée ΨTmin)­. L’alimentation en azote a été étudiée à partir d’une zone carencée en azote. Une part de cette zone a été supplémentée avec de l’azote minéral.

Acid aspergillopepsins-i (ap-i) have been suggested for use in winemaking due to their ability to degrade proteins, which reduces haze formation and the necessity for bentonite to achieve protein stability. These endopeptidases cleave non-terminal amino acid bonds of proteins, resulting in their degradation.

AIM Durello is a sparkling wine produced in the Lessini mountains near Verona. The wine is made from Durella grapes, a native white grape variety with a particularly high acidity. In spite of the small production area (375 ha for only 35 producers), there is a growing interest in this product. However, little is known about the aromatic profiles of these wines. The aim of this work was to characterize the aroma profile of Durella base wines suitable for the production of Lessini Durello sparkling wine. METHODS 14 base wines from Durella grapesfrom different producers were used for this study. Solid Phase Microextraction (SPME) and Solid Phase Extraction (SPE) sampling techniques coupled to GC-MS analysis allowed to identify and quantify a total of 62 volatile compounds. RESULTS Durello base wines showed relatively high levels of vitispirane, ß-damascenone, ß-citronellol and esters.

Flavescence dorée, a serious threat to grapevine cultivation in several European Countries, is caused by phytoplasmas in the 16Sr-V ribosomal group, classified as quarantine organisms in the EU and transmitted mainly by the insect vector Scaphoideus titanus. The disease is controlled only by indirect and preventive measures, with important economic and environmental concerns. Genetic resources from the great variety of Vitis vinifera germplasm together with application of new genomic techniques could be applied to produce resistant/tolerant plants, once the genetic bases of susceptibility are elucidated. In a current Italian project (BIORES*) we are evaluating different international and local grapevine cvs. as well as microvine plants for their response to FD transmission and multiplication in controlled conditions.