Studi sui tratti di qualità negativa nelle nuove viti mediamente resistenti alle malattie fungine

Abstract

The varieties of vines tolerant to the main fungal diseases are the object of growing interest because they require fewer treatments for the production of quality grapes. These varieties are considered qualitatively unsuitable especially for some characteristics such as the foxy aroma, the level of anthocyanin diglucosides and the level of methyl alcohol in wines. In the three-year period 2016-2018, from a population of 74 medium resistant varieties placed in a single collection, in Marlengo (BZ), young leaves were taken for DNA analysis; annually 2 surveys of the OIV 452 453, 455 and 456 descriptors were carried out, and, at 18° Brix, sombunches were collected for the analysis of different metabolites. Nano-vinifications were carried out for 32 genotypes. Genotypes with different levels of stacked loci associated with resistance to downy and powdery mildew were detected, with different resistance behaviors over the years. Only some genotypes have aromas of foxy and only 20% of the genotypes analyzed have levels of anthocyanin diglucosides higher than the levels required by current legislation. Some vinifications showed methanol levels higher than the legal limit set. High percentages of genotypes respected the legal levels of metabolites required by current regulations and only genotypes with the presence of V. labrusca showed the aroma of foxy.