Studio delle interazioni tra virus asintomatici (GFkV e GRSPaV) e Vitis vinifera: risultati preliminari dell'indagine

Grapevine fleck virus (GFkV), the causal agent of fleck disease, and Grapevine rupestris stem pitting-associated virus (GRSPaV), associated to a disorder of rugose wood complex, are two of the most widespread viruses in grapevine. Both viruses are symptomless in Vitis vinifera, although some negative effects of their presence are reported on vine agronomic and physiological performances. In order to provide more information about the impact of these viruses, a trial was carried out in 2013 comparing the behavior of plants belonging to V. vinifera Nebbiolo clone CVT 423 infected by both GFkV and GRSPaV or by GRSPaV only. The results showed a basically positive effect on yield and grape ripeness due the GFkV elimination although associated to a reduction of grape phenols. This reduction, in terms of anthocyanin profile, regarded the peonidin while the malvidin content was increased. These modifications may have important implication on wine color. The canopy physiological parameters measured during summer did not show significative differences between the two theses except for a slight increase in photosynthesis and transpiration in the early dates in vines infected by GRSPaV only.