Leafroll, one of the most important virus diseases in grapevine, is mainly due to single or mixed infection of the Ampelovirus Grapevine Leafroll associated Virus 1 (GLRaV-1) and 3 (GLRaV-3). Grapevine virus A (GVA) is a Vitivirus associated with the aetiology of Kober Stem grooving. According to the available literature, GLRaV-1, often in mixed infection with GVA, is reported to reduce growth and yield, generally without affecting fruit maturity, and resulting in a reduction of leaf net photosynthesis and chlorophyll content. The aim of this study was to add information on the effect of GLRaV-1 alone or in mixed infection with GVA on grapevine agronomic and grape qualitative parameters. The trial was conducted with a clone of 'Nebbiolo' (Vitis vinifera L.), one the most important red wine cultivar of Piedmont (North-west Italy). The presence of GLRaV-1+GVA induced an evident decrease of vine vigor and of the amount of crop/vine. The lower crop was consequent to the lower number of clusters/vine with smaller size. Not so when only the GVA was present. In this case all those parameters resulted comparable to the ones of the healthy vines. Juice sugar concentration did not differ among the three sanitary status; however the GLRaV-1+GVA diseased vines produced grapes with a higher content of organic acids. Grape composition did not differ very much between GVA infected and healthy vines. Among grape qualitative parameters, total anthocyanins (responsible of wine colour) were increased by virus elimination on a per berry basis, although without the support of statistical significance. However, expressing data per kg of berry weight, healthy vines produced less anthocyanins due to the higher berry weight respect to GLRaV1+GVA infected vines. When only GVA was involved, the results were closer to the ones with double infection. In terms of eco-physiological performances, the presence of the double infection highly penalized all the parameters involved when compared to healthy vines: photosynthesis (Pn), transpiration (E) and substomatal Co2 concentration (Ci). These results, although limited to the conditions of this trial, showed a strong negative synergistic effects on the overall vine performances due GLRaV-1 and GVA mixed infection and a lower impact on vines due to GVA alone.
Field performances and grape quality of the same clone of 'Nebbiolo' (Vitis vinifera L.) when infected by GLRaV-1+GVA, GVA or healthy
Cuozzo D;Chitarra W;Gribaudo I;Gambino G;Mannini F
2018
Abstract
Leafroll, one of the most important virus diseases in grapevine, is mainly due to single or mixed infection of the Ampelovirus Grapevine Leafroll associated Virus 1 (GLRaV-1) and 3 (GLRaV-3). Grapevine virus A (GVA) is a Vitivirus associated with the aetiology of Kober Stem grooving. According to the available literature, GLRaV-1, often in mixed infection with GVA, is reported to reduce growth and yield, generally without affecting fruit maturity, and resulting in a reduction of leaf net photosynthesis and chlorophyll content. The aim of this study was to add information on the effect of GLRaV-1 alone or in mixed infection with GVA on grapevine agronomic and grape qualitative parameters. The trial was conducted with a clone of 'Nebbiolo' (Vitis vinifera L.), one the most important red wine cultivar of Piedmont (North-west Italy). The presence of GLRaV-1+GVA induced an evident decrease of vine vigor and of the amount of crop/vine. The lower crop was consequent to the lower number of clusters/vine with smaller size. Not so when only the GVA was present. In this case all those parameters resulted comparable to the ones of the healthy vines. Juice sugar concentration did not differ among the three sanitary status; however the GLRaV-1+GVA diseased vines produced grapes with a higher content of organic acids. Grape composition did not differ very much between GVA infected and healthy vines. Among grape qualitative parameters, total anthocyanins (responsible of wine colour) were increased by virus elimination on a per berry basis, although without the support of statistical significance. However, expressing data per kg of berry weight, healthy vines produced less anthocyanins due to the higher berry weight respect to GLRaV1+GVA infected vines. When only GVA was involved, the results were closer to the ones with double infection. In terms of eco-physiological performances, the presence of the double infection highly penalized all the parameters involved when compared to healthy vines: photosynthesis (Pn), transpiration (E) and substomatal Co2 concentration (Ci). These results, although limited to the conditions of this trial, showed a strong negative synergistic effects on the overall vine performances due GLRaV-1 and GVA mixed infection and a lower impact on vines due to GVA alone.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
