Assessment of the volatile and non-volatile profile of Savatiano PGI wines as affected by various terroirs in Attica, Greece.

Establishing the concept of terroir in wines, combined with the exploitation of native grape varieties, is considered a viable alternative to produce quality wines for increasing interest in the wine market. The aim of this study is the characterization of Protected Geographical Indication (PGI) Savatiano white wines from different regions of Attica (Greece), through the chemical and sensory description of the aroma of wines and the determination of their phenolic profiles. The wines produced with the same vinification protocol were evaluated using the descriptive sensory analysis method while they underwent profiling of volatile and phenolic compounds by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) respectively. The presence of regional differences within the wines was also explored, elaborated with variables that contribute to their differentiation, such as soil type, monthly average temperature, and rainfall. Volatile and sensory profiles of the wines separated the regions and confirmed that sub-regional differences attributed mainly to soil characteristics affect wine aroma. The wines from the east part of Attica were higher in esters, terpenes and higher alcohols with high scores in fruity and blossoms attributes while wines from the north part of Attica presented higher intensity of mineral, nutty and herbaceous attributes. The separations based solely on the phenolic compounds concentration were less clear but a relationship was found between the content of phenolic acids and flavonoids and the studied regions. To our knowledge this is the first characterization of Savatiano PGI wines of Attica generating a fingerprint including chemical composition and sensory aroma characteristics to differentiate wines, combining this pattern with particular sub-regions.

Acibenzolar-S-methyl may prevent vector-mediated flavescence dorée phytoplasma transmission, but is ineffective in inducing recovery of infected grapevines.

BACKGROUND: Acibenzolar-S-methyl (BTH), a functional analogue of salicylic acid (SA), is known to elicit a systemic resistance across a broad range of plant-pathogen interactions, but so far it has not been tested against flavescence dorée (FDP), one of the most devastating grapevine diseases. The aim of this work was to evaluate the activity of BTH in preventing FDP transmission by the insect vector and in inducing recovery of infected grapevines. RESULTS: Repeated 2 mM applications of BTH to test grapevine cuttings (cv. Barbera) exposed to adults of the infectious vector Scaphoideus titanus Ball reduced the rate of infected plants. The effect was not recorded following similar BTH applications to highly susceptible young in vitro propagated vines. A high natural recovery rate (more than 70%) was observed over a 3 year period in field-infected grapevines of the same cultivar. Under these conditions, BTH repeated applications over the whole period clearly failed to increase recovery of field-infected grapevines. CONCLUSION: Following a 3 year experiment, it can be concluded that, although high doses and repeated applications of BTH reduced vector transmission of FDP, BTH was ineffective in inducing recovery of FDP-infected grapevines cv. Barbera under field conditions. © 2016 Society of Chemical Industry.

Acquisition of Flavescence Dorée Phytoplasma by Scaphoideus titanus Ball from Different Grapevine Varieties.

Flavescence dorée (FD) is a threat for wine production in the vineyard landscape of Piemonte, Langhe-Roero and Monferrato, Italy. Spread of the disease is dependent on complex interactions between insect, plant and phytoplasma. In the Piemonte region, wine production is based on local cultivars. The role of six local grapevine varieties as a source of inoculum for the vector Scaphoideus titanus was investigated. FD phytoplasma (FDP) load was compared among red and white varieties with different susceptibility to FD. Laboratory-reared healthy S. titanus nymphs were caged for acquisition on infected plants to measure phytoplasma acquisition efficiency following feeding on different cultivars. FDP load for Arneis was significantly lower than for other varieties. Acquisition efficiency depended on grapevine variety and on FDP load in the source plants, and there was a positive interaction for acquisition between variety and phytoplasma load. S. titanus acquired FDP with high efficiency from the most susceptible varieties, suggesting that disease diffusion correlates more with vector acquisition efficiency than with FDP load in source grapevines. In conclusion, although acquisition efficiency depends on grapevine variety and on FDP load in the plant, even varieties supporting low FDP multiplication can be highly susceptible and good sources for vector infection, while poorly susceptible varieties may host high phytoplasma loads.