Alterations in phenolic contents were studied in Esca symptomatic (Sym) and asymptomatic (Asym) vines of 'Cabernet Sauvignon' based on wood conditions (healthy, HLT; necrotic, Nec; and rotten, Rot) and vine parts (head, trunk, and rootstock). In Asym vines, only Alternaria alternate was identified in Nec wood, while the HLT wood of Sym vines was colonized by Botryospaeriaceae sp. and Aureobasidium pullulans, Nec wood by Fomitiporia mediterranea, and Rot wood by Fomitiporia mediterranea and Phaeomoniella chlamydospora. Esca infection caused a significant accumulation of gallic acid, total flavanols, stilbenes (STB), and total analyzed phenolics (TAP) in all studied woods, especially in Nec wood. In Asym vines, TAP in the head increased with necrosis, but in Sym it decreased, while TAP in the trunk and rootstock of Sym showed an opposite response. The significantly highest contents of procyanidins (Pcys), catechin, epicatechin, epicatechin gallates, and Pcys dimers and tetramers were measured in HLT wood in the head and in Nec wood in the trunk of Sym vines. The significant increase of STB content was not caused only by Esca infection in HLT wood but also by necrosis in Asym vines, especially of ε-viniferin glucoside, resveratrol glycosides, and astringin. The obtained results suggest that the alteration in phenolics differed not only due to Esca infection but also due to the wood conditions and vine part, which might reflect the impact of the duration of the presence of the pathogen in different parts of the vine.

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Twenty-one grapevine varieties grown all over Greece and belonging to 'Mavroudia' group were ampelographically described and genotyped by AFLP molecular analysis in order to discriminate the varieties, synonyms, homonyms and variations of the group. In most cases, the molecular findings confirmed the results of the ampelographic description. In general, and despite the high degree of genetic similarity between certain pairs of the studied cultivars, the group of 'Mavroudia' was characterized as being heterogeneous. From the studied cultivars, 'Kountoura mavri', 'Mavro Spetson' and 'Pappoudes' showed very high degree of genetic similarity, sustaining the hypothesis that the last two are clones of the first. Grapevine cultivar 'Pappoudes' was for the first time ampelographically described and identified as being closely related to 'Kountoura mavri'. High degree of genetic similarity was observed between cultivars 'Gaidouricha' and 'Agiomavritiko', suggesting that they probably originated from the same parent variety through the accumulation of mutations. This may also be true for cultivars 'Mavrokorakas' and 'Kartsiotis'. Also, the results from the statistical analysis showed that 'Mavro Arachovis', 'Mavroudi Voulgarias' and 'Voulgaroudes', despite the relatively high genetic similarity between them, are different. The same applies for the rest of the cultivars studied, while 'Mavro Kalavriton', the most widespread variety of the 'Mavroudia' group, showed the lowest degree of genetic similarity within the all the cultivars studied. The ampelographic description in combination with the molecular method AFLP are effective for the study of the between and within genetic diversity of grapevine cultivars as well as for their identification and discrimination.

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