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Abstract: Grape temperature is a crucial driving variable for the wide variety of biochemical and physiological processes taking place during berry ripening which determine the oenological quality potential of grapes. The aim of this work is to develop, calibrate and validate a model simulating surface berry temperature (BerryTone), taking into account the effect of different sun exposures and leaf shadings. BerryTone has been developed using a mechanistic approach founded on the energy balance and it is driven only by maximum and minimum daily air temperatures. Calibration and validation have been carried out on independent dataset in Northern Italy during 2005 and 2006. In order to evaluate the effectiveness of the model in other environmental conditions, a further test on a time series from 2008 in Central Italy was also carried out. Final results show that the model satisfactorily described berry thermal behaviour under solar forcing for different exposures, improving upon the description usually given by air temperature. [Copyright &y& Elsevier]

Highlights: [•] Tannins have a physiological and enological central role in grapes. [•] A separation method for vacuolar, non-covalent and covalent bonded tannins was developed. [•] Cultivar, exposition and Ethephon treatment effects are discussed. [Copyright &y& Elsevier]

Color has a fundamental role for the qualitative evaluation and cultivar characterization of fruits. In grape, a normally functional pigment biosynthesis leads to the accumulation of a high quantity of anthocyanins. In this work, 28 Vitis vinifera L. cultivars accumulating low anthocyanins in berries were studied to characterize the biosynthetic dysfunctions in both a phenotypic and genotypic point of view. Reflectance spectroscopy, HPLC profiles and molecular markers related to VvMybA1 and VvMybA2 genes allowed a detailed description of the pigment-related characteristics of these cultivars. Data were consistent concerning the heterozygosity of the non-functional allele in both investigated genes, resulting in a low colored phenotype as described by reflectance. However, the variability in berry colour among our samples was not fully explained by MybA locus, probably due to specific interferences among the biosynthetic pathways, as suggested by the anthocyanin profile variations detected among our samples. The results presented in this work confirmed the importance of the genetic background: grapes accumulating high levels of cyanidin-3-O-glucosides (di-substituted anthocyanin) are generally originated by white cultivar retro-mutations and they seem to preserve the anomalies in the flavonoid hydroxylases enzymes which negatively affect the synthesis of tri-substituted anthocyanins. [ABSTRACT FROM AUTHOR]

In grape berries, extreme oxidative stress results in skin tissue bleaching and brownish areas appearance. Thus, these damages could negatively affect the fruit quality and the commercial value. The paper focuses on the chlorophyll roles in sunburn symptoms appearance in white skinned grape berries. In the present work, 20 cultivars were studied in three phenological stages. Berries were kept under temperature and light controlled conditions. Chlorophyll content and symptom appearance were quantified by reflectance spectroscopy indexes. The central role of radiation (and, thus, photo-oxidative damages) in berry sunburn injuries was underlined. Cultivars were classified, based on their susceptible or tolerant responses to radiation excess. [ABSTRACT FROM AUTHOR]

Abstract: ‘Ribolla Gialla’ is a very old grape variety cultivated today in the Friuli Venezia Giulia region in north-eastern Italy. The historical reputation of this variety in central Eastern Europe was strongly related to the vast distribution of the Venetian Republic markets. In the 1960s, the interest of Italian winegrowers in ‘Ribolla Gialla’ decreased and it was replaced by international varieties. Despite historical documents reporting the longstanding tradition of ‘Ribolla Gialla’ cultivation and winemaking in Friuli Venezia Giulia, the origin of this variety is still questionable. The aims of this work were to study the genetic identity of ‘Ribolla Gialla’ and to investigate the possible genetic relationships with ‘Rebula’ and ‘Robola’ that have been traditionally cultivated in other European Countries (Goriška brda in Slovenia and Kefalonia Island in Greece). For this purpose, 35 SSR loci were analyzed to fingerprint 19 accessions with denominations or morphologies that are similar to ‘Ribolla Gialla’. The Italian ‘Ribolla Gialla’ accessions (#5) and the Slovenian ‘Rebula’ accessions (#2) revealed identical genotypes in all 35 analyzed SSR markers, and can therefore be confirmed as synonyms. The group of Greek ‘Robola’ accessions resulted as the most heterogeneous, showing several distinct allelic profiles. By phylogenetic analysis, two ‘Robola’ accessions were clustered with ‘Ribolla Gialla’ (or ‘Rebula’), and parentage analysis strongly suggested a full-siblings relationship between ‘Ribolla Gialla’ and ‘Robola’. [Copyright &y& Elsevier]