Giancarlo Scalabrelli

Retrotransposon-based molecular markers for grapevine species and cultivars identification.

Insertional polymorphisms of two copia-like (Vine-1, Tvv1) and one gypsy-like (Gret1) retrotransposon found in the grapevine genome were studied in 29 Vitis genotypes (Vitis arizonica, Vitis cinerea, Vitis labrusca, Vitis rupestis, Vitis rotundifolia, Vitis vinifera subsp. sylvestris and 23 V. vinifera subsp. sativa) using inter-retrotransposon amplified polymorphism (IRAP), retrotransposon-microsatellite amplified polymorphism (REMAP) and sequence-specific amplified polymorphism (SSAP) techniques. IRAP, REMAP and SSAP polymorphisms were compared with amplified fragment length polymorphism (AFLP), Inter-single sequence repeats (ISSR) and SSR polymorphisms by evaluating the information content, the number of loci simultaneously analysed per experiment, the effectiveness of the analyses in assessing the relationship between accessions and the number of loci needed to obtain a coefficient of variation of 10%. The UPGMA dendrograms of each molecular marker system were compared and the Mantel matrix correspondence test was applied. Furthermore, the corresponding insertion ages of the transposable elements were estimated for each retrotransposon subfamily analysed. The presence of Gret1, Tvv1 and Vine-1 retrotransposons in all analysed genotypes suggests that copia-like and gypsy-like retrotransposons are widespread in Vitis genus. The results indicate that these retrotransposons were active before Vitis speciation and contributed to Vitis genus evolution. IRAP, REMAP and SSAP markers allow the discrimination of Vitis species and V. vinifera subsp. sativa cultivars with certainty as has been shown with AFLP, ISSR and SSR analyses, but phylogenetic trees obtained by retrotransposon-based molecular markers polymorphisms show some significant differences in the allocation of the analysed accessions compare to those obtained by ISSR, AFLP and SSR molecular markers. The phylogenetic tree resulting from REMAP polymorphism appeared the most representative of the effective relationship between all analysed accessions.

Expression of terpene synthase genes associated with the formation of volatiles in different organs of Vitis vinifera

Plants produce a plethora of volatile organic compounds (VOCs) which are important in determining the quality and nutraceutical properties of horticultural food products, including the taste and aroma of wine. Given that some of the most prevalent grape aroma constituents are terpenoids, we investigated the possible variations in the relative expression of terpene synthase (TPS) genes that depend on the organ. We thus analysed mature leaves, young leaves, stems, young stems, roots, rachis, tendrils, peduncles, bud flowers, flowers and berries of cv Moscato bianco in terms of their VOC content and the expression of 23 TPS genes. In terms of the volatile characterization of the organs by SPME/GC-MS analysis, flower buds and open flowers appeared to be clearly distinct from all the other organs analysed in terms of their high VOC concentration. Qualitatively detected VOCs clearly separated all the vegetative organs from flowers and berries, then the roots and rachis from other vegetative organs and flowers from berries, which confirms the specialization in volatile production among different organs. Our real-time RT-PCR results revealed that the majority of TPS genes analysed exhibited detectable transcripts in all the organs investigated, while only some were found to be expressed specifically in one or just a few organs. In most cases, we found that the known products of the in vitro assay of VvTPS enzymes corresponded well to the terpenes found in the organs in which the encoding gene was expressed, as in the case of (E)-β-caryophyllene synthases, α-terpineol synthase and α-farnesene synthase. In addition, we found groups of homologous TPS genes, such as (E)-β-caryophyllene and β-ocimene synthases, expressed distinctively in the various tissues. This thus confirmed the subfunctionalization events and a specialization on the basis of the organs in which they are mostly expressed.

Analysis of the expression of terpene synthase genes in relation to aroma content in two aromatic Vitis vinifera varieties

Grape (Vitis vinifera L.) flavour management in the vineyard requires knowledge of the derivation of individual flavour and aroma characteristics. Some of the most prevalent wine grape aroma constituents are terpenoids and this study represents a wide report about grape terpene synthase (TPS) gene transcript profiling in different tissues of two aromatic grapevine varieties, particularly flowers and developing berries, correlated with the accumulation patterns of free aroma compounds. All investigated genes belonging to the TPS-a and TPS-b subfamilies reached the highest expression in accordance with the peak of accumulation of the respective compounds. In the TPS-g subfamily, only one of the genes characterised for linalool synthases showed major transcript abundance in ripening berries, whereas the only geraniol synthase had a peak of expression in green berries and at the beginning of ripening, when geraniol concentration started to increase and overcome the linalool concentration. The genes identified in this study as being mainly responsible for linalool and geraniol synthesis during berry development, and the phenological phases in which they are mostly expressed, should be of interest to viticulturists and wine makers to improve decision making along the chain of production.

The expression of a full-bodied red wine as a function of the characteristics of the glass utilized for the tasting

With the aim to better understand how the differences related to the glass type can influence the consumer perception of the wine, the same product was assessed in each glass, at the same moment, for three times (t = 0, 40 and 120 min) during every tasting session. The evolution of wine in each glass was characterized also by a chemical and physical point of view, in order to verify if the different characteristics of the glasses utilized influenced the chemical parameters analyzed, so to justify the changes in the sensorial perception expressed by the panel components. Thanks to the general overlapping between the developments related to the evolution of sensorial, chemical and physical characteristics of the wine, it was possible to define a final classification of the types of glasses utilized and identify which glass seemed to show the best influence on the sensory perceptions of the wine tasted.

Glass and wine: a good example of the deep relationship between drinkware and beverage

ABSTRACT As the choice of the drinkware could deeply affect consumer perception during beverage consumption, an experimental research was carried out by expert testers to investigate the evolution of chemical–physical and sensory profiles of a typical rosé wine maintained in different types of glasses. The aim of this research was to select some parameters to well correlate beverage sensory properties with glass characteristics which can be used for drinkware design. The different sensorial profiles, obtained as a function of the geometric characteristics of glasses, were compared with one another. In order to find any significant parameter useful to represent the time evolution of the wine inside each vessel, the wine poured in all glasses was also characterized at different times from a chemical and physical point of view. As the design parameters are now guided more by aesthetic reasons rather than by functional ones, this new ‘integrated approach’, deriving from the merging of chemical, physical and sensorial data, can be used to design the optimum vessel for the enjoyment of the consumer during assessing sessions. This innovative procedure could be easily adapted for every beverage such as fruit juices, sparkling wines or beer.

Gas Exchange, Stem Water Potential and Xylem Flux on Some Grapevine Cultivars Affected by Esca Disease

The effect of esca disease on gas exchange, stem water potential and xylem flux of adult grapevines of Cabernet Sauvignon, Sangiovese and Trebbiano cultivars was studied over three growing seasons. Water relations were measured at veraison and cluster ripening on three types of vines: i) healthy (control); ii) symptomatic and iii) apparently healthy in the year of measurements but that had showed esca symptoms in the previous season. Xylem flux was determined on cane segments by perfusion using a tracing dye before and after the appearance of esca symptoms. Esca induced a marked reduction (about 70%) in carbon assimilation and stomatal conductance, especially in Cabernet Sauvignon and Sangiovese. Esca did not affect the stem water potential. Gas exchange parameters measured before the symptoms appeared in plants affected by esca were similar to those of healthy plants. Measurements made one month before the appearance of the symptoms cannot be used as screening method to determine whether the vine will show esca. No differences in dye translocation were found before the symptoms’ appearance. However, a decrease in xylem flux was measured in symptomatic vines of Cabernet Sauvignon. After the appearance of esca symptoms, only the Trebbiano had a lower xylem flux than the healthy vines.

Preliminary histological observations on grapevine affected by esca disease

Esca is a destructive disease of the woody tissues of grapevine (Vitis vinifera L.) and due to the complexity of disease many aspects of host-pathogen interactions are not clearly understood. The histological characteristics of esca symptomatic petioles and internodes, collected from Cabernet Sauvignon and Sangiovese grapevine were studied. The tissues were fixed in FAA, dehydrated and embedded in Histoplast. To identify the lignified cell walls the sections were stained by Crystal violet and Erythrosin B and observed using an optical microscope. The main feature of tissues infected by esca disease was the minor lignification of vascular tissues, which was observed in petiole tissues before appearance of esca symptoms. The opportunity to utilize the histological examination of tissues as a method for the early detection of esca infections is hypothesized for the future application.

Phylogenetic analysis of viruses in Tuscan Vitis vinifera sylvestris (Gmeli) Hegi

The health status of the native grapevine Vitis vinifera subsp. sylvestris (Gmeli) Hegi in natural areas in Europe has received little attention. A survey was carried out on wild grapevines in Tuscany (Italy), where isolates of the Grapevine rupestris stem pitting virus (GRSPaV), Grapevine leafroll-associated virus 1 and 3 (GLRaV-1 and GLRaV-3) and Grapevine virus A (GVA) were detected. The complete coat protein (CP) region of these isolates was sequenced to investigate the relationship of the viral variants from Tuscan wild grapevines with isolates from different geographical origins. According to the phylogenetic analyses, GLRaV-1 and GLRaV-3 isolates from Tuscan wild grapevines clustered with isolates from cultivated grapevines with nucleotide sequence identities ranging from 66% to 87% and from 72.5% to 99% respectively, without any correlation between the distribution and geographical origin. Conversely, GRSPaV and GVA isolates clustered together with other Italian isolates from V. vinifera with nucleotide sequence identities ranging from 71.14% to 96.12% and from 73.5% to 92%, respectively. Our analysis of the whole amino acid sequences revealed a high conservation level for the studied proteins explained by a selective pressure on this genomic region, probably due to functional constraints imposed on CP, such as specific interactions with cellular receptors in the insect vectors necessary for successful transmission. In addition, analyses of genetic recombination suggest no significant point mutations that might play a significant role in genetic diversification. The dN/dS ratio also estimated a low number of non-silent mutations, highlighting the purifying selective pressure. The widespread distribution of the Rugose wood complex (GRSPaV and GVA associated disease) in comparison with the Grapevine Leafroll associated viruses (GLRaV-1 and -3) could explain the major geographical correlation found for the viral variants detected in Tuscany.

Effectiveness of Azospirillum brasilense Sp245 on young plants of Vitis vinifera L.

Abstract Information about the influence of the plant growth promoting rhizobacteria Azospirillum brasilense Sp245 on the development of grapevine plants could be promoted to enhance sustainable agricultural practices for globally important fruit crops such as grapes. Thus, this study was initiated to evaluate the potential influence of A. brasilense Sp245 on two separate experimental trials, A) potted young grape plants: cv. ‘Colorino’ grafted onto two rootstocks 420A and 157/11 which received a fixed volume of inoculum at different times of vegetative cycle; B) hardwood cuttings from rootstock mother-plants of 420A and 775P inoculated during the phase of hydration, before bench-grafting in a specialized nursery. Overall, our results revealed that A. brasilense Sp245 has considerable potential to enhance the root apparatus and vegetative development in grapevines. Potted plants inoculated with A. brasilense Sp245 showed an improved development. Repeated supply was revealed to be more effective, inducing a greater accumulation of dry mass. Interesting findings were obtained in nursery experiments resulting from a considerable enhancement of the final quality of roots. The stimulating effect of A. brasilense Sp245 on vegetative development of rootstocks and vines may indeed improve sustainability in viticulture, through the promotion of healthy growth and a reduced dependence on fertilizers and other chemicals.

Genotyping of Grapevine Varieties from Garfagnana (Northern Tuscany): Evidence of a Historical Center of Diversity

The aim of this investigation was to recover, characterize, and increase the value of local grapevine varieties from Garfagnana, a mountainous area situated in the north of Tuscany (located in central Italy). A total of 130 accessions (vines) were identified in old Garfagnana vineyards, characterized by Organisation Internationale de la Vigne et du Vin morphological-phenological and productive parameters, and genotyped with 14 microsatellite loci. The microsatellite analysis identified 50 genotypes. Some of these genotypes matched Tuscan genotypes, others corresponded to varieties cultivated in other Italian and European regions, and 18 appeared to be genotypes currently identified only in Garfagnana and presumably autochthonous to this area. Cluster and similarity analyses based on both microsatellite and morphology data indicated a clear grouping of the majority of the autochthonous genotypes from Garfagnana. A parentage analysis revealed that the Garfagnana autochthonous genotypes are highly first degree–related among each other, suggesting that Garfagnana is a distinct historical center of diversity of cultivated varieties. The data from all varieties have been entered into the Italian Vitis Database (www.vitisdb.it).