Karyotype and genome size in Euterpe Mart. (Arecaceae) species.

Euterpe (Martius, 1823), a genus from Central and South America, has species with high economic importance in Brazil, because of their palm heart and fruits, known as açaí berries. Breeding programs have been conducted to increase yield and establish cultivation systems to replace the extraction of wild material. These programs need basic information about the genome of these species to better explore the available genetic variability. The aim of this study was to compare E. edulis (Martius, 1824), E. oleracea (Martius, 1824) and E. precatoria (Martius, 1842), with regard to karyotype, type of interphase nucleus and nuclear DNA amount. Metaphase chromosomes and interphase nuclei from root tip meristematic cells were obtained by the squashing technique and solid stained for microscope analysis. The DNA amount was estimated by flow cytometry. There were previous reports on the chromosome number of E. edulis and E. oleracea, but chromosome morphology of these two species and the whole karyotype of E. precatoria are reported for the first time. The species have 2n=36, a number considered as a pleisomorphic feature in Arecoideae since the modern species, according to floral morphology, have the lowest chromosome number (2n=28 and 2n=30). The three Euterpe species also have the same type of interphase nuclei, classified as semi-reticulate. The species differed on karyotypic formulas, on localization of secondary constriction and genome size. The data suggest that the main forces driving Euterpe karyotype evolution were structural rearrangements, such as inversions and translocations that alter chromosome morphology, and either deletion or amplification that led to changes in chromosome size.

Influence of leaf removal on berry thermal efficiency for anthocyanin accumulation

The aim of this work was to analyse the effects of leaf removal on Touriga Nacional berry temperature and consequent thermal efficiency for anthocyanins biosynthesis. The field experiment was located at Dão Wine Research Station, Nelas, Portugal in an adult vineyard planted with North-South oriented rows, with the red grape variety Touriga Nacional grafted on 110R rootstock. The vines were trained on a vertical shoot positioning, spur-pruned on a bilateral Royat cordon system and deficit irrigated (50% ETc). The experimental design was a randomized complete block design with four replications of twelve vines per elemental plot, and the following two treatments: basal leaf removal (LR) and a control non-defoliated (ND). Berry temperature (Tb) was measured continuously during the second half (3rd to 19th September) of the 2009 ripening period using two-junction, fine-wires copper-constantan thermocouples manually inserted into the berries and connected to a data logger. A sample of clusters located in different canopy positions (exposed and internal; facing East and West) of 4 vines per treatment were used. To quantify the effect of Tb on anthocyanins biosynthesis, the berry hourly mean temperatures were converted into normal heat hours (NHH) and accumulated per day (NHHd) and per monitoring period (NHHc). For quantification of thermal requirements for anthocyanins synthesis and accumulation, a minimum of 10°C, a maximum of 35°C, and an optimum of 26°C were used. Meteorological variables were measured at an automatic weather station installed within the experimental plot. For all days of the monitoring period, daily average berry temperature (dTb) of all monitored berries was lower in ND treatment than in LR, being the maximum differences between treatments registered on 11th September. The highest dTb differences between treatments were registered on the clusters located at the west side of the canopy on 7th September while dTb of the clusters located in the centre of the canopy was less affected by leaf removal. The control non-defoliated treatment (ND) presented a significantly higher NHHc than that of LR being the higher differences presented by the clusters located in the west side. The lowest differences in NHHc were obtained in the clusters located in the centre of the canopy. Our results show that the thermal efficiency for berry anthocyanins accumulation was significantly affected by leaf removal and that this effect was dependent of the meteorological conditions, time of the day and berry/cluster location into the vine canopy.

Effects de l'application d'acide gibbérellique (GA3) sur la qualité de raisins et de vins produits en climat tropical au Nord-Est du Brésil.

The honeydew moth Cryptoblabes gnidiella is the main problem for the wineries in the Northeast of the Brazil, because it attacks the bunch and reduces the quality of the grapes and the wines. In order to stretch out the bunch to facilitate the penetration of the insecticides, it was used gibberellic acid. Six treatments with different concentrations and different dates of application, and the control were compared. The bunches are compact, characteristic of the "Syrah" grapes in the region. The grape berries were analysed at harvest and wines were made by microvinifications. The grape berries showed different qualitative characteristics, as berry weight, number of berries. °Brix, total acidity and heterogeneity of the maturation. The microvinifications were carried out with 50 kg of grapeberries into glass bottles of 20 L at 22°C, for the alcoholic and malolactic fermentations, then stabilized and bottled. The wines were tasted by a panel of ten people and compared on smell and taste plans. The tasting results showed that the control treatment was the best graded wine. The application of gibberellic acid allowed to control the honeydew moth attack, but it caused a heterogeneity on grape maturation, with a lower quality of the grapes and wines compared to the control.

Grape and Wine Metabolites: Biotechnological Approaches to Improve Wine Quality

Grape metabolites can be affected by many extrinsic and intrinsic factors, such as grape variety, ripening stage, growing regions, vineyard management practices, and edaphoclimatic conditions. However, there is still much about the in vivo formation of grape metabolites that need to be investigated. The winemaking process also can create distinct wines. Nowadays, wine fermentations are driven mostly by single-strain inoculations, allowing greater control of fermentation. Pure cultures of selected yeast strains, mostly Saccharomyces cerevisiae, are added to grape must, leading to more predictable outcomes and decreasing the risk of spoilage. Besides yeasts, lactic acid bacteria also play an important role, in the final wine quality. Thus, this chapter attempts to present an overview of grape berry physiology and metabolome to provide a deep understanding of the primary and secondary metabolites accumulated in the grape berries and their potential impact in wine quality. In addition, biotechnological approaches for wine quality practiced during wine alcoholic and malolactic fermentation will also be discussed.

Environmental factors correlated with the metabolite profile of Vitis vinifera cv. Pinot Noir berry skins along a European latitudinal gradient

Mature berries of Pinot Noir grapevines were sampled across a latitudinal gradient in Europe, from southern Spain to central Germany. Our aim was to study the influence of latitude-dependent environmental factors on the metabolite composition (mainly phenolic compounds) of berry skins. Solar radiation variables were positively correlated with flavonols and flavanonols and, to a lesser extent, with stilbenes and cinnamic acids. The daily means of global and erythematic UV solar radiation over long periods (bud break-veraison, bud break-harvest, and veraison-harvest), and the doses and daily means in shorter development periods (5–10 days before veraison and harvest) were the variables best correlated with the phenolic profile. The ratio between trihydroxylated and monohydroxylated flavonols, which was positively correlated with antioxidant capacity, was the berry skin variable best correlated with those radiation variables. Total flavanols and total anthocyanins did not show any correlation with radiation variables. Air temperature, degree days, rainfall, and aridity indices showed fewer correlations with metabolite contents than radiation. Moreover, the latter correlations were restricted to the period veraison-harvest, where radiation, temperature, and water availability variables were correlated, making it difficult to separate the possible individual effects of each type of variable. The data show that managing environmental factors, in particular global and UV radiation, through cultural practices during specific development periods, can be useful to promote the synthesis of valuable nutraceuticals and metabolites that influence wine quality.

Concentrazione di potassio nelle bacche e valori di pH e zuccheri nel mosto della cv Cabernet Sauvignon innestata su diversi portinnesti nel Sud del Brasile.

In field conditions two experiments were carried out in 2000/2001 and 2001/2002, to evaluate potassium (K) content in berries, and pH and total soluble solid values in the must. The experiment 1 was carried on a Udorthent soil and the experiment 2 on a Haplumbrept soil, both at Southern Brazil, Bento Gonçalves city. The Cabernet Sauvignon grapevine was grafted on different rootstocks (Rupestris Du Lot, R. 99, R. 110, SO4, 420 A, 1103, 101-14 and 3309). At full ripening, berries were collected and potassium concentration (2000/2001 and 2001/2002 seasons), pH and total soluble solids (2001/2002 season) were determined. Rootstock didn?t affect potassium content of berries, and pH and total soluble solid values in the must.

Effects and Modes od Action of Canopy Management Practices on Vine Physiology and Berry Composition in Organically-Cultivated cv. Sangiovese (Vitis Vinifera L.)

In organic and biodynamic vineyards, canopy management practices should be carefully and timely modulated, particularly in a context of climate change, for successfully achieving balanced plants, ventilated and exposed berries, elevated grape and wine quality. In 2013 and 2014, characterized by contrasting climatic conditions, the implications of post-veraison (late) or pea-size trimming, post-veraison or pre-harvest late defoliations and shoot-positioning (post-veraison) were assessed against long-shoots non treated controls, under field conditions on organically-cultivated cv. Sangiovese. The key agronomic and enological relevance of late trimming and defoliations clearly emerged in both seasons. Berry skin phenolics (e.g. anthocyanins, flavonols) increased markedly, without changes in technological parameters. In case of early trimming, such positive effects were observed only in 2013. Maintaining long shoots for shading decreased anthocyanins, flavonols and total phenolics concentrations and promoted the production of compact bunches. Experimental data strongly designated late trimming, a practice proved to contain yield and bunch compactness, as a valuable alternative to cluster thinning. Late trimming, defoliations and shoot positioning reduced the severity of Botrytis cluster rot. The highest levels of berry skins phenolic compounds in late trimmed and defoliated plants could have contributed control the severity of this pathogen. The enological benefits induced by late trimming and defoliations and shoot positioning emerged in both young and aged wines. For the first time, cell cultures from cv. Sangiovese berry tissues were obtained and enabled to investigate, in controlled conditions, the relations between mechanisms regulating secondary metabolism in grapevine cells and changes induced by environmental and agronomic factors. The Doctoral Dissertation strongly highlights the need to consider, for a proper interpretation of the multiple modifications induced by canopy management strategies, physiological mechanisms other than the canonic source-sink relationships, in particular their impact on the vine hormonal status.

Deciphering the role of plant microbiome on strawberry and raspberry growth, resistance, fruit quality and aroma

Besides their own adaptation strategies, plants might exploit microbial symbionts for overcoming both biotic and abiotic stresses and increase fitness. The current scenario of rapid climate change is demanding more sustainable agricultural management practices. The application of microbe-based products as a valid alternative to synthetic pesticides and fertilizers and their use to overcome stresses exacerbated by climate change, have been reviewed in the first part of this thesis. Berry fruits are widely cultivated and appreciated for their aromatic and nutraceutical properties. This thesis is focused on the role of plant and fruit microbiome on strawberry and raspberry growth, resistance, fruit quality and aroma. A taxonomical and functional description of the microbiome of different organs of three strawberry genotypes was performed both by traditional cultural dependent method and Next Generation Sequencing technique, highlighting a significant role of plant organs and genotype in determining the composition of microbial communities. Additionally, a selection of bacteria native of strawberry plants were isolated and screened for their plant growth promoting abilities and tested under the biotic stress of Xanthomonas fragariae infection and the abiotic stress of induced salinity. The monitoring of biometric parameters allowed the selection of a more restricted panel of bacterial strains, whose beneficial potential was tested in coordinated inoculations, or singularly. Raspberry plant was used for investigating the effect of cultivation method in determining fruit microbiome, and its consequent influence of berry quality and aroma. Interestingly, the cultivation method strongly influenced fruit nutraceutical traits, aroma and epiphytic bacterial biocoenosis. The involvement of the bacterial microbiota in fruit aroma determination was evaluated by performing GC–MS analysis of VOCs occurring in control, sterile and artificially reinoculated berries and by characterizing control and reinoculated berry microbiome. Differently treated berries showed significantly different aromatic profile, confirming the role of bacteria in fruit aroma development.

In vitro application of biocontrol agents to improve the safety and quality of grapevine products

Pathogenic fungi are responsible for vine diseases affecting the grapevine yield and the organoleptic quality of the final wine products. Using of biocontrol agents can represent a sustainable alternative to the use of synthetic fungicides whose intense use can have negative effects on the ecosystem and cause increase resistant pathogen population to synthetic agents. The principal aim of my PhD thesis was the isolation and characterization of new yeast strains and Bacillus subtilis SV108 as biocontrol agent and the comprehension of the mechanism of their antimicrobial action. Accordingly, twenty wild yeast and one selected bacterium isolated among 62 samples, isolated from different Italian and Malaysian regions and molecularly identified, were evaluated in a preliminary screening test on agar. Results showed the highest effects on inhibiting mycelial growth by Starmerella bacillaris FE08.05, Metschnikowia pulcherrima GP8 and Hanseniaspora uvarum GM19. On the other side, Bacillus subtilis SV108 showed the ability of inhibit the mycelial growth of selected fungi by producing antimicrobial compounds on Malt Extract Broth medium recovered by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and identified by electrospray ionization (ESI) tandem mass spectrometer Triple TOF 5600. Moreover, in order to analyze the volatile fraction of compounds, the quantitative analysis of the VOCs profiles was performed by GC/MS/SPME. The analysis highlighted the presence of isoamyl and phenylethyl alcohols and an overall higher presence of low-chain fatty acids and volatile ethyl esters. All the data collected suggest that the tested yeasts, found among the epiphytic microbiota associated with grape berries, can be potentially effective for the biological control of pathogenic moulds. On the other hand, the proteomic study conducted on B. subtilis SV108 revealed that there are two cyclic antifungal peptides which can explain the antimicrobial effect of Bacillus subtilis SV108 acting as biocontrol agent against fungal pathogens in grapevine.