20 research outputs found
Molecular differentiation of ‘Candidatus Phytoplasma mali’ and its spreading in Friuli Venezia Giulia region (north-east Italy)
No full textExpression of flavonoid genes in the red grape berry of 'Alicante Bouschet' varies with the histological distribution of anthocyanins and their chemical composition
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Effect of water deficit on Merlot grape tannins and anthocyanins across four seasons
No full textTannins and anthocyanins impart important sensory attributes and potential health benefits in wine. The effect of water deficits (WDs) on fruit growth, anthocyanins, and skin tannins was investigated in field grown Vitis vinifera L. 'Merlot' berries across four seasons (2004, 2005, 2007, and 2008) by imposing deficits from the onset of ripening until maturity. WD reduced berry weight and increased the concentration of anthocyanins all four seasons, and increased the concentration of tannins three of four seasons. Under WD, anthocyanin concentration at harvest (mg/g of berry fresh weight) was 53.0-61.6% greater than in Controls (C), and anthocyanin content (mg/berry) was 28.7-35.3% greater than in C. By contrast, WD increased tannin concentration (mg/g of berry fresh weight) at harvest by 12.6-36.9% compared to C in 2004, 2005, and 2008, and did not influence the concentration in 2007. Tannin content (mg/berry) at harvest was unaffected except in 2004 when it was 25.7% greater than in C. Thus, water deficits consistently increased anthocyanin concentration by increasing content per berry and reducing fruit growth, but increased tannin concentration less and only by reducing fruit growth, except in one year where the tannin content was increased. These results demonstrate that management of vine water deficit during ripening is a much more effective tool to increase anthocyanins than tannins in Merlot grapes. © 2011 Elsevier B.V
Effect of manure application timing on roots, canopy and must quality in Vitis vinifera \u27Merlot\u27: a case study in Italy, North-East
No full textThe maintenance and improvement of soil fertility are among the most important management practices in viticulture. The system efficiency fertilization (SEF) which is a new concept based on a maximum utilization of organic fertilizers (i.e., manure) has become very important, especially within the organic viticulture sector, since other fertilizers are not allowed. The aim of this study was to determine the effect of different manure application timing on the root, shoot, and the grapevine yield, accumulation, and quality of biochemical compounds in the grape must since the timing effect was not previously investigated. The study was carried out on \u27Merlot\u27 variety organically cultivated, whose production aims at obtaining high-quality red wines. Three treatments were applied: NT (Non-Treated), T1 (Treated1- manure applied in late October) and T2 (Treated2 - manure applied in late February). After two study-years, the undertaken research has shown positive influences of soil manure application on the canopy features (T1), yield, and yield components (T2), along with a major accumulation of the primary metabolites (T2) (soluble solid, carbohydrates, chlorophyll). Yet, the secondary metabolites (polyphenols and anthocyanins) were promoted in the grape must at harvest time, especially when the manure was applied in late October (T2). Considering the benefits of manure application in the T2, after two study years, this timing is recommended in order to improve \u27Merlot\u27 grapes for high-quality red wine production
Effect of early cane pruning on yield components, grape composition, carbohydrates storage and phenology in Vitis vinifera L. cv. Merlot
No full textPyramiding resistance genes and widening the genetic base of the apple (Malus × domestica Borkh.) crop
No full textApple breeding is active worldwide and yet the apple crop is in a precarious state as it relies on few dominant cultivars and only the Rvi6 (formerly Vf) gene, that confers resistance to scab, has been extensively exploited in the cultivars entered the market in recent years. However, there are some 20 disease resistance genes described in apple and the apple germplasm includes thousands of accessions in the repositories. In this paper, a breeding programme is described, whereby 36 genotypes, including ancient and contemporary apple cultivars, were crossed to produce a new set of selections that combine extensive genetic resources with pyramided resistance genes to several apple diseases, such as scab and powdery mildew. The 110 cross combinations carried out successfully, of the 260 initially planned, produced 7,876 offsprings, reduced to 2,969 after screening with molecular markers associated with five resistance genes. Selections with three or two resistance genes and good agronomic characteristics were kept for further field observations with the aims of creating new cultivars for the market and new parents for future breeding projects
Evaluation of sensitivity and specificity in RNA-Seq-based detection of grapevine viral pathogens
No full textVirus detection is a crucial step for the implementation of clean stock programs that preserve healthy crop species. Viral infections in grapevine, a vegetatively propagated perennial crop, cannot be eradicated from the vineyards by the application of agrochemicals and must be curtailed at the stage of nursery production during the propagation of planting material. Viral detection is routinely performed using enzyme-linked immunosorbent assays (ELISA) or Reverse Transcription-quantitative Polymerase Chain Reactions (RT-qPCR). High throughput sequencing (HTS) approaches have the potential to detect all viral pathogens in a plant specimen. However, to date, no published HTS-based study has used threshold selection based on ROC curves for discriminating positive from negative samples. To fill this gap, we assessed the specificity and sensitivity of different sequencing and bioinformatics approaches for nine common viruses, which were tested in the same specimens using ELISA and/or RT-qPCR. The normalized detection thresholds giving the best results were 19.28 Fragments Per Kilobase of transcript per Million mapped reads (FPKM) for alignment-based total RNA-Seq approaches, 386 Reads Per Million mapped reads (RPM) for metagenomics-based total RNA-Seq, 1572 FPKM for alignment-based small RNA-Seq analysis and 0.97 % of contigs for de novo analysis of small RNA-Seq data. Validation of the proposed thresholds using independent specimens collected over time from the same stocks and other specimens collected from nearby stocks that had derived from the same propagating material showed that HTS approaches are accurate, with RNA-Seq approaches showing better performance than small RNA-Seq
Phenolics in grape berry and key antioxidants
No full textPhenolic compounds are important components of die grape berry in the determination of wine style and quality. In the past decade, significant advances towards a better understanding of the genetics, biochemistry, and physiology governing the synthesis of this class of secondary metabolite have been made. This deeper knowledge of phenylpropanoid and flavonoid metabolism strengthens the foundation for practical applications in the vineyard; investigations involving cultural practices and manipulation of environmental effects can help viticulturists deliver grapes to winemakersthat are better suited to particular enological objectives, as well as possibly enriching the product in health-promoting compound
