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Variability in grape composition and phenology of \u27Tempranillo\u27 in zones located at different elevations and with differences in the climatic conditions
Get PDFThe objective of this research was to analyse the variability on phenology and berry composition of \u27Tempranillo\u27 among different elevations and different climatic conditions. The study was conducted on \u27Tempranillo\u27 vineyards located in Rioja DOCa at elevations between 367 and 650 m a.s.l. Phenology and the evolution of berry composition during ripening, related to pH, total acidity, malic acid, total anthocyanins, total polyphenols index, colour intensity and sugar content were analysed for the period 2008-2018 at each elevation. The weather conditions recorded during the period of study were evaluated. The results indicate that, on average, differences between the analysed elevations of up to 21 days existed in the dates in which the maturity was reached, being the differences higher in the years with extreme conditions (very wet or dry and very hot or cool). The comparative analysis among elevations and in years with differences in temperature and in precipitation allowed knowing the differences in the vine response under different climatic conditions. From this analysis some conclusions may be extracted that may be useful for police makers to define new planting areas in which less imbalanced situations may occur under warm conditions
Grapevine trunk diseases in German viticulture. III. Biodiversity and spatial distribution of fungal pathogens in rootstock mother plants and possible relation to leaf symptoms
Get PDFThree rootstock mother blocks, planted with cultivars SO4 (planted 2004), 125AA (2005) and 5BB (2005), and located in southwestern Germany were examined for the existence of grapevine trunk disease (GTD) pathogens and related internal and external symptoms between 2011 and 2017. Frequency of leaf symptoms ranged from 0.2 % in six-year old blocks to appr. 1.5 % in 12-year-old blocks. While the typical "tiger stripe pattern" was less common, the majority of affected leaves was characterized by irregularly arranged necrotic spots spread over the leaf surface. Irrespective of leaf symptoms, in cross sections of 9-12 year old vines all sampled trunks (n ≥ 20 for each block) showed the typical GTD symptoms in the wood, with symptoms prevalent in the trunk head compared to the middle section and the basis of trunks. Pathogens were isolated from all trunks, with Fomitiporia mediterranea (Fmed), Cadophora luteo-olivacea (Clo), Phaeomoniella chlamydospora (Pch), Eutypa lata (Elata), and Phaeoacremonium aleophilum (Pal) being the most common. Other GTD species included Cadophora cf. novi-eboraci (new for German viticulture), Diaporthe eres, D. nobilis (new for German viticulture), D. rudis (new for German viticulture), Eutypa laevata (new for German viticiculture), Ilyonectria europaea, I. liriodendri, and Pestalotiopsis sp. The significance of the once found Sarocladium strictum remains unclear. GTD species were revealed from all sampled trunk parts, with maximum diversity and overall frequency in the trunk head. Further species, not related to GTDs, existed in all parts of the trunk. GTD pathogens were also demonstrated for all shoots (two shoots each of ten vines SO4, 125AA and 5BB, with five vines each externally symptomatic and non-symptomatic), but mostly could be detected by molecular means only. Clo, Pch, and Pal were the predominant species in shoots; further GTD species were Ilyonectria europaea, I. liriodendri, and Phaeoacremonium angustius
Evaluation of glutathione content in white grape varieties
Get PDFThe aim of this work was to evaluate the content of glutathione in the grape, must and wine of nine white varieties authorized in the Qualified Designation of Origin Rioja (Spain): \u27Chardonnay\u27, \u27Garnacha Blanca\u27, \u27Malvasía\u27, \u27Maturana Blanca\u27, \u27Tempranillo Blanco\u27, \u27Turruntés\u27, \u27Sauvignon Blanc\u27, \u27Verdejo\u27 and \u27Viura\u27. The results obtained showed important varietal differences in the concentration of GSH. \u27Sauvignon\u27 and \u27Tempranillo Blanco\u27 presented high levels of this compound in grape, must and wine. \u27Verdejo\u27 and \u27Turruntés\u27 registered high values in grape, which decreased notably in must and wine. In general, the GSH content decreased in musts due to oxidative processes. In \u27Chardonnay\u27, \u27Garnacha Blanca\u27, \u27Maturana Blanca\u27 and \u27Viura\u27 an increase was observed in wines, which could be caused by the inoculated yeast. The \u27Malvasía\u27 and \u27Maturana Blanca\u27 varieties registered the lowest level of this compound. The ratio of hydroxycinnamic acids to glutathione, indicator of the susceptibility of oxidation of musts, showed significant varietal differences, was lower in \u27Sauvignon Blanc\u27 and higher in \u27Garnacha Blanca\u27
Discrimination of aging wines with alternative oak products and micro-oxygenation by FTIR-ATR
Get PDFThe use of alternative oak wood products (AOP), such as chips, cubes and staves, among other, from different geographical origins is a common practice for wine aging, where the micro-oxygenation (MOX, adding small doses of oxygen constantly over time) is essential to obtain a final wine more stable in time and with similar characteristics of barrel-aged wine. The aim of this work was to identify if spectroscopic techniques allow to discriminate wines aged with alternative oak products (chips and staves) from different oak woods (American, French and Spanish) and a floating micro-oxygenation (20 µg·L−1) after 10 years of bottling and compared to those aged in barrels. The spectral information and analysis were performed in a FTIR-ATR, with 128 scans per spectrum at a spectral resolution of 8 cm-1 in the wavenumber range from 4,000 to 450 cm-1. Principal component analyses of spectral information were performed using the Unscrambler® X. The results indicate that with this technique it is possible to clearly separate the wines aged by the three systems (chips, staves and barrels) in the case of American oak. In the case of French oak, wines aged in chips were clearly differentiated from wines aged in staves with those aged in barrels between the two. It is also possible to clearly separate aged wines with different Spanish oak systems. The application of FTIR-ATR appears to be a powerful technique for discriminating the quality of wines aged by different AOPs and wood barrels from different geographical origins
Deciphering the genomic diversity of Bombyx mori nucleopolyhedrovirus isolates from Southeast Asia
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Detection of ‘Candidatus Phytoplasma pyri’ (pear decline agent) in pear trees by different diagnostic procedures in the seasonal course
Get PDFIn einem faktoriellen Versuch wurde der Einfluss von drei nukleinsäure-basierten Nachweisverfahren und zwei Probenumfängen auf die Nachweisrate von ‘Candidatus Phytoplasma pyri’ (Birnenverfallserreger) bei drei Birnensorten/Unterlagenkombinationen im Jahresverlauf untersucht. Triebproben wurden in etwa monatlichem Abstand über einen Zeitraum von 17 Monaten von natürlich infizierten Bäumen entnommen. Als Nachweismethoden wurden die nested PCR (nPCR), real-time LAMP (rtLAMP) und in geringerem Umfang real-time PCR (rtPCR) verwendet. Die Probenumfänge umfassten zwei Teilprobenmengen, bestehend aus drei bzw. zwei Triebstücken (insgesamt fünf) je Baum. Das Nachweisniveau war stark von der getesteten Sorte abhängig. Es war hoch bei der Kreuzungsnummer ‘48–40–95’ (81,4%), aber niedrig bei ‘Conference’ (26,2%) und ‘Xenia’ (19,2%), in deren Wiederholungsbäumen teilweise für längere Zeitabschnitte keine positiven Nachweise erhalten wurden, was zu insgesamt geringen Nachweisraten führte. In der Summe aller Sorten gab es keine signifikanten Nachweisunterschiede zwischen der nPCR und rtLAMP, dagegen wurden mit der rtPCR signifikant höhere Nachweisraten im Vergleich mit den anderen Nachweisverfahren erzielt. Durch die Untersuchung von beiden Teilproben anstatt nur einer je Baum konnte die Nachweisrate in den meisten Fällen verbessert werden und ergab in der Summe aller Untersuchungen für die Methoden und Sorten eine Steigerung um 29.4%. Die Nachweisrate variierte im Jahresverlauf in Abhängigkeit von der Methode und der Sorte, die meisten Bäume konnten jedoch im Zeitraum Spätwinter bis Anfang Frühjahr positiv getestet werden, außer bei ‘48–40–95’, in welcher der Erreger fast ganzjährig nachgewiesen werden konnte. Ein Vergleich des Einflusses der untersuchten Faktoren auf die Nachweisrate ergab für die Sorte/Unterlage den größten Effekt, gefolgt von der Methode und dem Probenumfang mit etwa gleich großen Auswirkungen.The influence of three nucleic acid-based detection procedures and two sample sizes on the detection rate of ‘Candidatus Phytoplasma pyri’ (pear decline agent) was studied in a factorial trial with three pear cultivar/rootstock combinations in the course of the year. Shoot samples were taken approximately every month over a period of 17 months from naturally infected trees. Nested PCR (nPCR), real-time LAMP (rtLAMP) and to a lesser extent real-time PCR (rtPCR) were used as detection methods. Sample sizes comprised two subsample sets consisting of three and two shoot pieces, respectively, (five in total) per tree. The detection level was highly dependent on the tested cultivar. The level was high for breeding code ‘48–40–95’ (81.4%) but low for cvs. ‘Conference’ (26.2%) and ‘Xenia’ (19.2%), whose replicate trees partly failed to be tested positive for longer periods resulting in overall low detection rates. Nested PCR and rtLAMP showed no significant detection rate differences in the sum of all cultivars, but rtPCR resulted in significantly higher detection rates compared to the other detection procedures. By analysing both subsample sets instead of only one per tree, the detection rates were improved in most cases with an overall increase of 29.4% considering the methods and cultivars. Detection rates varied depending on the method and the cultivar in the course of the year, but most of the trees were tested positive in the period from late winter to early spring, except for ‘48–40–95’, where the pathogen could be detected almost all year round. Comparing the impact for the factors investigated on the detection rate, the cultivar/rootstock combination was the greatest, followed by the method and sample size, both showing a similar effect
Differential diagnosis of the pathogens Pseudomonas syringae pv. aesculi and Phytophthora spp. at Aesculus spp. in the urban area of Hamburg
Get PDFWährend der dritten Reihenuntersuchung in der Freien und Hansestadt Hamburg an Aesculus spp. wurden 94 Rosskastanien der Arten A. hippocastanum und A. carnea auf die Phytopathogene Pseudomonas syringae pv. aesculi und Phytophthora spp. untersucht. Die Bäume wurden gezielt nach dem makroskopisch erfassten Schadbild und der räumlichen Verteilung im Stadtgebiet ausgewählt. Das Verfahren der Probenahme wurde minimalst invasiv durchgeführt. Die molekularbiologische Untersuchung erfolgte am Tag der Probenahme, sodass bereits am Folgetag die Laborbefunde vorlagen. Insgesamt wurden 82 Rosskastanien positiv auf P. syringae pv. aesculi und 7 Rosskastanien positiv auf Phytophthora spp. getestet. Die Sequenzierung ergab, dass es sich bei dem Phytophthora-Erreger um Phytophthora cactorum handelt. Zusätzlich wurde an 3 Rosskastanien eine Koinfektion festgestellt.During the third survey in the Free and Hanseatic City of Hamburg on Aesculus spp. 94 horse chestnut trees of the species A. hippocastanum and A. carnea with bleeding canker symptoms were examined. Subject of the screening were the pathogens Pseudomonas syringae pv. aesculi and Phytophthora spp. The trees were selected according to the macroscopically recorded damage pattern and the spatial distribution in the urban area. The sampling procedure was performed in a minimally invasive manner. The molecular biology examination was carried out on the day of sampling, allowing the laboratory findings to be available the following day. In total, 82 horse chestnut trees were tested positive for P. syringae pv. aesculi and 7 horse chestnut trees for Phytophthora spp. The sequencing revealed that the Phytophthora pathogen is Phytophthora cactorum. In addition, co-infection with both pathogens was found in 3 Horse Chestnut trees
