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Eisenstadt, Australia

Riedle-Bauer M.,Hohere Bundeslehranstalt und Bundesamt fur Wein und Obstbau Klosterneuburg | Hanak K.,Hohere Bundeslehranstalt und Bundesamt fur Wein und Obstbau Klosterneuburg | Regner F.,Hohere Bundeslehranstalt und Bundesamt fur Wein und Obstbau Klosterneuburg | Tiefenbrunner W.,Bundesamt fur Weinbau
Journal of Phytopathology | Year: 2010

In recent years, visual and analytical observations revealed a significant increase of 'Bois noir' (BN) in Austrian vineyards. Removing infected parts by pruning can prevent or reduce spread of the pathogen within the vines. Knowledge about the effect of pruning practices on recovery rates is essential for grapevine growers. Vines showing BN for the first time were visually categorized into classes of symptoms according to disease severity. In the ensuing winter, plants were pollarded 15 cm above the graft union (511 vines), cane pruned (529 vines) or spur pruned (heavy pruning of canes leaving spurs only; 31 vines). Pollarding resulted in significantly higher recovery rates (yearly average 62-84%) in the next growing season and significantly lower recurrence rates in the following years than cane pruning (yearly average 29-49% in the next growing season). Spur pruning was statistically indistinguishable from cane pruning. Our data allowed the conclusion that extensive removal of infected wood is crucial for immediate and persistent success of pruning measures. Recovery was significantly influenced by the severity of BN, by the cultivar and by the observation year. With pollarding treatments, a significant correlation between recovery and plant age was noticed. © 2010 Blackwell Verlag GmbH.

Compant S.,CNRS Chemical Engineering Laboratory | Gangl H.,Bundesamt fur Weinbau | Sessitsch A.,AIT Austrian Institute of Technology
Acta Horticulturae | Year: 2012

It is well documented that endophytic bacteria can colonize vegetative plant organs, but the evidence is still scarce regarding colonization of internal tissues of fruits and seeds. We previously gave indications on which taxa can inhabit under natural conditions fruits and seeds of grapevine and studied their niches of colonization. In this study we particularly investigated colonization of Bacillus spp., which colonize fruits and seeds of grapevine plants endophytically. Bacteria were visualized via fluorescence in situ hybridization inside berry pulp and seeds of grapevine grown in an Austrian vineyard. The bacteria colonized intercellular spaces inside the pulp of berries. Although it is difficult to visualize bacteria inside seeds due to the difficulty to make sections for microscopy, we could demonstrate that these bacteria can also be detected along some cell walls inside seeds in few sections, whereas in other sections no bacteria were observed. The findings further demonstrated that plant-colonizing bacteria can establish endophytic subpopulations inside parts of fruits and seeds of grapevine plants.

Compant S.,AIT Austrian Institute of Technology | Compant S.,CNRS Chemical Engineering Laboratory | Compant S.,Toulouse University Midi-Pyrenees | Mitter B.,AIT Austrian Institute of Technology | And 4 more authors.
Microbial Ecology | Year: 2011

Endophytic bacteria can colonize various plants and organs. However, endophytes colonizing plant reproductive organs have been rarely analyzed. In this study, endophytes colonizing flowers as well as berries and seeds of grapevine plants grown under natural conditions were investigated by cultivation as well as by fluorescence in situ hybridization. For comparison, bacteria were additionally isolated from other plant parts and the rhizosphere and characterized. Flowers, fruits, and seeds hosted various endophytic bacteria. Some taxa were specifically isolated from plant reproductive organs, whereas others were also detected in the rhizosphere, endorhiza or grape inflo/infructescence stalk at the flowering or berry harvest stage. Microscopic analysis by fluorescence in situ hybridization of resin-embedded samples confirmed the presence of the isolated taxa in plant reproductive organs and enabled us to localize them within the plant. Gammaproteobacteria (including Pseudomonas spp.) and Firmicutes (including Bacillus spp.) were visualized inside the epidermis and xylem of ovary and/or inside flower ovules. Firmicutes, mainly Bacillus spp. were additionally visualized inside berries, in the intercellular spaces of pulp cells and/or xylem of pulp, but also along some cell walls inside parts of seeds. Analysis of cultivable bacteria as well as microscopic results indicated that certain endophytic bacteria can colonize flowers, berries, or seeds. Our results also indicated that some specific taxa may not only derive from the root environment but also from other sources such as the anthosphere. © 2011 Springer Science+Business Media, LLC.

Lopandic K.,University of Natural Resources and Life Sciences, Vienna | Pfliegler W.P.,Hungarian Academy of Sciences | Tiefenbrunner W.,Bundesamt fur Weinbau | Gangl H.,Bundesamt fur Weinbau | And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2016

The yeasts of the Saccharomyces genus exhibit a low pre-zygotic barrier and readily form interspecies hybrids. Following the hybridization event, the parental genomes undergo gross chromosomal rearrangements and genome modifications that may markedly influence the metabolic activity of descendants. In the present study, two artificially constructed hybrid yeasts (Saccharomyces cerevisiae x Saccharomyces uvarum and S. cerevisiae x Saccharomyces kudriavzevii) were used in order to evaluate the influence of high-sugar wine fermentation on the evolution of their genotypic and phenotypic properties. It was demonstrated that the extent of genomic modifications differs among the hybrids and their progeny, but that stress should not always be a generator of large genomic disturbances. The major genome changes were observed after meiosis in the F1 segregants in the form of the loss of different non-S. cerevisiae chromosomes. Under fermentation condition, each spore clone from a tetrad developed a mixed population characterized by different genotypic and phenotypic properties. The S. cerevisiae x S. uvarum spore clones revealed large modifications at the sequence level of the S. cerevisiae sub-genome, and some of the clones lost a few additional S. cerevisiae and S. uvarum chromosomes. The S. cerevisiae x S. kudriavzevii segregants were subjected to consecutive loss of the S. kudriavzevii markers and chromosomes. Both the hybrid types showed increased ethanol and glycerol production as well as better sugar consumption than their parental strains. The hybrid segregants responded differently to stress and a correlation was found between the observed genotypes and fermentation performances. © 2016 Springer-Verlag Berlin Heidelberg

Tiefenbrunner W.,Bundesamt fur Weinbau | Gangl H.,Bundesamt fur Weinbau | Leitner G.,Bundesamt fur Weinbau | Riedle-Bauer M.,Lehr und Forschungszentrum fur Wein und Obstbau | Tiefenbrunner A.,LMS Data
Mitteilungen Klosterneuburg | Year: 2011

In all Austrian winegrowing regions soil samples were taken from viticultural as well as agricultural areas and tested for nematodes of the family Longidoridae. In order to obtain a complete overview of the distribution of Longidoridae, samples were also taken from the riparian forests along the rivers Danube and March. Six species of the genus Xiphinema have been found in Austria up to now, but in vineyards only the following within the framework of this study: X. vuittenezi, the most present and abundant Longidoridae, and the X. americanum s. l. species X. brevicollum and X. pachtaicum. The latter is frequently found in vineyards north of the central Burgenland. The virus vectors X. index and X. diversicaudatum are rare according to current knowledge, although X. diversicaudatum is fairly abundant in common pastures and under fruit trees in Styria. Ten species of the genus Longidorus were found, two of which reached a high abundance in some samples: L. leptocephalus and L. raskii. The species L. elongatus, L. leptocephalus and L. poessneckensis are fairly widespread. Four species of this genus are vectors of various plant viruses: L. arthensis, L. attenuatus, L. elongatus and L. macrosoma. L. attenuatus transfers a grapevine virosis. From the genus Paralongidorus the species P. maximus, vector of a grapevine virus, has been found.

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