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Matousek J.,Academy of Sciences of the Czech Republic | Radisek S.,Slovenian Institute for Hop Research and Brewing | Jakse J.,Center for Plant Biotechnology and Breeding | Duraisamy G.S.,Academy of Sciences of the Czech Republic | And 5 more authors.
Acta Horticulturae | Year: 2013

A viroid disease syndrome that was recently described on Slovenian cultivar 'Celeia' was investigated. The disease was transferred using biolistic approach to Czech hop under isolated experimental conditions. A complex of strong symptoms appeared on cultivar 'Osvald's 72' that was quite comparable to cultivar 'Celeia'; low plant fitness strong stunting, leaf malformation, small (tiny) leaves and frequently visible leaf mosaic, which was not associated with virus infection. Hop stunt viroid (HpSVd) was analyzed in detail in the inoculated Czech hop that survived initial infection. It was confirmed that a population of viroid was detectable in the leaves with a clearly dominant HpSVd-cucumber pale fruit viroid-like (HpSVd-cuc) sequence. Besides HpSVd, also traces of truncated Citrus viroid (CVd IV) were detected in surviving biolistically infected hop samples. In some samples, HpSVd was detectable by Northern blots, but not by RT PCR, suggesting some viroid sequence change(s) upon adaptation in hop. An expression of several pathogenesis-associated marker genes were investigated. It was found that experimentally induced viroid syndrome in 'Osvald's 72' led to gene deregulation and especially to strong depression of HlbHLH2 transcription factor participating in metabolome regulation in hop.

Pavlovic M.,International Hop Growers Convention | Pavlovic M.,Slovenian Institute for Hop Research and Brewing
Bulgarian Journal of Agricultural Science | Year: 2012

Since its inception, the common agricultural policy (CAP) has been under constant internal and external reform pressures. This study belongs to a Health Check of the EU's latest CAP reform phase, which started in 2007. It analyzes the main effects of the CAP reform in 2003 (decoupled aid, as established by Council Regulation 1782/2003) on the hop industry sector. The research results demonstrate to what extent the CAP measures supporting hops have affected the production decisions of farmers in the EU's traditional hop production areas. There were three judgment criteria considered and discussed: (i) the extent to which the CAP reform has influenced the profitability of hops (production areas, capital investments); (ii) the extent to which the effects on production vary between, on the one hand, countries adopting fully decoupled support and, on the other, countries adopting partial coupling; and (iii) the extent to which producer groups contributed to stabilizing markets. The results illustrate that there was no evidence that CAP measures introduced after the reform had a significant influence on the production decisions of farmers in the traditional hop production areas from 2004 to 2008.

Sres A.,Bayer CropScience | Trdan S.,University of Ljubljana | Leskosek G.,Slovenian Institute for Hop Research and Brewing | Vidrih M.,University of Ljubljana | Vucajnk F.,University of Ljubljana
Cereal Research Communications | Year: 2015

The effect of spraying speed (5, 8.5 or 12 km/h) on deposition quality of fungicide on a winter wheat head, yield, grain quality, occurrence of Fusarium head blight (FHB) and deoxynivalenol (DON) content in grains was investigated in 2011 and 2012. Asymmetric double flat fan air-injector nozzles were used in the trial at a spraying pressure of 5.0 bars. A prothiconazole + tebuconazole fungicide mixture was used for spraying. An increase of spraying speed significantly lowered coverage values at the front and rear parts of a wheat head. At all three spraying speeds, the rear part of a wheat head reached a better coverage value. The effect of spraying speed was significant in 2011, when the 5 km/h spraying speed generated a significantly higher grain yield and a significantly higher thousand-grain weight in comparison with the other treatments. In both trial years, the lowest grain yield occurred on the unsprayed control. In 2011 and 2012, the latter also reached the lowest hectolitre weight and thousand-grain weight. In both trial years, the unsprayed control had a significantly higher DONcontent than the other treatments. In 2012, the DONcontent on the unsprayed control exceeded the allowed maximum level. The spraying speed did not affect the DON content in the grains. The effect of spraying speed was also noted in the FHB incidence. A significantly lower FHB incidence occurred at the 5 and 8.5 km/h spraying speeds.

Mandelc S.,University of Ljubljana | Timperman I.,Ghent University | Radisek S.,Slovenian Institute for Hop Research and Brewing | Devreese B.,Ghent University | And 2 more authors.
Plant Physiology and Biochemistry | Year: 2013

Verticillium wilt, caused by the soil borne fungal pathogen Verticillium albo-atrum, is a serious threat to hop (Humulus lupulus L.) production in several hop-growing regions. A proteomic approach was applied to analyse the response of root tissue in compatible and incompatible interactions between hop and V.albo-atrum at 10, 20 and 30 days after inoculation, using two-dimensional difference gel electrophoresis (2D-DIGE) coupled with de novo sequencing of derivatized peptides. Approximately 1200 reproducible spots were detected on the gels, of which 102 were identified. In the compatible interaction, 252 spots showed infection-specific changes in spot abundance and an accumulation of defence-related proteins, such as chitinase, β-glucanase, thaumatin-like protein, peroxidase and germin-like protein, was observed. However, no significant infection-specific changes were detected in the incompatible interaction. The results indicate that resistance in this pathosystem may be conferred by constitutive rather than induced defence mechanisms. The identification and high abundance of two mannose/glucose-specific lectin isoforms present only in the roots of the resistant cultivar suggests function of lectins in hop resistance against V.albo-atrum. © 2013 Elsevier Masson SAS.

Majer A.,University of Ljubljana | Javornik B.,University of Ljubljana | Cerenak A.,Slovenian Institute for Hop Research and Brewing | Jakse J.,University of Ljubljana
Molecular Breeding | Year: 2014

Although sources of resistance to major pathogens exist in cultivated hop germplasm, little effort has been invested to date in developing resistance-linked markers. The aim of this study was to design and evaluate resistance gene analogs (RGAs) potentially useful for marker-assisted selection towards novel resistant hop cultivars. A set of 34 putative hop RGAs was retrieved by screening publicly available hop expressed sequence tags (ESTs) for conserved sequence motifs of common resistance protein domains. Seventeen of these were identified as putative RGAs by BLAST analyses. Exon/intron boundary prediction enabled re-sequencing of 24 EST-RGAs, allowing the acquisition of approximately 5 kbp of novel intronic sequence and 8 kbp of re-sequenced exons. Fifteen EST-RGAs exhibited polymorphisms and were added to a framework linkage map of hop. In addition to providing EST-derived markers potentially useful for resistant hop cultivar development, this study provides valuable insights into the utility of targeting hop introns for marker development. © 2013 Springer Science+Business Media Dordrecht.

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