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Žatec, Czech Republic

Patzak J.,Hop Research Institute Co. | Matousek J.,Academy of Sciences of the Czech Republic
Biologia Plantarum | Year: 2011

The use of expressed sequence tag-simple sequence repeat (EST-SSR) markers might reflect the better relationship among species or cultivars than markers previously used. The first set of 30 EST-SSR was developed in hop (Humulus lupulus L.). They represent 25 gene loci with total of 1268 EST sequences. They were used for characterization of 11 hop samples and cross-amplification in Humulus japonicus Sieb. et Zucc. The number of alleles per locus ranged from two to nine. The observed and expected heterozygosities ranged from 0. 182 to 0. 956 and from 0. 233 to 0. 775, respectively. We used EST-SSR markers for cluster analysis of hop genotypes. Dendrogram well matched with genealogical and geographical data for hop genotypes. © 2011 Springer Science+Business Media B.V.

Still increasing attention has been paid to the development of IPM systems within EU countries. Natural enemies play a very important role in these systems. Therefore, it is necessary to use only such pesticides, whose harmfulness is generally lower and acceptable. Downy mildew (Pseudoperonospora humuli) is commonly controlled by fungicides applied during the season. Nevertheless, at that time numerous aphidophagous predators, especially coccinellids are present on leaves of the treated plants feeding on aphids. Ladybird Propylea quatuordecimpunctata L. belongs to the most important species attacking damson-hop aphid (Phorodon humuli Schrank). Fungicides, which are in current use, were tested on eggs, larvae, pupae and adults of this ladybird species to determine their real effect and convenience of their inclusion within IPM systems. The fungicides tested in the bioassays increased the mortality rate of each developmental stage of P. quatuordecimpunctata. Adults of coccinellids were more resistant to the fungicides than the other developmental stages. Very low susceptibility was found out after treatment with azoxystrobin. High tolerance of adults was confirmed also in the other tested fungicides. Eggs and larvae were generally more susceptible than adults. Azoxystrobin again showed the lower toxicity and its convenience for IPM system as the mortality of eggs as well as larvae was the lowest. On the contrary, copper fungicides showed commonly higher mortality.

Patzak J.,Hop Research Institute Co.
Genome / National Research Council Canada = Génome / Conseil national de recherches Canada | Year: 2012

The aim of this study was to compare traditional hierarchical clustering techniques and principal coordinate analysis (PCoA) with the model-based Bayesian cluster analyses in relation to subpopulation differentiation based on breeding history and geographical origin of apple (Malus×domestica Borkh.) cultivars and landraces. We presented the use of a set of 10 microsatellite (SSR) loci for genetic diversity structure analyses of 273 apple accessions from national genetic resources. These SSR loci yielded a total of 113 polymorphic SSR alleles, with 5-18 alleles per locus. SSR molecular data were successfully used in binary and allelic input format for all genetic diversity analyses, but allelic molecular data did not reveal reliable results with the NTSYS-pc and BAPS softwares. A traditional cluster analysis still provided an easy and effective way for determining genetic diversity structure in the apple germplasm collection. A model-based Bayesian analysis also provided the clustering results in accordance to traditional cluster analysis, but the analyses were distorted by the presence of a dominant group of apple genetic resources owing to the narrow origin of the apple genome. PCoA confirmed that there were no noticeable differences in genetic diversity structure of apple genetic resources during the breeding history. The results of our analyses are useful in the context of enhancing apple collection management, sampling of core collections, and improving breeding processes.

Urban J.,Mendel University in Brno | Krofta K.,Hop Research Institute Co. | Kucera J.,EMS Brno
Acta Horticulturae | Year: 2012

Evapotranspiration of the Czech hop cultivar Agnus (Humulus lupulus L.) plantation was investigated during three consecutive growing seasons. We measured two components of the water balance: total evapotranspiration (using the Bowen ratio energy balance method) and transpiration of the bines (using the stem heat balance sensors type EMS SF 62). Actual evapotranspiration peaked when the crop was fully developed, at 80 - 90% of the potential evapotranspiration. Most of the water was evaporated and less than half of the total amount of vaporized water was transpired (the partitioning depended on a stage of crop development). EMS heat balance sensors don't require any empirical calibration. However, to ensure the correctness of the sap flow measurements, a calibration of the sap flow sensors was performed. Just before the harvest, a total of eighteen bines were removed from the plants and their water uptake was measured potometrically (volumetrically). Accuracy of the sap flow measurement was -3 % when compared against potometry.

Matousek J.,Academy of Sciences of the Czech Republic | Matousek J.,University of South Bohemia | Kocabek T.,Academy of Sciences of the Czech Republic | Patzak J.,Hop Research Institute Co. | And 4 more authors.
BMC Plant Biology | Year: 2012

Background: Lupulin glands of hop produce a specific metabolome including hop bitter acids valuable for the brewing process and prenylflavonoids with promising health-beneficial activities. The detailed analysis of the transcription factor (TF)-mediated regulation of the oligofamily of one of the key enzymes, i.e., chalcone synthase CHS_H1 that efficiently catalyzes the production of naringenin chalcone, a direct precursor of prenylflavonoids in hop, constitutes an important part of the dissection of the biosynthetic pathways leading to the accumulation of these compounds.Results: Homologues of flavonoid-regulating TFs HlMyb2 (M2), HlbHLH2 (B2) and HlWDR1 (W1) from hop were cloned using a lupulin gland-specific cDNA library from the hop variety Osvald's 72. Using a "combinatorial" transient GUS expression system it was shown that these unique lupulin-gland-associated TFs significantly activated the promoter (P) of chs_H1 in ternary combinations of B2, W1 and either M2 or the previously characterized HlMyb3 (M3). The promoter activation was strongly dependent on the Myb-P binding box TCCTACC having a core sequence CCWACC positioned on its 5' end region and it seems that the complexity of the promoter plays an important role. M2B2W1-mediated activation significantly exceeded the strength of expression of native chs_H1 gene driven by the 35S promoter of CaMV, while M3B2W1 resulted in 30% of the 35S:chs_H1 expression level, as quantified by real-time PCR. Another newly cloned hop TF, HlMyb7, containing a transcriptional repressor-like motif pdLNLD/ELxiG/S (PDLNLELRIS), was identified as an efficient inhibitor of chs_H1-activating TFs. Comparative analyses of hop and A. thaliana TFs revealed a complex activation of Pchs_H1 and Pchs4 in combinatorial or independent manners.Conclusions: This study on the sequences and functions of various lupulin gland-specific transcription factors provides insight into the complex character of the regulation of the chs_H1 gene that depends on variable activation by combinations of R2R3Myb, bHLH and WDR TF homologues and inhibition by a Myb repressor. © 2012 Matousek et al; licensee BioMed Central Ltd.

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