Development of alder carr after the abandonment of wet grasslands during the last 70 years     

Jan Douda  Alžběta Čejková  Karel Douda  Jana Kochánková 《Annals of Forest Science》2009,66(7):712-712

? The secondary succession of wet grasslands to communities of alder carr dominated by Alnus glutinosa was recorded in different parts of Europe during the 20th century. However, knowledge of such development of alder carr remains insufficient.

? The development of alder carr was reconstructed at five sites in the Czech Republic, using historical aerial photographs and methods of dendrochronology. The aims were to investigate the succession from wet grasslands to alder carr at sites previously intensively managed for agriculture and to find out the role of fluctuations in the groundwater table, caused by artificial drainage channels, in the observed stand dynamics and tree growth.

? The spread of forest (i.e., an increase in forest cover) predominated until the 1970s at all sites. This trend was disrupted by a large-scale dieback of forest stands in four of the five sites after the 1970s, followed by an increase in patch heterogeneity, as indicated by landscape metrics. The radial growth increment in Alnus glutinosa has been affected predominately by local environmental factors, probably including the changing degree of waterlogging. Forest dieback was presumably connected with a lesser extent of drainage channels.

? Our results indicate that observed successional pathways at sites of alder carr were probably caused by local changes in the groundwater table.

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Relationships between line per se and testcross performance for agronomic traits in two broad-based populations of maize   总被引：1，自引：0，他引：1  

Goran Bekavac  Božana Purar  Đorđe Jocković 《Euphytica》2008,162(3):363-369

Degree of the association between line per se performance (LP) and testcross performance (TP) is important in breeding programs and simultaneous improvement of commercial hybrids and their parental lines. This experiment was designed to study genetic variability and genetic correlation for several agronomic traits in two maize (Zea mays L.) broad-based populations (NS12-SG and NS14-SG). Independent trials with 80 entries of S₁ progenies as well as their testcrosses were arranged according to an incomplete block design with replicates in sets. Grain yield, stay green, anthesis-silking interval, stalk water content and grain moisture were evaluated in four environments. The anthesis-silking interval had the highest genetic variation, followed by stay green. High heritability estimates (>0.50) for all traits, pointed out that further selection would be possible. Genetic correlations between line per se and testcross performance were lowest for grain yield (0.396** and 0.592**, for NS12-SG and NS14-SG, respectively), and highest for grain moisture (0.937** and 0.821**, respectively). High correlations between line per se and their testcrosses for stay green, anthesis-silking interval, stalk water content and grain moisture indicated that additive gene action might be more important than dominance in controlling the expression of these traits.  相似文献   

Taurine does not improve the quality of short‐term stored rabbit spermatozoa in vitro          下载免费PDF全文

D Paál  F Strejček  E Tvrdá  J Vašíček  A Baláži  P Chrenek  P Massányi 《Reproduction in domestic animals》2017,52(6):1046-1051

This study examines the impact of taurine on the viability, morphology and acrosome integrity of rabbit spermatozoa in vitro. Semen samples, obtained from four to five sexually mature and healthy New Zealand White rabbits, were pooled in heterospermic semen sample. This was divided and treated with taurine in a concentration of 0 (control), 1.5, 7, 12.5, 50 mM to a final concentration of 10⁸ spermatozoa/ml. The samples were then incubated at 37°C for 4 hr. A combination of fluorescent probes SYBR‐14/propidium iodide/PNA‐Alexa Fluor 647 was used to assess spermatozoa viability and acrosome integrity on a flow cytometer. The sperm morphology was evaluated under a light microscope following fixation in 1.5% paraformaldehyde. The experiment was repeated three times. According to the obtained results, the spermatozoa neither could have benefit from immediate taurine treatment, nor had they after 4‐hr incubation with respect to viability and acrosome integrity. Taurine did not initially alter the total and acrosome morphology of treated spermatozoa nor has it by 4 hr upon treatment. In conclusion, taurine may have no protective effect on the viability, morphology and acrosome integrity of short‐term stored rabbit spermatozoa.  相似文献   

Confirmation of <Emphasis Type="Italic">Peronospora agrimoniae</Emphasis> as a distinct species     

Irena Petrželová  Young-Joon Choi  Michaela Jemelková  Ivana Doležalová  Julia Kruse  Marco Thines  Miloslav Kitner 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(4):887-896

Leaves with typical symptoms of downy mildew were found on common agrimony in the Czech Republic in 2014 and 2015 and at several locations in Germany from 2010 to 2014. The causal agent of downy mildew of agrimony was often reported as Peronospora agrimoniae, but sometimes also as P. sparsa. Morphological characteristics of the pathogens found in both countries are in the range of previous works for P. agrimoniae, but also other downy mildews parasitic on Rosaceae, rendering their discrimination based on published observations difficult. For molecular identification sequencing of several loci (nrITS rDNA, cox1 and cox2) was performed. Phylogenetic analyses based on nrITS rDNA clearly separated P. agrimoniae from other Peronospora species infecting Rosaceae. Thus, considering P. agrimoniae as separate species seems justified. Two German specimens were identical to two Czech samples in both nrITS rDNA and cox1 mtDNA sequences, but differed in a single nucleotide substitution in cox2 region. To our knowledge, this is the first verified record of P. agrimoniae on common agrimony in the Czech Republic.  相似文献   

Comparative genomic hybridization in detection of DNA changes in canine lymphomas          下载免费PDF全文

Monika Drážovská  Katarína Šiviková  Ján Dianovský  Miroslav Horňák 《Animal Science Journal》2017,88(1):27-32

In this study, chromosomal imbalances in tumor tissues (lymphomas) and nucleotide changes in tumor suppressor TP53 were studied in a Bernese Mountain dog bitch and a cross breed bitch. Using comparative genomic hybridization, numerous chromosomal rearrangements were detected, which indicated the heterogeneity in tumor growth: in the cross breed bitch, a deletion on the chromosome 9, and duplications on chromosomes 5, 8 and 17 have been found. In the Bernese Mountain Dog bitch, losses on chromosomes 1, 5, 8, 12, 18, 22, 27, 29 and gains on chromosomes 1, 2, 9, 11, 15, 16, 18, 20, 23, 24, 25, 28, 29, 30, 34, 36, 37 and 38 were identified. With the sequencing of the TP53 gene, one silent mutation, transition A/G at position 138 in exon 5 was detected, without changing the amino acid.  相似文献   

Influence of different forest protection strategies on spruce tree mortality during a bark beetle outbreak     

Pavel Mezei  Miroslav Blaženec  Wojciech Grodzki  Jaroslav Škvarenina  Rastislav Jakuš 《Annals of Forest Science》2017,74(4):65

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A haplotype specific to North European wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)     

Jelena Tsõmbalova  Miroslava Karafiátová  Jan Vrána  Marie Kubaláková  Hilma Peuša  Irena Jakobson  Mari Järve  Miroslav Valárik  Jaroslav Doležel  Kadri Järve 《Genetic Resources and Crop Evolution》2017,64(4):653-664

A previous study indicated decreased DNA content of chromosome 4A in the wheat (Triticum aestivum L. cv. Tähti) compared to cvs. Chinese Spring and Rennan. Here we show that the lower 4A DNA content is associated with a specific haplotype in the distal part of 4AL. In 41 cultivars of bread wheat (T. aestivum L.), including cv. Tähti, a common haplotype was identified in the linkage disequilibrium region on the long arm of chromosome 4A (4AL). The haplotype (haplotype A) is characterized by 7 SSR and 5 EST marker alleles, including five zero-alleles. Haplotype A was found in 46 % of the Swedish/Finnish/Estonian spring wheat genotypes, while only one of the modern wheat accessions from Germany carried the same haplotype. Fluorescent cytometry analysis linked haplotype A to diminished DNA content of chromosome 4A. The haplotype was introduced into the Canadian and US breeding programs at the beginning of the twentieth century (cvs. Marquis, Thatcher, Ruby) from the common progenitor, the Polish landrace Fife, and it is still found in modern wheat germplasm in these countries. Zero-alleles characteristic for haplotype A were also detected in several accessions of European spelt (Triticum spelta L.), and in two accessions of tetraploid Triticum timopheevii Zhuk. The presence of haplotype A in European spelt indicates the considerable antiquity of the haplotype, as it must have been inherited from the hexaploid or tetraploid parent of spelt in at least one hybridization event.  相似文献   

A method for mobility estimation of textile-polymeric systems     

Vitalija Masteikaitė  Virginija Sacevičienė 《Fibers and Polymers》2010,11(6):869-876

Laminated or coated fabrics are technical textile products and are defined as materials composed of two or more layers; at least one of them is a textile fabric and one or more polymer film. The presence of film layer changes all fabric’s properties and behaviour during its deformation. The goal of this research is to propose a new method for evaluation the influence of structural stability of coated fabrics and laminates on their shear stiffness. Seven commercial coated fabrics and laminates with woven or knitted base layer are used in this test. The shear behaviors of coated and laminated fabrics are analyzed during the uniaxial tension of parallelepiped shape specimens whose top and bottom edges are cut with pitch of 16 degrees. The extension test of such type specimens is carried out using a Zwick tension machine. The behaviour of the coated fabrics and laminates during shearing are evaluated from strain-stress curves and the results are presented.  相似文献   

Root distribution of under-planted European beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.) below the canopy of a mature Norway spruce stand as a function of light     

Čater Matjaž  Simončič Primož 《European Journal of Forest Research》2010,129(4):531-539

Aboveground and belowground biomass of 15-year-old under-planted European beech seedlings (Fagus sylvatica L.) in Norway spruce stand were studied along a light gradient in three plots, in the northern part of Slovenia. Differences in soil water content, aboveground and fine root biomass distribution were confirmed between studied plots. Light had significant effect on the total biomass, root-shoot ratio (0.388 ± 0.076 under canopy, 0.549 ± 0.042 in the edge, 0.656 ± 0.047 in the open), specific root length (SRL) of fine beech roots (561.9 ± 42.2 under canopy, 664.3 ± 51.2 in the edge, 618.2 ± 72.8 in the open) and specific leaf area in beech, indicating morphological adjustment to shade. However, SRL of beech fine roots indicated no change between plots. The correlation between total aboveground and root biomass and light below the mature stand canopy was higher in the case of diffuse light intensity. Most fine roots of spruce were concentrated in the top (0–20 cm) soil layer. Beech fine roots under canopy and edge conditions were also concentrated in top (0–20 cm) soil layer and exhibited shift downwards to deeper soil horizons in open plot. Root proportion between beech and spruce changed with light toward beech with increasing light intensity for both fine and coarse roots.  相似文献   

The invasive ergot Claviceps purpurea var. spartinae recently established in the European Wadden Sea on common cord grass is genetically homogeneous and the sclerotia contain high amounts of ergot alkaloids     

Christian Boestfleisch  Astrid M. Drotleff  Waldemar Ternes  Stefan Nehring  Sylvie Pažoutová  Jutta Papenbrock 《European journal of plant pathology / European Foundation for Plant Pathology》2015,141(3):445-461

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