Biochemical and genetical analysis reveal a new clade of biovar 3 <Emphasis Type="Italic">Dickeya</Emphasis> spp. strains isolated from potato in Europe

Sixty-five potato strains of the soft rot-causing plant pathogenic bacterium Dickeya spp., and two strains from hyacinth, were characterised using biochemical assays, REP-PCR genomic finger printing, 16S rDNA and dnaX sequence analysis. These methods were compared with nineteen strains representing six Dickeya species which included the type strains. A group of twenty-two potato strains isolated between 2005-2007 in the Netherlands, Poland, Finland and Israel were characterised as belonging to biovar 3. They were 100% identical in REP-PCR, dnaX and 16S rDNA sequence analysis. In a polyphasic analysis they formed a new clade different from the six Dickeya species previously described, and may therefore constitute a new species. The strains were very similar to a Dutch strain from hyacinth. On the basis of dnaX sequences and biochemical assays, all other potato strains isolated in Europe between 1979 and 1994 were identified as D. dianthicola (biovar 1 and 7), with the exception of two German strains classified as D. dieffenbachia (biovar 2) and D. dadantii (biovar 3), respectively. Potato strains from Peru were classified as D. dadantii, from Australia as D. zeae and from Taiwan as D. chrysanthemi bv. parthenii, indicating that different Dickeya species are found in association with potato.     

Pore‐system characteristics of pavement seam materials of urban sites

The original light‐brown sandy seam filling of pavements in urban areas turns dark and changes its properties by the time due to various inputs of urban dust. Deposited C_org inputs do mostly not have natural characteristics but are man‐made, e.g., diesel dust. Thus, properties of the seam material are not predictable from experiences with forest or agricultural soils. Semiperviously sealed urban areas are sites of contaminant deposition as well as groundwater recharge. For an assessment of the resulting groundwater‐contamination risk in these areas, the properties of the seam material, which influences transport processes, must be known. The aim of this study was to investigate the pore‐system build‐up, which includes size distribution and fractal character in the seam material of urban sites. The investigated samples were taken from pavements adjacent to roads in Berlin and Warsaw. The micropore parameters (nanometer range) were characterized using water‐vapor desorption isotherms, mesopore parameters (micrometer range) were estimated from mercury‐intrusion porosimetry and macropore parameters (millimeter range) from water‐retention curves. Particle density, dry bulk density, and particle‐size distribution were measured using standard methods. Volumes of micro‐ and mesopores as well as particle densities and dry bulk densities correlated with C_tot contents. However, no such relation was found for macropore volumes. Compared to the original sandy seam filling, the altered seam material shows significantly higher C_org contents and higher amounts of micro‐ and mesopores. Therefore, the available water capacity increases by 0.05–0.11 m³ m^–3, as compared to the original sandy seam filling. Compared to natural sandy soils having similar C_org contents, the seam material shows similar macropore volumes, but the volume of mesopores and micropores is a few times smaller. That is mainly because of the particulate character of the organic matter.     

Water storage,surface, and structural properties of sandy forest humus horizons

In this paper, we tried to find interrelations between water retention properties, surface characteristics, and structural features of sandy soils rich in organic matter. Raw humic, epihumic, and endohumic horizons of four acidic sandy forest soils were selected for this study. Specific areas and water adsorption energies were estimated from water vapor adsorption isotherms, micropore (nanometer range) parameters from desorption isotherms, mesopore (micrometer range) parameters from mercury intrusion porosimetry, and macropore (millimeter range) parameters from water retention curves measured using combined suction plate and pressure chamber methods. In the studied soils, pore volumes in all pore ranges were proportional to soil organic matter content. Thin column wicking technique was used to determine migration velocity vs. time dependence in the samples beds for a range of liquids of various surface tensions. From these dependencies the surface free energy and its components were estimated that were used for calculation of water contact angles and forces of interparticle interaction via a water meniscus. The dominant interactions in the studied soils were dispersive Lifshitz‐Van der Waals forces. In the two upper horizons polar acid‐base interactions were absent, however in the deepest horizons, high input of polar interactions occurred, due practically to electron‐donor component of the surface free energy. The electron‐acceptor contribution was low. The wettability of the soils was low in upper horizons as indicated by high water contact angles.     

Single-stage Bilateral Tibial Tuberosity Advancement With Cranial Fixation in an English Bulldog – A Case Report

This article presents a report of single-stage bilateral tibial tuberosity advancement for the treatment of cranial cruciate ligament rupture in an English bulldog. The reconstruction was performed by a new surgical technique involving tibial tuberosity advancement and fixation with two cranially placed lag screws. The patient was able to ambulate normally at a walk without lameness four days postoperatively. Except for bruising of the surgical site, no complications were observed during a six-month follow-up period.     

Assessing new SSR markers for utility and informativeness in genetic studies of brown rust fungi on wheat,triticale, and rye

The aim of the present study was to validate new simple-sequence repeat (SSR) markers and use them to assess genetic variability among 24 isolates of Puccinia triticina collected from wheat (Pt-wheat) and triticale (Pt-triticale), and 15 isolates of P. recondita f. sp. secalis (Prs) collected from rye. The Pt and Prs isolates were tested for virulence on a set of 35 Thatcher wheat near-isogenic lines, eight rye lines with known resistance genes, and 53 triticale cultivars with uncharacterized leaf rust resistance. Molecular genotypes were determined using a newly developed set of 34 SSR microsatellite primer pairs. All SSR markers tested on Pt isolates successfully amplified fragments of appropriate size. When tested on the Prs isolates, 21 out of the 34 Pt SSRs amplified expected fragments. Sixteen of these 21 SSRs were polymorphic, providing for the first time microsatellite markers to study genetic variation in Prs. Based on virulence data, variation among Prs isolates was low, probably due to the small number of rye differential lines available. Much higher variation for virulence was observed within the collection of Pt isolates from wheat and triticale, and two separate groups were established with mixed host origin. Substantial genetic variation was detected among the isolates studied with the SSR markers, assuming two different models of SSR evolution (infinite alleles model and stepwise mutation model). The newly developed set of SSR markers proved their effectiveness in detecting genetic variation and should be useful in further population genetics investigations of the two pathogens.     

Influence of Humic Acid on Water Adsorption Characteristics of Kaolin and Quartz

Water vapor adsorption isotherms were measured for samples of kaolin and quartz amended with different amounts of humic acid extracted from a Cambic Arenosol under forest. Applying the approximation of the adsorption isotherms with the BET equation the monolayer capacities (surface areas) for the studied systems were calculated. For kaolin systems the surface area decreased sharply at low humic acid additions and this slowly increased with the further rise of the humic acid content, whereas for the quartz the increase of surface area was only noted for high humic acid contents. Using an exponential isotherm equation with a local BET model, the adsorption energy distribution functions were calculated for kaolin systems. The shape of the adsorption energy distributions showed that the increase in humic acid content changed the character of the surface from more hydrophilic to more hydrophobic. For intermediate humic acid contents, the energy distribution function had two maxima – more polar and less polar. At high humic acid contents the energy distribution function tended to the estimated value for pure humic acid, indicating high surface coverage with organic material. As measured by the mercury intrusion porosimetry, for the kaolin samples the amount of the largest pores decreases and the amount of the smallest pores increases with the accumulation of humic acid. For the quartz systems only very high doses of humic acid are reflected in changes of pore size distribution.     

Barley varieties in semi‐controlled and natural conditions—Response to water shortage and changing environment

The yield potential of 60 spring barley varieties was examined under controlled drought and natural conditions in the years 2011–2013. The studied varieties were genotyped with the 1536‐SNP barley oligonucleotide assay. In experiments with controlled drought conditions, the grain yield, 1,000‐grain weight, number of productive tillers and length of the main stem were measured. Physicochemical properties such as the specific surface area, water adsorption energy, fractal dimension and nanopore radius of the plant leaves were determined and correlated with yield‐forming traits. Field trials were conducted over 3 years at 14 locations, where along with the yield‐related traits, monthly rainfall and average temperature were monitored. Five varieties of high yield and five varieties relatively stable under both semi‐controlled and natural conditions were distinguished. The yield‐related traits observed in various locations were related to environmental variables relevant to water availability. The sum of the rainfall in April and May was negatively correlated with the 1,000‐grain weight and positively with the plant height. Positive relationships were found between plant height and temperatures in June and July. Five markers detected earlier as linked to the quantitative trait loci in the mapping populations were identified to have a coherent effect among varieties of various pedigree.     

Red operculum spots,body size,maturation and evidence for a satellite male phenotype in non‐native European populations of pumpkinseed Lepomis gibbosus

Carotenoid‐based pigmentation is a striking feature of many taxa, yet the function, if any, of colour traits is often unclear. Pumpkinseed Lepomis gibbosus, a widely introduced freshwater sunfish that exhibits alternative male mating strategies, express a striking, red operculum spot. To investigate the potential function of this red spot as a signal in this species' mating system, we determined the presence and measured the size of red operculum spots in fish collected from 12 populations in five European countries in which pumpkinseed is an established non‐native species. We subsequently related the presence and size of the red spot to body size and mating strategy, based on an analysis of relative gonad size (gonado‐somatic index, GSI), using a mixed modelling approach. The study demonstrated that the presence of a red operculum spot in pumpkinseed is associated with sexual maturation, with GSI frequency distributions suggesting that cuckolders in some non‐native populations comprised both sneaker and satellite males, the latter not having previously been reported for this species. Further, the size of red spot correlated strongly with body size in parental and cuckolder males, although there was no difference in the presence or size of the red operculum spot between male mating strategies. The function of a red operculum spot in females is not clear but may be partly mediated by pleiotropic genetic mechanisms. Red operculum spots appear to function as signals of male maturation and body size in pumpkinseed, irrespective of mating strategy.     

Influence of temperature and Artemia enriched with ω‐3 PUFAs on the early ontogenesis of Atlantic sturgeon,Acipenser oxyrinchus Mitchill, 1815

Successful breeding of fish species in aquaculture depends on several factors, among which the temperature and feed are the most significant ones. This study was designed to evaluate the effect of temperature in the range of 14–18°C on the rate of embryogenesis and duration of larva period and to estimate the efficiency of Artemia nauplii enriched with PUFAs in growing sturgeon larvae. The temperature of 16°C is the most suitable for both egg incubation and Atlantic sturgeon prelarvae maintenance under aquaculture conditions. Even minor temperature fluctuations of 1 degree up or down leads to increased loss both of eggs and prelarvae. Increased temperature shortens the incubation period but has a lesser impact on the duration of prelarvae onset of external feeding. The technology of Artemia nauplii bioencapsulation with a PUFA‐containing supplement in A. oxyrinchus rearing increases sturgeon larvae weight by 1.5 times at a constant survival dynamic.