Effects of cyclamen mite (Phytonemus pallidus) and leaf beetle (Galerucella tenella) damage on volatile emission from strawberry (Fragaria x ananassa Duch.) plants and orientation of predatory mites (Neoseiulus cucumeris, N. californicus, and Euseius finlandicus)

Volatile emission profile of strawberry (Fragaria x ananassa Duch.) plants (cvs. Polka and Honeoye) damaged by cyclamen mite (Phytonemus pallidus Banks) or leaf beetle Galerucella tenella (L.) (cv. Polka) was analyzed to determine the potential of these strawberry plants to emit herbivore-induced volatiles. The total volatile emissions as well as emissions of many green leaf volatiles (e.g., (Z)-3-hexen-1-ol and (Z)-3-hexenyl acetate) and methyl salicylate were greater from cyclamen mite-damaged strawberry plants than from intact plants. Leaf beetle feeding increased emissions of monoterpenes (Z)-ocimene and (E)-beta-ocimene, sesquiterpenes (E)-beta-caryophyllene, (E,E)-alpha-farnesene, and germacrene-D, and a homoterpene (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) significantly. Nevertheless, the na?ve generalist predatory mites, Neoseiulus cucumeris, Neoseiulus californicus, and Euseius finlandicus did not prefer P. pallidus- or G. tenella-damaged plants over intact plants in a Y-tube olfactometer, suggesting that these predatory mite species are not attracted by the herbivore-induced volatiles being released from young strawberry plants.     

Carbohydrates as Chemical Constituents of Biowaste Composts and their Humic and Fulvic Acids

The decomposition of organic matter of source-separated biowaste during composting was followed during 18 months. Compost samples were fractionated into three parts: (i) hot water soluble extract (HWE) (ii) bitumen fraction and (iii) humic substances (humic acids (HA) and fulvic acids (FA)). Original compost samples and the HA and FA fractions were hydrolyzed with sulfuric acid for hexoses and pentoses. Quantitative spectrophotometric and qualitative GC/MS analyses of monosaccharides as trimethylsilyl ethers of the corresponding alditols were carried out.

During composting, the amount of HA in the organic matter of the compost increased, the amounts of HWE and bitumen decreased and the amount of the FA fraction changed only a little. Carbohydrates were found to be important constituents of biowaste composts and their HA and FA fractions. Elemental analysis (C, N and H) of compost and HA samples showed an increase in the C:H ratio and in unsaturation of compounds during composting. The decrease in the C:N ratio was marginal.

The amounts of hexoses and pentoses in original compost samples and the HA and FA fractions decreased during composting. The sugar alcohols erythritol, xylitol, L-arabitol, ribitol, L-rhamnitol, L-fucitol, D-mannitol, D-glucitol and galactitol were identified in both the HA and FA fractions. 2-Deoxy-D-erythro-pentitol was identified in one HA fraction and inositol in two FA fractions. An analysis of gas chromatographic data for relative abundances showed that, in every sample except one and in every stage of composting D-glucitol was the main sugar alcohol. In general, the relative amount of D-glucitol decreased during composting, while the relative amounts of all other sugar alcohols increased.

As chemical indicators of compost maturity, carbohydrates would appear to be a important group of compounds. Most informative as a general indicator would be the ratio of the amount of HA to the amount of organic matter in the total compost samples.

According to our studies, the carbohydrates in composts are covalently bound to the structures of FA and HA. Carbohydrate determination clearly deserves more attention in the structural elucidation of FA and HA.     

Species diversity in Eucalyptus camaldulensis woodlots and miombo woodland in Northeastern Zimbabwe

The tree species diversity, groundvegetation species richness, and soilcharacteristics were studied forEucalyptus camaldulensis woodlots and thenatural miombo woodlands in the Mukarakate Areaof Northeastern Zimbabwe. The woodlandcharacteristics were measured and soil sampleswere taken at a total of thirty-four miombowoodland plots and twenty-seven eucalyptusplantations.The number of tree species was significantlyhigher for the miombo woodland sites than forthe eucalyptus woodlots. The Berger-Parker andShannon-Wiener Index values for speciesdiversity were higher for the tree speciesfound on the miombo woodland sites. There wereno significant differences between theeucalyptus woodlots and the miombo woodlands inthe percentage of grass cover and the number ofgrass and herb species. The same grass and herbspecies were common in both the woodlots andthe woodlands. The older woodlots hadsignificantly more tree and herb species thanthe younger woodlots.Soil nutrient analyses showed no significantdifferences between the woodlots and thewoodlands regarding their available phosphorusand total nitrogen, but the total phosphorusand total carbon were higher for the miombowoodlands. The results suggest that E.camaldulensis woodlots established in areasthat were formerly fields and grazing areas inthe savannah-like conditions pertaining inSouthern Africa do not cause the loss ofspecies richness or soil nutrients. In heavilydeforested areas eucalyptus woodlots may evencontribute positively to the protection andpreservation of indigenous trees species andother flora.     

The chemical characteristics of squeezable sap from silver birch (Betula pendula) logs hydrothermally treated at 70 °C: the effect of treatment time on the concentration of water extracts

Wood Science and Technology - In order to study the detailed water extract of wood components in birch under hydrothermal treatment, xylem sap obtained by mechanical...     

Delayed soil thawing affects root and shoot functioning and growth in Scots pine

In boreal regions, soil can remain frozen after the start of the growing season. We compared relationships between root characteristics and water relations in Scots pine (Pinus sylvestris L.) saplings subjected to soil frost treatments before and during the first week of the growing period in a controlled environment experiment. Delayed soil thawing delayed the onset of sap flow or totally blocked it if soil thawing lagged the start of the growing period by 7 days. This effect was reflected in the electrical impedance of needles and trunks and in the relative electrolyte leakage of needles. Prolonged soil frost reduced or completely inhibited root growth. In unfrozen soil, limited trunk sap flow was observed despite unfavorable aboveground growing conditions (low temperature, low irradiance, short photoperiod). Following the earliest soil thaw, sap flow varied during the growing season, depending on light and temperature conditions, phenological stage of the plant and the amount of live needles in the canopy. The results suggest that delayed soil thawing can reduce tree growth, and if prolonged, it can be lethal.     

Real-time PCR for Quantification of Toxigenic Fusarium Species in Barley and Malt

A real-time PCR technique was applied for the quantification of trichothecene-producing Fusarium species (TMTRI assay) as well as the highly toxigenic Fusarium graminearum (TMFg12 assay) present in barley grain and malt. PCR results were compared to the amounts of trichothecenes detected in the samples to find out if the PCR assays can be used for trichothecene screening instead of expensive and laborious chemical analyses. DNA was extracted from ground kernels using a commercial DNA extraction kit and analysed in a LightCycler® system using specific primers and fluorogenic TaqMan probes. Both naturally and artificially contaminated grains were analysed. The TMTRI assay and the TMFg12 assay enabled the quantification of trichothecene-producing Fusarium DNA and F. graminearum DNA present in barley grain and malt samples, respectively. Both TaqMan assays were considered to be sensitive and reproducible. Linearity of the assays was 4–5 log units when pure Fusarium DNAs were tested. The amount of Fusarium DNA analysed with the TMTRI-trichothecene assay could be used for estimation of the deoxynivalenol (DON) content in barley grain. Furthermore, the TMFg12 assay for F. graminearum gave a good estimation of the DON content in north American barley and malt samples, whilst the correlation was poor among Finnish samples. DON content and the level of F. graminearum DNA were found to be naturally low in Finnish barleys.     

Seasonal variation in the photosynthetic capacity of a willow (Salix cv. Aquatica gigantea) canopy. 2 Comparison of the structure and function of chloroplasts at different levels in the canopy

Development of leaf chloroplast ultrastructure at five levels in a willow (Salix cv. Aquatica gigantea) canopy was followed during one growing season in the field. Changes in chloroplast ultrastructure were compared with the rate of CO(2) uptake of the same leaves. The highest rates of CO(2) uptake were recorded in young leaves exposed to full available sunlight. In these leaves, the area of the grana stacks was less than 20% of the total chloroplast area and the degree of thylakoid stacking was less than 1.5. The chloroplasts of these leaves contained large amounts of starch and small amounts of plastoglobuli. As the canopy grew and the leaves in the lower parts of the canopy became shaded, the structure of the chloroplast thylakoids gradually changed. In leaves at the two lowest levels of the canopy, the degree of stacking at the end of the growing season was close to 2 and correspondingly the rate of CO(2) uptake was low. The areas of grana stacks and plastoglobuli in these chloroplasts increased and were about 30 and 10% of the chloroplast area, respectively, by the end of the growing season. The increase in the degree of thylakoid stacking was caused by increased biosynthesis of grana lamellae, which in general were thinner than the lamellae of young leaves. The length of the stroma lamellae did not change with leaf age. Morphometric measurements showed that the structure of the chloroplasts in leaves 160 cm above ground was dynamic and responsive to environmental conditions so that photosynthetic capacity remained high for 7 weeks despite an increase in leaf shading.     

Development of Strain-specific Primers for a Strain of Gliocladium catenulatum Used in Biological Control

The randomly amplified polymorphic DNA (RAPD) technique was used to develop strain-specific primers for Gliocladium catenulatum strain J1446, which is promising in biological control. One of the primer pairs developed proved to be strain-specific; strain J1446 was differentiated from 16 G. catenulatum strains and six other strains of two Gliocladium species, as well as from Trichoderma virens, and isolates of Nectria spp. and Fusarium spp. Specific primers were also tested with DNA isolated from cucumber leaves, treated or untreated with a solution made from Gliocladium powder. The expected amplification product was produced only from treated leaves. DNA isolated from Gliocladium-treated potato tubers and fungi grown in peat was also used in amplification reactions. Strain-specific primers detected strain J1446 when the amount of DNA was 5pg or more. Some variation between the Gliocladium strains was found by the random amplified microsatellites method (RAMS) and the universally primed polymerase chain reaction method (UP-PCR), but no clear fragments specific to strain J1446 were produced. Cross-blot hybridisation of UP-PCR products differentiated strain J1446 from T. virens, but not from the Gliocladium isolates. The 28S rDNA sequences and -tubulin sequences were identical or very similar in all Gliocladium strains. Thus, it is possible that the Gliocladium strains of the present study are conspecific, which means that a revision in the taxonomy of Gliocladium species may be necessary.     

Chemical restraint-reversal with medetomidine and atipamezole in veterinary small animal practice: a survey on the opinions of the dog owners and veterinarians.

The opinions of animal owners and practising veterinarians concerning a new restraint-reversal medication (medetomidine-atipamezole) for dogs were obtained by two questionnaires in connection with a clinical study. Four alternative answers to each statement question scored as "completely agree", "somewhat agree", "somewhat disagree" and "completely disagree". The questionnaires were completed by 21 veterinarians and 245 dog owners. The overall response to the treatment was clearly positive. Both groups had a favourable attitude towards drug use with mean combined scores (from 1 to 4; 4 = most favourable) of 48.1 (max 56) for the dog owners and 39.2 (max 52) for the veterinarians. Only a little information was gained about the background of negative sentiments. Some pet owners (19%) opposed to medication on a priori grounds, some (26%) reacted strongly to the dizziness of their animals and some owners (21%) complained because of general anxiety before, during and after their pets were treated.