Electrochemical bioassay for the investigation of chlorpyrifos-methyl in vine samples

This paper reports the optimization of an electrochemical bioassay for the determination of chlorpyrifos-methyl and its application to the analysis of grape and vine leaf samples treated with that pesticide. The analytical method was based on electrochemical determination of the extent of the inhibition exerted by the pesticide on acetylcholinesterase using the substrate acetylthiocholine. Two similar calibration plots were obtained, in the range of 1-300 ng/mL, respectively, for chlorpyrifos-methyl in pure standard form and in the commercial preparation Reldan, with comparable coefficients of variation (CV) in the range of 10% < CV < 20%. After an insecticide treatment, samples were analyzed to evaluate its persistence both in grapes and in vine leaves. Samples were evaluated using different extraction procedures: one based on solvent extraction of pesticide residue from grapes and the other based on aqueous extraction from vine leaves using phosphate buffer. The grape solvent extracts were analyzed using both gas chromatography and electrochemical bioassay, whereas the vine leaf buffer extracts were analyzed using the electrochemical bioassay. Quantitative analysis of chlorpyrifos-methyl determined in the two samples, with the electrochemical bioassay, showed a comparable decrease profile over the experimental period.     

Estimating the variance of the sample mean in two-dimensional systematic sampling

This article investigates the problem of estimating the sampling error when the population mean (total) is estimated from a single two-dimensional systematic sample. In particular, two-dimensional extensions of known approximate variance estimators used in linear systematic sampling are introduced. These almost new variance estimators have the advantage of taking into account the spatial ordering of sample units and, consequently, the spatial autocorrelation among them. An investigation of their properties is carried out through a series of simulations and an empirical study.     

Biocontrol of soil-borne fungal plant diseases by 2,4-diacetylphloroglucinol-producing fluorescent pseudomonads with different restriction profiles of amplified 16S rDNA

Fluorescent pseudomonads producing the antimicrobial compound 2,4-diacetylphloroglucinol (Phl) are being studied extensively for use as biocontrol agents of soil-borne fungal diseases. Some of them can produce pyoluteorin (Plt) in addition to Phl, whereas others synthesise only Phl. Here, a collection of seven Phl⁺ Plt^- pseudomonads, seven Phl⁺ Plt⁺ pseudomonads and seven Phl^- biocontrol pseudomonads were compared for protection of plant roots against fungal pathogens. The seven Phl⁺ Plt⁺ pseudomonads were identical by restriction analysis of amplified spacer ribosomal DNA (spacer ARDRA), whereas the Phl⁺ Plt^- pseudomonads and especially the Phl^- biocontrol pseudomonads were quite diverse by spacer ARDRA. Collectively, the Phl⁺ Plt^- pseudomonads proved superior to the Phl⁺ Plt⁺ pseudomonads and the Phl^- biocontrol pseudomonads for protection of tomato against Fusarium crown and root rot (in rockwool microcosms) or cucumber against Pythium damping-off (in non-sterile soil microcosms). There was no correlation between protection in vivo and inhibition of the corresponding fungal pathogen on plates. However, there was a significant correlation between the amount of Phl produced on plates and protection of tomato against Fusarium crown and root rot, but not with protection of cucumber against Pythium damping-off. Interestingly, the minority of strains unable to produce HCN, an extracellular protease, or both, were among those unable to protect plants in both pathosystems. A seedling assay was developed to compare pseudomonads for suppression of Fusarium crown and root rot in vitro, and a significant correlation was found between disease severity in vitro and in vivo. Overall, results suggest that promising biocontrol pseudomonads may be identified based on the ability to produce Phl and/or specific ARDRA-based fingerprints.     

Isoprenoid, lipid, and protein contents in intact plastids isolated from mesocarp cells of traditional and high-pigment tomato cultivars at different ripening stages

This study reports quali-quantitative analyses on isoprenoids, phospholipids, neutral lipids, phytosterols, and proteins in purified plastids isolated from fresh fruits of traditional (Donald and Incas) and high-pigment (Kalvert and HLY-18) tomato cultivars at four ripening stages. In all of the investigated cultivars, lycopene, β-catotene, lutein, and total carotenoids varied significantly during ripening. Chromoplasts of red-ripe tomato fruits of high-pigment cultivars accumulated twice as much as lycopene (307.6 and 319.2 μg/mg of plastid proteins in Kalvert and HLY-18, respectively) than ordinary cultivars (178.6 and 151.7 μg/mg of plastid proteins in Donald and Incas, respectively); differences in chlorophyll and α-tocopherol contents were also evidenced. Phospholipids and phytosterols increased during ripening, whereas triglycerides showed a general decrease. Regardless of the stage of ripening, palmitic acid was the major fatty acid in all cultivars (ranging from 35 to 52% of the total fatty acids), followed by stearic, oleic, linoleic, linolenic, and myristic acids, but their relative percentage was affected by ripening. Most of the bands detected on the SDS-PAGEs of plastid proteins were constantly present during chloroplast-to-chromoplast conversion, some others disappeared, and only one, with a molecular weight of ~41.6 kDa, was found to increase in intensity.     

Clinical,hematological, and biochemical findings in puppies with coronavirus and parvovirus enteritis

The clinical and laboratory findings in puppies naturally infected with canine coronavirus (CCoV) and/or canine parvovirus (CPV) were compared with findings in uninfected puppies. Lymphopenia was the only parameter related to CCoV infection that was statistically significant; vomiting, anorexia, lethargy, hemorrhagic fluid diarrhea, leukopenia, lymphopenia, thrombocytopenia, hypoglycemia, and hypoproteinemia were correlated with CPV infection.     

Immersion anaesthesia in goldfish (Carassius auratus) with three concentrations of alfaxalone

Objective

To evaluate the anaesthetic effects of three different alfaxalone doses to induce anaesthesia in goldfish.

The completely additive effects of two barley phenology‐related genes (eps2S and sdw1) are explained by specific effects at different periods within the crop growth cycle

We used the ‘Baronesse’/‘Full Pint’ doubled haploid population to analyse the genetic factors controlling flowering date under South American conditions. Both parents have similar heading dates, but the population shows transgressive segregation. Two genes, eps2S on chromosome 2H and sdw1 on chromosome 3H, explained most of the phenotypic variation for anthesis date, with the later allele carried by ‘Baronesse’ and ‘Full Pint’ , respectively. Both effects were completely additive with no interaction. We studied three plant developmental periods: seedling emergence to tillering (Z10–Z20), tillering (Z20–Z30) and end of tillering to anthesis (Z30–Z49) under field conditions at three contrasting planting dates. Z10–Z20 was also measured under semi‐controlled conditions. eps2S controlled Z30–Z49 periods, while sdw1 controlled Z20–Z30. Each of the two genes for the end‐point phenotype—anthesis date—was a determinant of flowering at a different developmental stage. No gene x planting date interactions were detected.     

A statistical approach to evaluate compost genotoxicity

Parallel experiments were carried out to evaluate the induction of genotoxic effects in Vicia faba seedlings treated both with aqueous and organic extracts (dimethyl sulphoxide 5%) of 13 composts, or grown on soil samples to which different doses of the same composts were added. Pearsons linear correlation coefficient and multiple regression were used to study how these two different methodological approaches (treatment with the extracts versus direct contact with the composts in soil) agree. In addition, multiple regression analysis was used to investigate the role of heavy metals and humic substances in genotoxic effects and to construct a model to be used to accurately predict potential genotoxicity of the composts. Experimental data obtained at the highest application rate of compost on soil were found to fit the model and evidenced the role of the humic substances in modulating the potential genotoxicity of the different composts.     

From Slope Morphometry to Morphogenetic Processes: An Integrated Approach of Field Survey,Geographic Information System Morphometric Analysis and Statistics in Italian Badlands

Calanchi (singular: calanco) represent a typical example of badlands in the Italian peninsula, which rapidly evolve on clayey terrains such as the widespread Pliocene–Pleistocene marine clays. The present study aimed at investigating the role of the slope morphometry on the typology and distribution of morphogenetic processes in a calanchi area located in southern Italy. The research included detailed geomorphological surveying as well as morphometric and statistical analyses. The study area was first subdivided into individual hydrographic units (HUs), for which field survey allowed to identify the dominant denudation processes, their intensity and the distribution of the associated landforms (pipes, rills, gullies and landslides). The morphometry of each HU was characterised by calculating the morphometric slope index (MSI) on a reconstructed digital elevation model. By statistically comparing the morphogenetic and morphometric data, the influence of the slope morphometry on the type, distribution and evolution of the calanchi erosion process has been highlighted. In particular, through a cluster analysis, the groups of HUs having similar dominant processes were identified, and by applying the analysis of variance, the effect of the MSI on the identified clusters was analysed. Two clusters were identified, which revealed the relative importance of morphogenetic processes and the strict connection between surface and subsurface landforms. These two clusters were discriminated by the MSI value (high MSI favoured mass movements, while low MSI favoured gully erosion and piping), highlighting the importance of slope morphometry in driving the morphogenetic hillslope processes. Copyright © 2015 John Wiley & Sons, Ltd.     

Analysis of the effect of ozone on soybean in the Mediterranean region: I. The consequences on crop-water status

This study was carried out over three successive years (2003–2004–2005) in the southern Mediterranean region of Europe. Soybean plants were subjected to well-watered and water-stress conditions, and three levels of ozone (zero, low and high) in open top chambers (OTC) during the growing seasons.

The paper has four objectives: (i) to reproduce in OTCs the ozone concentrations actually observed in the field; (ii) to analyze the effect of ozone on well-watered crops by comparing a “control” (OTC ozone filtered treatment) with two ozone levels (at the end of the soybean growing seasons accumulated AOT40 values were 3400 and 9000 ppb h for low and high ozone treatments, respectively); observations were carried out both at leaf scale (stomatal conductance) and at canopy scale (determination of daily evapotranspiration, AET); (iii) to take into consideration the effect of drought, where the leaf and canopy scale observations were also implemented on water-stressed crops; and (iv) to analyze and verify the reliability of the ozone exposure–plant response relationship.

In well-watered conditions, an increase in ozone concentration levels reduced stomatal conductance and AET. Reductions in AET were 14% and 28% at low and high ozone levels, respectively, as compared to the control treatment. Hence, the results of daily AET were consistent with stomatal conductance results.

In water stress conditions, on the contrary, an increase in ozone had no effect on stomatal conductance and AET.

During the 3-year study, significant relationships were found between AOT40 and relative (low or high to control ozone treatment) values of stomatal conductance and AET in well-watered conditions. The reliability observed for these relationships suggest that they will be useful in soybean growth and yield-prediction models.