Multiplex qPCR assay for simultaneous quantification of CYP51-S524T and SdhC-H152R substitutions in European populations of Zymoseptoria tritici

Demethylation inhibitor (DMI) and succinate dehydrogenase inhibitor (SDHI) fungicides are currently relied upon for the control of septoria tritici blotch (STB) in European wheat fields. However, multiple mutations have occurred over time in the genes encoding the targeted proteins that have led to a practical loss of fungicide efficacies. Among the different amino acid substitutions in Zymoseptoria tritici associated with resistance to these fungicides, S524T in CYP51 (DMI target) and H152R in SdhC (SDHI target) are regarded as conferring the highest resistance factors to DMI and SDHI, respectively. To facilitate further studies on the monitoring and selection of these substitutions in Z. tritici populations, a multiplex allele-specific quantitative PCR (qPCR) assay allowing for estimation of both allele frequencies in bulk DNA matrices was developed. The assay was then used on complex DNA samples originating from a spore trap network set up in Belgium, Denmark, Sweden, and Ireland in 2017 and 2018, as well as on leaf samples with symptoms. The S524T allele was present in all field samples and its proportion was significantly higher in Ireland than in Belgium, whereas the proportion of H152R was only sporadically present in both countries. The frequency of S524T varied greatly in the airborne inoculum of all four countries; however, the H152R allele was never detected in the airborne inoculum. The method developed in this study can be readily adopted by other laboratories and used for multiple applications including resistance monitoring in field populations of Z. tritici.     

A broad spectrum screening of Schmallenberg virus antibodies in wildlife animals in Germany

To identify native wildlife species possibly susceptible to infection with Schmallenberg virus (SBV), a midge-transmitted orthobunyavirus that predominantly infects domestic ruminants, samples from various free-living ruminants, but also carnivores, small mammals and wild boar were analyzed serologically. Before 2011, no SBV-specific antibodies were detectable in any of the tested species, thereafter, a large proportion of the ruminant population became seropositive, while every sample taken from carnivores or small mammals tested negative. Surprisingly, SBV-specific-antibodies were also present in a large number of blood samples from wild boar during the 2011/2012 and 2012/2013 hunting seasons. Hence, free-ranging artiodactyls may play a role as wildlife host.     

Influence of tree species on gross and net N transformations in forest soils

We compared N fluxes in a 150-year-old Fagus sylvatica coppice and five adjacent 25-year-old plantations of Fagus sylvatica, Picea abies, Quercus petraea, Pinus laricio and Pseudotsuga menziesii. We measured net N mineralization fluxes in the upper mineral horizon (A1, 0–5 cm) for 4 weeks and gross N mineralization fluxes for two days. Gross rates were measured during the 48-h period after addition of ¹⁵NH₄ and ¹⁵NO₃. Mineralization was measured by the ¹⁵NH₄ dilution technique and gross nitrification by ¹⁵NO₃ production from the addition of ¹⁵NH₄, and by ¹⁵NO₃ dilution. Net and gross N mineralization was lower in the soil of the old coppice, than in the plantations, both on a soil weight and organic nitrogen basis. Gross nitrification was also very low. Gross nitrification measured by NO₃ dilution was slightly higher than measured by ¹⁵NO₃ production from the addition of ¹⁵NH₄. In the plantations, gross and net mineralization and nitrification from pool dilution were lowest in the spruce stand and highest in the beech and Corsican pine stands. We concluded that: (1) the low net mineralization in the soil of the old coppice was related to low gross rate of mineralization rather than to the concurrent effect of microbial immobilisation of mineral N; (2) the absence of nitrate in the old coppice was not related to the low rate of mineralization nor to the absence of nitrifyers, but most probably to the inhibition of nitrifyers in the moder humus; (3) substituting the old coppice by young stands favours nitrifyer communities; and (4) heterotrophic nitrifyers may bypass the ammonification step in these acid soils, but further research is needed to check this process and to characterize the microbial communities.     

Recent advances in alien gene transfer in wheat

Summary The recent advances in alien gene transfer from distantly-related species into wheat are reviewed in the present paper. The main achievements during the last ten years include the great expansion of the range of wide hybridization and development of new techniques for production and characterization of wheat-alien chromosome translocations. Updated results of wide hybridization since 1983 and comprehensive characterization of wheat-alien translocation lines in our laboratory are compiled. The future outlook for alien gene transfer in wheat is also discussed.     

Non-homoeologous wheat-rye chromosomal translocations conferring resistance to greenbug

Summary C-banding andin situ hybridization were used to determine the chromosomal constitution of the greenbug-resistant germplasm GRS 1204. The results showed that this line had the radiation-induced non-homoeologous wheat-rye translocation chromosomes T2AS-1RS·1RL and T2AL·2AS-1RS. C-banding analysis further revealed the presence of a wheat-Agropyron elongatum translocation chromosome T1BL·1BS-3Ae#1L in line GRS 1204, that was derived from Teewon. The greenbug resistance of line GRS 1204 is similar to that of line GRS 1201 that was earlier shown to have the greenbug resistance geneGb6 located on the 1RS arm of the wheat-rye translocation chromosome T1AL·1RS. BecauseGb6 in line GRS 1204 is present on one of the non-homoeologous translocation chromosomes, agronomically line GRS 1201 should be the better adapted source ofGb6 resistance and be used in cultivar improvement.     

Effect of general anesthesia on plasma cardiac troponin I concentrations in healthy horses

Objective

To evaluate the effect of general anesthesia on plasma cTnI concentrations in horses.

Animals, materials and methods

Thirty-two horses undergoing general anesthesia and either elective surgery or MRI without surgery were prospectively studied. Twenty-nine horses (22 surgical, 7 imaging) completed the study. Plasma cTnI concentrations were determined prior to anesthesia and at 6, 12 and 24 h following discontinuation of the inhalant anesthetic.

Results

All horses had cTnI values within the reference range at all time points. Six horses (21%) developed detectable cTnI 6 or 12 h following anesthesia. Risk factors for detectable cTnI include increasing age and dorsal recumbency. Horses with detectable cTnI had significantly lower mean and diastolic arterial blood pressures than those without detectable cTnI.

Conclusion

Uncomplicated general anesthesia with or without surgery does not result in cardiac troponin I elevations above the reference range in the first 24 h postoperatively.     

Prolonged Testing of Metal Mobility in Mining-Impacted Soils Amended with Phosphate Fertilisers

The aim of the study was to determine whether the application of superphosphate fertiliser to soils contaminated with mine wastes can inhibit metal and metalloid mobility (Cu, Pb, Zn, Cd, Fe, Mn, As, Sb) in the long term. Contaminated soils contained sulfide- and sulfate-rich waste materials from the Broken Hill and Mt Isa mining centres. Results of long-term (10 months) column experiments demonstrate that fertiliser amendment had highly variable effects on the degree of metal and metalloid mobilisation and capture. Rapid release of metals from a sulfate-rich soil showed that phosphate amendment was ineffective in stabilising highly soluble metal-bearing phases. In a sulfide-rich soil with abundant organic matter, complexing of metals with soluble organic acids led to pronounced metal (mainly Cd, Cu and Zn) release from fertiliser-amended soils. The abundance of pyrite, as well as the addition of fertiliser, caused persistent acid production over time, which prevented the formation of insoluble metal phosphate phases and instead fostered an increased mobility of both metals and metalloids (As, Cd, Cu, Sb, Zn). By contrast, fertiliser application to a sulfide-rich soil with low organic carbon content and a sufficient acid buffering capacity to maintain near-neutral pH resulted in the immobilisation of Pb in the form of newly precipitated Pb phosphate phases. Thus, phosphate stabilisation was ineffective in suppressing metal and metalloid mobility from soils that were rich in organic matter, contained abundant pyrite and had a low acid buffering capacity. Phosphate stabilisation appears to be more effective for the in situ treatment of sulfide-rich soils that are distinctly enriched in Pb and contain insignificant concentrations of organic matter and other metals and metalloids.