SSR marker analysis of Monilinia fructicola from Swiss apricots suggests introduction of the pathogen from neighbouring countries and the United States

Monilinia fructicola is a quarantine fungal pathogen in Europe, but many major stone fruit growing countries in Europe have reported its presence recently. In Switzerland, the fungus was first found in a single apricot orchard in 2008. This study confirms the presence of M. fructicola in nine out of 22 commercial orchards in Canton Valais, Switzerland. Five simple sequence repeat markers (SSRs) were developed for M. fructicola and samples from Switzerland, Spain, Italy, France and the United States were analysed and compared in order to assess the genetic diversity of the pathogen, identify the origin of the disease, and verify if the fungus reproduces sexually in Europe. In the 119 European samples analysed, 12 different haplotypes were found, indicating a relatively high genetic diversity of the pathogen considering that the first report in Europe was 10 years ago. Three haplotypes found in Europe were identical to those found in the American samples (two from the east coast and one from the west coast). Population structure analysis suggests that the European population is derived from at least two ‘invasion’ events probably originating from the US (one from the east coast, the other from the west coast). Preliminary evidence of sexual reproduction of M. fructicola in Europe is reported.     

A Reliable Method for Testing the Sensitivity of Botryotinia fuckeliana to Anilinopyrimidines In Vitro

Cyprodinil is a representative of the new class of broad-spectrum anilinopyrimidine fungicides. The effect of cyprodinil on mycelial growth of Botryotinia fuckeliana on solid agar medium depends on the composition of the medium and on the age of the mycelium to be used for the bioassay. An in-vitro method was developed to study the sensitivity distribution to cyprodinil in two wild-type populations of B. fuckeliana from fruits of strawberry with grey mould. To validate the applicability of the method, sensitivities to cyprodinil, mepanipyrim and pyrimethanil were monitored in populations of B. fuckeliana from grapes with grey mould from different vineyards, including one trial vineyard where reduced performance of cyprodinil had been encountered. The monitoring procedure was based on the inhibition of the mycelial growth on a synthetic medium containing L -asparagine (asp-agar) amended with the active ingredients. The mycelium was grown on asp-agar discs, starting from a spore suspension, for 17 h prior to the beginning of the test. This procedure proved to be efficient. The two wild-type populations from different sampling sites showed similar distributions of the sensitivity to cyprodinil. Some isolates from the trial site with reduced performance of anilinopyrimidines showed reduced sensitivities to cyprodinil, mepanipyrim and pyrimethanil, demonstrating cross-resistance between these anilinopyrimidines.     

Polycyclic aromatic hydrocarbons and polychlorinated biphenyls in urban and semi-urban soils of Havana,Cuba

Purpose

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in Havana were quantified and analyzed in relation to possible emission sources to assess metropolitan soil contaminations in a highly dynamic, urban environment. The results of this study will serve Cuban legislators as a basis to develop environmental quality standards for organic pollutants in soils.

Materials and methods

Possible emission sources as, e.g., the vicinity to roads or industrial plants and the influence of the land use were related to the organic contaminants concentrations. Therefore, 28 topsoils in the Havana urban and semi-urban area were sampled at agricultural (n?=?12), organoponic (urban gardens in the capital, n?=?8), public park (n?=?7), and remediation (on-site bioremediation of an oil refinery, n?=?1) sites. Their PAH and PCB concentrations were measured with gas chromatography mass spectroscopy and the total organic carbon (TOC) and black carbon (BC) concentrations with the chemo-thermal oxidation.

Results and discussion

The sum of the 16 PAH concentrations ranged from 0.04 mg/kg in agricultural and organoponic soils to up to 72 mg/kg in a public park at about 1.5 km distance from an oil refinery. The lowest sum of the seven PCB congener concentrations was also measured in organoponic soils (0.002 mg/kg) and the highest in an arable patch of land between the rail roads and a main road (0.1 mg/kg). Both, PAH as well as PCB soil concentrations in Havana were almost up to two orders of magnitudes higher compared to a soil monitoring in the neighboring province of Mayabeque, but overall in the typical range of urban soils reported by other studies. The pollutants showed no relationship between TOC and BC except for PAHs with BC. For PAHs, combustion was the main source.

Conclusions

A comparison of the pollutant concentrations with regulatory guidance values (RGV) of other countries revealed PCB concentrations in Havana soils far below these RGV. In contrast, some concentrations of benzo[a]pyrene, the most carcinogenic PAH, in agricultural and park soils in Havana exceeded some RGV. Thus, some public parks pose a risk according to the Canadian quality guidelines when people have direct contact with these soils but not if they were consuming products thereof.

     

Quantitative determination of PAHs in biochar: a prerequisite to ensure its quality and safe application

Biochar is increasingly promoted as a beneficial soil conditioner. However, it may contain residues of polycyclic aromatic hydrocarbons (PAHs) as a result of its production by pyrolysis. To date, analytical methods to analyze PAHs in biochar quantitatively are hardly available. This study presents an optimized and validated procedure to quantify the 16 U.S. EPA PAHs in biochar. PAHs were best extracted with Soxhlet for 36 h using 100% toluene. Average absolute recoveries of isotope labeled internal standards used for each analyte from three different biochars ranged from 42% to 72%, and relative recoveries were between 71% and 105%. The limits of detection were biochar-dependent, but on average a factor of >50 lower than quantified PAH concentrations (9-355 mg kg(dry weight)(-1)). The established method prepares the ground for a harmonized protocol for PAH analysis of biochars, a necessity for biochar quality control, registration, and legislation.     

Assessment of polycyclic aromatic hydrocarbons in biochar and biochar-amended agricultural soil from Southern Spain

Journal of Soils and Sediments - The goal of this study was to determine if the application of four biochars produced from different feedstock leads to soil contamination with the 16 US...