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J.E. Garcia J. Kirchhoff F. Grossmann 《Journal of environmental science and health. Part. B》2013,48(4):473-491
Summary In a 4‐year study, the behaviour of the residues of triadimefon and its metabolite triadimenol in different plant parts of winter wheat and in soil was investigated. The fungicide Bayleton DF (triadimefon + captafol) was applied at the beginning of earing. Triadimefon residues were quickly degraded in the great majority of the examined samples (more than 90% within the first 2 weeks after application in all aerial parts of the plant). Triadimenol residues were considerably more persistent. No residues either of triadimefon or triadimenol were found in grain at harvest time (detection limit 0.01 mg/kg). 相似文献
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Jui-Hung Yen Jin-Shu Chang Pin-Jui Huang Yei-Shung Wang 《Journal of environmental science and health. Part. B》2013,48(7):681-689
The impact of fungicides triadimefon and propiconazole on soil bacterial populations from a strawberry field was investigated. Two fungicides were applied to the soil at concentrations of 10 mg/kg or 100 mg/kg with soil water contents 20.2% (fresh soil water content) or 26.0% (field capacity). Changes in bacterial communities were assessed using DNA extraction, polymerase chain reaction (PCR) amplification of the 16S rDNA and denaturing gradient gel electrophoresis (DGGE). High performance liquid chromatography (HPLC) was utilized to detect the residue of fungicides in soils. The results showed that propiconazole was more persistent than triadimefon in soils, and the two soil water contents did not cause significant differences in dissipation rates between the two fungicides. A high concentration of propiconazole could inhibit the existence of soil microbes while one of triadimefon might induce the microbial population in the first stage. From unweighted pair-group method using arithmetic averages (UPGMA) dendrograms, the effect of triadimefon and propiconazole at the two applied concentrations on a soil bacterial community could be long term. After triadimefon was applied for 60 days and propiconazole for 75 days, the compositions of microbial communities were not recovered. From the viewpoint of environmental protection, it was of significant importance to pay more attention not only to the residues of pesticide but also to the change in soil microbial communities. 相似文献
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Papis E Bernardini G Gornati R Prati M 《Environmental science and pollution research international》2006,13(4):251-255
- DOI: http://dx.doi.org/10.1065/espr2006.01.014
Background, Aims and Scope Triazole-derivatives are potent antifungal agents used as systemic agricultural fungicides and against fungal diseases in
humans and domestic animals. They act by inhibiting the cytochrome P-450 conversion of lanosterol to ergosterol, thus resulting
in faulty fungal cell wall synthesis. Some data have been published about the teratogenic activity of triazoles on rodent
embryos: Hypoplasias, abnormal shape, agenesis of the branchial arches, for example, were reported as typical induced malformations.
Unfortunately, no data are available on the embryotoxicity of these compounds in amphibians, despite the increasing concern
among the scientific community about the phenomenon of global amphibian population declines. The aim of the present work is
to evaluate the embryo-lethal and teratogenic potentials of Triadimefon (FON), a triazolederivative widely used as an antimycotic
in agriculture, by the test FETAX (Frog Embryos Teratogenic Assay, Xenopus) with particular attention being paid to the analysis
of branchial arch malformations.
Methods Xenopus laevis embryos were exposed continuously from stage 9 to increasing concentrations of FON and analyzed at stage 47
for mortality and teratogenicity (group I) to determine the median lethal (LC50) and teratogenic (TC50) concentrations. Another
two pools of larvae were exposed to FON for a 2 hour period at early gastrula (Group II) or neurula (Group III) stages to
verify which period of development is the most sensitive to FON. The malformations observed were further investigated by histological
section and cartilage staining with Alcian blue.
Results and Discussion The assay has estimated LC50 and TC50 values of 63.8 μM and 2.73 μM, respectively; the resulting TI (Teratogenic Index =
LC50/TC50) value of 23.4 has underlined the very high teratogenic risk associated with this compound. Neurulation was more
sensitive to FON exposure than gastrulation, since the TC50 estimated values for group III (neurula exposed) specimens was
7.6 times lower than those of group II (gastrula exposed). Interestingly, for each group analyzed, 100% of malformed embryos
showed alterations at branchial arch derived cartilages: Anterior cartilages were reduced, missing, fused or incorrectly positioned
while gill cartilages were altered only in the most severely affected specimens. In some cases these malformations were associated
with hyperpigmentation. Our results support the hypothesis that FON can interfere with Neural Crest Cell (NCC) migration,
since craniofacial components and melanophores are derived from neural crest material.
Conclusion In conclusion, our data show Triadimefon to be a potent teratogen able to induce specific craniofacial malformation in Xenopus
laevis embryos, probably interfering with the NCC migration into the branchial mesenchyme. These results are also interesting
for ecotoxicological reasons as FON, as well as other pesticides, are likely to be present in water systems near agricultural
or urban areas which may serve as habitats for developing amphibians and fishes.
Recommendation and Outlook Our results are in agreement with the data obtained on in vitro cultured rat embryos suggesting that the FON mechanism of
action involves strongly conserved molecules. The choice of Xenopus laevis as the model organism allows us to extend the toxicological
and teratological observations to a molecular level, in order to search for novel genes regulated by FON exposure. 相似文献
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