| Pyraoxystrobin (SYP-3343) is a new fungicide which is developed by Shenyang Research Institute of Chemical Industry and has its own intellectual property in China. This kind of compound could control downy mildew, anthracnose, powdery mildew, and has high bactericidal activity. It still has protection and treatment effects. The field tests showed that Pyraoxystrobin has obvious insecticidal, acaricidal activity. Compared with the commonly used fungicides, the Pyraoxystrobin has the features of broad spectrum, high efficiency and safety. However, the mechanism of Pyraoxystrobin has not been reported. This study not only helps to clarify its mechanism of absorption, distribution, metabolic pathway, product composition and other important problems, but also helps the similar compound synthetize and structure optimize. In addition, according to the regulations of the department of pesticide ministry. It is necessary to research the environmental behaviour of new drugs so as to ensure the safety of the environment and farm produce. So the study on this new type of compound plays an essential role to promote the use of pesticides.Based on the radioactive isotope tracer technique and modern analysis technology, the study of this paper include the following several parts:(1) Study the absorption, transportion and distribution of14C-SYP3343in cucumber plants by foliage daub method, and the uptake of soil bound residues(BR) by cucumber in three different soils including Loamy soils (S1), Coastal saline soils (S2) and Red clayey soils (S3). The results showed that total absorption of14C-SYP3343into cucumber plants reached68%at5days after treatment (DAT). The absorbing capacity remained at this level to14DAT. The translocation of14C-SYP3343was acropetal mainly and the absorbed14C-SYP3343was mainly remained in the treated leaf.14C-SYP3343could not be easily released from the BR soils and transported into plants again. The uptake of14C-SYP3343in three soils was followed in the order of S3(acidic soil)> S2(alkaline soil)> S1(neutral soil).(2) The metabolites of14C-SYP3343mainly included7species in cucumber plants. There were4kinds of conjugated products, and the rest3were degradation products. By comparing different period of the proportion of the metabolites, M1, M2, M3, M4, M6and M7were gradually increasing, but the M5decreased.65.7%of14C-SYP3343had been degradated12DAT. The BR of14C-SYP3343in cucumber plants had the linear relation with the time, while its extractable residues(ER) increased during the firstl-8d, and then decreased.(3) Study the absorption, transportion and distribution of14C-SYP3343in cucumber plants and rice by root spraying method. Overall, it was difficult to absorb and transport the14C-SYP3343into the two plants. Although in the first2days, there is a greater portion of14C-SYP3343in shoots compared with in the roots in cucumber plants. But to16DAT, whether in rice or cucumber plants, the radioactivity in roots was higher than in the shoots. Moreover, the absorption and mobility of14C-SYP3343in rice was greater than in cucumber plants. However, it will inhibit the rice growth when at a concentration of4.92x10-4g/L... |
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