Degradation Of Pyrimethanil By Botrytis Cinerea

In China,a large agricultural country,the key to the smooth production of agri culture and the stable and high yield of crops is the use of chemical fertilizers and pesticides.Pesticides play an important role in the production of fruits and vegetable s in China.With the long-term irrational use of pesticides,pesticide pollution has be come more and more serious.Botrytis cinerea caused by Botrytis cinerea is a very serious disease in the agricultural production process such as vegetable and fruit pro duction and storage in China and even in the world.The widespread use of pyrimet hanil in production has led to the long-term use of pyrimethanil fungicide and the c ontinuous increase of its dosage,resulting in different degrees of resistance to Botryt is cinerea in different places.Strawberry production has been affected and farmers h ave suffered heavy losses.In order to understand the resistance status of Botrytis cinerea to pyrimethanil a nd the reasons for its resistance,this paper uses Botrytis cinerea strains resistant to pyrimethanil as experimental materials,monitors the degradation process of fungicide by Botrytis cinerea based on metabonomics technology,explores the causes of resis tance,and provides basis for rational use of pyrimethanil.(1)In this study,the determination method of pyrimethanil in culture medium was established.The test results showed that the average recovery rate of the two m ethods was from 80.0% to 90.0%,and the relative standard deviation was from 0.10% to 7.50% in the range of 70.0% to 120.0%.Pyrimethanil was degraded in straw berry Botrytis cinerea bacterial liquid,and the degradation rate was in line with the first-order kinetic equation,which fully met the requirements of pesticide environmen tal behavior test.Qu ECh ERS-liquid chromatography method was also established to determine the concentration change of pyrimethanil in Botrytis cinerea.The results s howed that Botrytis cinerea had obvious degradation effect on the two concentrations of pyrimethanil,50.00 mg/L and 100.00 mg/L.Under the same environmental condi tions,the degradation rate of pyrimethanil by Botrytis cinerea in 50.00 mg/L bacteri al solution reached 55.62% after 21 days,while the degradation rate in 100.00 mg/L bacterial solution was 46.98%.(2)The metabolites of pyrimethanil from Botrytis cinerea were mainly studied.In this paper,the determination methods of pyrimethanil fungicide in Botrytis ciner ea by gas chromatography-mass spectrometry and liquid chromatography-mass spectro metry were established.Distribution and transformation kinetics of pyrimethanil meta bolites and active compounds were analyzed by GC-MS and LC-MS/MS.High resol ution mass spectrometry and structure analysis tools were used for metabolite identifi cation.Pesticide pyrimethanil metabolites were identified in different plant pathogenic bacteria at specific time intervals and in the final products.The main degradation p roducts were identified as: 2,4-di-tert-butylphenol,2-phenylacetamide,cyclopentolate,2-(3,4-dihydroxyphenyl)ethylamine,p-hydroxyphenylethylamine,phenol and p-cresol.The intermediate degradation products are: monoethylhexyl phthalate,benzoic acid an d o-hydroxyphenylacetic acid.In this paper,the degradation and metabolites of Botry tis cinerea in the growth process were studied to provide theoretical basis for the sa fe use of pesticides in orchards and the formulation of quality and safety guarantee measures for agricultural products.