Contamination Status Of Fusarium Toxin And Study On Fusarium Species From Wheat In Shandong Province

Wheat scab caused by Fusarium gramineae is one of the important wheat fungal diseases in China.The occurrence of scab will not only cause serious yield loss,but also produce a variety of fusarium toxin pollution,such as trichothecene,zearalenone(ZEN)and fumonisins(FBs),which seriously threaten human and animal health.In recent years,with the change of both global climate and farming practices,wheat scab in China has frequently occurred and accompanied by the phenomenon of northward expansion and westward movement.Shandong is the second largest province of wheat cultivation in China,and the consumption of wheat accounts for a large proportion.Therefore,it is of great practical significance to grasp the contamination status of Wheat Fusarium toxin in Shandong Province and clarify the population types and chemical types of Fusarium toxin-producing in Shandong Province for ensuring the quality and safety of wheat products in Shandong Province.In this study,a method of solid phase extraction,high performance liquid chromatography tandem mass spectrometry was developed to detect 9 kinds of fungus toxins in wheat.Based on the detection method,I focused on the major wheat producing areas in Shandong province in 2017 and 2018,and 540 wheat samples were collected in harvest season.The pollution level of the 9 kinds of fungus toxins,DON,3 A-DON,15 A-DON,NIV,4 A-NIV,ZEN,FB1,FB2 and FB3,which have influenced on wheat product quality and safety was analyzed.The strain types and toxic chemical types of those samples were also illuminated.1.A detection method of fusarium toxin in wheat using solid phase extraction-high performance liquid chromatography tandem mass spectrometry was established.Based on solid phase extraction,the purification effects of four different SAX,PSA,C18 and NH2 solid phase extraction columns were compared.Six different proportions of acetonitrile-water extracts and eluents for fumonisin acidified methanol in different proportions were optimized.It was found that acetonitrile-water(85:15,v/v)extracts were used to extract,NH2 column was purified,acetonitrile-water(85:15,v/v)was leached once,Methanol-methyl alcohol-methyl alcohol was used.Two-step method of acid(85:15,v/v)secondary elution was used.In addition,the better methods of chromatography and mass spectrometry were selected to determine the nine Fusarium toxins.The correlation coefficients R2 were all greater than 0.99.The recoveries were between 80%-100.0%.The relative standard deviations were between 5.8%-9.0%,all less than 10%.The detection limits of DON,3ADON and 15 ADON were 3.0 ?g/kg,NIV 2.0 ?g/kg,4ANIV 4.0 ?g/kg,ZEN 0.3 ?g/kg,FB1 3.0 ?g/kg,FB2 2.0 ?g/kg and FB3 2.0 ?g/kg.A method of data acquisition and analysis for simultaneous determination of various Fusarium toxins by gas chromatography tandem mass spectrometry with the same pretreatment method was established to avoid the disadvantages of multiple analysis for the same batch of samples,save the cost of the instrument and improve the work efficiency.2.To grasp the contamination of Wheat Fusarium toxins in Shandong Province.The above methods were used to determine about 598 batches of wheat samples in the main wheat producing areas of Shandong Province in 2017 and 2018.The results showed that DON,3A-DON and 15A-DON were the main contaminants of Fusarium graminearum toxins.The overall detection rate of toxins was 25.33% in 2017 and 48.51% in 2018,showing an annual upward trend,and the overall contamination rate was not high.The locality is serious,showing the characteristics of regionalization.Tainong 18,Linmai 2 and Jimai 22 are all moderately resistant to scab.Luyuan 502 is highly susceptible to scab.Other varieties are relatively miscellaneous.They are mainly low or moderately susceptible to scab because of the influence of climate and other external conditions.3.Strain types and toxic chemical types of fusarium virulent in wheat in Shandong province was illuminated.After isolation and purification of Fusarium graminearum from wheat in Shandong Province,DNA was extracted from the purified strains,and the Fusarium strains were identified by multiplex PCR.It was concluded that the main Fusarium producing Fusarium in Shandong Province were F.asiaticum and F.graminearum,of which 15 ADON chemical types were the main one.Fusarium graminearum was the dominant population of Fusarium graminearum complex.The toxicity of 3ADON chemical type Fusarium graminearum was stronger than 15 ADON chemical types Fusarium graminearum and NIV chemical type Fusarium graminearum.