Correlation Analysis Of Factors Affecting DON Content In Wheat Grains And Effects Of Amino Acids On Toxicity Of Fusarium Graminearum

Fusarium graminearum（F.g）is the main pathogen causing Fusarium head blight of wheat,resulting in a significant decrease in wheat yield and quality.In addition,deoxynivalenol（DON）produced by F.g.was a worldwide food contaminant.The annual harvest of wheat in China has a concentration exceeding the standard,which seriously affecting the quality and quality of China’s agricultural products.In the paper analyzed the natural disease index,disease grainrate,ergosterol content and DON content of 52 wheat varieties,to determine the relationship between grain DON content and its related factors.The aim is to provide a scientific basis for wheat resistance to scab breeding,scab control and DON pollution control.At the same time,according to the correlation between the DON content of wheat grains and the amino acid content,combined with the stimulating effect of amino acids such as GABA,ornithine and arginine on DON toxin,we investigated the effects of 17 amino acids on the production of F.g.It intended to screen out the amino acids produced by detoxification or inhibition of toxins,and used as a pharmaceutical formulation for the control of F.g.In this paper,the investigation of different disease index,disease grainrate,grain ergosterol and toxin content of wheat varieties was carried out,and the total amino acid and free amino acid content of the grain were analyzed.Using different amino acids as nitrogen sources to study the growth and toxicity of Fusarium graminearum PH-1 in liquid medium.Draw the following conclusions:（1）Under the natural conditions,the content of DON in 52 tested wheat cultivars was significantly positively correlated with disease grainrate,ergosterol content and disease index,and the correlation coefficient was 0.858（p<0.01）.,0.792（p<0.01）and 0.512（p<0.01）,respectively.The DON content of grain has the highest correlation with the disease grainrate.The results of cluster analysis based on disease index,disease grainrate and grain DON content showed that 52 tested varieties can be roughly divided into 7 types.（2）The effect of free amino acids in wheat grains on the anti-accumulation of toxin in wheat was significantly greater than that in acid-soluble amino acids.The seven free amino acids of GABA,Pro,Cit,Glu,Ala,Val and Met in the grain have significant effects on toxin accumulation.（3）According to the action of exogenous amino acids on F.g,exogenous amino acids can be classified into three categories.The first type is stimulating for mycelial growth:Tyr,Orn+Glu（1:1）,Ala,Ser,Gly,Arg,Glu;The second category is stimulating toxin production:Orn,Arg,Tyr,Trp,Lys and（NH₄）₂SO₄;The third category is Arg and Tyr which are beneficial to both toxin production and mycelial growth.The endogenous free amino acids of hyphae are different from the exogenous amino acids,and they are negatively correlated with toxins,and Glu amino acids are significantly negatively correlated.Combined with the analysis of factors related to DON content in wheat grain,exogenous and endogenous amino acid content and bacterial liquid toxin content analysis Glu had a good inhibitory effect on the toxigenic ability of F.g.