Study On The Relationship Between The Incidence Of Corn Earrot And The Accumulation Of Mycotoxins In Grains In Northern China

Corn is one of the three major food and feed crops in the world.Corn is susceptible to Fusarium ear rot during the growth process,which seriously affects the yield and quality of corn in China.At present,the research on corn ear rot is mainly focused on the relationship between corn worms,pathogenic bacteria and the incidence of corn ear rot,and there are few studies on the relationship between the incidence of corn ear rot and the mycotoxin content in grains.In this paper,the relationship between the incidence of corn ear rot and the accumulation of mycotoxin in the grain is studied from the two aspects of Fusarium oxysporum and Fusarium graminearum in the natural state,which provides a theoretical basis for the prevention and control of corn diseases.It is of great significance to the development of China's corn industry.The following results were obtained through research:To establish a common method for detecting 17 mycotoxins in corn: based on the QuEChERS principle,using 80% acetonitrile aqueous solution of 1% formic acid as extraction solvent,0.1% formic acid aqueous solution and acetonitrile as mobile phase,and purifying the extract with 100 mg C18.A common method for detecting 17 mycotoxins in maize,the detection limit range is(LOD)0.1~20.0?g/kg,the limit of quantification range is(LOQ)0.5~50.0 ?g/kg,and the relative standard deviation is 2.21%.~11.34%,the average recovery rate is 70.76%~115.14%.The method has the advantages of simple steps,high accuracy,strong operability,low detection cost,and is suitable for large-volume corn samples containing various mycotoxins.Corn is susceptible to natural conditions.When the incidence of ear rot is from 1 to 5,the accumulation of mycotoxins in corn kernels increases with the increase of the disease level.At the same disease level,there is a difference in toxin content in each maize variety.After artificial inoculation of Fusarium graminearum,there are mainly two toxins of DON and ZEA in corn.There were significant differences in the levels of the two mycotoxins in the same variety at different hair levels.By studying the relationship between the incidence of ear rot and the mycotoxin content of 11 maize varieties,it was found that when the incidence of corn ear rot was 1 to 5,The content of DON and ZEA was positively correlated with the level.When the incidence of corn ear rot was 5 to 9,the content of DON and ZEA was negatively correlated with the level.There is no symptoms of ear rot in the appearance of corn,and there is also mycotoxin contamination in corn kernels.The existing maize variety certification standard only uses the incidence of corn ear rot as the criterion.In order to increase food safety and improve consumer food safety,the resistance of corn accumulation to mycotoxins should be determined as the criteria for the determination of corn varieties.