Mycotoxin Determination In Storing Period Of Wheat Scab And Sieving Of Effectual Fungicides For Control

Fusarium head blight or scab caused by species of Fusarium is an most devastating disease of wheat, prevalently in the areas with high temperature and high humidity worldwide. It can not only make yield loss, but also produce a variety of mycotoxins that can harm the health of humans and animals. Carbendazim (abenzimadazole fungicide, MBC), has been extensively used for the control of FHB, resulting in severe MBC resistance in China.This article is mainly based on wheat scab generate widespread resistance to carbendazim as a research background, and studied of10common fungicides on Fusarium graminearum indoor virulence determination.In this article, we established a sensitivity baseline of Epoxiconazole on Fusarium graminearum; screened three active pharmaceutical compound; established a new derivative method for GC. An ELISA method was adopted to find out the relationship between the storage of wheat scab and the storage environmental factors and changes, the results are as follows:Those10commom fungicides were tested by the methods of mycelial growth inhibition on AnHui strains(No.15). The results proved that the10fungicides suppression effect were markedly different. Among those fungicides, we found that the Thiram has the worst inhibition of Fusarium,EC50value was5.4521μg·mL-1，and Difenoconazole azole showed the strongest inhibition, EC50value was0.0192μg·mL-1. In addition to Thiram, Dimethomorph morpholine, carbendazim three insecticides, EC50values was larger than1μg·mL-1.The other seven agents of wheat scab EC50values were less than1μg·mL-1.The sensitivities of63Fusarium graminearum strains to Epoxiconazole was tested by the methods of growth inhibition. The results proved the EC50values of63isolates ranged from0.1088μg·mL-1to1.2098μg·mL-1, and the mean EC50value was0.5309μg·mL-1.All of the63isolates from AnHui province has been still sensitive to Epoxiconazole.The Pharmacy compounding test found all the ratio of the two agents (F/Q) within the extent of testing,0.5<SR values<1.5,showed additive effect. And the best combination of the ratio was7:1, the EC50was0.2499μg/mL, SR was1.13;Q/B,except the ratio1:7, all of the others are shows Synergies, SR values>1.5. In addition,the ratio of5:1shows a high obvious synergy, the EC50was0.0901μg/mL, SR was2.3027.Followed by the ratio of7:1, the EC50was0.0964μg/mL, SR was2.1122. Use the N-methyl-bis-trifluoroacetamide (MBTFA) as a derivatization reagent of GC on DON determination. We investigated the optimum temperature of the derivatization reaction was80℃. Toxin detection spectrum peak shape clear and obvious.It has no interference peak, and it has a smooth baseline.According to the relationship between the detected absorption peak area of the DON concentration of the standard sample and the DON, we established a standard curve of DON. The detection method within the scope of a good linear regression equation y=132009.0x+6303.3, Correlation coefficient was0.9988, the Linear range of0.1-50ug/ml.We use an ELISA Method of detection of DON with storage of environmental factors, the content of a corresponding change in regularity as follows:In the test within the control range, with the increase of storage time, and toxin content in reducing; the higher relatively of water retaining capacity, the higher the content of the toxin. Dried by silica gel(8%relative of water retaining capacity) and Wheat grain has the lowest toxin levels, and of water retaining capacity30%, the highest toxin levels.The DON content are increased with the increase of the breakage rate and the rate of diseased kernel. As the temperature changes, the content of the toxin showed a single peak curve. At the15℃, the highest content of toxins.