| Common bunt of wheat Tilletia caries (DC.)Tul.(TCT) occurred widely in Jiangsu, Shanxi, Shandong, and Henan provinces of China, it had been cared by China, the United States, Japan and other countries. It had been listed as complement plant quarantine pests by Heilongjiang, Shandong, henan, Tianjin and so on. Ethylene oxide fumigation was the traditional treatment, however ethylene oxide was highly flammable and carcinogenic. In this thesis, new fumigation, microwave treatment and heat treatment were used as replacing technologies of ethylene oxide fumigation, and the effects were tested on moisture content, grain weight, germination rate, respiration, reducing sugar, fatty acid value and other quality indicators of wheat. The major findings were as follows:1.New fumigation technology against TCTFumigation tests with 7 kinds of potential new fumigants including carbonyl sulfide, methyl isothiocyanate et al against TCT were performed at 20℃and 60% humidity conditions. The results indicated that six kinds of potential fumigants could not completely kill TCT except of MITC.The applied doses of MITC to achieve 90%,95%,99% and 99.9963% mortality were 15.225,16.829,20.307 and 32.212 g/m3 respectively after 120 h fumigation. However,50 and 100 g/m3 MITC failed to kill TCT under the wheat loading tests, because there was a high adsorption of wheat and the concentration of MITC was too low during the fumigation. Residue analysis showed that methyl isothiocyanate residues finally declined to 0.29,1.07 mg/kg after 16-day aeration. Quality test showed that after MITC fumigation, absorption of wheat samples was inhibited, decomposition of nutrients in wheat were slowed down, wheat respiration and dry grain weight was observed. The germination rate of wheat can be guaranteed at low concentrations fumigation.These results indicated that MITC fumigation had no adverse effect on wheat quality under 100g/m3, however, improved fumigation methods were required to overcome the high adsorption of wheat.2.Microwave treatment technology against TCTMicrowave treatments were conducted against TCT under 800,640,480,320 and 160W.The results showed that the higher the microwave power, the shorter the time completely killed TCT. Under each condition, the treatments that can effectively kill TCT were 800,640,480,320 and 160W for 40,40,50,80 and 180 s respectively. Quality testing results showed that after microwave treatment, moisture content of wheat were significantly reduced, dry weight were changed a little, germination rate were reduced, respiratory rate and decomposition of nutrients were speeded up, treatment under 160W for 180s completely killed TCT, while ensuring the best combination of wheat quality. However, microwave treatment had significant effect on wheat quality, accelerated the rate of deterioration of wheat, and the results showed that the treatment under low power and long time could ensure the quality of wheat, further research should be performed at low power to achieve the best results.3.Heat treatment technology against TCTHeat treatments were conducted aginst TCT at 70,80℃and 50%,65%,80% RH. The results showed that treatments that could completely kill TCT were 70℃,under 50% RH for 240 min, and 80℃,under 50%,65%,80% RH for 40,20,5 min respectively. Quality results showed that after heat treatment, moisture content of wheat were significantly affected and dry matter content were changed a little, viability of wheat were reduced, respiratory rate and decomposition of nutrients were accelerated. In this experiment,80℃,50% RH was the best heat treatment. However, the handling object of the test was bare bacteria gall, further verification tests should be done before the method was applied in quarantine.
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