用胨-PCNB-四环素选择性培养基涂布平板法检测了关中灌区麦田土壤中禾谷镰孢接种体数量。结果表明,除多年休闲的麦田外,前作物为水稻、玉米、大豆、首蓿、蔬菜的麦田都带有禾谷镰孢,接种体密度幅度为每克土壤58～2800个;在表土中以5cm深处土壤带菌密度最高,禾谷镰孢在麦田土壤中可形成厚垣孢子;麦田土壤中还含有大量带菌细小植物残渣,带菌率1.5％～10％,其密度为每亩(0.31～7.67)×10~4个。 The amount of Fusarium graminearum inoculated in the wheat field soil in Guanzhong irrigation area was determined by peptone -PCNB-tetracycline selective plating coating method. The results showed that Fusarium graminearum was present in the wheat fields with the former crops of rice, maize, soybean, first crop and vegetable, except for years of leisure wheat fields. The inoculum density ranged from 58 to 2800 per gram of soil; Fusarium graminearum can form chlamydospores in the soil of wheat field. The soil of wheat field also contains a lot of small plant-carrying debris with the rate of 1.5% -10%, and its density is 0.31 ~ 7.67 ) × 10 ~ 4.