【摘要】 对 3个米象的抗性品系 (其中两个是国内的 ,一个为澳大利亚提供的 )进行群体选择 ,对 1个米象的敏感品系进行单对选择。对 3个谷蠹的抗性品系和 1个敏感品系也进行同样处理。用FAO方法测出 3个米象抗性品系中最高抗性品系的抗性倍数为 198倍 ,但因谷蠹在高浓度磷化氢测定中有保护性昏迷现象 ,用FAO方法无法测出 3个抗性谷蠹的抗性倍数。对抗性虫用低浓度 0 .5mg/L和对敏感虫用低浓度 0 .0 1mg/L进行不同时间的处理 ,用LCT50 的方法可得出抗性虫的抗性倍数。使用这种LCT50 方法得到最高抗性谷蠹的抗性倍数为 2 0 9。同时用这种LCT50 得出最高抗性米象的抗性倍数是 193.7,非常接近于用FAO方法测出的 198的抗性倍数。证明该方法可以用来替代FAO方法更多还原

【Abstract】 Three phosphine-resistant strains of Sitophilus oryzae were mass selected and a phosphine-susceptible strain was selected by inbreeding.Three phosphine-resistant and one susceptible strain of Rhyzopertha dominica were similarly treated.The highest resistant strain of Sitophilus oryzae had a resistance factor of 198 in the FAO test.The response of the resistant strains of Rhyzopertha dominica could not be determined in the FAO test,because higher concentrations of phosphine may cause insects narcosis.An alternative method fixed lower concentrations of phosphine,0.5mg/L for resistant strains and 0.01mg/L for susceptible strain was used with varying times of exposure,and obtain the resistance factor based on LCT 50 . Using the modified LCT 50 method determined the highest resistant strain of R.dominica and obtained the resistance factor 209.The resistance factor of the highest resistant strain of S.oryzae is 193.7 by using modified LCT 50 method,and is very similar to the resistance factor 198 by using FAO method.更多还原