草地贪夜蛾对国产Bt玉米的抗性风险评估

为评估草地贪夜蛾Spodoptera frugiperda对国产Bt玉米的抗性风险，基于抗性风险分析模型对草地贪夜蛾在3种Bt玉米和2种庇护所条件下的抗性时间进行预测分析。结果显示，无论是采用种子混合庇护所还是结构化庇护所，草地贪夜蛾对Cry1Ab+Vip3Aa-玉米的抗性时间均远长于对Vip3Aa-玉米和Cry1Ab-玉米的抗性时间。在Bt与非Bt植株之间存在异花授粉和幼虫转移的条件下，采用种子混合庇护所的抗性时间较采用结构化庇护所的抗性时间大大缩短。以采用Cry1Ab+Vip3Aa-玉米和比例为0.20的庇护所为例，当异花授粉Bt显性度为0.5、幼虫转移概率为0.95时，采用结构化庇护所的抗性时间超过200代，而采用种子混合庇护所的抗性时间只有59代。结果表明，草地贪夜蛾对Cry1Ab-玉米的抗性风险远大于对Cry1Ab+Vip3Aa-玉米的抗性风险，而种子混合庇护所条件下的抗性风险远大于结构化庇护所条件下的抗性风险。

A risk assessment of the resistance of fall armyworm Spodoptera frugiperda to Bt maize in China

In order to understand the resistance risk of the fall armyworm, Spodoptera frugiperda, to Bt maize in China, the time for developing resistance was predicted by using the resistance risk analysis model for three Bt maize varieties and two types of refuges. The results showed that, for both seed mix refuge or structured refuge, the time for developing resistance was much longer for Cry1Ab+Vip3Aatransgenic maize than for Cry1Ab-transgenic maize or Vip3Aa-transgenic maize. In the case of crosspollination and larval movement between Bt and non-Bt maize plants, the time for developing resistance was generally shorter for seed mix refuge than for structured refuge. When the Bt dominance of cross-pollination was 0.5, the probability of larval movement was 0.95, if the proportion of refuge was 0.20, the time for developing resistance for Cry1Ab+Vip3Aa-transgenic maize was longer than 200 generations for structured refuge, but only 59 generations for seed mix refuge. These results suggested that the resistance risk of S. frugiperda to Cry1Ab-maize was much higher than to Cry1Ab+Vip3Aa-maize, and the resistance risk in the case of seed mix refuge was much higher than in the case of structured refuge.