转基因(Cry1Ac)抗虫棉对土壤微生物的影响

对不同种植年限的转基因(Cry1Ac)抗虫棉田土壤中主要微生物数量变化进行了测定，结果表明：（1）种植转基因抗虫棉后对土壤微生物细菌、放线菌和真菌数量的影响趋势基本相似；（2）种植抗虫棉1年后，土壤中细菌、放线菌、真菌数量将有所增加，连续4年达到高峰，然后数量开始下降，连续种植7年后，棉田微生物数量接近于种植1年的棉田；（3）种植1年后又种植非转基因棉花的棉田，土壤微生物数量低于种植1年抗虫棉的棉田，与种植非转基因棉的数量无明显差异。由此可见，种植转基因抗虫棉对土壤微生物数量有一定的影响。

Effects of Transgenic Cry1Ac Cotton on Soil Microbes

Counting the number of bacteria、antinomyces and fungi in the soil after different years of planting Bt cotton.The results showed as follow：（1）the trend of influence of planting Bt cotton to the bacteria、antinomyces and fungi number in the soil is basically similar.（2）After one year of planting Bt cotton the number of bacteria、antinomyces and fungi in the soil would increase. With 4 successive years of planting，it reaches to the peak and then begins to fall. After 7 successive years the number even is close to that of 1 year.（3）After one year of planting Bt cotton and then one year of non-Bt cotton，the number of microbes in the soil is smaller than that of planting one year of Bt cotton which is close to the number of planting non-Bt cotton. So, there are some effects on the number of microbes in the soil, while planting Bt cotton for more years.