Effects Of Transgenic Bt Maize On Soil Microorganism And Soil Active Components In The Maize Rhizosphere

From 1996 to 2016,the acreage of GM crops increased from 1.7 million hectares to 185.1 million hectares,and the acreage of transgenic crops increased by more than 100 times over a 20-year period.Bt cotton,corn and other crops to reduce the use of Bt crops to reduce the use of pesticides for the world's farmers to increase production and solve the problem of poverty in the world to contribute.The safety of genetically modified crops has also affected the environmental release and commercialization of GM crops.In this study,we investigated the effects of transgenic Bt maize on soil enzyme activity,microbial community and degradation of Bt protein in Bt maize plants,and provided scientific safety evaluation data for the environmental release and commercialization of Bt maize.The results are as follows:(1)There was no significant difference in alkaline protease,alkaline phosphatase,urease and acid invertase activity between Bt maize and non-transgenic Bt maize rhizosphere during the five growth stages.There was no significant difference of soil catalase activity between Bt maize and non-transgenic Bt maize rhizosphere during the first four growth stages.During the harvest period,the activity of catalase in the rhizosphere soil of Bt maize were significantly lower than that of non-transgenic Bt maize.(2)There were no significant differences in Shannon diversity index,McIntosh evenness index and Simpson dominance index of soil microbial community in Bt maize and non-transgenic Bt maize rhizosphere during the five growth stages.(3)The principal component analysis of the Biolog experiment of three soil microbial communities showed that the variance contribution of the first 14 components reached 100%,and the cumulative contribution rate of the first two main components reached 69.69%.There was no obvious difference in the utilization of the two main components between rhizosphere microbial community of Bt maize and non-transgenic Bt maize.(4)505-12-5 and RF-12-5,the Bt protein degradation of four treatments(indoor drying,on the ground,underground treatment and planting wheat)after two Bt corn harvests showed that although the four treatments of Bt protein degradation of the different rates,but the Bt protein are not detected at105 d.