Effects Of Transgenic Maize Containing Cry1Ab And Epsps Gene C0030.3.5 On The Abundance And Community Structure Of Soil Carbon Dioxide Fixation Microbes

In this paper,to provide the theoretical basis for comprehensive evaluation of the ecological and environment risk of transgenic maize containing cry1 Ab and epsps gene C0030.3.5.Through field experiments,conventional methods combined with quantitative real-time PCR(qPCR)and terminal fragment polymorphism(T-RFLP)technique,study the study the effect of transgenic maize containing cry1 Ab and epsps gene C0030.3.5 on soil microbial community structure and abundance of carbon doxide fixation microbes.The main results are as follows:1.During the experimental study,soil physicochemical properties of the transgenic maize containing cry1 Ab and epsps gene C0030.3.5,acceptor maize and conventional maize had no significant difference(P>0.05).2.During the experimental period,transgenic maize containing cry1 Ab and epsps gene C0030.3.5,receptor corn,and conventional maize had no significant effect on TOC,WSOC and POXC.There was a significant difference in the POXC in the jointing and ripening stages in 2016(P<0.05).CCA analysis was conducted between soil organic carbon and its labile components and soil physicochemical properties.The results showed that the soil ammonium,soil nitrate,soil total nitrogen,soil total phosphorus,soil organic matter,soil moisture content and soil pH and soil organic carbon and its labile components are closely related.3.During the experimental period,transgenic maize containing cry1 Ab and epsps gene C0030.3.5,acceptor maize and conventional corn had no significant effect on soil carbon cycle related enzymes,soil cellulase,soil peroxidase and soil polyphenol oxidase activity(P>0.05).4.During the experimental period,there was no significant difference in the abundance of carbon doxide fixation microbes functional gene cbbL in 2016(P>0.05)there was significant difference in the jointing stage in 2017(P<0.05).With the advancing of the maize growth stages,the soil carbon doxide fixation microbes community abundance in the first show rises and then decreases in 2016.In 2017,it showed the trend of first decreasing and then increasing.The growth stages had a significant effect on the abundance of the cbbL gene.5.Transgenic maize containing cry1 Ab and epsps gene C0030.3.5 had no significant effect on soil microbial community structure.In 2016 and 2017,soil carbon doxide fixation microbes functional gene cbbL shared dominant populations of 26 and 57 bp.6.The Shannon and Evenness index of transgenic maize containing cry1 Ab and epsps gene C0030.3.5,receptor maize and conventional maize rhizosphere soil carbon doxide fixation microbes functional gene cbbL had no significant difference in each growth stage in 2016(P>0.05).There was a significant difference in the jointing stage and milky stage in 2017(P<0.05).7.The results of PCA analysis of soil carbon doxide fixation microbes functional gene cbbL showed that there was no significant separation between receptor corn and transgenic maize containing cry1 Ab and epsps gene C0030.3.5.The results of CCA analysis showed that the soil physicochemical properties affecting soil microbial community structure did not change significantly during the experimental period(2016 and 2017).Soil organic matter,soil total phosphorus and soil available phosphorus were the main factors affecting soil carbon doxide fixation microbes community structure.Results above studys point out that the transgenic maize containing cry1 Ab and epsps gene C0030.3.5 had no significant effect on soil physicochemical properties,soil organic carbon and its labile components,and soil carbon-cycle enzyme activities.Transgenic maize containing cry1 Ab and epsps gene C0030.3.5 had significant effects on the community structure and abundance of soil carbon-fixing microbial functional genes in some growth stages.The abundance of soil carbon doxide fixation microbes functional gene cbbL was significantly affected by the growth stages.