Impact Of Transgenic Cry1Ab/c Rice On Microbial Ecology In Rhizosphere Soil

With the development of genetically modified crops (GMC), the safety evaluation of them becomes a research hottopic. Study on soil ecological system attracts more and more widely attention. Study on soil microorganisms is an important content on ecological safety evaluation of transgenic crops which is an important component of soil ecological system. We used Bt rice "TT51" and its receptor "MH63" as materials, combined with some traditional methods and modern technology to study if there are any differences of rhizosphere soil microbe on ecology, and provided the scientific data on environmental safety accessment of commercialization for TT51. The main results were as follows:(1) We tested physical and chemical properties of the pH, organic matter, available phosphorus, available potassium and alkaline hydrolysis nitrogen in rhizosphere soil between the MH63and TT51in2011and2012. Respectively by the one-way ANOVA, the results proved that there were some significant differences on pH for the early tillering stage in2012, on the organic matter in the booting stage in the2012, on the available phosphorus in the booting stage and after harvesting in2011, in the early tillering stage in2012, on the available potassium in post-harvesting stage in2012, on the alkaline hydrolysis nitrogen in the maturation stage in2011, in later tillering stage and post-harvesting stage in2012.Whereas there were no significant differences in the other stages.(2)We tested the activities of the urease, sucrose and phosphatase enzymes in rhizosphere soil between the MH63and TT51in2012.Respectively by the one-way ANOVA, the results showed that MH63and TT51had some significant differences on the urease activities in the early tillering stage and the post-harvesting stage, on the sucrose activities in the post-harvesting stage, on the phosphatase activities in the early tillering stage and post-harvesting stage, Whereas there were no significant differences in the other stages. (3) We tested the number of bacteria, fungi and actinomycete in2011and2012and the number of nitrogen-fixing bacteria in2012in rhizosphere soil between the MH63and TT51in2012.Respectively by the one-way ANOVA, the results showed that MH63and TT51had some significant differences on the bacteria in5stages of the later tillering stage, booting stage, post-harvesting in2011and the Maturation stage and post-harvesting in2012,on the fungi in2stages of early tillering stage and later tillering stage in2011, and on the actinomycete in3stages of booting stage and post-harvesting in2011,early tillering stage in2012,on the nitrogen-fixing bacteriain1stage of early tillering stage in2012. Whereas there were no significant differences in other stages.(4) We tested the microbial community diversity by Biolog-Eco and PLFA between MH63and TT51in rhizosphere soil in2012, according to biological and physiological method, the results proved that there were some significant differences on AWCD in the booting stage, maturation stage and post-harvesting stage, on Shannon indexes in the later tillering stage, booting stage, maturation stage and post-harvesting, on Simpson indexes in the post-harvesting stage and on Mcintosh indexes in maturation stage. Whereas there were no significant differences in other stages. At the same time, the result of PCA analysis showed that there were no obvious differences in different stages between MH63and TT51.According to PLFA of biochemical method, the results proved that there were some significant differences between MH63and TT51on the PLFAs in early tillering stage, later tillering stage, and maturation stage, on bacteria/fungi for later tillering stage and post-harvesting stage, and on G+/G" in the booting stage. Whereas there were no significant differences in other stages. The result of PCA analysis showed that there were no obvious differences in different stages between MH63and TT51.