Effects Of Insect Resistant And Herbicide Tolerant Transgenic Soybean On Soil Physical And Chemical Properties And Arbuscular Mycorrhizal Fungi Diversity

Genetically modified crops have been commercialized since 1996,and more than 70 countries and regions have cultivated them.With the a growing of world population,the commercial cultivation of genetically modified crops will help to alleviate the problem of food shortage,and continue to provide feed and food for human beings.However,the environmental safety problem in the process of planting genetically modified crops is still a controversial topic.Soil ecosystem is closely related to the planting process of genetically modified crops,therefore,the impact of genetically modified crops on soil ecosystem is an important part of safety evaluation before its commercial planting.In this paper,the g2m-epsp,gr79m-epsps and cry1 c genes transgenic soybean named "Jingdou 321" and the g2m-epsps,cry1 c and Gm NFYB genes transgenic soybean named "Jingdou 606" with a compound character of herbicide resistance and insect resistance were used as experimental materials.Both soybean crops planted in the experimental base of Shunyi crop institute,Institute of crop science,Chinese Academy of Agricultural Sciences.The rhizosphere soil samples were collected at seedling stage,flowering stage,podding stage and mature stage of soybean growth.The diversity of arbuscular mycorrhiza was used to evaluate the effects of transgenic soybean with complex characters on soil ecosystem.The main results are as follows:1.Compared with the rhizosphere soil samples of recipient soybean,the planting of insect resistant and herbicide tolerant transgenic soybean "Jingdou 321" and "Jingdou 606" had no significant effect on soil moisture content and p H value;compared with the untreated transgenic soybean,the transgenic soybean treated with herbicide had no significant difference in water content and p H value;the rhizosphere soil water content at different growth stages had significant difference.2.There was significant difference in the number of Fusarium in rhizosphere soil samples of "Jingdou 606" at different growth stages;there was no significant difference in the number of Fusarium in rhizosphere soil samples of "Jingdou 321" at different growth stages;however,there was no significant difference in the number of Fusarium in rhizosphere soil between transgenic soybean and recipient soybean,or between transgenic soybean treated with herbicide and untreated transgenic soybean.3.The relative abundance of dominant genera in the rhizosphere soil of "Jingdou 606" was significantly different in different growth stages,but there was no significant difference compared with the recipient varieties and herbicide treatments,which had no significant effect on the composition and diversity of arbuscular mycorrhizal fungi;"Jingdou 321" had no significant effect on the composition and diversity of arbuscular mycorrhizal fungi,and there was no significant difference between different growth stages.In conclusion,the planting of insect resistant and herbicide tolerant soybeans "Jingdou321","Jingdou 606" and herbicide treatment had no significant effect on the physical and chemical properties of soil,the number of pathogenic fungi Fusarium and the structural diversity of arbuscular mycorrhizal fungi.But different growth periods may lead to a significant difference in the rhizosphere soil water content.Long term monitoring is needed to further evaluate the effects of transgenic soybean planting on rhizosphere soil.