Analysis In Microbial Flora In Rhizosphere Soil Of Transgenic Bar Wheat And Ecological Risk Assessment

Bar gene is separate from streptomyce hygroscopicus, and it codes PAT. Transgenic Bar wheat can resist glufosinate. Rhizosphere is the especial entironment. Different plants or the same plant in different growth stage, their secretion will affect the growth of rhizosphere microbes. And rhizosphere microbes participate in the organic matter decomposition, humus forming, nutrient transforming and circulation in soil. And enzyme which microbes procreant can decompose, mineralize the organic matter, add the efficacious nutrient in soil and increase the absorptivity which plants absorbed nutrient from soil. Therefore the plants will grow faster and that lead to the increase of rhizosphere secretion. Thus, making a analysis on the effects which transgenic plants to the rhizosphere microbes will be important to the ecological risk assessment.Transgenic Bar gene wheat 87158 (BG87) and 98005(BG98) are planted at pot as experiment material as well their parent wheat YangMai87158(YM87) and AnNong98005(AN98) as control. Effects of Bar gene on rhizosphere microbes of wheat were studied through anglicizing change of microbial flora in reizosphere soil at different wheat growth stages.(1) The results indicated that the microbes'quantity in rhizosphere soil is varied at different bearing stage of wheat. At seedling stage and tillering stage there are less microbes'quantity in rhizosphere soil, as well as at the booting and heading stage, the quantity is the most. Microbes'quantity in rhizosphere soil is decreased gradually from heading stage to filling stage of wheat growth. After the elongation stage, significant differences were observed in microbial amount in rhizosphere soil between transgenic Bar wheat and the common wheat, and the same as the fungi quantity. While there is no difference on quantity of actinomyces.(2) The rhizosphere bacterias in rhizosphere soil of transgenic Bar wheat included Bacillus,Pseudomonas,Agrobacterium,Alcaligenes,Cellulomonas,Azotobacter,Micrococcus,Flavobacterium and Curtobacterium. The main bacterias are Pseudomonas,Bacillus,Agrobacterium et al. Few difference were observed on kinds of bacteria in rhizosphere soil between transgenic Bar wheat and the common wheat.(3) The rhizosphere actionmyces in rhizosphere soil of transgenic Bar wheat are composed of Sterptomyces and Nocardia.The main kinds of rhizosphere actionmyces in rhizosphere soil of Transgenic Bar wheat are Series Albus, Series Griseus, Series Viridis and Series Aureus. And the main actionmyces kinds have no difference between transgenic Bar wheat and the common wheat.(4) The rhizosphere fungi in rhizosphere soil of transgenic Bar wheat have Penicillium,Gliocladium,Aspergillus,Rhizopus,Trichoderma,Alternaria,Fusarium and Cephalosporium. And the main fungi kinds in rhizosphere soil of transgenic Bar wheat are Penicillium,Aspergillus,Rhizopus,Trichoderma. Few difference were observed on kinds of fungi in rhizosphere soil between transgenic Bar wheat and the common wheat.(5) Although there is difference in rhizosphere microbes kinds in the different growth stage, the main kinds have few difference between transgenic Bar wheat and common wheat. The kinds of rhizosphere bacteria of transgenic Bar wheat are lower than the common wheat before the elongation stage. But after the elongation stage, the kinds of rhizosphere bacteria of transgenic Bar wheat are higher than the common wheat. The kinds of rhizosphere fungi of transgenic Bar wheat are higher than the common wheat in every growth stage.