The Environmental Risk Assessment Of Genetically Modified Bacillus Thuringiensis WG-001

This dissertation is focus on the effect of genetically modified Bacillus thuringiensix WG-001 on the cotton field ecology. The research results are summarized as following .1. The dissemination range of Bacillus thuringiensis WG-001 in the cotton fieldWhen Bacillus thuringiensis WG-001 was applied to the cotton phylloplane by spray. 15m in downwind direction and 5m in upwind direction is the maximum horizontal dissemination range respectively. In addition, the vertical dissemination depth of WG-001 in soil is no more than 5 cm in the spray area.2. The establishment of Bacillus thuringiensis WG-001 in the environment.The ability of Bacillus thuringiensis WG-001 to establish on cotton leaves is restricted and no colon) of Bacillus thuringiensis WG-001 was detected from the cotton leaves after 35 days. The colonies of Bacillus thuringiensis 171/304-gfp in soil decreased continuously in pot plant experiment in the first se\'en days and then kept steady at the level of 450 cfu /g soil in the following two weeks.3. Effect of Bacillus thuringiensis WG-001 on indigenous microbial populations.No significant negative impacts on indigenous microbial populations were found in soil after Bacillus thuringiensis WG-001 was applied to the cotton phylloplane by spray. The total amount of indigenous bacteria! populations fluctuated at the range of 3.9 105 cfu g soil and 4.2 105 cfu g soil and the range of the total numbers of indigenous fungi populations is 1.2 105 cfu g soil to 1.7 105 cfu. g soil.4. Horizontal gene transfer of crylAa and cryl AccrylAa or crylAc wasn't found in 260 microbial colonies. 138 fungi colonies, and 41 cotton leaf samples that were determined to verified the presence of the corresponding gene by the way of PCR amplification.5. Acute toxicity of Bacillus thuringiensis WG-001 to fish and mammalNo any toxicity effect on mammal was found and 15000mg/kg is the maximum tolerance dose of mouse to Bacillus thuringiensis WG-001. While obviously negative effect of high concentration Bacillus thuringiensis WG-001 on fish in water was found.