Impact Of Fungus-Resistent Transgenic Rice On Microbial Populations In Rhizospheric Soils

With the fast development of transgenic crops industrialization, environmental safety of transgenic crops had become a concerned issue by more and more people. So far, there were two completely different notions between the proponents and the opponents to apply the transgenic crops. It's still not sure that the transgenic crops would destroy our environment and the health of human beings or not, we hadn't had enough theory and experience to testify.Transgenic rice Qizhuan39,E10(expresing RC2４andβ-1, 3-Glu),E90(expresing RC24,RCH10 and RAC22) and non-transgenic rice Qisiruanzhan were selected to assess their impacts on microbial populations in rhizospheric soils. We used both conventional culture method and molecular approach (RAPD) to analyze the diversity of soil microbes. The results were as follows.1. The results of culture method showed that the amounts of culturable bacteria in the rhizospheric soil in the whole growing period of rice changed a lot. From the tillering stage to the filling stage, the amounts of bacteria increased slowly, and reached the biggest value in the period of filling stage. Then the amounts decreased gradually in the period of ripe stage. In any stage, the amounts of bacteria in the rhizospheric soil of transgenic rice Qizhuan39, E10, E90 and non-transgenic rice Qisiruanzhan was not significantly different.2. The results of culture method showed that the amounts of culturable fungi in the rhizospheric soil were different in stages. The amounts of fungi were less in tillering stage. In the booting stage, the amounts increased fast, and reached the biggest value in the period of heading stage. Then the amounts decreased sharply from the period of filling stage to the lowest in the period of ripe stage. In any stage, the amounts of fungi in the rhizospheric soil between Qizhuan39, E10, E90 and Qisiruanzhan were not siginificantly different. 3. The results of culture method showed that the amounts of culturable actinomyces in the rhizospheric soil increased from the tillering stage to the filling stage, then decreased in the last stage. The amounts of actinomyces in the rhizospheric soil between Qizhuan39, E10, E90 and Qisiruanzhan were not significantly different in the whole period.4. The results of RAPD showed that the diversity of the total DNA was not significantly different between the rhizospheric soils of non-transgenic rice and transgenic rice, through the study of the genenic diversity of soil microbes. The results of the analysis showed that the transgenic rice was not the main factor influencing the change of the microbial community in the rhizospheric soil of the rice.The results above showed that Qizhuan39, E90 and E10 had not affected the soil microbial population in the rhizospheric significantly. So we assess that the transgenic rice expressing RC24,β-1,3-Glu,RCH10,RAC22 would not affect the microbial population in the soil environment.But weather, water, light intensity and other conditions would have impact on soil microbial communities.Here we combined the conventional culture method and the molecular approach trying to provide the environmental safety assessment of transgenic crops with some insighting data.