Effects Of Transgenic Drought Resistant Soybean On Soil Microorganisms

In recent years, with the promotion of transgenic soybean and continuous expansion of cultivated area, which bring about important social and economic benefits. At the same time, it may cause some of the negative impact which has attracted attention of scientists around the world. Therefore, it is very necessary that transgenic soybeans carry out ecological risk assessment before geting into the field trials and commercial production stage . Microorganisms is an important component of the soil, that transgenic soybean impact on soil microbial community of the ecology safety evaluation is an important essential content for safety assessment of transgenic soybeans .study selected transgenic drought resistant soybean Dong nong 50 and no transgenic drought resistant soybean Dong nong 50 (Northeast Agricultural University, Key Laboratory of Soybean Biology of Ministry of Education to provide) as experimental material, pot culture method was used to study the effect of transgenic drought resistant soybean and no transgenic drought resistant soybeanon soil bacteria numbers, actinomycetes number, fungi number ,two kinds of the beneficial microorganisms named trichoderma and azotobacter and,two kinds of the pathogenic microorganisms named phytophthora and fusarium . utilize the method of the indoor pure culture , different concentrations of transgenic soybean and no transgenic soybean root extract were added in the culture medium,access trichoderma,azotobacter,fusarium and phytophthora , research on the impact of colony growth. The results show:1. The soil bacteria number was decreased in rhizosphere of transgenic drought resistant soybean only at VE and R1 growth stages under normal soil water condition, and at VE growth stage,difference is significant. the soil bacteria number was increased in rhizosphere of transgenic drought resistant soybean only at R4 and R8 growth stages,but differences are significant. Under water stress condition, the soil bacteria number was increased in rhizosphere of transgenic drought resistant soybean at VE,R1,R4 and R8 growth stages,but differences are significant.Under water stress condition bacteria number was significant decreased only at R1 growth stage in rhizosphere of no transgenic drought resistant soybea compared with that of in the normal water condition.2. The soil actinomycetes number was decreased in rhizosphere of transgenic drought resistant soybean only at VE,R1and R4 growth stages under normal soil water condition, and at VE growth stage,difference is significant. Under water stress condition, the soil actinomycetes number was decreased in rhizosphere of transgenic drought resistant soybean at VE,R1 and R4 growth stages,but differences are significant. Under water stress condition actinomycetes number was significant increased only at VE growth stage in rhizosphere of no transgenic drought resistant soybean compared with that of in the normal water condition.3. The soil fungi number was increased in rhizosphere of transgenic drought resistant soybean at VE,R1 and R8 growth stages under normal soil water condition, and at VE growth stage,differences are significant. Under water stress condition, the soil fungi number was decreased in rhizosphere of transgenic drought resistant soybean at VE,R4 and R8 growth stages, differences are significant. Under water stress condition fungi number was significant decreased only at R8 growth stage in rhizosphere of ransgenic drought resistant soybean and no transgenic drought resistant soybean compared with that of in the normal water condition.4. The soil trichoderma number was increased in rhizosphere of transgenic drought resistant soybean only at VE,R1 and R4 growth stages under normal soil water condition, Under water stress condition, the soil trichoderma number was increased in rhizosphere of transgenic drought resistant soybean at all growth stages,but under normal soil water condition and water stress condition,differences are significant.5. The soil azotobacter number was increased in rhizosphere of transgenic drought resistant soybean only at VE,R4 and R8 growth stages under normal soil water condition, Under water stress condition, the soil azotobacter number was decreased in rhizosphere of transgenic drought resistant soybean at R1 and R4 growth stages,but under normal soil water condition and water stress condition,differences are significant.6. The soil fusarium number was increased in rhizosphere of transgenic drought resistant soybean at all growth stages under normal soil water condition, but noly at R1 growth stage,difference is significant. Under water stress condition, the soil fusarium number was increased in rhizosphere of transgenic drought resistant soybean at R1,R4 and R8 growth stages,but noly at R1 growth stage,difference is significant.There was no significant effect on fusarium numbers of at all growth stages under normal water condition and under water stress condition in rhizosphere of transgenic soybean and no transgenic soybean.7. Under indoor pure culture conditions, different density of transgenic drought and no transgenic of soybean root extracts be placed in culture medium ,effect of different density of root extract on pathogenic microorganisms, there was no significant effect on colony diameter of fusarium , phytophthora ,trichoderma and azotobacter at some density of transgenic drought and no transgenic of soybean root extracts condition.