The interactions of natural enemies and transgenic Bt plants.;

Research on the economic threshold of cotton plant bugs to transgenic Bt cotton;

Changes in diversity of culturable microorganisms on leaf surface of transgenic Bt cotton;

Using transgenic Bt cotton straw and non-transgenic cotton straw to deal with the same kind of soil,and the activities of polyphenol oxidase,cellulase and toxin in soil were determined at different stages.

Changes in microbial flora and bacterial physiological group diversity in rhizosphere soil of transgenic Bt cotton;

Choosing Bt cotton of Hebei province as study object, the ecological risks, such as transgene escape, resistance of the insect pests and so on and food safety of Bt cotton were analyzed.

Based on a survey involving 245 small cotton farming households from 6 counties in Hebei province,effects of using Bt cotton and non-Bt cotton varieties was analyzed.

Anti-feeding activity of Bt transgenic cotton to cotton bollworm and its possible mechanisms.;

The insect community feature in two types of cotton fields with boll-worm resistant varieties(Bt transgenic cotton) of DP99B, 20B and 1560BG, and the conventional varieties(non-Bt cotton) of E-za-mian NO.

With conventional cotton cultivar-Sumian 16 and Yumian 1, Bt transgenic cotton cultivar-Kemian 1 and Kemian 4 as the testedmaterial, the populations of major pests and predations at early and full flowering periods were investigated.

Effects of insect resistant transgenic plants on natural enemies;