Effect of Bt cotton leaves under elevated greenhouse gases (CO2 and O3) on soil Oribatida populations
Author of the article:CHANG Liang1, 2 WANG Bai-Feng3 LIU Xiang-Hui1 GE Feng1**
Author's Workplace：1. State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; 2. Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102 China; 3. Agro-Biotechnology Research Institute, Jilin Academy of Agriculture Sciences, Changchun 130033, China
Key Words：CO2, O3, transgenic Bt cotton, open-top chamber, Acar
Abstract：
[Objectives] Transgenic Bt cotton was modified to express a gene derived from the bacterium Bacillus thuringiensis (Bt) to combat lepidopteran pests. Elevated CO2 and O3 are expected to further alter the chemical composition of cotton, and may thus affect the role that soil fauna plays in the decomposition of Bt plants. [Methods] A three month litterbag field study, consisting of eight treatments using leaves from Bt cotton and near-isolines of non-Bt cotton grown under normal control, OTC control, elevated O3 and CO2 levels, was conducted to investigate the abundance of soil Acari that developed on the decaying leaf materials. [Results] The abundance of Acari was significantly impacted by sampling times. Acari abundance was highest in July and significantly decreased in elevated CO2 treatments. Moreover, only the common Simian3 significantly decreased in elevated CO2 levels. Acari abundance was significantly reduced in Bt cotton litter in the OTC control but not in the normal control, elevated CO2 and O3 treatments. [Conclusion] Soil fauna were not affected by elevated O3 cotton litter but cotton litter grown under elevated CO2 levels could significantly reduce the abundance of Acari compared to those found under the normal control, OTC control and elevated O3 treatments.