[Studies on the ecological distribution of Bacillus thuringiensis in forest soils of China]

A total of 384 forest soils samples at 0-5cm depth collected from 8 forest site zones (13 Natural Reserves) in China were examined for the distribution of Bacillus and Bacillus thuringiensis. The 79 cultures (4.21%) in 1873 isolates of Bacillus collected referable to the Bacillus thuringiensis. Soil pH, moisture content and soil nutrient were determined. Rules of the ecological distribution of Bacillus thuringiensis of 8 forest site zones in China were analysed. Toxicities against 6 species of insect were tested. Strain some efficient serains were obtained. It was shown that resource of Bacillus thuringiensis is much fruitful in forest soils of China.