Abstract: With the rapid development of transgenic techniques, many new cultivars of genetically modified crops (i.e., GM crops) have been successfully bred, and many GM crops have been commercially planted in fields due to their excellent traits such as disease and insect resistance, herbicidetolerance, high quality and production, and environmental friendliness. However, the ecological risks resulted from widely planting of GM crops have been becoming the public concern. The ecological risk of exogenous transgene flow is one of the most important contents of biosafety assessment for GM crops. The corresponding control techniques of exogenous transgene flow risk developed and applied in the agricultural product could not be ignored, especially during the recent 19 years of commercial cultivation of GM crops. In this paper, we introduced the four releasing pathways of pollen, seed, root exudates and asexual reproductive organs, as well as the ecological risks and the corresponding control techniques of exogenous transgene flow of GM crops. This paper can provide some scientific bases for the environmental biosafety assessment and risk management of GM crops.

Key words: soil microbial community, Hippophae rhamnoides plantation, forest age, season., enzyme activity