[Occurrence and ecological consequences of transgenic rice gene flow: a review]

China is one of the origin centers of rice (Oryza sativa), with a distribution of abundant wild rice germplasm resources. Since the biosafety certificates were issued to Bt transgenic rice containing cry1Ac gene against lepidopteran pests, concerns are raised on the gene flow from transgenic rice to its wild relatives. This paper reviewed the occurrence of transgenic rice gene flow and its potential ecological consequences. Most studies suggested that transgenic rice could successfully hybridize with cultivated rice, wild rice (O. rufipogon), red rice (O. sativa f. spontanea), and barnyard grass (Echinochloa caudata), and the gene flow from transgenic rice had a lower occurrence frequency and was highly variable. Once the gene flow successfully occurred, the transgenes could introgress into a wild population within only a few generations because of the fitness advantage of transgenic rice due to the new selective traits of transgenes. When the transgenic plants invaded and persisted in a wild population, the dynamic changes of the mixed population would depend on the relative fitness and competition capability. To study the effects of the gene flow of transgenic rice and its long-term ecological consequences would have significance in rationally protecting and utilizing wild rice germplasm resources in China.