Abstract:

In a simulated nutrient-deficient soil (without fertilizer application or target insect stress),transgenic cry1 Ab /c rice HH1 (Bt rice) and its non-transgenic parental cultivar (CK rice) were planted for comparison of the two rice cultivars in ecological fitness. Results show that the Bt rice planted in either the simulated soil or the field followed a similar basic rule of cry1 Ab / c gene expression but the expression level of Bt protein was much lower in the former case. Bt rice showed significantly higher fitness benefits in plant height,chlorophyll content,leaf shape and root system development in most developmental stages than CK rice,and apparent positive effects of ecological fitness,as well,on reproductive parameters such as seed number per plant,seed number per spike,seed weight per plant and total weight per 1 000 seeds.All these findings suggest that Bt rice might exceed CK rice in survivability and reproductibility in nature,and hence it may pose some environmental risks.

Key words: cry1 Ab/c transgenic rice, environment, ecological fitness, risk assessment