Abstract:

Field investigations were conducted during the rice growing season to monitor residues of Cry1Ab/c protein in water and soil of paddy fields cultivated with Bt-shanyou63 (Bt- SY63) rice for years in a row,4 years in Wuhan,3years in Suizhou,3 years in Wuxue and 2 years in Xiaogan of Hubei and 3 years in Dezhou of Shandong,using the enzyme-linked immunosorbent assay (ELISA) method. Results show that no significant differences were found in concentration of Cry1Ab/c protein in water between the fields cultivated with Bt- SY63 rice for 2-4 years and those with SY63 rice (P>0. 05),and the highest residue of Cry1Ab/c protein was measured to be 0. 373 ng·mL^-1 only. Similar to residue in the water,residue of the protein in the soil,regardless of growth stage,was found below the detection limit of the testing kit（ 0. 25 ng·g^-1） in all the paddy fields,except for the field in Suizhou where 0. 261 ng·g^- 1was detected in the soil at the seedling stage,and the field in Dezhou where 0. 540 and 0. 361 ng·g^-1 was at the jointing and blooming stages,respectively,forming significant difference from the control fields. Besides,no significant difference was detected in residue of Cry1Ab/c protein in soil and water between fields different in Bt- SY63's cultivation history. It is,therefore,held that Bt- SY63 rice may release only a trace amount of Cry1Ab/c protein into the water and soil of the field after 2,3 or 4 years of cultivation of the crop in a row. However,the amount is so low that it would not result in accumulation of Cry1Ab/c protein in the water and soil of the field.

Key words: transgenic rice, Bt-SY63, water, soil, Cry1Ab/c protein, residue