Bt水稻杀虫蛋白时空变化及秸秆还田后在土壤中的持留规律

以Bt抗虫水稻华池B6、TT51及其非转基因水稻亲本嘉早935、明恢63,以及与它们亲缘较远但农艺性状相近的水稻品种中九B、R9311为试验材料,研究了田间种植条件下Bt抗虫水稻杀虫蛋白的时空变化及其在根际土中的持留规律,同时,还研究了秸秆还田后Bt蛋白在土壤中的持留规律。结果表明：1）Bt抗虫水稻华池B6植株各个部位...

EXPRESSION OF BT INSECTICIDAL PROTEIN IN BT RICE AND ITS RESIDUES IN SOIL AFTER RETURNING RICE STRAW TO FIELD

Two varieties of Bt transgenic rice, Huachi B6 and TT51 with their correspondingparents and distant hybridization varieties, respectively, were used to determine expression of Bt gene in plants and its residue in rhizosphere soil under field condition, as well as dynamic changes of Bt protein after returningBt rice straw into field. Results showed that, significant differences in expression of Bt protein were observed in different parts of Huachi B6 plants duringdifferent breedingstages (P<0.05), generally followingthe order of seed filling>heading>maturing>flourish tillering, which was similar to the expression in TT51, while no obvious differences were found in Bt protein from TT51 duringdifferent breedingstages (P>0.05). Furthermore, expression of Bt protein in both of TT51 and Huachi B6 kept to the order of spike>shoot>>root duringall the growth. Totally, its expression in TT51 was significantly lower than that in Huachi B6. The levels of expression in spike, shoot and root of Huachi B6 were 10.75-19.76μg/g FW, 8.74-14.49μg/g FW and 2.18-5.41μg/g FW, respectively. The correspondingin TT51 were 3.38-5.27μg/g FW, 2.27-2.86μg/g FW and 0.76-1.15μg/g FW, respectively. Duringthe whole period, the Bt protein expressed via roots of Bt transgenic rice (TT51 and Huachi B6) was lower than detection limit of 0.25ng/g FW in rhizosphere soil, which can not cause serious accumulation of Bt protein in soil. Therefore, it seemed that environmental risk may not be caused by Bt protein in agroecosystem. In addition, during98-128 d after returningrice straw of Huachi B6 into field, Cry1Ab protein degraded more rapidly and followed a lagstage. Till 195 d, the content kept at the level of 0.35ng/g FW in soil. For TT51, during98-195 d, Cry1Ab/Cry1Ac fusion protein kept a level of 0.35-0.60ng/g FW, which degraded more slowly. By fresh weight, no significant differences were found in two varieties of Bt transgenic rice, their correspondingparents and distant hybridization varieties TT51 grows much better than Huachi B6.