The effects of transgenic rice containing both cry1Ac and CpTI genes on survival of the stripped stem borer (SSB), Chilo suppressalis, and the pink stem borer (PSB), Sesamia inferens, and the field composition of stem borers were studied in both laboratory and field tests. The laboratory bioassay results showed that the survival of SSB and PSB on transgenic rice was significantly lower than that on non-transgenic control. The toxicity of transgenic rice to SSB and PSB declined at the late growing stage of rice. The lethal effect of the transgenic rice to SSB was stronger than that to PSB. As for SSB, only a few larvae (0.5%-6.4%) could survive at the 4th day after infestation at the heading and maturity stage in transgenic rice, and the survival rate of PSB on transgenic rice was higher than that of SSB. Furthermore, there were a few larvae (<1.6%) could pupate and emerge although the pupation and emergence rates were substantially lower than those on non- transgenic control. The results of field tests in both early and late rice indicated that the number of SSB and PSB larvae on transgenic rice were significantly reduced compared with the control. Compared with non-transgenic check, the number of SSB in transgenic rice was reduced by over 99%, and the effect of transgenic rice on PSB was relatively low and varied with different cropping seasons. The number of PSB was decreased by over 93% in early rice and by 44%-64% in late rice. Among the surviving stem borers in transgenic rice field, the percentage of PSB increased significantly. It is inferred that the change is possibly caused by the different susceptibilities for the two stemborers to transgenic rice expressing Cry1Ac and CpTI toxins.
GAO Yu-lin ,FU Qiang ,WANG Feng et al. Effects of Transgenic Rice Harboring cry1Ac and CpTI Genes on Survival of Chilo suppressalis and Sesamia inferens and Field Composition of Rice Stemborers[J]. , 2006, 20(5): 543-548 .