The Economic Efficiency Analysis Of Transgenic Pest-resistant Rice And Preliminary Study On Resistance Of Rice Stem Borer To Transgenic Rice

As the important component of sustainable development of agriculture, transgenic Bt rice takes on the potential advantages on the reduction of chemical pesticides, improvement of crop yields and quality, which was played an important role in the control of rice stem borer. In this study, We used transgenic cry1Ab/cry1Ac (Bt) to analyze the yield and economic effeciency of transgenic Bt rice and parental control after spraying pesticides, study the potential resistance of stem borer to transgenic rice, discuss the effect of refuge strategy on resistance delay of rice stem borer to transgenic rice. The results as follows:No significant difference was observed in the yield and control effect of transgenic Bt rice compared with the control by Fipronil. However, significantly higher yield was found in the transgenic rice compared with the control rice by other pesticides or no pesticides application. Significantly higher economic benefits and outputs were observed in the transgenic Bt rice compared with control rice. The labor and pesticides costs were occurred to decrease in the transgenic Bt rice compared with control rice by pesticides application.The results of resistant assessment in the field showed that the transgenic rice had significant lethal effect to rice stem borer during all growth stages. In the nature environment, the white fringe and fold-leaf rate were significantly lower in Bt rice compared with other treatments with no chemical pesticides during the growth period. Bioassays experiments were indicated that significant lethal effect of Bt rice was observed to rice stem borer in the period of seedling, tillering jointing stage, booting stage and filling stage.Part of rice stem borer could survive on transgenic Bt rice in the field experiment. The damaged transgenic Bt rice was not occurred to silent and the expressed toxic protein could kill the stem borer. The shift experiment through field to laboratory was showed that a few rice stem borer were survival and develop after feeding on transgenic Bt rice. The results above were indicated the resistance was observed in rice stem borer after feeding on transgenic Bt rice for successive years. There was no significant difference was observed in the oviposit behaviour of stem borer fed on transgenic Bt rice compared with control rice, which indicated that mix growth model was adopted in our country. The results showed that the cropping pattern was the rate 19:1 and 14:1 between transgenic Bt rice and control rice. These two growth models could significant control stem borer, and also provide habitats for rice stem borer.