Production And Evaluation Of Three Kinds Of Insect-resistant Bt (cry1Ac,cry2A～* And Cry9C～*) Rice

Rice is one of the most important crops, and the staple food for over two billion people in the world. Insect damage is one the major cause of yield loss. Synthesized pesticides have significantly contributed to decreasing yield losses caused by the pests in modern agriculture. However, the long-term employment of synthesized pesticide has inevitably led to the environmental pollution and human health problems.As a novel pest control technology, genetic modified (GM) insect-resistant crops began to grow on a large scale in 1996. These insect-resistant crops can express the insecticidal proteins from Bacillus thuringiensis (Bt) that has been used in agricultural production as a biological insecticide for more than 60 years. Commercialization of Bt crops has significantly reduced the use of synthetic insecticides. It not only cut down the cost of the growers, but also is friendly to environment and human health.In this study, three modified-synthesized Bt genes (cry1Ac, cry2A~* and cry9C~*) were introduced into an elite rice CMS restorer line Minghui 63 respectively, and an array of high insect-resistant transgenic lines were obtained. The main results in this study are as follows:1. It was confirmed that the two Bt genes (cry2A~* and cry9C~*), which were designed and synthesized in our lab, could express effectively in the transgenic rice plants. And the transgenic plants exhibited excellent insect resistance. Thus, the artificial modification of the two Bt genes is successful.2. Eleven homozygous transgenic lines, including two CrylAc lines (designated as TAc-1 and TAc-2), four Cry2A~* lines (designated as T2A-1, T2A-2, T2A-3 and T2A-4) and five Cry9C~* lines (designated as T9C-1, T9C-2, T9C-3, T9C-4 and T9C-5), were obtained in this study. The selection of these transgenic lines followed the same criteria: high insect-resistance, no significant phenotypic changes, single-copy insertion, and Mendelian segregation. These insect-resistant transgenic lines can be used to produce insect-resistant hybrids and serve as a resistant source for development of two-toxin Bt rice.3. All transgenic Bt lines exhibited highly resistant against two main rice stem bores, yellow stem borer (YSB, Tryporyza incertulas walker) and striped stem borer (SSB,...