The ability of various pests and diseases to adapt to a single plant resistance gene over time leads to loss of resistance in transgenic rice. Therefore, introduction of different pest and disease resistance genes is critical for successful cultivation of transgenic rice strains with broad-spectrum resistance to multiple pathogens. Here, we produced resistance rice lines with multiple, stacked resistance genes by stacking breeding and comprehensively evaluated their resistance to Chilo suppressalis (striped rice stemborer), Magnaporthe oryzae (rice blast), and Nilaparvata lugens (brown planthopper) in a pesticide-free environment. CRY1C and CRY2A are exogenous genes from Bacillus thuringiensis. Pib, Pikm, and Bph29 are natural genes in rice. CH121TJH was introduced into CRY 1C, Pib, Pikm, and Bph29. CH891TJH and R205XTJH were introduced into CRY 2A, Pib, Pikm, and Bph29. Compared with those observed in their recurrent parents, CH121TJH significantly increased the mortality of borers. The other two lines CH891TJH and R205XTJH are the same result. Three lines introduction of Pib and Pikm significantly reduced the area of rice blast lesions, and introduction of Bph29 significantly reduced seedling mortality from N. lugens. Introduction of the exogenous genes had relatively few effects on agronomic and yield traits of the original parents. These findings suggest that stacking of rice resistance genes through molecular marker-assisted backcross breeding can confer broad spectrum and multiple resistance in differently genetic backgrounds.
Keywords: Chilo suppressalis; Magnaporthe oryzae; Nilaparvata lugens; rice blast; transgenic rice.