Cloning Of Rice Bacterial Blight Resistance Gene Xa24 And Construction Xa3/Xa26 Transgenic Lines

Rice is the staple worldwide, but damages by disease and insect injury rice in various degrees. In all common diseases and insect pests and control measures, the most economic and effective measure is improvement rice with excellent resistance gene resources. This common bacterial blight disease of rice will make the rice yield and quality declined, improvement of rice varieties with resistance genes against a broad spectrum of bacterial leaf blight is a ideal measure against bacterial blight.Bacterial blight resistance gene xa24 is a recessive main effect gene from the wild rice DV86. Utilizing DV86/IR24 F2 random groups of inoculation the bacterial blight inoculation race PXO99, xa24 is located in the less than 10kb section at the end of rice chromosome 2 by Wu xiaoming, and there are two candidate genes CG1 and CG2 in this section. Comparing the two candidate genes CG1 and CG2 sequences and expression level in rice varieties DV86 and IR24 and tansformation with DV86 and IR24 could verify the gene function.Xa3/Xa26 is a cloned main effect resistance gene against a broad spectrum of bacterial blight, and a strong promotor could induce Xa3/Xa26 overexpress in tansgenic plants. Combined with the room Agrobacterium mediated transformation method, we tansformed Xa3/Xa26 into Japonica rice Mudanjiang 8 and obtained transgenic plants. The single copy and no significant varience in agricultural characteristics homozygot lines are selected from the batch of transgenic plants progenies. Innoculate the lines with diffrent races in our lab, we get the resistance spectrum at booting stage and seedling stage. The result from innoculation shows the lines have wide resisrance spectrum at booting stage and seedling stage. The analyzed results show that the trangenic lines and transgenic receptor variety Mudanjiang 8 have no significant difference in tested agronomic traits. Because the Xa3/Xa26 gene is linked to the Bar gene in the transgenic lines, these lines can be used as basal materials for breeding both Xoo-and herbicide-resistance rice.