【Objective】The present study was conducted to screen rice materials pyramiding brown planthopper and rice blast genes for providing reference on breeding new rice germplasms with resistance against brown planthopper (BPH) (Nilaparvata lugens Sta°l) and rice blast caused by the fungus Magnaporthe grisea. 【Method】By using conventional breeding, molecular marker-assisted breeding and BPH resistance bioassay, BPH resistance genes viz., bph20(t) and bph21(t), and the broad-spectrum and highly resistant blast resistance gene Pi9 were pyramided into the genetic background of an elite maintainer line BoIIIB. 【Result】The molecular markers RM540 and BYL7 for bph20(t), as well as RM5348 and RM222 for bph21(t), could not amplify specific bands and showed no obvious polymorphism among the resistant parents and susceptible parents, so they could not be used in molecular marker-assisted selection of the present breeding population. The dominant molecular marker pB8 and codominant molecular marker PB9-1 for Pi9 could amplify specific bands and showed polymorphism among the resistant parents and susceptible parents, and could be used in the molecular marker assisted selection of the present breeding population. The marker PB9-1 was used for PCR amplification of 22 rice plants in BC6F2 population after insect resistant identification, It was found that 10 plants was heterozygote with Pi9 gene, 6 plants was homozygote and 7 plants had no Pi9 gene. By insect resistant identification using rice plants susceptible to brown planthopper and rice blast in field of Nanning, a series of rice plants against to brown planthopper, and 5 accessions had Pi9 gene and resistance to rice blast among 6 accessions with equivalent resistance of parent BPH54. 【Conclusion】By using conventional breeding, molecular detection and insect-disease resistance bioassay, 5 accessions of above resistant rice intermediate materials pyramiding brown planthopper genes and rice blast gene, which could provide germplasm meterials for breeding new double resistant maintainer line and sterile line.
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