Evaluation of blast resistance and identification of resistance genes in main indica rice patent materials in South China

ObjectiveBlast resistance of main indica rice parent materials in South China and resistance genes were studied, in order to provide reference for blast resistant rice breeding. MethodBlast resistance of 52 indica rice parent materials in South China was analyzed by artificial inoculation. The resistance genes were detected by specific molecular markers. The relationship between blast resistance and resistance genes was analyzed.ResultFour materials(two with 100.0%resistant spectrum and two with 92.9% resistant spectrum) with broad spectrum resistance to blast were screened out of 52 parent materials. The conventional cultivars showed better resistance than that of maintainer and restorer lines. In comparison with ZB1 and ZB5, the races of ZA1, ZA9 and ZB9 showed stronger pathogenicity, with lower resistance frequency. The occurrence rates of Pi-ta gene and Pi54 gene(both were 0.42) were the highest, that of Pib(0.37) ranked the second. Pi-km gene had the lowest rate(0.06). Pi9 gene was not found in all parent lines. The materials containing Pib+Pi54+Pi-km or Pi-ta+Pib+Pi54 showed higher resistance level than the plants with single or double resistance genes. ConclusionMain indica rice patent materials in South China contain broad-spectrum resistance resources, which can broaden genetic background and breed resistant rice varieties. Multiple resistance genes pyramiding can strengthen the resistance of rice plant to different races of blast. More attention should be paid to the research and application of plants with multiple resistance genes.