关键词: 水稻, 基因聚合, 白叶枯病, 分子标记

Abstract:

Using rice lines Zheng 084 and IRBB5 as the donors of the bacterial blight resistance genes, two resistance genes （xa5 and Xa7） were introgressed into an indica restorer line Huazhan by crossing, backcrossing and multi-crossing. Based on marker-assisted selection method combined with evaluation of resistance and agronomic traits, one improved line carrying both xa5 and Xa7 was obtained, two improved strains carrying a single resistance gene xa5 or Xa7 were also obtained. The improved strains were identified for resistance to bacterial blight. The results showed that the improved lines B1（harboring xa5） and B2（harboring Xa7） were highly sensitive to the strain PXO99, and highly resistant or resistant to the other four strains; and the line B3 with both xa5 and Xa7 showed moderate sensitive to PXO99 and high resistance to the other four strains, which was superior in resistance to B1 and B2 with only a single gene.

Key words: rice, gene pyramid, bacterial blight, molecular marker