Developing Restorer Lines Pyramiding Different Resistant Genes to Blast and Bacterial Leaf Blight by Marker-assisted Selection in Rice

Abstract

The novel blast resistance genes, Pi-GD-1(t), Pi-GD-2(t), and GLP8-6(t) from rice variety Sanhuangzhan 2 (here abbreviated them as G1, G2, and G8, respectively) and bacterial blight (BB) resistance gene, Xa23, were introgressed into three elite restorer lines (Minghui 86, Shuhui 527, and Zhehui 7954) by marker-assisted pyramiding breeding approaches in combination with artificial inoculation and stringent phenotypic selections. The five derived blast and bacterial blight resistance restorer lines, Minghui 86-G1-G2-Xa23, Shuhui 527-G2-Xa23, Mingzhe-G2-G8-Xa23-1, Mingzhe-G2-G8-Xa23-2, and Mingzhe-G1-G2-G8Xa23, demonstrated similar or wider blast resistance spectrum as compared with the donor parent, Sanhuangzhan 2. The five derived BB resistant restorer lines and their derived hybrid combinations with II-32A demonstrated similar BB resistance spectrum to the donor parent, IRBB23. The newly developed BB resistant restorers and their derived hybrids were identical to their respective original versions for agronomic traits especially under disease free condition. However, under severe disease condition, the five BB resistant restorer lines exhibited significantly higher grain weight, spikelet fertility, and grain yield as compared with the respective original restorer lines, thus further resulting in significantly higher grain yields in BB resistant hybrids than in their 第 9期 潘晓飚等: 分子标记辅助选育水稻抗白叶枯病和稻瘟病多基因聚合恢复系 1583 respective original hybrids.