关键词: 水稻, 聚合育种, 白叶枯病, 分子标记辅助选择

Abstract: Most of the male sterile lines have no resistance to bacterial blight (BB) and the cultivars with a single BB resistance gene will break-down easily. Two resistance genes，Xa21 and Xa23 were pyramided into a male sterile line through crossing, backcrossing and selfing to improve its resistance. The PGMS line 3418S（carrying Xa21）was crossed with CBB23 (carrying Xa23). The F1 was backcrossed with 3418S to get BC1F1, then, selfing for 3 times to pyramid the two genes and bred a new line R106 with homozygous resistance by inoculation and MAS. The new line R106 was also as a recipient for developing a cytoplasmic genetic male sterility (CMS) line R106A by the back-crossing procedure. The line R106A was highly resistant to 7 Chinese pathotypes of Xanthomonas oryzae pv. oryzae (Xoo) and showing overall resistance, which might maintain durability. The methods including backcrossing times, selecting generation were also discussed.

Key words: Rice, Pyramiding breeding, Bacterial blight, Molecular marker -assisted selection