三基因聚合改良恢复系福恢673的稻瘟病抗性

Pyramiding of 3-resistant-gene to improve rice blast resistance of a restorer line, Fuhui 673

摘要:

为了改良水稻优良恢复系福恢673的稻瘟病抗性，以该恢复系为轮回亲本，以携有3个稻瘟病抗性基因(Pi-1、Pi-9和Pi-kh) 的优质恢复系金恢1059为供体亲本，通过回交育种结合分子标记辅助选择，选育出10个导入了这3个抗稻瘟病基因的福恢673近等基因系，其遗传背景恢复率为92.96%–98.59%。抗性鉴定结果表明，这些近等基因系及其与不育系宜香A配制的杂种一代均表现抗稻瘟病，抗性明显强于对照福恢673和宜优673，且半数以上杂种一代基本保留了原组合的主要优点。用近等基因系Line 9配组的杂交稻新组合两优7283和金泰优683在区试中均表现出产量高、稻瘟病抗性强、生育期适中等特点，表明该近等基因系具较好的应用前景。

Abstract:

To improve the blast resistance of elite rice restorer line Fuhui 673, 3 blast resistance genes Pi-1, Pi-9 and Pi-kh were introduced into Fuhui 673 from a good-quality restorer line Jinhui 1059 through 3 successive backcrosses followed by one selfing using the technique of marker-assisted selection. Ten near-isogenic lines (NILs) of Fuhui 673 carrying the 3 introduced resistance genes were created. Genotype analysis using 68 SSR markers evenly distributed in the genome indicated that 92.96%–98.59% of the NILs’ genetic background had been recovered to Fuhui 673. Both indoor and field resistance tests indicated that the NILs and their hybrids with sterile line Yixiang A were all resistant to rice blast, with resistance levels significantly higher than those of controls Fuhui 673 and hybrid Yiyou 673 (Yixiang A ′ Fuhui 673). In addition, among the 10 hybrids between the NILs and Yixiang A, 2 showed significantly higher yield than and 4 displayed similar yield to that of control Yiyou 673, suggesting that most of the NILs retained the elite characteristics of Fuhui 673. Two new hybrid rice cultivars Liangyou 7283 and Jintaiyou 683 from NIL Line 9 showed high yield, good resistance to blast and moderate growth period in regional trial, suggesting that the NIL Line 9 has a good prospect for application.