水稻抗稻瘟病基因Pi1和Pi2聚合系的获得及其抗性评价

Development and Evaluation of Disease Resistance of Pyramided Lines with Blast Resistance Genes Pi1 and Pi2 in Rice

[目的]获得水稻抗稻瘟病基因Pi1和Pi2聚合系,并对其进行抗性评价。[方法]以GD-7为稻瘟病抗性基因供体,扬稻6号为受体,通过回交转育结合分子标记辅助选择,选育出10个Pi1基因和Pi2基因双基因纯合且农艺性状优良的水稻新品系,在湖北省水稻品种区域试验的稻瘟病抗性鉴定点恩施和宜昌分别对这些品系的稻瘟病抗性进行了田间鉴定。[结果]这些品系的抗性综合指数在0.8-2.0,抗级为1,表现为抗,而受体亲本扬稻6号的抗性综合指数分别为8.8和8.5,抗级为9,表现为高感,其中一个品系R587与不育系广占63S配制的杂交组合的抗性综合指数分别为2.5和3.5,抗级为3,表现为中抗,而对照扬两优6号的抗性综合指数分别为7.9和8.2,抗级为9,表现为高感。[结论]通过分子标记辅助选择聚合Pi1基因和Pi2基因能显著提高聚合系及其相应杂交组合的稻瘟病抗性。

[Objective] The aim was to develop and evaluate disease resistance of pyramided lines with blast resistance genes Pil and Pi2 in rice. [ Method] Using GDr7 as donors as rice blast resistance genes, and Yangdao 6 as recipient, ten new gene-pyramided lines with the rice blast resistance genes Pil and Pi2 and desirable agronomic traits were developed by bake-cross breeding with molecular marker-assisted selection （MAS）. The field resistance of these lines and their original parents was identified in Ensi and Yichang of Hubei. The evaluation of these lines was conducted on the resistance to blast. [ Result] The results showed that the disease index of these lines were 0.8 - 2.0 and they were resistant. And the disease index of Yangdao 6 was 8.8 and 8.5 and it was high susceptible. The disease index of Guangzhan63S/R587 was 2.5 and 3.5 and it was moderately resistant. And the disease index of Yangliangyou 6 was 7.9 and 8.2 and it was high susceptible. [ Conclusion] The conclusion was drawn that the field resistance of gene-pyramided lines and their hybrid was significantly increased by MAS.