MAS育种改良籼稻恢复系R599及其杂交种的稻瘟病抗性

Improving Blast Resistance of Indica Rice Restorer R599 and Its Hybrid by MAS Technology

根据已克隆的广谱持久抗稻瘟病基因Pi9的启动子序列设计了特异显性DNA标记MS-1,通过分子标记辅助选择(MAS)技术,开展连续回交育种,定向改良籼稻恢复系R599及其杂交种的稻瘟病抗性。结果表明,Pi9基因供体亲本75-1-127与受体亲本R599对23份供试稻瘟菌菌株的抗性表现及抗菌谱差异显著,两亲本的抗性频率分别为91.3%和30.4%。分子标记MS-1在75-1-127与R599之间呈现明显且稳定的多态性,标记基因型对抗病性表型的辅助选择效率达100%。从BC6F3株系中选育出一个与R599遗传背景相似但高抗苗瘟和穗瘟的改良恢复系R599-Pi9,并用它配制出抗稻瘟病的两系杂交种Y两优599-Pi9。

To directionally improve blast resistance of the indica rice restorer line R599 and its hybrid, a dominant DNA marker MS-1 was designed based on the promoter sequence of the cloned broad-spectrum and durable blast resistance gene Pi9, and the technology of molecular marker-assisted selection （MAS） was implemented in the successive backcrossing breeding. The results showed that the blast resistance performance and resistance spectrum to 23 M. oryzae isolates were quite different between the Pi9 gene donor 75-1-127 and the receptor R599, and their resistance ratio were 91.3% and 30.4%, respectively. MS-1 showed obvious and stable polymorphism between 75- 1-127 and R599 ,and the efficiency of selection for blast resistance phenotypes on MS-1 marker genotypes reached 100%. The improved restorer line R599-Pi9 highly similar to R599 in phenotype was selected from the BC6F3 pop- ulation and its two-line hybrid Y Liangyou 599-Pi9 （Y58S/R599-Pi9） was developed, which showed high-level seedling and panicle blast resistance in field nursery.